NAV20 From Australia, joined Nov 2003, 7226 posts, RR: 43 Reply 4, posted (6 months 2 weeks 2 days 11 hours ago) and read 47178 times:
Made this post about ten seconds before the Mod closed the thread. So her it is again - just to keep the discussion gonig.
Quoting PanAm1971 (Reply 234):
Question; if you have constantly changing wind speed and direction (like in a violent storm) how would measure proper airspeed adjustments to make? For example, if your airspeed suddenly goes from 290kts to 220kts and then to 250kts, would you necessarily want to push it back up to 290kts?
Short answer is, it just wouldn't, Panam1971. If you had the throttle set to hold say roughly 120 knots (for mere mortals like me) or the auto-throttle set to hold exactly 340 knots (for professionals like Zeke or Pihero), and a tailwind of 50 knots, your airspeed would be 120 or 340 knots respectively, but your groundspeed would be say 170/390 knots.
If the wind switched to right in your teeth at 50 knots (common enough in the two places I've flown, the UK and Oz) your airspeed would stay at 120/340. But your groundspeed would drop to say 70/290......
Time for Pihero to start talking about differential drag and how I know eff-all about flying and 'drag co-efficients' and things, and that my figures are as much as two per cent out either or both ways. But I hope the principles are clearer now....
[Edited 2009-06-04 08:35:33]
"Once you have flown, you will walk the earth with your eyes turned skywards.." - Leonardo da Vinci
WILCO737 From Germany, joined Jun 2004, 6141 posts, RR: 90 Reply 5, posted (6 months 2 weeks 2 days 11 hours ago) and read 47087 times:
Quoting NAV20 (Reply 4): If the wind switched too right in your teeth at 50 knots (common enough in the two places I've flown, the UK and Oz) your airspeed would stay at 120/340. But your groundspeed would drop to say 70/290......
If the windspeed changes 50 knots in a really short time, the airspeed drops as well. The airflow over the wing is not the same anymore. If you fly with a constant speed 120 knots as you said and suddenly a gust from the front is hitting you with 20 knots, then your airspeed increases as well.
NAV20 From Australia, joined Nov 2003, 7226 posts, RR: 43 Reply 6, posted (6 months 2 weeks 2 days 11 hours ago) and read 46909 times:
Quoting WILCO737 (Reply 5): If you fly with a constant speed 120 knots as you said and suddenly a gust from the front is hitting you with 20 knots, then your airspeed increases as well.
Sure - except that, if it was from the front, I'd LOSE the 20 knots of groundspeed. In about three minutes in my case, twenty seconds in Pihero's...
[Edited 2009-06-04 08:45:45]
"Once you have flown, you will walk the earth with your eyes turned skywards.." - Leonardo da Vinci
David L From United Kingdom, joined May 1999, 8281 posts, RR: 42 Reply 7, posted (6 months 2 weeks 2 days 11 hours ago) and read 46844 times:
Quoting NAV20 (Reply 4): If the wind switched too right in your teeth at 50 knots (common enough in the two places I've flown, the UK and Oz) your airspeed would stay at 120/340. But your groundspeed would drop to say 70/290......
... Eventually, yes, but not immediately. The aircraft has a lot of inertia and would take time to slow down to the original airspeed. The result would be a temporary rise in airspeed of up to 100 kts (depending on how suddenly the wind changed direction) which would drop back to 340 kts as drag slowed the aircraft.
WILCO737 From Germany, joined Jun 2004, 6141 posts, RR: 90 Reply 8, posted (6 months 2 weeks 2 days 11 hours ago) and read 46748 times:
Quoting NAV20 (Reply 6):
Sure - except that, if it was from the front, I'd LOSE the 20 knots. Smile For about three minutes in my case, twenty seconds in Pihero's.....
Initially you gain 20 knots in Indicated airspeed, but the groundspeed decreases 20 knots.
MarSciGuy From United States, joined Jun 2007, 369 posts, RR: 0 Reply 9, posted (6 months 2 weeks 2 days 11 hours ago) and read 46684 times:
Quoting Ginou:
I have a question on the black boxes (sorry if it was answered before, if it's the case I totally mised it):
We heard that French officials are not overly optimistic about the black box recovery. However I know that they send some sort of signals for about 30 days and that they are very resistant. I would think that they are two different issues then:
1/ is it possible to locate the black box?
2/ is it possible to retrieve it?
I am not a specialist at all, but I would tend to think that if they have not be destroyed, 1/ shouldn't be too difficult, no ??? or let me be more specific: what is the range of the signals sent by the black box ? How can it be "captured"???
As to retrieve teh black box, wouldn't that be the toughest part?
If #1 is achieved and they get a good - and I mean quite good - fix on the location then retrieval is no problem even after the pinger stops - Remotely Operated Vehicles (ROVs) or Automonously Operated Vehicles (AUVs) could all operate that deeply easily enough, and do so on a fairly frequent basis. I'm not sure what the deepest a manned (and not Bathyscaphe) submersible can penetrate but I'd assume some specialized ones could reach 4 km depths without a hitch.
[Edited 2009-06-04 08:43:11]
"There weren't a ton of gnats there where a ton of gnats and their families as well!"
KingFriday013 From United States, joined May 2007, 225 posts, RR: 4 Reply 10, posted (6 months 2 weeks 2 days 11 hours ago) and read 46610 times:
Quoting NAV20 (Reply 4): If the wind switched to right in your teeth at 50 knots (common enough in the two places I've flown, the UK and Oz) your airspeed would stay at 120/340. But your groundspeed would drop to say 70/290......
I know I'm a bit of a n00b here, but what does 120/340 and 70/290 mean?
WILCO737 From Germany, joined Jun 2004, 6141 posts, RR: 90 Reply 11, posted (6 months 2 weeks 2 days 11 hours ago) and read 46606 times:
Quoting KingFriday013 (Reply 10):
I know I'm a bit of a n00b here, but what does 120/340 and 70/290 mean?
He just used them as examples. 120 knots (for a smaller airplane) or 340 knots for a bigger plane.
And 70 knots with a 50 knots headwind and 290 with a 50 knots headwind
JBirdAV8r From United States, joined Jun 2001, 3091 posts, RR: 21 Reply 12, posted (6 months 2 weeks 2 days 11 hours ago) and read 46517 times:
Quoting KingFriday013 (Reply 10):
I know I'm a bit of a n00b here, but what does 120/340 and 70/290 mean?
He's just differentiating the "little guys" in slower aircraft from the "big guys" in faster planes.
See here:
Quoting NAV20 (Reply 4):
Short answer is, it just wouldn't, Panam1971. If you had the throttle set to hold say roughly 120 knots (for mere mortals like me) or the auto-throttle set to hold exactly 340 knots (for professionals like Zeke or Pihero), and a tailwind of 50 knots, your airspeed would be 120 or 340 knots respectively, but your groundspeed would be say 170/390 knots.
Wjcandee From United States, joined Jun 2000, 3774 posts, RR: 19 Reply 13, posted (6 months 2 weeks 2 days 11 hours ago) and read 46450 times:
Quoting WILCO737 (Reply 8): Initially you gain 20 knots in Indicated airspeed, but the groundspeed decreases 20 knots
Not if the airspeed INCREASES in the gust, no? Isn't it largely that one offsets the other? If you get a gust strong enough to increase the airspeed, then the increased airspeed compensates for the increased air on the nose, no?
In other words, of course you're right about the aircraft's airspeed increasing in the gust, but what about the effect on groundspeed?
Also, in reality I think that part of any gust is going to be felt as headwind, and part as increased airspeed.
Quoting NAV20 (Reply 4): Short answer is, it just wouldn't, Panam1971. If you had the throttle set to hold say roughly 120 knots (for mere mortals like me) or the auto-throttle set to hold exactly 340 knots (for professionals like Zeke or Pihero), and a tailwind of 50 knots, your airspeed would be 120 or 340 knots respectively, but your groundspeed would be say 170/390 knots.
Trystero From Portugal, joined Oct 2008, 163 posts, RR: 0 Reply 15, posted (6 months 2 weeks 2 days 11 hours ago) and read 46355 times:
There are two different things about the boxes. One thing is finding the other is retrieving them. You could locate with precision, but can you taken them out of the debris at a great depth? I mean, one thing is to collect rocks and stuff like that at whatever depth you are, but is it possible to move large parts of the aircraft, foe example? There's another thing ( which make three and not two...) can this boxes resist the pressure at 4 or 5 km deep and for how long? I assume that if they resist impact and fire, pressure would OK too, but don't really know.
WILCO737 From Germany, joined Jun 2004, 6141 posts, RR: 90 Reply 16, posted (6 months 2 weeks 2 days 11 hours ago) and read 46258 times:
Quoting Wjcandee (Reply 13): Not if the airspeed INCREASES in the gust, no? Isn't it largely that one offsets the other? If you get a gust strong enough to increase the airspeed, then the increased airspeed compensates for the increased air on the nose, no?
When I fly let's say 250 knots with no wind, lets say gives me a ground speed of 300 knots (easiert to calculate). And then the wind suddenly increases to 20 knots and is right onto my nose, then my airspeed indicator would show a 20 knots increase in airspeed, so 270 knots then. The groundspeed will slowly drop from 300 knots to 280 knots as the wind is pushing you back.
The indicated airspeed just basically represents the speed of the airflow over the wing. And if the increase in windspeed happens, then the wing thinks: duh, some nice wind here, let's produce more lift
So-called because - believe it or not - the way that Nelson and Co. used to measure speed was to throw over a sort of baffle on a rope. The rope (known as the log-line, because originally the baffle was actually a log) had 'knots' in it every 'cables' length' (200 yards). The guy who threw it over had the job of counting the number of 'knots' that went through his fingers while a minute's worth of sand ran through the sandglass that his petty officer was holding.
Then they hauled it back in. The length of cable that had run out told them the speed of the ship.....
If Napoleon's lot had won at Trafalgar, aviation would probably be counting in kilometres, not 'nautical miles.'
"Once you have flown, you will walk the earth with your eyes turned skywards.." - Leonardo da Vinci
Richierich From United States, joined Nov 2000, 3260 posts, RR: 8 Reply 19, posted (6 months 2 weeks 2 days 11 hours ago) and read 45974 times:
Part 10 with no end in sight, this thread might be the one that unseats Peter Max for the longest topic discussion in a.net history!
Back to seriousness, does anybody have updates on the recovery effort today? I think somebody asked this question in Part 9 but I didn't see a response - has the 23-ft large piece of debris been lifted out of the water yet? Has any more tangible debris been located? (I don't consider an oil slick to be tangible debris). Have the proper recovery vessels started arriving in the general area?
I was looking at this part of the Atlantic Ocean on Google Earth and obviously it is a vast swath of ocean we are talking about here. If the distance from the continental mainland of Brazil to Fernando de Noronha (the island archipelago) is about 300nm and the plane crashed somewhere about another 300nm beyond there, I noticed a feature of rocks just north of that area. St. Peter and Paul rocks are a small uninhabited archipelago of islands and volcanic rocks. They are in Brazilian water - Google says they are 870km from FER and 1,100km from Natal.
My question: how far from St. Peter and Paul rocks are the debris fields? I had never heard of this geographical feature before.
KingFriday013 From United States, joined May 2007, 225 posts, RR: 4 Reply 20, posted (6 months 2 weeks 2 days 11 hours ago) and read 45935 times:
Quoting WILCO737 (Reply 11): He just used them as examples. 120 knots (for a smaller airplane) or 340 knots for a bigger plane.
And 70 knots with a 50 knots headwind and 290 with a 50 knots headwind Smile
Quoting JBirdAV8r (Reply 12): He's just differentiating the "little guys" in slower aircraft from the "big guys" in faster planes.
Thanks guys! I misunderstood the post, got a little caught up by the slashes. Appreciate the help
Quoting NAV20 (Reply 18):
No problem, KingFriday013.
How much of an [adverse] impact do negative changes in speed (both airspeed and groundspeed, I guess) have on an aircraft (a larger one, like the A330, at cruise)? I know changes can't be instantaneous, but say over the period of five seconds. Just wondering if that could have done anything.
Richierich From United States, joined Nov 2000, 3260 posts, RR: 8 Reply 21, posted (6 months 2 weeks 2 days 11 hours ago) and read 45791 times:
Edit to my previous post - somebody has updated the St. Peter and Paul Rocks page on wikipedia to include a short paragraph about AF447 debris being found near the area.
It appears there is a lighthouse on the rocks, presumably manned?
The Air France jet that crashed into the Atlantic killing 228 may have stalled after pilots slowed down too much as they encountered turbulence, new information suggests.
Airbus is to send advice on flying in storms to operators of its A330 jets, Le Monde reported today. It would remind crews of the need to maintain adequate thrust from the engines and the correct attitude, or angle of flight, when entering heavy turbulence.
Pilots slow down aircraft when entering stormy zones of the type encountered by Air France Flight 447 early on Monday as it was flying from Rio to Paris.
The fact that the manufacturer of the aircraft is issuing new advice indicates that investigators have evidence that the aircraft slowed down too much, causing a high-altitude aerodynamic stall. This would explain why the aircraft apparently broke up at altitude over the Atlantic.
Jean Serrat, a retired airline pilot, told Agence-France Presse: "If the BEA [accident investigation bureau] is making a recommendation so early, it is because they know very well what happened. If they know what happened, they have a duty to make a recommendation, for safety reasons ... The first thing you do when you fly into turbulence is to reduce speed to counter its effects. If you reduce speed too much you stall."
Although the flight recorders lie about 12,000ft below the ocean surface, the BEA has data on the last four minutes of Flight 447, transmitted automatically by satellite to Air France's base at Paris Charles de Gaulle airport.
A stall, in which the wings lose lift and the aircraft becomes uncontrollable, would be consistent with the sequence of events that have leaked to the media from the Air France data. According to this, the first anomaly was the disconnection of the automatic pilot and computerised flight controls. This means that the pilots were hand-flying the aircraft.
It is not known whether Captain Marc Dubois, 58, was at the controls or just his two co-pilots, who were in their 30s.
A stall at 35,000ft – the altitude at which Flight 447 was cruising – is hard to recover from in still air. In the heart of a furious tropical storm at night, it could be near impossible. High-altitude stalls claimed several aircraft in the early days of jet aircraft.
Speculation over the fate of Flight 447 continued to rage as ships began trawling the crash area, spread over a 200-mile stretch. Debris, including airliner seats, has been identified from the air, about 800 miles off the Brazil coast. No bodies have been spotted
Nelson Jobim, Brazil's Defence Minister, said that a 12-mile-long slick of fuel had been found under the planned route of the Airbus. This meant it was improbable that there had been a fire or explosion, because the jet fuel would have ignited, he said.French experts dismissed this theory, noting that an explosion could fracture the fuselage and cause the break-up of an aircraft without igniting the fuel, which is mainly carried in the wings
Mcg From United States, joined Sep 2003, 164 posts, RR: 14 Reply 24, posted (6 months 2 weeks 2 days 11 hours ago) and read 45785 times:
I don't understand how the 'authorities' are so quick to eliminate terrorism as a potential cause of this accident. It would seem to me that until the wreckage is carefully examined for the telltale signs of a bomb initiated explosion and until the likely cause of the destruction of the airplane is determined that terrorism can't be ruled out.
Note that I'm not saying that this accident was caused by a terrorist act, only that the 'authorities' seem to have crossed it off the list of potential causes before the slightest bit analysis has been done.
WILCO737 From Germany, joined Jun 2004, 6141 posts, RR: 90 Reply 25, posted (6 months 2 weeks 2 days 11 hours ago) and read 45691 times:
Quoting KingFriday013 (Reply 20): How much of an [adverse] impact do negative changes in speed (both airspeed and groundspeed, I guess) have on an aircraft (a larger one, like the A330, at cruise)? I know changes can't be instantaneous, but say over the period of five seconds. Just wondering if that could have done anything.
Depends how intense it is. If it is a drop in speed of 10 knots, then no big deal as there is enough margin to the stall speed. maybe even 30 knots is not really a serious problem. You get close to the stall speed, but still not there.
So the change in windspeed needs to be pretty sudden and intense to get to the stall speed. But usually you have the capability to recover from a stall. I mean at 36,000 feet you have quite some time to keep up some speed. You have to lose altitude and apply max thrust, but usually you should be able to recover that. Unless something else happened...
KingFriday013 From United States, joined May 2007, 225 posts, RR: 4 Reply 26, posted (6 months 2 weeks 2 days 11 hours ago) and read 50245 times:
Quoting PanAm1971 (Reply 23): Ok-layperson trying to communicate-could a sudden extreme wind speed change cause a stall? Could we be looking at that here?
Like wind shear? (Just to further clarify PanAm's question and ask my own)
SEPilot From United States, joined Dec 2006, 4039 posts, RR: 26 Reply 27, posted (6 months 2 weeks 2 days 11 hours ago) and read 50260 times:
Quoting NAV20 (Reply 18): If Napoleon's lot had won at Trafalgar, aviation would probably be counting in kilometres, not 'nautical miles.'
Perhaps. The reason we use nautical miles in aviation is thanks to Juan Trippe. He was fascinated by all things nautical and was the one who introduce nautical measure to aviation. He was also the one who insisted that the pilot be called Captain. But to your point, if Napoleon had won and converted the nautical world to kilometers it is possible you are right. But the kilometer was a creation of the Revolution; Napoleon was not a fan of the Revolution, but just took advantage of the chaos it produced to seize power. I doubt he would have cared, and even if he had the rest of the world would have had to follow. Juan Trippe might still have had knots to turn to.
The problem with making things foolproof is that fools are so doggone ingenious...Dan Keebler
Quoting SEPilot (Reply 27): Perhaps. The reason we use nautical miles in aviation is thanks to Juan Trippe. He was fascinated by all things nautical and was the one who introduce nautical measure to aviation.
Off-topic comment - The reason we use nautical miles is because it's convinient. One nautical mile equals one arc minute of latitude. So, if you are travelling, for example, at 20 knotts (20 nautical miles per hour), you know that you are covering 20 arc minutes of latitude per hour. At low latitudes, you can aslo approximate 1 nautical mile to 1 arc minute of longitude. In the pre-computer times it made making navigational calculations easier.
David L From United Kingdom, joined May 1999, 8281 posts, RR: 42 Reply 30, posted (6 months 2 weeks 2 days 10 hours ago) and read 49860 times:
Quoting KingFriday013 (Reply 20):
How much of an [adverse] impact do negative changes in speed (both airspeed and groundspeed, I guess) have on an aircraft (a larger one, like the A330, at cruise)? I know changes can't be instantaneous, but say over the period of five seconds. Just wondering if that could have done anything.
In the examples above we're talking about a tailwind suddenly becoming a headwind. If a strong headwind suddenly moves round to hit you from the side or from above or from below then the aircraft will suddenly be knocked off line sideways, downwards or upwards. If that wind keeps changing and the aircraft is trying to stabilise itself, it can be knocked around quite a bit.
I would pay more attention to Wilco737's replies, to be honest. The airspeed will change, if only temporarily, if the wind speed/direction changes abruptly.
ULMFlyer From Brazil, joined Sep 2006, 328 posts, RR: 2 Reply 31, posted (6 months 2 weeks 2 days 10 hours ago) and read 49935 times:
Wilco,
please forgive my ignorance, but how does the magnitude of horizontal windshear encountered at cruise while flying through a cell compare with that encountered at low altitudes when flying, say, under a CB on approach? You said you have, thankfully, only encountered 20 kts shear. Was that at cruise or approach? I would have thought that at altitude the shear would be primarily in the vertical direction, but that's why I'm asking the question.
Danke.
BTW, I'm with Pihero. AFAWK, this accident could have been caused by a midair with an alien craft. We know too little at this point.
As ThrottleHold put it on Part 8, weather events can be very localized. However, I urge you to read Mr. Vasquez's weather analysis here: http://www.weathergraphics.com/tim/af447/
While it's obvious the plane went through an area of convective weather, Mr. Vasquez also writes that
Quote: the analysis indicates that the weather is not anything particularly exceptional in terms of instability or storm structure. It's my opinion that tropical storm complexes identical to this one have probably been crossed hundreds of times over the years by other flights without serious incident.
And for those already bashing the crew for penetrating such system, Mr. Vasquez also updated the analysis with a PROBABLE radar depiction of the weather and AF447's flight path. Looks reasonable to me.
Mrocktor From Brazil, joined Jan 2005, 1429 posts, RR: 45 Reply 32, posted (6 months 2 weeks 2 days 10 hours ago) and read 49804 times:
Quoting Mcg (Reply 24): I don't understand how the 'authorities' are so quick to eliminate terrorism as a potential cause of this accident.
The purpose of terrorism is to cause fear and to exploit that fear for political ends. Anonymity defeats the purpose of terrorism. Since no one claimed the act, the likelihood of this being terror is indeed small and the possibility can be eliminated until and unless some evidence pointing in that direction is found.
Pihero From France, joined Jan 2005, 1884 posts, RR: 63 Reply 33, posted (6 months 2 weeks 2 days 10 hours ago) and read 49847 times:
Quoting NAV20 (Reply 4): If the wind switched to right in your teeth at 50 knots (common enough in the two places I've flown, the UK and Oz) your airspeed would stay at 120/340. But your groundspeed would drop to say 70/290......
Time for Pihero to start talking about differential drag and how I know eff-all about flying and 'drag co-efficients' and things, and that my figures are as much as two per cent out either or both ways. But I hope the principles are clearer now....
No, the principles are not clearer and it's time I chime in :
First of all, 50 kt gusts are quite severe and in your example, a 50 kt tail wind followed by a 50 kt head wind is the sign of a very violent micro-burst and you'd be lucky to survive that one.
Why /
The main reason is that a gust, be it horizontal or vertical causes some "turbulence" as perceived by the occupants of an aircraft :
1/-Horizontal gust : It accelerates - headwind - or decelerates -tailwind - the airflow over the wing, thus affecting the lift of the wing . Head gust = sudden upward movement, tail gust = sudden drop of the airplane.
2/-For a vertical gust,, the problem is somewhat more important as a) the vectorial sum of the forward velocity and the gust result in an increased airspeed and b) because the angle of attack of the resulting vector has changed : again an increased lift on an upward gust, a vastly diminished lift for the down draft.
Now, just picture yourself in a situation where you encounter rapidly shifting winds, causing up and down movements of your aircraft. And think about the scissoring effects of these gusts on your wings.
Reducing airspeed to the manufacturer's recommended penetration IAS is therefore the initial measure taken by all aircrews. These IAS depend of course on the airplane weight and the flight level. A lot of aircrews I know, as a matter of preparation, note the parameters for turbulence penetration (N1 / EPR) and keep them handy.
Breiz From France, joined Mar 2005, 1394 posts, RR: 3 Reply 34, posted (6 months 2 weeks 2 days 10 hours ago) and read 49637 times:
Quoting MarSciGuy (Reply 9): I'm not sure what the deepest a manned (and not Bathyscaphe) submersible can penetrate but I'd assume some specialized ones could reach 4 km depths without a hitch.
The "Nautile", manned exploration sub, can reach 6 000 m. She is on her way o/b the French oceanographical vessel "Pourquoi pas?".
WILCO737 From Germany, joined Jun 2004, 6141 posts, RR: 90 Reply 35, posted (6 months 2 weeks 2 days 10 hours ago) and read 49710 times:
Quoting ULMFlyer (Reply 31): please forgive my ignorance, but how does the magnitude of horizontal windshear encountered at cruise while flying through a cell compare with that encountered at low altitudes when flying, say, under a CB on approach? You said you have, thankfully, only encountered 20 kts shear. Was that at cruise or approach? I would have thought that at altitude the shear would be primarily in the vertical direction, but that's why I'm asking the question.
The effect at low altitudes is a lot higher and worse. From my experience. I try to avoid CB's at all times. I don't like to be near them at all.
During approach the airplane seems to react a lot more to these changes in windspeed. I only had a rather gusty approach this morning into Frankfurt. And the airspeed isn't constant. The indicated airspeed goes up and down all the time. Only a couple of knots as the gusts weren't too bad.
Could it be possible that the Captain wasn't at the Stick during this tragical accident due to crew rest times?
How are the AF regulations regarding crew rest on the GIG-CDG leg?
We know the time of the accident. 3 hours after take-off the Captain is still at the stick or is he already resting?
Regarding the fact that air speed dropped to fast before entering the Turbulences, could it be possible that the two other pilots due to being younger and obviously less experienced in such a situation decreased the air-speed to much in such an extra-ordinary situation.
Before you flame me, I did not say they were bad pilots or don't have enough experience. I just want to ask, if it could be possible that they were unexperienced with such a heavy storm.
PanAm1971 From United States, joined Aug 2007, 183 posts, RR: 0 Reply 38, posted (6 months 2 weeks 2 days 10 hours ago) and read 49398 times:
Quoting Pihero (Reply 33): Now, just picture yourself in a situation where you encounter rapidly shifting winds, causing up and down movements of your aircraft. And think about the scissoring effects of these gusts on your wings.
This is what I've been trying to communicate-and doing it badly.
So-called because - believe it or not - the way that Nelson and Co. used to measure speed was to throw over a sort of baffle on a rope. The rope (known as the log-line, because originally the baffle was actually a log) had 'knots' in it every 'cables' length' (200 yards). The guy who threw it over had the job of counting the number of 'knots' that went through his fingers while a minute's worth of sand ran through the sandglass that his petty officer was holding.
Then they hauled it back in. The length of cable that had run out told them the speed of the ship.....
If Napoleon's lot had won at Trafalgar, aviation would probably be counting in kilometres, not 'nautical miles.'
Nice story, but that's not what a nautical mile has ever been. It's one minute of latitude, or a tad under 2027 yards. The old term "knots" was just close enough that it got used and stuck.
ULMFlyer From Brazil, joined Sep 2006, 328 posts, RR: 2 Reply 40, posted (6 months 2 weeks 2 days 10 hours ago) and read 49169 times:
And folks, please stop listening to what the Brazilian defense minister says. He's a lawyer by training and a joke by choice. To Americans, I could describe him as an Arlen Specter-type of politician. Will do or say anything that's in his own best interest and advances his personal agenda.
Tugger From United States, joined Apr 2006, 1918 posts, RR: 2 Reply 41, posted (6 months 2 weeks 2 days 10 hours ago) and read 49005 times:
Quoting Breiz (Reply 34): Quoting MarSciGuy (Reply 9):
I'm not sure what the deepest a manned (and not Bathyscaphe) submersible can penetrate but I'd assume some specialized ones could reach 4 km depths without a hitch.
The "Nautile", manned exploration sub, can reach 6 000 m. She is on her way o/b the French oceanographical vessel "Pourquoi pas?".
But the manned submersibles won't be the hero's here, it will be the 4-6 ROV's working almost non-stop at the bottom, investigating whatever the surface dwellers find interesting, that will do the real work and find the important stuff. The hard truth is that the primary purpose of a manned submersible is to keep the occupants alive while for the ROV's their primary purpose is to work.
Tugg
everything I have learned I have learned by mistake
ChrisK2 From Germany, joined Mar 2009, 30 posts, RR: 0 Reply 42, posted (6 months 2 weeks 2 days 10 hours ago) and read 48820 times:
Hello,
Quoting YWG (Reply 22): A very convincing article if you ask me....
Didn't know the last 4 mins of the FDR were uplinked via satellite. That's very important.
No, they weren't. Nothing from the FDR was uplinked via satellite (FDRs don't work that way - not in this day and age, anyway), and the article you quoted in its entirety (a few lines might have been sufficient) doesn't state that, either.
All that got out from the plane via (relatively expensive) satellite comms were those ACARSs messages that have been discussed ad nauseam here already.
Please, don't interpret stuff into news reports (which may already be inaccurate) that isn't in there.
David L From United Kingdom, joined May 1999, 8281 posts, RR: 42 Reply 43, posted (6 months 2 weeks 2 days 10 hours ago) and read 48458 times:
Quoting PanAm1971 (Reply 23): Ok-layperson trying to communicate-could a sudden extreme wind speed change cause a stall?
Yes. If the aircraft is flying, for example, at 30 kts above the stall speed in a 40 kt headwind and that headwind suddenly drops to 0 kts then the airspeed at that instant will be 40 kts less, i.e. 10 kts below the stall speed and stall protection can't stop it because it's already happened.
We could be but we don't know. However, I don't think a stall at 30,000 ft in itself would necessarily be disastrous in the right circumstances (you'd have to ask the experts). Being severley buffeted/slammed around could be.
Quoting Mcg (Reply 24): I don't understand how the 'authorities' are so quick to eliminate terrorism as a potential cause of this accident.
They haven't completely eliminated it. They just don't believe there's any particular reason to focus on that. It's not uncommon for the official line after an accident to be something like "we have no reason to suspect terrorism". After that's been reported by the media, translated and reported again, sometimes the exact words are distorted.
LongHaul67 From Norway, joined Jan 2007, 187 posts, RR: 1 Reply 44, posted (6 months 2 weeks 2 days 10 hours ago) and read 47996 times:
Let's say AF447 was flying into the main cell at 35.000 feet doing 350 knots. Let's also assume the plane is hit by upward winds of 88 knots as stated by Tim Vasquez in his analysis.
Is that strong enough to seriously interfere or obstruct the airflow underneath the wing if it was to last - say up 30 seconds?
What kind of speed reduction is normal before entering strong turbulence for an A332?
HawkerCamm From United Kingdom, joined Jul 2007, 266 posts, RR: 0 Reply 45, posted (6 months 2 weeks 2 days 10 hours ago) and read 47582 times:
Quoting NAV20 (Reply 4):
Short answer is, it just wouldn't, Panam1971. If you had the throttle set to hold say roughly 120 knots (for mere mortals like me) or the auto-throttle set to hold exactly 340 knots (for professionals like Zeke or Pihero), and a tailwind of 50 knots, your airspeed would be 120 or 340 knots respectively, but your groundspeed would be say 170/390 knots.
If the wind switched to right in your teeth at 50 knots (common enough in the two places I've flown, the UK and Oz) your airspeed would stay at 120/340. But your groundspeed would drop to say 70/290......
Gusts and sudden wind direction and speed changes upset the equilibrum of Thrust=Drag and Lift=Weight. This induces an oscillation called the phugoid and/or "Short period" which restores the equilibrum. Nice and simple for NAV20s aircraft but Zeke aircraft has a million lines of computer code that adapt the control surface to achieve a desired damping, load alleviation, altitude and pitch stability with a reduced static stability compared to light aircraft.
ChrisK2 From Germany, joined Mar 2009, 30 posts, RR: 0 Reply 47, posted (6 months 2 weeks 2 days 10 hours ago) and read 47175 times:
Hello,
Quoting Mrocktor (Reply 32): The purpose of terrorism is to cause fear and to exploit that fear for political ends. Anonymity defeats the purpose of terrorism.
Yes! Exactly.
Quote: Since no one claimed the act, the likelihood of this being terror is indeed small and the possibility can be eliminated until and unless some evidence pointing in that direction is found.
Yes!
What people seem to be forgetting quickly: The whole term "terrorism" has been used soooo many times the last eight years or so in the media, it's all blurry and used as a general term for "evil stuff done by bad people" or whatever. And when it's used, it causes all sorts of excitement and discussions going in strange directions, because somehow everybody gets the image on their minds of people doing things which cause towers to collapse and many people to die. The "ultimate evil", if you will. And that kills topical, useful discussion pretty easily.
What I'm meaning to say: AF447 may have crashed because of a fire on board. Yes. May well have happened - nobody can rule it out. It may even have been an explosion: trouble with the fuel tank, O2 bottles doing things they shouldn't do, yes even a bomb. Maybe some loonie is blackmailing an airline. Who knows? And who could rule it out right now, with hardly *any* evidence at all at hands? The only thing anybody knows for sure is there was a) bad weather and b) the plane crashed.
BUT! This doesn't make things terrorism. Terrorism is about messages, about psychology, and about a political agenda that you try to push through by creating fear on a larger scale. You don't achieve *anything* by having an airliner crash somewhere at the end of the world, in the middle of the night, in bad weather, without any witnesses. Without any images for the world media. Terrorism doesn't work this way.
(Such a plane crash wouldn't even be suitable for terrorist "training", as some have suggested. Why take the big efforts to get a bomb on board if you cause a huge international SAR mission, a huge investigation (the countries involved will easily want to put dozens of millions of EUR / USD into this) and - if it were to turn out that it was a bomb - a massive increase in security measures? What would you have gained, if you were a terrorist? Criminals aren't necessarily incredibly stupid.)
Nobody is ruling out a bomb, an explosion, pilot suicide, or anything. Simply, because we don't know much at all about this plane crash right now. But if we speculate, we should at least try to speculate based on the few things we do know and that which we can *plausibly* deduct from it. Weather is a top candidate here. Most other causes - not just the t-word - aren't *at_this_moment*, but may of course be in a couple weeks or months. Patience is helpful.
Mir From United States, joined Jan 2004, 13264 posts, RR: 65 Reply 48, posted (6 months 2 weeks 2 days 10 hours ago) and read 46776 times:
Quoting NAV20 (Reply 4): If the wind switched to right in your teeth at 50 knots (common enough in the two places I've flown, the UK and Oz) your airspeed would stay at 120/340. But your groundspeed would drop to say 70/290......
Other way around. At the momet you encounter the change in wind, your groundspeed will still be 120 or 340. Your airspeed will jump to 170 or 390. You'll then get more drag from the higher speed, which will start reducing both airspeed and groundspeed, though not nearly as dramatically as the shear in wind.
Also from the previous thread:
PanAm1971: Is it possible that a flash freeze encountered in a thunderstorm could have briefly clogged the pitot? If so, could this have sent the ADIRU into a series of malfunctions based on loss of data? The autopilot might make some rather dramatic manuvers (such as pitch and airspeed) if this were to happen.
Unlikely. The air data probes are all heated, so any ice that managed to get blown in would be melted quickly. What is more possible is that there was hail that managed to damage the probes. But, like most everything else on the plane, there are redundancies for that, so that shouldn't cause a crash on its own.
C010T3 From Brazil, joined Jul 2006, 1842 posts, RR: 16 Reply 50, posted (6 months 2 weeks 2 days 10 hours ago) and read 46875 times:
Air France is making some alterations to the second GIG-CDG flight. Tonight leaves the last AF447, which will become AF445 effective June 7th. The schedule and equipment stay the same.
ChrisK2 From Germany, joined Mar 2009, 30 posts, RR: 0 Reply 52, posted (6 months 2 weeks 2 days 10 hours ago) and read 45985 times:
I second this. Tim's article is quite an excellent read.
And, before I forget ... thanks a lot for this one:
Quoting NAV20 (Reply 18): If Napoleon's lot had won at Trafalgar, aviation would probably be counting in kilometres, not 'nautical miles.'
It's good to read something from the lighter side of things ... It's good to have a smile every now and then, even in the face of tragic losses like AF447.
FCA767 From United Kingdom, joined Nov 2006, 734 posts, RR: 2 Reply 53, posted (6 months 2 weeks 2 days 9 hours ago) and read 45565 times:
Quoting YWG (Reply 22): the last four minutes of Flight 447, transmitted automatically by satellite
How does the Black Box know when the last 4 minutes of flight will be?
If it can do 4 minutes when it's settled on water then why not send all the recording?
747MegaTop From United States, joined May 2007, 62 posts, RR: 0 Reply 54, posted (6 months 2 weeks 2 days 9 hours ago) and read 45381 times:
Black Box recovery - I really hope that the black boxes are recovered. Given the fact that deep sea submersibles have reached Mariana Trench ...the deepest known part of the world's oceans..there is hope. Given the fact that as recently as May 31st "Nereus" dived and sampled sediments from the Mariana Trench at a depth of 10,902 meters (6.8 miles) we all have reason to be optimistic (agreed that the conditions are extremely difficult for locating and retrieving the black boxes). Here are a couple of articles that make interesting reading and increases our optimism of the black boxes being retrieved
David L From United Kingdom, joined May 1999, 8281 posts, RR: 42 Reply 56, posted (6 months 2 weeks 2 days 9 hours ago) and read 44913 times:
Quoting ChrisK2 (Reply 47): Nobody is ruling out a bomb, an explosion, pilot suicide, or anything. Simply, because we don't know much at all about this plane crash right now. But if we speculate, we should at least try to speculate based on the few things we do know and that which we can *plausibly* deduct from it. Weather is a top candidate here. Most other causes - not just the t-word - aren't *at_this_moment*, but may of course be in a couple weeks or months. Patience is helpful.
As you said earlier in that post...
Yes! Exactly.
That's what I tried to say several times before but you summarised it much better than I did.
David L From United Kingdom, joined May 1999, 8281 posts, RR: 42 Reply 57, posted (6 months 2 weeks 2 days 9 hours ago) and read 44904 times:
Quoting FCA767 (Reply 53): How does the Black Box know when the last 4 minutes of flight will be?
If it can do 4 minutes when it's settled on water then why not send all the recording?
It wasn't the last 4 minutes of FDR data, it was ACARS messages from the last 4 minutes before transmissions ceased. The FDR doesn't transmit any data, hence the desire to find it and extract its data.
NAV20 From Australia, joined Nov 2003, 7226 posts, RR: 43 Reply 58, posted (6 months 2 weeks 2 days 9 hours ago) and read 45042 times:
[quote=Pihero,reply=33]First of all, 50 kt gusts are quite severe and in your example, a 50 kt tail wind followed by a 50 kt head wind is the sign of a very violent micro-burst and you'd be lucky to survive that one.[/quote
They were only examples - 'round figures,' you could say, simple arithmetic - for clarity...........
But what are you saying, 'friend' - I actually mean that sincerely. That I've got the whole thing wrong in principle - or that I've just exaggerated the figures somewhat?
I actually HAVE had to deal with fifty-knot wind gusts, once, by the way. In a venerable DH Tiger Moth, in a Buckinghamshire thunderstorm. I can probably make a justifiable claim to being one of the very few pilots who ever flew a landing approach in poor visibility at (thankfully momentarily) a negative groundspeed.
Things got better at about 300 feet AGL. The landing worked out fine in the end, and only about six pints of beer were required to sooth the minds of both myself and my poor bloody passenger.......
Seriously though, please don't think that I'm in any way trying to belittle what guys like you and Zeke do. I flew for pleasure, when and if I could afford it. You guys are asked to achieve the diffiicult, in bad weather, most days - and the 'more or less impossible' at least once a week. And then probably do the same again the next day, after maybe six hours' sleep, if you're eastbound........
[Edited 2009-06-04 10:53:22]
"Once you have flown, you will walk the earth with your eyes turned skywards.." - Leonardo da Vinci
Readytotaxi From United Kingdom, joined Dec 2006, 1077 posts, RR: 0 Reply 59, posted (6 months 2 weeks 2 days 9 hours ago) and read 44567 times:
I was wondering what percentage of of the population think that there is total radar coverage on the globe, would they be shocked at the gaps out there?
you don't get a second chance to make a first impression!
FCA767 From United Kingdom, joined Nov 2006, 734 posts, RR: 2 Reply 60, posted (6 months 2 weeks 2 days 9 hours ago) and read 44285 times:
Quoting David L (Reply 57): It wasn't the last 4 minutes of FDR data, it was ACARS messages from the last 4 minutes before transmissions ceased. The FDR doesn't transmit any data, hence the desire to find it and extract its data
Thanks David but also then I thought someone said they always transmit the last 4 minutes but how would they know the last 4 minutes was coming...I'm just aware that they are always transmitting info
David L From United Kingdom, joined May 1999, 8281 posts, RR: 42 Reply 61, posted (6 months 2 weeks 2 days 9 hours ago) and read 43874 times:
Quoting NAV20 (Reply 59): That I've got the whole thing wrong in principle - or that I've just exaggerated the figures somewhat?
I have to say... you got the whole thing wrong in principle (well, you did ask). If the wind changes speed and/or direction suddenly then the airspeed will change suddenly and gradually revert to what it was before while the ground speed will start off approximately the same and gradually change as the original airspeed is regained.
You forgot about inertia, a property quite abundant in A330-type aircraft. And it is perfectly good, traditional inertia, not that rubbish, new-fangled Inertia by Wire.
Hywel From Chad, joined Apr 2008, 462 posts, RR: 0 Reply 62, posted (6 months 2 weeks 2 days 9 hours ago) and read 43735 times:
I haven't read all of the posts in the 10 threads so far, so apologies if this has already been mentioned.
Has anyone thought about the possibility of large hail stones from the thunderstorm smashing the cockpit windows, incapacitating the pilots and then leading to a loss of cabin pressure?
Famfflores From Brazil, joined Jun 2009, 40 posts, RR: 0 Reply 63, posted (6 months 2 weeks 2 days 9 hours ago) and read 44241 times:
A Brazilian ship has just picked up the first piece from the water. It´s a pallet used in the cargo hold compartment. They should confirm that it is from AF447 soon.
David L From United Kingdom, joined May 1999, 8281 posts, RR: 42 Reply 65, posted (6 months 2 weeks 2 days 9 hours ago) and read 43855 times:
Quoting FCA767 (Reply 60): but how would they know the last 4 minutes was coming
Interesting question, Grasshopper - they "just know". Well, it could keep transmitting untill it lost power and the receiving station could buffer 4 minutes' worth and stop recording when the carrier signal was lost. However, it doesn't happen at all so it's academic.
As far as having access to the "last 4 minutes" of ACARS messages, I assume AF at CDG store all messages from all aircraft, for a while anyway, so they wouldn't be difficult to find. ACARS messages over HF can be accessed and stored by anyone with an airband radio and freeware software - they just have to be careful what they do with those messages in some countries, such as the UK.
Edit: Just realised you're probably far too young to get the "Grasshopper" reference. It was from a 1970s TV series called Kung Fu. It's not worth delving into. Sorry.
I know this is nitpicky, but being a hydrographer I'll nitpick - a nautical mile is actually 6076 feet, so SLIGHTLY over 2,000 yards....
Quoting Breiz (Reply 34):
Quoting MarSciGuy (Reply 9):
I'm not sure what the deepest a manned (and not Bathyscaphe) submersible can penetrate but I'd assume some specialized ones could reach 4 km depths without a hitch.
The "Nautile", manned exploration sub, can reach 6 000 m. She is on her way o/b the French oceanographical vessel "Pourquoi pas?".
I was going to guess that the Mir class Submersibles could dive that deep, but without wanting ot reference wiki too much in a day, I left it at that good to know though that there is one on the way!
Quoting Tugger (Reply 41): Quoting Breiz (Reply 34):
Quoting MarSciGuy (Reply 9):
I'm not sure what the deepest a manned (and not Bathyscaphe) submersible can penetrate but I'd assume some specialized ones could reach 4 km depths without a hitch.
The "Nautile", manned exploration sub, can reach 6 000 m. She is on her way o/b the French oceanographical vessel "Pourquoi pas?".
But the manned submersibles won't be the hero's here, it will be the 4-6 ROV's working almost non-stop at the bottom, investigating whatever the surface dwellers find interesting, that will do the real work and find the important stuff. The hard truth is that the primary purpose of a manned submersible is to keep the occupants alive while for the ROV's their primary purpose is to work.
Tugg
My guess would be either the Porquoi Pas or some of the other vessels in the area so equipped will fully survey the area using multibeam, probably sidescan, and maybe another more novel type of sonar firstly before dispatching the submersibles (unmanned and manned). Once they find wreckage they'll deploy the ROVs, wait for them to reach the seabed and identify wreckage, and then send down the manned sub. If they have a general location within a km by km quadrant or so narrowed down for where the boxes are it won't take too long to survey the area, if not it could use up most of the remaining time before the pinger stops, if not more. a several kilometer deep dive op could take quite some time for the submersibles to descend to depth.
"There weren't a ton of gnats there where a ton of gnats and their families as well!"
Quoting 747MegaTop (Reply 54): Black Box recovery - I really hope that the black boxes are recovered. Given the fact that deep sea submersibles have reached Mariana Trench ...the deepest known part of the world's oceans..there is hope. Given the fact that as recently as May 31st "Nereus" dived and sampled sediments from the Mariana Trench at a depth of 10,902 meters (6.8 miles) we all have reason to be optimistic (agreed that the conditions are extremely difficult for locating and retrieving the black boxes). Here are a couple of articles that make interesting reading and increases our optimism of the black boxes being retrieved
So I understand that once balck boxes are located, it's technically possible to retrieve them with such submersible (or other types mentioned in other posts).
But as for identifying the location ... I would tend to think that it's not too complex given that these black boxes spend signals for the next 30 days ? I am not a specialist, but it would sound to me not too complicated task if they can track their signal ... unless they were destroyed.
LongHaul67 From Norway, joined Jan 2007, 187 posts, RR: 1 Reply 68, posted (6 months 2 weeks 2 days 9 hours ago) and read 43088 times:
Quoting C010T3 (Reply 50): Air France is making some alterations to the second GIG-CDG flight. Tonight leaves the last AF447, which will become AF445 effective June 7th. The schedule and equipment stay the same.
I never really understood why the northbound flight # was out of sequence with the southbound to begin with.
PhB95 From France, joined May 2009, 12 posts, RR: 0 Reply 69, posted (6 months 2 weeks 2 days 9 hours ago) and read 43320 times:
Just saw in the french newspaper site "20 minutes" that the first debris have been retrieved, and none of it is from the missing plane:
"La tâche de kérosène serait due à un «dégazage en mer» et la pièce de 7 mètres de diamètre qui avait également été repérée viendrait «d'une petite embarcation abandonnée». La bouée orange également retrouvée «serait un flotteur de casier à la dérive», précise le site d'informations."
The kerosin is from a ship, the 7 metres piece is from a little boat, and the orange ring isfrom a fisher's equipement. I'm not too good at translating acurately so feel free to enhance it.
PanAm1971 From United States, joined Aug 2007, 183 posts, RR: 0 Reply 70, posted (6 months 2 weeks 2 days 9 hours ago) and read 42998 times:
Quoting MarSciGuy (Reply 66): My guess would be either the Porquoi Pas or some of the other vessels in the area so equipped will fully survey the area using multibeam, probably sidescan, and maybe another more novel type of sonar firstly before dispatching the submersibles (unmanned and manned).
Perhaps a SURTASS vessel could be sent to find the boxes if they're having trouble hearing the pinging bacuse of the depth and layers.
Famfflores From Brazil, joined Jun 2009, 40 posts, RR: 0 Reply 72, posted (6 months 2 weeks 2 days 9 hours ago) and read 43158 times:
hum....
An "expert" just gave an interview. His name is Gustavo Tavares da Cunha Mello. I guess his is not from this forum. He just said that the ADIRU is the cause of the crash, that the ADIRU manages the plane and can take over control from the pilot at any given moment. He said that every plane in the world with the ADIRU should suffer a recall to change everything and till then it should at least be removed from all aircrafts....
Anyone recalls if AA587's A300-600 was ever involved on an incident prior to the November 2001 crash? I am not sure but wasn't there a rumor that AA587's A300 had fallen on its tail while parked at some time during its career?
These accidents bring to mind China Airlines 747-200 that broke up apart in mid-air in 2002. Wasn't that 747 involved in an incident, then repaired and therefore had a structural failure? Perhaps these accidents have some similarities maybe airplanes that suffer an incident that could compromise its structural integrity should never be flown again. Anyone recalls JAL's domestic 747 aft bulkhead collapse???
Klwright69 From United States, joined Jan 2000, 1184 posts, RR: 6 Reply 78, posted (6 months 2 weeks 2 days 9 hours ago) and read 42001 times:
Quoting PRAirbus (Reply 74): Anyone recalls if AA587's A300-600 was ever involved on an incident prior to the November 2001 crash? I am not sure but wasn't there a rumor that AA587's A300 had fallen on its tail while parked at some time during its career?
These accidents bring to mind China Airlines 747-200 that broke up apart in mid-air in 2002. Wasn't that 747 involved in an incident, then repaired and therefore had a structural failure? Perhaps these accidents have some similarities maybe airplanes that suffer an incident that could compromise its structural integrity should never be flown again. Anyone recalls JAL's domestic 747 aft bulkhead collapse???
No. In AA587, the pilots overcorrected, stressing out the rudder and breaking off the tail. Watch the Crash Investigation documentary on youtube.
But the other accidents came to my mind when I first heard about this AF crash.
Honeythief From United Kingdom, joined Jun 2009, 14 posts, RR: 0 Reply 79, posted (6 months 2 weeks 2 days 9 hours ago) and read 41909 times:
Quoting PhB95 (Reply 69): Just saw in the french newspaper site "20 minutes" that the first debris have been retrieved, and none of it is from the missing plane:
"La tâche de kérosène serait due à un «dégazage en mer» et la pièce de 7 mètres de diamètre qui avait également été repérée viendrait «d'une petite embarcation abandonnée». La bouée orange également retrouvée «serait un flotteur de casier à la dérive», précise le site d'informations."
The kerosin is from a ship, the 7 metres piece is from a little boat, and the orange ring isfrom a fisher's equipement. I'm not too good at translating acurately so feel free to enhance it.
If the above report is correct, would that imply that the search has been concentrating in the wrong area or has further debris already been found at another location ?
NAV20 From Australia, joined Nov 2003, 7226 posts, RR: 43 Reply 80, posted (6 months 2 weeks 2 days 9 hours ago) and read 41911 times:
Quoting Famfflores (Reply 72): I guess his is not from this forum. He just said that the ADIRU is the cause of the crash, that the ADIRU manages the plane and can take over control from the pilot at any given moment.
Utterly wrong; but, oddly, also right, Famfflores.
By which I mean that, as far as I know, the ADIRU just feeds information to the 'central' Flight Data Computer. It is the FDC that 'decides' what should be done with information from 'ancillaries' like the ADIRU.
[Edited 2009-06-04 11:11:55]
"Once you have flown, you will walk the earth with your eyes turned skywards.." - Leonardo da Vinci
MarSciGuy From United States, joined Jun 2007, 369 posts, RR: 0 Reply 81, posted (6 months 2 weeks 2 days 8 hours ago) and read 41837 times:
Quoting Gniou (Reply 67):
But as for identifying the location ... I would tend to think that it's not too complex given that these black boxes spend signals for the next 30 days ? I am not a specialist, but it would sound to me not too complicated task if they can track their signal ... unless they were destroyed.
If the signal is heard in several different locations it should be fairly easy to triangulate it to a fairly small region of the seabed.
Quoting PhB95 (Reply 69):
Quoting MarSciGuy (Reply 66):
My guess would be either the Porquoi Pas or some of the other vessels in the area so equipped will fully survey the area using multibeam, probably sidescan, and maybe another more novel type of sonar firstly before dispatching the submersibles (unmanned and manned).
Perhaps a SURTASS vessel could be sent to find the boxes if they're having trouble hearing the pinging bacuse of the depth and layers.
I'm not sure how far they can extend the arrays, but if they can get them below the surface layer (or if there are multiple thermal layers, deeper then that) and have more then one hydrohpone pick up the pings it should be fairly simple to trinagulate it and those would definitely be the ideal platform for such a task as they are quiet!
Quoting PhB95 (Reply 69): Just saw in the french newspaper site "20 minutes" that the first debris have been retrieved, and none of it is from the missing plane:
"La tâche de kérosène serait due à un «dégazage en mer» et la pièce de 7 mètres de diamètre qui avait également été repérée viendrait «d'une petite embarcation abandonnée». La bouée orange également retrouvée «serait un flotteur de casier à la dérive», précise le site d'informations."
The kerosin is from a ship, the 7 metres piece is from a little boat, and the orange ring isfrom a fisher's equipement. I'm not too good at translating acurately so feel free to enhance it.
So if that's the case and the other debris recovered is not from the aircraft either, we're literally searching for a needle in a haystack on the seabed...
"There weren't a ton of gnats there where a ton of gnats and their families as well!"
FCA767 From United Kingdom, joined Nov 2006, 734 posts, RR: 2 Reply 82, posted (6 months 2 weeks 2 days 8 hours ago) and read 41651 times:
Quoting David L (Reply 65): Interesting question, Grasshopper - they "just know". Well, it could keep transmitting untill it lost power and the receiving station could buffer 4 minutes' worth and stop recording when the carrier signal was lost. However, it doesn't happen at all so it's academic.
As far as having access to the "last 4 minutes" of ACARS messages, I assume AF at CDG store all messages from all aircraft, for a while anyway, so they wouldn't be difficult to find. ACARS messages over HF can be accessed and stored by anyone with an airband radio and freeware software - they just have to be careful what they do with those messages in some countries, such as the UK.
Edit: Just realised you're probably far too young to get the "Grasshopper" reference. It was from a 1970s TV series called Kung Fu. It's not worth delving into. Sorry
true they would store the info ah yeah i wouldnt know that reference Yeah I read the Acars at home
Actually the link didn't work. But my answer would probably remain the same.
I still want to see the images but, nevertheless...
Quoting Famfflores (Reply 72): I guess his is not from this forum. He just said that the ADIRU is the cause of the crash, that the ADIRU manages the plane and can take over control from the pilot at any given moment
I can think of someone from here...
Quoting Famfflores (Reply 72): He said that every plane in the world with the ADIRU should suffer a recall to change everything and till then it should at least be removed from all aircrafts....
... ah, maybe not, then.
Seriously, on how many incidents is he basing that "revelation"? And "take over control" - what?
Mir From United States, joined Jan 2004, 13264 posts, RR: 65 Reply 84, posted (6 months 2 weeks 2 days 8 hours ago) and read 41296 times:
Quoting Hywel (Reply 62): Has anyone thought about the possibility of large hail stones from the thunderstorm smashing the cockpit windows, incapacitating the pilots and then leading to a loss of cabin pressure?
It's possible, but it wouldn't have led to this. Even if the pilots were incapacitated, the aircraft would keep going on its programmed route, and it had the fuel to last for quite a while. And it wouldn't explain the autopilot disconnection, as the pilots being incapacitated wouldn't have any effect on the A/P.
Famfflores From Brazil, joined Jun 2009, 40 posts, RR: 0 Reply 85, posted (6 months 2 weeks 2 days 8 hours ago) and read 41524 times:
Quoting PhB95 (Reply 69): Just saw in the french newspaper site "20 minutes" that the first debris have been retrieved, and none of it is from the missing plane:
Very different from what´s being reported here. it´s mentioned that the ship Constituição just removed the first piece and it´s a part of a pallet or some sort of fixing for cargo in airplanes, till to be confirmed if part of AF 447.
Osiris30 From Barbados, joined Sep 2006, 3134 posts, RR: 25 Reply 86, posted (6 months 2 weeks 2 days 8 hours ago) and read 41266 times:
Quoting YWG (Reply 22): Although the flight recorders lie about 12,000ft below the ocean surface, the BEA has data on the last four minutes of Flight 447, transmitted automatically by satellite to Air France's base at Paris Charles de Gaulle airport.
Since *when* does this happen.... oh shit I'm going to crash in 4 minutes, better uplink everything... this whole thing sounds like a crock to me.
Quote: The Air France jet that crashed into the Atlantic killing 228 may have stalled after pilots slowed down too much as they encountered turbulence, new information suggests.
Very convenient. But I can't see a stall being at issue with 35K ft to play with, doesn't sound reasonable.
I don't care what you think of my opinion. It's my opinion, so have a nice day :)
Sailfly From United States, joined Jun 2009, 2 posts, RR: 0 Reply 88, posted (6 months 2 weeks 2 days 8 hours ago) and read 40506 times:
First hello to all this will be my first post. I work in the drilling industry and have enjoyed reading in the news and the posts the uncertainty surrounding the chances of finding the FDR. So for my two cents, assuming the devices are still active there is no reason they cannot be located, I assume our underwater positioning and reference equipment is similar technology and would be very easy to locate once the general area on the sea floor is found. Finding that area may prove difficult, surface currents and sub sea currents will not all be in the same direction, especially in that water depth, in fact it is quite possible that there will be two or three separate currents as you go deeper, not an overwhelming task and I’m sure there is some smart person or modeling which can handle that. Then depending on the size and weight of any pieces this could be an issue, not knowing what the ocean floor bottom conditions are in that area, I will say it is possible that pieces have buried themselves to a point that they will never be located. A previous poster noted that majority of the work will be accomplished with ROV's (Remote operated vehicles), I agree with that but would also add that Sub Sea Construction and Support vessels will likely be brought in to do the heavy lifting if warranted. This tragedy has really hit close to home for a lot of use in the drilling industry here in Brazil. AF447 is regularly used by offshore crews flying to and from Europe, I myself have flown that route and know people that were on the same route the day before and days after the incident. My deepest sympathies to all families affected by this tragedy.
and now at the risk of getting off to a bad start here on the forums, the origin of a knot (speed reference) was in fact with the use of a chip log which was a wooden device thrown over the stern of a moving vessel then knots tied in a line every 42 feet were counted for 30 seconds, later knots tied every 47 feet 3 inches counted over 28 seconds was used. As for nautical mile that one is another long story the method of calculating has changed quite a few times over history but if interested I'm sure you can look that up.
David L From United Kingdom, joined May 1999, 8281 posts, RR: 42 Reply 89, posted (6 months 2 weeks 2 days 8 hours ago) and read 40738 times:
Quoting Osiris30 (Reply 86): Since *when* does this happen.... oh shit I'm going to crash in 4 minutes, better uplink everything... this whole thing sounds like a crock to me.
AF have details of the ACARS messages transmitted via SATCOM over the last 4 minutes. The messages are almost certainly stored and/or printed out so it's no mystery that they have the details of the messages sent during the last 4 minutes. I think the significance of "the last 4 minutes" is that that is when the flurry of messages began - nothing "predictive" about it.
A388 From Netherlands Antilles, joined May 2001, 5791 posts, RR: 15 Reply 90, posted (6 months 2 weeks 2 days 8 hours ago) and read 40514 times:
Quoting Osiris30 (Reply 86): Quoting YWG (Reply 22):
Although the flight recorders lie about 12,000ft below the ocean surface, the BEA has data on the last four minutes of Flight 447, transmitted automatically by satellite to Air France's base at Paris Charles de Gaulle airport.
Since *when* does this happen.... oh shit I'm going to crash in 4 minutes, better uplink everything... this whole thing sounds like a crock to me.
New generation aircraft apparently have this feature. The systems on board the A332 of AF apparently also have a constant link to the maintenance and/or operations control center. This is nothing uncommon as KL also has this. Everything from engine behavoir, fuel consumption etc is constantly send to the headquarters with aircraft which have this new feature. I do admit that I don't know how detailed the data is that is being transmitted. The A380 also has this feature as far as I know.
Honeythief From United Kingdom, joined Jun 2009, 14 posts, RR: 0 Reply 91, posted (6 months 2 weeks 2 days 8 hours ago) and read 40464 times:
Quoting Osiris30 (Reply 86): Quoting YWG (Reply 22):
Although the flight recorders lie about 12,000ft below the ocean surface, the BEA has data on the last four minutes of Flight 447, transmitted automatically by satellite to Air France's base at Paris Charles de Gaulle airport.
Since *when* does this happen.... oh shit I'm going to crash in 4 minutes, better uplink everything... this whole thing sounds like a crock to me.
There seems to be a misunderstanding here. The 'four minutes' of data is a reference to the ACARS messages that were sent over a four minute period and NOT to any data from the FDR or CVR.
Carls From Germany, joined Aug 2007, 356 posts, RR: 0 Reply 92, posted (6 months 2 weeks 2 days 8 hours ago) and read 40219 times:
Quoting JBirdAV8r (Reply 76): That was in a (HOAX) forwarded email. That damage was purportedly caused by a lightning strike, but was instead actually an electrical fire.
Skin damage from a lightning strike doesn't look like that in any way. It's MUCH smaller.
The picture was sent to me as a lightning strike, and I have to admitte that I did not confirmed if it was true or not. But if you say that a lightning strike will be much smaller, then at 35000 something like a 1/4 of this damage could be the begging of a much more bigger problem.
Just a wild guess.
Oroka From Canada, joined Dec 2006, 424 posts, RR: 0 Reply 93, posted (6 months 2 weeks 2 days 8 hours ago) and read 40082 times:
Quoting Osiris30 (Reply 86): Very convenient. But I can't see a stall being at issue with 35K ft to play with, doesn't sound reasonable.
What if they decreased airspeed a bit late and over did it in their rush, stalled, and encountered sever downdrafts? You go from a stall to a plunge. Maybe that is the reason for the stall... they encountered a downdraft just as they throttled back, causing a nearly unrecoverable stall?
MoMan From United States, joined Aug 2004, 898 posts, RR: 6 Reply 94, posted (6 months 2 weeks 2 days 8 hours ago) and read 40431 times:
Quoting PRAirbus (Reply 74): Anyone recalls if AA587's A300-600 was ever involved on an incident prior to the November 2001 crash? I am not sure but wasn't there a rumor that AA587's A300 had fallen on its tail while parked at some time during its career?
No. There is also AA 903, a sister A300 which suffered a pilot-induced stall near Miami, the pilots used excessive rudder inputs, and the vertical stabilizer exceeded ultimate load, but stayed intact. After 587, this aircraft was re-examined and the vertical stabilizer was found to have cracks much like the one on 587, yet no other A300s had the cracks.
I suspect this talk of a previous incident is not related to the crash.
That is my initial reaction as well due to the skin effect of electricity. The electric charge from the lightening would remain on the outside of the aircraft. I don't think that lightening alone could bring down a plane.
What if, however, there were some structural damage with the aircraft due to turbulence/hail or whatever, and lightning struck several times and the charge perhaps penetrating the outside skin of the aircraft through a small crack or what not. Could the charge then cause problems to the flight controls/computers by means of extreme charge or short circuit?
JBirdAV8r From United States, joined Jun 2001, 3091 posts, RR: 21 Reply 96, posted (6 months 2 weeks 2 days 8 hours ago) and read 39544 times:
Quoting Carls (Reply 92): The picture was sent to me as a lightning strike, and I have to admitte that I did not confirmed if it was true or not. But if you say that a lightning strike will be much smaller, then at 35000 something like a 1/4 of this damage could be the begging of a much more bigger problem.
No problem--I wasn't accusing you of trying to hoax us
Actually the damage from a lightning strike is generally much smaller than even 1/4ths of this damage--down to a diameter of a few inches. From a structural standpoint, there usually isn't much damage to the airplane except for a burn mark.
Every commercial airliner in the world is hit by lightning an average of once a year. I think it's almost impossible that lightning by itself caused this accident.
YYZYYT From Canada, joined Apr 2005, 646 posts, RR: 0 Reply 97, posted (6 months 2 weeks 2 days 8 hours ago) and read 39710 times:
Quoting Klwright69 (Reply 78): Quoting PRAirbus (Reply 74):
Anyone recalls if AA587's A300-600 was ever involved on an incident prior to the November 2001 crash? I am not sure but wasn't there a rumor that AA587's A300 had fallen on its tail while parked at some time during its career?
These accidents bring to mind China Airlines 747-200 that broke up apart in mid-air in 2002. Wasn't that 747 involved in an incident, then repaired and therefore had a structural failure? Perhaps these accidents have some similarities maybe airplanes that suffer an incident that could compromise its structural integrity should never be flown again. Anyone recalls JAL's domestic 747 aft bulkhead collapse???
No. In AA587, the pilots overcorrected, stressing out the rudder and breaking off the tail. Watch the Crash Investigation documentary on youtube.
But the other accidents came to my mind when I first heard about this AF crash.
According to the report, the aircraft had had a prior turbulence incident, but had undergone a thorough inspection (including the tail). No findings that prior damage existed or contributed to the crash.
PhB95 From France, joined May 2009, 12 posts, RR: 0 Reply 98, posted (6 months 2 weeks 2 days 8 hours ago) and read 39110 times:
Quoting Famfflores (Reply 85): Very different from what´s being reported here. it´s mentioned that the ship Constituição just removed the first piece and it´s a part of a pallet or some sort of fixing for cargo in airplanes, till to be confirmed if part of AF 447.
Yes, this has just been said minutes ago on french TV. Let's hope it's indeed a part of the plane. It would be awfull to have to start all over searching.
What I find curious is that at the same time french SAR planes still search a fair bit further along the supposed route, as if they were not really sure yet about the location.
Anyway they seems to be a lot of junk floating around, which will not make the matter easy.
ThrottleHold From South Africa, joined Jul 2006, 472 posts, RR: 0 Reply 99, posted (6 months 2 weeks 2 days 8 hours ago) and read 38483 times:
Turbulence penetration speed for the A330-200 at this altitude is M0.80. Managed cruising speed would be around M0.80 to M0.82, depending on the variables.
Therefore, the speed reduction required would be quite small, even none at all. The A/T would only command a slight power reduction to slowly bring the speed towards M0.80.
PRAirbus From Puerto Rico, joined Apr 2005, 738 posts, RR: 2 Reply 100, posted (6 months 2 weeks 2 days 8 hours ago) and read 38089 times:
Quoting MoMan:
No. There is also AA 903, a sister A300 which suffered a pilot-induced stall near Miami, the pilots used excessive rudder inputs, and the vertical stabilizer exceeded ultimate load, but stayed intact. After 587, this aircraft was re-examined and the vertical stabilizer was found to have cracks much like the one on 587, yet no other A300s had the cracks.
I suspect this talk of a previous incident is not related to the crash.
Do you know if the AA A300 you mentioned of AA903 that was found to have cracks is still in service?
Dougbr2006 From Brazil, joined Oct 2006, 349 posts, RR: 1 Reply 101, posted (6 months 2 weeks 2 days 7 hours ago) and read 37874 times:
Quoting FCA767 (Reply 60): Quoting David L (Reply 57):
It wasn't the last 4 minutes of FDR data, it was ACARS messages from the last 4 minutes before transmissions ceased. The FDR doesn't transmit any data, hence the desire to find it and extract its data
Thanks David but also then I thought someone said they always transmit the last 4 minutes but how would they know the last 4 minutes was coming...I'm just aware that they are always transmitting info
The ACARS system sends a signal at a fixed time interval this data is a maintenance tool and does not represent data from the Data Recorder though the same warnings if relative are recorded by the Data Recorder. The ACARS data is usually just stored for maintenance purposes or health monitoring. Air France only started to look at these after contact could not be made with the flight. There is no human monitor of the incoming signals as far as I am aware. The manual message about entering the turbulence was probably sent by the crew via Satcom.
The flight data recorders record many more detailed parameters than the ACARS system probably sends back as maintenance data.
Its strange that this airspeed issue has just started to come to light. But a stalling aircraft is still unlikely to break up, unless the crew lost total control. They don't mention any stick push etc.
UltimateDelta From United States, joined Sep 2007, 1185 posts, RR: 0 Reply 102, posted (6 months 2 weeks 2 days 7 hours ago) and read 37312 times:
Quoting Dougbr2006 (Reply 101): But a stalling aircraft is still unlikely to break up, unless the crew lost total control. They don't mention any stick push etc.
I suppose that if the plane was in a wildly uncontrolled stall while being thrown around in midair by the storm it could have been just ripped apart. But like with everything else, this certainly remains to be seen.
Those who think they know everything annoy those of us who actually do.
Pihero From France, joined Jan 2005, 1884 posts, RR: 63 Reply 103, posted (6 months 2 weeks 2 days 7 hours ago) and read 37094 times:
Quoting Dougbr2006 (Reply 101):
The ACARS system sends a signal at a fixed time interval
No. This system transmits via Acars a message for every fault that is sensed by all systems, when it happens -there is a time stamp on each message in the event that the aircraft doesn't have a contact with base - VHF or Satellite. Then the messages are queued, waiting for the contact to be re-established.
Quoting Dougbr2006 (Reply 101): Air France only started to look at these after contact could not be made with the flight.
You don't know that.
Quoting Dougbr2006 (Reply 101): There is no human monitor of the incoming signals as far as I am aware
But in a big airline there's a 24/7 maintenance OPS watch of the airborne flights.
Quoting Dougbr2006 (Reply 101): The flight data recorders record many more detailed parameters than the ACARS system probably sends back as maintenance data.
7673mech From United States, joined Mar 2004, 221 posts, RR: 0 Reply 105, posted (6 months 2 weeks 2 days 7 hours ago) and read 36628 times:
Been skimming the thread and I have not seen it mentioned - something being overlooked.
The aircraft could have sustained ground damage - a errant baggage cart, a belt loader, a can loader - small dent - small crack - under pressure grew and eventually turned tragic.
Everyone is focusing on the ACARS messages - have seen it before where these are in error.
Just saying this because I have seen it happen - fortunately not with tragic consequences - however it is possible.
Over eight-hundred twenty times a day the people of TWA take to the air with just one mission. Yours.
PanAm1971 From United States, joined Aug 2007, 183 posts, RR: 0 Reply 106, posted (6 months 2 weeks 2 days 7 hours ago) and read 36229 times:
Quoting 7673mech (Reply 105): The aircraft could have sustained ground damage - a errant baggage cart, a belt loader, a can loader - small dent - small crack - under pressure grew and eventually turned tragic.
N905TW From United States, joined Jul 2004, 38 posts, RR: 0 Reply 107, posted (6 months 2 weeks 2 days 7 hours ago) and read 35792 times:
While it may be clarified later on, I am fairly certain that Air France is like other airlines in that they have a priority system for these messages that are automatically generated from the aircraft.
I fly the smaller A320/319/321 which have a similar if not identical system, and at our airline these messages are flagged if they are of a certain importance. At that point, attention is drawn to the staff working in Maintenance control that a certain aircraft has a certain fault occurring.
For example, a while back we lost one of our engine driven generators, and before we even had time to finish the procedures listed in our manuals, our staff in Maintenance control were already sending us messages over ACARS asking if all was ok - they knew exactly what had failed - because the aircraft already told them!
On the other hand, smaller, non-critial messages (such as LAV E Flush Motor fault), etc, while sent and received in the same way, are of a less important nature and do not show up the same way to staff at the home base.
Of course, this is how our system works... AF could of course be different....
KingFriday013 From United States, joined May 2007, 225 posts, RR: 4 Reply 108, posted (6 months 2 weeks 2 days 7 hours ago) and read 35550 times:
Quoting 7673mech (Reply 105): The aircraft could have sustained ground damage - a errant baggage cart, a belt loader, a can loader - small dent - small crack - under pressure grew and eventually turned tragic.
Or maybe a broken window panel? I know I've been on at least two flights (once a 757, the other a Dash 8) where the window panel was broken and i could even stick my finger in between the hole. Nothing happened on either flight (well... on the 757 flight, NAS-LGA on DL, I had a cold and my ears were hurting because of pressure the entire flight (it was just me). I vowed to never fly again, and over a year later I realized I hadn't flown since It was my last 757 for a few years, too). But *could* this eventually lead to a problem?
The ACARS system sends a signal at a fixed time interval
No. This system transmits via Acars a message for every fault that is sensed by all systems, when it happens -there is a time stamp on each message in the event that the aircraft doesn't have a contact with base - VHF or Satellite. Then the messages are queued, waiting for the contact to be re-established.
Yes, that's the way I understand it, too. It's a store-and-forward service, with queues, and with the focus on reliable transmission, not necessarily very fast or real-time transmission, though it can be real-time when you're lucky.
If transmission is not possible at some time, queued messages will simply be sent later. (In day-to-day practice, that wouldn't be a problem, and that's why the system is designed the way it is: if messages relevant to maintenance arrive, say, ten minutes or half an hour after they have been generated, that usually doesn't change much, since the plane will still be on its way, and enough time left to schedule a visit to the mechanic's or order spare parts or whatever. Real-time reaction is not usually required.)
Which makes me wonder: it's quite conceivable that in a catastrophic event, further ACARS messages get generated by the system, but cannot be sent anymore. Either because of technical trouble in the plane (antenna breaking off, power failing), or because of outside reasons (after all, it was quite "electrical" weather, which makes radio transmissions of any kind, satellite including, more difficult).
Which means, it may well be that the messages received by AF were not the last messages to be generated by the plane - just the last ones that could be sent off successfully by the plane's systems. One shouldn't forget that when evaluating them - they could just have been messages from "right in the middle" of the catastrophic event.
Oh man, I really hope they'll find the FDR and it's still readable. Much much more info stored on it ...
Ikramerica From United States, joined May 2005, 18493 posts, RR: 60 Reply 110, posted (6 months 2 weeks 2 days 7 hours ago) and read 35162 times:
Quoting 7673mech (Reply 105): Been skimming the thread and I have not seen it mentioned - something being overlooked.
I mentioned crack propagation a few threads back as a possible scenario for break apart when I suggested that the storm isn't necessarily the cause of the accident, but merely what accelerated the effects of the root cause. Or it could be coincidental and completely unrelated.
Of all the things to worry about... the Wookie has no pants.
FCA767 From United Kingdom, joined Nov 2006, 734 posts, RR: 2 Reply 111, posted (6 months 2 weeks 2 days 7 hours ago) and read 35084 times:
Quoting Sailfly (Reply 88): First hello to all this will be my first post. I work in the drilling industry and have enjoyed reading in the news and the posts the uncertainty surrounding the chances of finding the FDR. So for my two cents, assuming the devices are still active there is no reason they cannot be located, I assume our underwater positioning and reference equipment is similar technology and would be very easy to locate once the general area on the sea floor is found. Finding that area may prove difficult, surface currents and sub sea currents will not all be in the same direction, especially in that water depth, in fact it is quite possible that there will be two or three separate currents as you go deeper, not an overwhelming task and I’m sure there is some smart person or modeling which can handle that. Then depending on the size and weight of any pieces this could be an issue, not knowing what the ocean floor bottom conditions are in that area, I will say it is possible that pieces have buried themselves to a point that they will never be located. A previous poster noted that majority of the work will be accomplished with ROV's (Remote operated vehicles), I agree with that but would also add that Sub Sea Construction and Support vessels will likely be brought in to do the heavy lifting if warranted. This tragedy has really hit close to home for a lot of use in the drilling industry here in Brazil. AF447 is regularly used by offshore crews flying to and from Europe, I myself have flown that route and know people that were on the same route the day before and days after the incident. My deepest sympathies to all families affected by this tragedy.
Welcome to the forum...and thanks for your info it was interesting about the currents
FlyLKU From United States, joined Apr 2006, 417 posts, RR: 0 Reply 112, posted (6 months 2 weeks 2 days 7 hours ago) and read 34921 times:
Quoting NAV20 (Reply 4): If the wind switched to right in your teeth at 50 knots (common enough in the two places I've flown, the UK and Oz) your airspeed would stay at 120/340. But your groundspeed would drop to say 70/290......
That is true if the change is direction is reasonably gradual. If it is very quick then the airspeed indicator will momentarily register this difference. An example of this is wind sheer on short final where the airspeed indicator is jumping around showing rapid changes in speed and direction.
MakeMinesLAX From United States, joined exactly 6 years ago today! , 442 posts, RR: 0 Reply 113, posted (6 months 2 weeks 2 days 7 hours ago) and read 34408 times:
With all the prior incidents this one is being compared with, it's interesting the company among which the aerodynamic stall theory places AF 447: the recent Colgan Air and Turkish crashes.
Wexfordflyer From Ireland, joined Jun 2009, 206 posts, RR: 0 Reply 114, posted (6 months 2 weeks 2 days 7 hours ago) and read 34270 times:
Wow this topic keeps going and going!!!
Great news to hear that they are collecting some of the debris. Hopefully soon we will have confirmation that it is that of AF447 and the investigation can really begin.
Quick question which has been hinted at in the previous few posts. I really dont know an awful lot technically. Just read the article where it mentions the wing collision with the 321. In the article he doesnt seem to think or suggest that it could have been connected. And my uneducated guess is that it wouldnt be but those of you who know more do you think it may have been at least a contributing factor? As the previous posters have mentioned. What was percieved to be a minor dent perhaps, or something like it, could have escalated??
Come with me, there's a place I want you to see, where the leaves are dark, I've got a hiding place in central park.
FCA767 From United Kingdom, joined Nov 2006, 734 posts, RR: 2 Reply 115, posted (6 months 2 weeks 2 days 7 hours ago) and read 34389 times:
Quoting KingFriday013 (Reply 108): Or maybe a broken window panel? I know I've been on at least two flights (once a 757, the other a Dash 8) where the window panel was broken and i could even stick my finger in between the hole. Nothing happened on either flight (well... on the 757 flight, NAS-LGA on DL, I had a cold and my ears were hurting because of pressure the entire flight (it was just me). I vowed to never fly again, and over a year later I realized I hadn't flown since Sad It was my last 757 for a few years, too). But *could* this eventually lead to a problem?
About the Plastic Window on your 757...I used to wonder why it was plastic...but I read somewhere that it is a cosmetic type window...and that the outer window is the one that provides the strength...hope that helps
Famfflores From Brazil, joined Jun 2009, 40 posts, RR: 0 Reply 116, posted (6 months 2 weeks 2 days 7 hours ago) and read 34125 times:
I remember early in this discussion the possibility of an electrical failure. What about that, with some/all systems doing down and screens going black? If they entered a heavy turbulence under those circumstances than I´m sure it´s very difficult to control the plane. Thoughts?
Quoting Mrocktor (Reply 32):
The purpose of terrorism is to cause fear and to exploit that fear for political ends. Anonymity defeats the purpose of terrorism.
Yes! Exactly.
Yes, However. Would it not cause more terror by not telling anyone who's doing the attack's.
Anomity will spiral into Confrentations, Accusations, Media-frenzi's
Wouldnt that just cause even more terror? I think It would.
Mandala499 From Indonesia, joined Aug 2001, 4569 posts, RR: 60 Reply 118, posted (6 months 2 weeks 2 days 7 hours ago) and read 33759 times:
Quoting LHR380 (Reply 28): Am I wrong in thinking though Its kinda hard to stall an airbus aircraft? If the computers were going offline I guess it could have happened.
Quoting Pihero (Reply 33): Now, just picture yourself in a situation where you encounter rapidly shifting winds, causing up and down movements of your aircraft. And think about the scissoring effects of these gusts on your wings.
I have a bit of a tech question on this...
What can cause the A/P to disconnect? An SEC/ELAC disagreement? If so, would the aircraft degrade to alternate law? and alternate law = no envelope protection?
I'm asking this because I have a feeling that the ACARS messages sent might point to which computers failed at what time... (of course, writing in the newspaper saying that SEC/ELAC failed, then followed by FACs FCDCs and ADIRUs failing probably wouldn't go very far!)
Mandala499
When losing situational awareness, pray Cumulus Granitus isn't nearby !
Ukair From United Kingdom, joined Mar 2001, 274 posts, RR: 0 Reply 119, posted (6 months 2 weeks 2 days 6 hours ago) and read 33476 times:
Does anyone think the outcome of this disaster would have been different if the flight was in daylight? As the pilots could see what was coming as apposed to just relying on charts and instruments?
EMA747 From United Kingdom, joined Jun 2006, 912 posts, RR: 2 Reply 120, posted (6 months 2 weeks 2 days 6 hours ago) and read 33172 times:
I've not been able to get on the net all day so can someone kindly write a quick summary of what has happened since yesterday evening? What's all this about stalls and also a collision with A321?
Failing doesn’t make you a failure. Giving up and refusing to try again does!
LongHaul67 From Norway, joined Jan 2007, 187 posts, RR: 1 Reply 121, posted (6 months 2 weeks 2 days 6 hours ago) and read 33157 times:
This has already been mentioned on previous threads, but I am convinced that this accident will push forward changes in how flight data is handled irrespective of whether the FDR is recovered or not. Just take a look at how the investigation team has been able to progress its work with the ARCARS messages so far. Because of this we have already learned about of details of the breakdown of flight systems and other events only a few days into the investigation with the FDR still at the bottom of the Atlantic ocean. This is actually ground breaking stuff!!
I agree that up till now it has been too expensive to fully transfer the complete set of data recorded by the FDR in real time via satelite.
But in the future with satelite communications becoming less and less expensive this will become a reality. Just take a look at the price drop for international telephone calls compared to just a few years ago and how cheap data transfer has become in todays broadband world. A lot of this has to do with cheaper satelite comms.
The black boxes will still probably be mounted in the aircraft like today, but only as a back up.
I am not so sure about the CVR though, but I suspect the voice recordings to be converted to IP and sent as data the same way.
Rj777 From United States, joined Dec 2000, 907 posts, RR: 3 Reply 122, posted (6 months 2 weeks 2 days 6 hours ago) and read 32851 times:
I have a feeling that the FDR that can be jettisoned will eventually make their way onto commercial jets. Also, were the black boxes from 9/11 ever recovered?
Mavs------- Will---------- Hunt, Mavs Will Hunt! (UNOmaha Drum Cadence)
Oakmad From Australia, joined Apr 2001, 53 posts, RR: 0 Reply 124, posted (6 months 2 weeks 2 days 6 hours ago) and read 32497 times:
Quoting AAMDanny (Reply 117): Yes, However. Would it not cause more terror by not telling anyone who's doing the attack's.
Anomity will spiral into Confrentations, Accusations, Media-frenzi's
Wouldnt that just cause even more terror? I think It would.
If that were truly the case I don't think the perpetrators would select a flight where there is likelihood of their act not being exposed as deliberate. I would think a flight would be chosen where the authorities could readily rule out all systems failures on the aircraft, such as one over land not sea. As it stands now the 'public' would generally accept this as just a terrible accident and without concrete evidence I think a sensible person would not be scared by such unknown 'terrorists'. By concrete evidence I mean traces of explosives or some other type of foul play. Until that is produced I don't see any benefit to any 'terrorists' cause, unless its some kind of sick self gratification of mass murder.
AverageUser From Finland, joined Oct 2007, 1604 posts, RR: 7 Reply 125, posted (6 months 2 weeks 2 days 6 hours ago) and read 32387 times:
Quoting Trystero (Reply 15): can this boxes resist the pressure at 4 or 5 km deep and for how long?
It really does not matter if they did not. Modern units store the data in semiconductor memories not unlike your USB data stick. In military/aviation grade applications these chips will be housed in ceramic packages (epoxy is used in commercial grade applications) that will be very resistant to all adverse environmental factors. Even if the unit leaked and salt water entered it, the actual chips can be removed and read separately.
So where is all this data going to be stored? With the airline or an agency? With the thousands of commercial airline flights each day the amount of data could be quite significant. The transmission of the data to a remote facility would likely also be subject to atmospheric interference, sunspots, etc.
I personally would rather them spend their R&D money on developing a more efficient way of locating the FDR and CVR regardless of where the incident occurred. During the time this aircraft was collecting the most critical data on it's FDR and CVR I would not want to risk losing the information all together by transmitting through very atmospherically unstable conditions. Sure the ACARS system was apparently transmitting well enough, but it doesn't work like a CVR or FDR.
Now figure out a way to real-time report, regardless of where on the globe a plane is flying, then improve the ability to locate the CVR and FDR. In this case you would have a relatively good idea where the plane went down and with enhanced detection capabilities built in the two boxes know where to send the ROVs.
David L From United Kingdom, joined May 1999, 8281 posts, RR: 42 Reply 127, posted (6 months 2 weeks 2 days 6 hours ago) and read 32351 times:
Quoting MakeMinesLAX (Reply 113): With all the prior incidents this one is being compared with, it's interesting the company among which the aerodynamic stall theory places AF 447: the recent Colgan Air and Turkish crashes.
A single stall at low altitude probably has very different consequences from a single stall at cruise altitude, though. But I'm hardly an expert.
Quoting AAMDanny (Reply 117): Yes, However. Would it not cause more terror by not telling anyone who's doing the attack's.
But that's not generally the way it works. Who would we be afraid of? Would we appease the perpetrators by staying out of the Middle East, stopping experiments on animals, helping some unspecified region gain independence?
CasInterest From United States, joined Feb 2005, 1189 posts, RR: 2 Reply 128, posted (6 months 2 weeks 2 days 6 hours ago) and read 32343 times:
Quoting LongHaul67 (Reply 121): The black boxes will still probably be mounted in the aircraft like today, but only as a back up.
I am not so sure about the CVR though, but I suspect the voice recordings to be converted to IP and sent as data the same way.
This would make sense. I work in Telecom, and this would be entirely possible.
The MTC hangers would have to have a serious data system though.
The boxes on the plane would still be needed in case of transmission failures, but it would help speed up investigations.
GlobeEx From Germany, joined Aug 2007, 545 posts, RR: 7 Reply 129, posted (6 months 2 weeks 2 days 6 hours ago) and read 32089 times:
Quoting WILCO737 (Reply 25): You get close to the stall speed, but still not there.
So the change in windspeed needs to be pretty sudden and intense to get to the stall speed
WEll, however, if you are dealing with other problems at the same time (malfunctioning ADIRU, thrust controll, A/P or whatever doesn't help to minimize the risk of getting to slow or fast.
Quoting WILCO737 (Reply 25): But usually you have the capability to recover from a stall. I mean at 36,000 feet you have quite some time to keep up some speed.
Well, if you get into a heavy spin, even a flat spin it will be pretty hard, especially when you are dealing with other failures of programs etc. and you are in heavy tourbulences, well, good luck!
Quoting LongHaul67 (Reply 44): Is that strong enough to seriously interfere or obstruct the airflow underneath the wing if it was to last - say up 30 seconds?
Well, if it is close to a stall already and by the airflow the yaw is increased a spin can occure..... same occured on a Pulkovo Flight in 2006 (I think) which tried to fly over a thunderstorm (I posted a like in one of the earlier threads)
Quoting Hywel (Reply 62): Has anyone thought about the possibility of large hail stones from the thunderstorm smashing the cockpit windows, incapacitating the pilots and then leading to a loss of cabin pressure?
Well, thought about, YES. Thinks that it is plausible, NO! But I will elaborate to give you a clue, why I think that this is not likey. If you look at the ACARS messages the loss of cabin pressure is among the last. If the Cockpit would have been damaged by hail, it would have been one of the first, if not the first.
Quoting Famfflores (Reply 72): He said that every plane in the world with the ADIRU should suffer a recall to change everything and till then it should at least be removed from all aircrafts....
He should be removed from the media
Quoting Klwright69 (Reply 78): No. In AA587, the pilots overcorrected, stressing out the rudder and breaking off the tail.
Which could very well happened to AF447 as well, as we know that it was flying in ALTN Law and therefore didn't have the normal protection against stalls or overstressing.
Quoting Osiris30 (Reply 86): Very convenient. But I can't see a stall being at issue with 35K ft to play with, doesn't sound reasonable.
See above...
Quoting Keta (Reply 87): Even more, just a stall wouldn't cause all systems to fail in cascade as the ACARS transmission suggests, I mean it couldn't be the cause.
No, but maybe the stall could have been caused by the failure of one of the systems, ever thought about this?!
Quoting A388 (Reply 90): New generation aircraft apparently have this feature. The systems on board the A332 of AF apparently also have a constant link to the maintenance and/or operations control center. This is nothing uncommon as KL also has this.
Yes, ACARS is used by alot/most airlines. It is used for maintenance managment among others.
Quoting JBirdAV8r (Reply 96): Every commercial airliner in the world is hit by lightning an average of once a year. I think it's almost impossible that lightning by itself caused this accident.
I'm totally with you!
Quoting David L (Reply 43): Quoting Mcg (Reply 24):
I don't understand how the 'authorities' are so quick to eliminate terrorism as a potential cause of this accident
Well, I jump and say, do absolutely abandon the terrorism theory. But again I will give you an explanation. If you look at the ACARS messages the message indicating that you have a loss in cabin pressure is among the last. Please tell me about a bomb that manages to interfere with electronical systems and about 4 minutes later explodes and rips the aircraft apart. I haven't heard about a nuke that starts with an EMP and about 4 minutes later detonates
Now, I posted my theory in Thread No.8 and didn't have the time since to follow all the rest of the discussion. My theory included the failure of the ADIRU, also based on the QF72 incident. Now knowing that QF had the Northrop and AF the Honeywell ADIRU it does have some limitations, and maybe I wouldn't focus to heavily on just the malfunction of the ADIRU but related systems and the ADIRU, which might have had similar effects (Disengage the A/P) or at least made it necessariy (for the pilot or airplane's system) to go into ALTN Law. Now we have heavy winds, problems with the systems and and a pilot flying the airplane without the usual protection against stalls, overstress etc. In this scenario he could 1st: overstress the airframe, rudder etc. by movement's which are usually not possible under normal Law. 2nd. "simply stall the aircraft" 3rd. due to heavy upwinds they could have gotten into a spin a high enough yaw rate. (For those who don't know what a spin is: A spin is not that dependent on the speed of the aircraft but rather on the yaw. In a spin one wing is stalled, wereas the otherone is not, or not as much resulting in a spin.
For those of you who don't know the post yet I repeat. I Will say that as we now know that the ADIRUs of QF and AF different it does have some limitations. However, still an ADIRU failure or a related on is still possible:
Well with the ADIRU coming up again and after my post #184 in thread no. 6 which noone really commented I will write some things, which struck me, looking at the Qantas incidents and the related messages of AF447.
I know we know very little at this stage, and we most probably should get into such details, however, the corelations are just striking!
#1: The A/P disengages automatically (as on Qantas)
#2: The pilots notice a problem with the ADC and IR (the ADIRU nowadays consists of the ADC and IR). Now the pilot deactivates the ADC (puts it on disagree). Now the Law switches automatically to ALTN Law, as happened. (This action is the new, altered regulation after the Qantas incidents) This is due to the fact that the PRIM (Primary Computer) cant step in anymore. Form now on it only delivers warnings.
For those how don't know I will elaborate why it is important seperate the false IR AND THE belonging IR and to switch to ALTN Law if you notice a failure with the ADIRU: In case the ADIRU delivers false data (higher/lower speed than actually flying) to the PRIM and you switch the A/P off (while in Normal Law) and you pull up, the A/C might not let you do this, as the speed provided won't allow such a manouver (were as at the actual speed this would be reasonable). Meaning that were the aircraft (still under normal Law) think's its protecting against a stall, whereas it actually provokes on)
#3: Now we get the failure message of the ADIRU (maybe they didn't switch of the IR, or the other two ADIRUS make some truble). That is a trick one, as the IR 1 and ADC 1 (ADIRU 1) should have already been diconnected, however, maybe the IR 1 and ADC 1 wasn't the problem, which would lead to the upcoming events. This could various reasons, one could be that ADIRU 1 was actually working just fine, but no. 2 and 3 were false. I mean, you have three vaules, one differs from the others, which would you choose..?... most probably the two which are identical. (I know it is extremly unlikely that two ADIRU aren't working at the same time, and I would guess there are other possibilities, maybe a pilot could fill in.... its just to give you an idea)
#4: we get the PRIM warning which also occured on the QF72
#5: next is vertical speed warning, and we all know that this was the main problem with QF72... and in the case of AF447 this all might have led to a crash
f somebody doesn't know which messages I'm talking about:
"New information provided by sources within Air France suggests, that the ACARS messages of system failures started to arrive at 02:10Z indicating, that the autopilot had disengaged and the fly by wire system had changed to alternate law. Between 02:11Z and 02:13Z a flurry of messages regarding ADIRU and ISIS faults arrived, at 02:13Z PRIM 1 and SEC 1 faults were indicated, at 02:14Z the last message received was an advisory regarding cabin vertical speed.
Now, my idea is, that at the moment, even though the weather was also one factor, and without the heavy weather this problem of the ADIRU (maybe) might not have ended in this tradgedy, it wasn't as many think the innitiator. You now catastrophes are always a chain of unfortunate events.
In the game of chess you can never let your adversary see your pieces.
Chumley From United States, joined Jul 2007, 82 posts, RR: 0 Reply 130, posted (6 months 2 weeks 2 days 6 hours ago) and read 32330 times:
Was just reading more from USAToday and came across this quote:
"There was some kind of in-flight violent" incident, said Bill Waldock, an air-crash expert at Embry-Riddle Aeronautical University in Prescott, Ariz.
Waldock suspects weather — namely, the 100-mph winds the airplane apparently encountered that could have gotten underneath the wings and shaken the plane. "If they hit a 100-mph updraft while they were going 525 mph, it would have thrown them violently," Waldock said. "It's way beyond what the airplane is designed to accept."
The force could have bent or torn off a wing, Waldock said.
-----
I thought that the wings were put through incredible break tests ahead of certification and they are capable of astonishing flexibility. If I recall, it is theoretically possible for newer wing designs to actually touch tip-to-tip above the fuselage without breaking (perhaps that was from a 787 or A380 thread I read?) Is a 100mph wind enough to break a wing? I didn't realize that was possible.
Bond007 From United States, joined Mar 2005, 4537 posts, RR: 11 Reply 131, posted (6 months 2 weeks 2 days 6 hours ago) and read 32138 times:
Quoting LongHaul67 (Reply 121): This has already been mentioned on previous threads, but I am convinced that this accident will push forward changes in how flight data is handled irrespective of whether the FDR is recovered or not.
Not so sure. They'll find the boxes, and it's not the first time it's taken a while to find them. The bandwidth required to transmit every parameter of every aircraft, real-time, is not trivial.
Quoting LongHaul67 (Reply 121): Just take a look at how the investigation team has been able to progress its work with the ARCARS messages so far. Because of this we have already learned about of details of the breakdown of flight systems and other events only a few days into the investigation with the FDR still at the bottom of the Atlantic ocean. This is actually ground breaking stuff!!
I'm not sure what they've learned ... it isn't much. We know some systems failed and have no clue why ... it's the 'why' that's important. We probably could have even guessed at some of the ACARS messages.
Jimbo
I'd rather be on the ground wishing I was in the air, than in the air wishing I was on the ground!
MadameConcorde From French Southern Territories, joined Feb 2007, 4799 posts, RR: 25 Reply 132, posted (6 months 2 weeks 2 days 6 hours ago) and read 32036 times:
PPRuNe post
French Air Force has just reported that most of the debris found by SAR didn't belong to AF 447. Fuel patch most probably comes from some ship dumping tank residue. Doesn't help.
There was a better way to fly. It was called Concorde.
Canoecarrier From United States, joined Feb 2004, 776 posts, RR: 2 Reply 134, posted (6 months 2 weeks 2 days 6 hours ago) and read 31630 times:
To follow up on what Bond is saying. It isn't that often that the boxes are not recovered. A high percentage of aircraft crashes occur on take off or landing and over land. The fact that this one occurred over open water at altitude is what makes it different. The majority of boxes are recovered within hours of the crash because they are on land.
Redesigning the entire system to be remote for the small percentage of crashes where it is difficult to retrieve the information or the information has been corrupted due to the intensity of the crash seems counter-intuitive to me. Put a different beacon on it, have it "phone home" like the mars rovers do when they have a problem. I'm not an engineer, but I'm sure there's an answer for that problem.
FCA767 From United Kingdom, joined Nov 2006, 734 posts, RR: 2 Reply 136, posted (6 months 2 weeks 2 days 6 hours ago) and read 32058 times:
Quoting Rj777 (Reply 122): I have a feeling that the FDR that can be jettisoned will eventually make their way onto commercial jets. Also, were the black boxes from 9/11 ever recovered?
I'm not trying to be funny...but I used to think about Ejecter seats for all passengers like fighter planes have...This is a serious question I am putting forward can anyone see this as reasonable...Also I agree with your statement too
Osiris30 From Barbados, joined Sep 2006, 3134 posts, RR: 25 Reply 137, posted (6 months 2 weeks 2 days 6 hours ago) and read 31608 times:
Quoting David L (Reply 89): AF have details of the ACARS messages transmitted via SATCOM over the last 4 minutes. The messages are almost certainly stored and/or printed out so it's no mystery that they have the details of the messages sent during the last 4 minutes. I think the significance of "the last 4 minutes" is that that is when the flurry of messages began - nothing "predictive" about it.
ACARS is NOT the FDR. I know all about the ACARS messages. The OP said FDR data uplinked via SATCOM, that's what I'm calling BS on.
Quoting Honeythief (Reply 91): The 'four minutes' of data is a reference to the ACARS messages that were sent over a four minute period and NOT to any data from the FDR or CVR.
Correct. An *extremely* important distinction. It's almost as big a difference as the difference in terminology between an 'incident' and an 'accident'.
Quoting Oroka (Reply 93): they encountered a downdraft just as they throttled back, causing a nearly unrecoverable stall?
I suppose it's possible they experienced an upset, but I would still think that a 330 would be able to recover. A) There would have been a stick shaker prior to stall which would have been warning one, B) That would be extremely unlucky timing all around. Also note there was no ACARS message until 3 minutes after the ADIRU message regarding cabin vert speed.
Quoting Dougbr2006 (Reply 101): The ACARS system sends a signal at a fixed time interval
Not entirely true. It will also tarnsmit certain data on demand in response to systems failures.
Quoting 7673mech (Reply 105): Everyone is focusing on the ACARS messages - have seen it before where these are in error.
Except in this case they ACARS messages do tell a (chilling) story that is plausable as far as a series of failures for an AC suffering a catastrophic problem. The ACARS messages are just giving us some input as to when things are failing, not *why* they failed, which is the *far* more important question.
Honestly I think a theory that goes something like this is far more plausable than a stall:
ADIRU fails (or is disabled either accidentally, by fault, by weather, or whatever)
Then either pilot action or misfed AP action (i.e. the AP relies on bad data) causes a series of maneuvers that stress the aircraft until something physically gives way. From there the plane starts coming apart at the seams.
Imagine the action of the QF 330 - first a 300 ft climb followed by a rapid transition to an extreme decent profile. Now imagine doing that in turbulent weather and it is *not* hard to see the AC exceed G limits and break something.
Similarly pilot error in those conditions could easily have the AC exceed G limits in the right turbulence.
I just find it incredibly hard to believe that any one item contributed to this crash. I won't just be the weather, it won't jsut be the pilots and it won't just be the plane. The large volume of jet fuel on the surface of the ocean, to me, rules out inflight explosion/fire. It also says to me that large pieces of the AC stayed intact until contact with the ocean (note this does not mean the entire frame, just large chunks of it). If not you wouldn't have a slick.
I don't care what you think of my opinion. It's my opinion, so have a nice day :)
SEPilot From United States, joined Dec 2006, 4039 posts, RR: 26 Reply 138, posted (6 months 2 weeks 2 days 6 hours ago) and read 30935 times:
Quoting Rj777 (Reply 122): I have a feeling that the FDR that can be jettisoned will eventually make their way onto commercial jets. Also, were the black boxes from 9/11 ever recovered?
I believe that some of them were, but perhaps not all of them. And I think I read that data was recovered from them.
The problem with making things foolproof is that fools are so doggone ingenious...Dan Keebler
Osiris30 From Barbados, joined Sep 2006, 3134 posts, RR: 25 Reply 139, posted (6 months 2 weeks 2 days 6 hours ago) and read 30999 times:
Quoting GlobeEx (Reply 129): Well, if you get into a heavy spin, even a flat spin it will be pretty hard, especially when you are dealing with other failures of programs etc. and you are in heavy tourbulences, well, good luck!
With both engines running a flat spin *shouldn't* occurr without an *extreme* set of circumstances. At 35/37K ft a non-flat spin should be recoverable before impact.
Quoting GlobeEx (Reply 129): Well with the ADIRU coming up again and after my post #184 in thread no. 6 which noone really commented I will write some things, which struck me, looking at the Qantas incidents and the related messages of AF447.
I know we know very little at this stage, and we most probably should get into such details, however, the corelations are just striking!
Incidentally, if you see my post just above I've held a similar theory since the release of the ACARS data.
Quoting MadameConcorde (Reply 132): French Air Force has just reported that most of the debris found by SAR didn't belong to AF 447.
Most or all? Even if it's most there is still some.. so they can't be far off.
Quoting FCA767 (Reply 136): I'm not trying to be funny...but I used to think about Ejecter seats for all passengers like fighter planes have...This is a serious question I am putting forward can anyone see this as reasonable...Also I agree with your statement too
Ejections seats are VERY heavy and *very* dangerous. Their use for PAX would not be practical. You would be far better off (honestly) giving everyone parachutes.
I don't care what you think of my opinion. It's my opinion, so have a nice day :)
David L From United Kingdom, joined May 1999, 8281 posts, RR: 42 Reply 140, posted (6 months 2 weeks 2 days 6 hours ago) and read 30673 times:
Quoting Bond007 (Reply 131): I'm not sure what they've learned ... it isn't much. We know some systems failed and have no clue why ... it's the 'why' that's important. We probably could have even guessed at some of the ACARS messages.
Don't forget that only a few of many messages have been made public.
Quoting FCA767 (Reply 136): I used to think about Ejecter seats for all passengers like fighter planes have...can anyone see this as reasonable...
Well... not really. Think about the weight, the cost, the larger seats, the possibility of inappropriate activation or malfunction, injuries sustained in operation. All for what? A tiny, tiny number of accidents. Sorry.
FCA767 From United Kingdom, joined Nov 2006, 734 posts, RR: 2 Reply 141, posted (6 months 2 weeks 2 days 6 hours ago) and read 30328 times:
Quoting Osiris30 (Reply 139): Ejections seats are VERY heavy and *very* dangerous. Their use for PAX would not be practical. You would be far better off (honestly) giving everyone parachutes
True
Quoting David L (Reply 140): Well... not really. Think about the weight, the cost, the larger seats, the possibility of inappropriate activation or malfunction, injuries sustained in operation. All for what? A tiny, tiny number of accidents. Sorry
True too...we really need to know what's happened...the wait is the worst...I'm always analysing things...
KingFriday013 From United States, joined May 2007, 225 posts, RR: 4 Reply 142, posted (6 months 2 weeks 2 days 6 hours ago) and read 30384 times:
Quoting FCA767 (Reply 136): I'm not trying to be funny...but I used to think about Ejecter seats for all passengers like fighter planes have...This is a serious question I am putting forward can anyone see this as reasonable...Also I agree with your statement too Smile
The mechanics of that are near impossible. And it would be extremely heavy, and expensive. It's probably safer to leave them out than risk a malfunction (opening ejector door leading to loss of cabin pressure, hatch not opening leading to suffocation (exhaust from rocket or ejection thrust device), collision, etc.) or act of terror. Also, the G-forces would be pretty strong; most people aren't accustomed to them, and fighter pilots (and others who are) wear special suits when flying in ejection seat-equipped vehicles. If it were feasible, however, that would indeed be very interesting.
RedFlyer From United States, joined Feb 2005, 3603 posts, RR: 30 Reply 143, posted (6 months 2 weeks 2 days 6 hours ago) and read 30289 times:
Quoting GlobeEx (Reply 129): Well, I jump and say, do absolutely abandon the terrorism theory. But again I will give you an explanation. If you look at the ACARS messages the message indicating that you have a loss in cabin pressure is among the last. Please tell me about a bomb that manages to interfere with electronical systems and about 4 minutes later explodes and rips the aircraft apart. I haven't heard about a nuke that starts with an EMP and about 4 minutes later detonates Wink
Best explanation I've heard thus far on why this probably isn't terrorism related. Maybe this is also why the authorities haven't focused on terrorism as a cause of this tragedy.
GlobeEx From Germany, joined Aug 2007, 545 posts, RR: 7 Reply 144, posted (6 months 2 weeks 2 days 6 hours ago) and read 30073 times:
Quoting Osiris30 (Reply 139): With both engines running a flat spin *shouldn't* occurr without an *extreme* set of circumstances. At 35/37K ft a non-flat spin should be recoverable before impact.
Well, if ADRIU failure, PRIM, SEC, etc. heavy winds up to 160 mph, thats pretty extreme to me. Well 35/37K ft.... check the Pulkovo flight, it went up from 35.000 to 37.000 and apparently experienced a flat spin which could not be recovered.
Normaly the whole thing is pretty unusual, but to to my knowledge it is also pretty unusual that an aircraft does get lost while in cruise, specially an AF A330. All I want to say is. Yes it sounds pretty unlikely, however, if it usually is a "likely" event, it would happy about every day.
In the game of chess you can never let your adversary see your pieces.
David L From United Kingdom, joined May 1999, 8281 posts, RR: 42 Reply 145, posted (6 months 2 weeks 2 days 5 hours ago) and read 29876 times:
Quoting Osiris30 (Reply 137): ACARS is NOT the FDR. I know all about the ACARS messages. The OP said FDR data uplinked via SATCOM, that's what I'm calling BS on.
My apologies. It was worded very similarly to a post from someone who did think it was from the FDR. While replying, I do remember thinking "I thought this Osiris30 person knew about these kinds of things - oh well, might as well set him straight while I'm here". Oops.
BAPILOT2B From United Kingdom, joined Mar 2001, 895 posts, RR: 35 Reply 146, posted (6 months 2 weeks 2 days 5 hours ago) and read 29915 times:
Quoting KingFriday013 (Reply 142): The mechanics of that are near impossible. And it would be extremely heavy, and expensive. It's probably safer to leave them out than risk a malfunction (opening ejector door leading to loss of cabin pressure, hatch not opening leading to suffocation (exhaust from rocket or ejection thrust device), collision, etc.) or act of terror. Also, the G-forces would be pretty strong; most people aren't accustomed to them, and fighter pilots (and others who are) wear special suits when flying in ejection seat-equipped vehicles. If it were feasible, however, that would indeed be very interesting.
Let alone the possibility of multiple ejects at the same time leading to some tangled parachutes if this method would ever work.
SixtySeven From Canada, joined Nov 2006, 221 posts, RR: 2 Reply 147, posted (6 months 2 weeks 2 days 5 hours ago) and read 29461 times:
The bottom line is these guys ended up in a thunderstorm in a place where they can be difficult to detect but are very, very powerful.
The airbus with it's fly by wire flight controls likely were sent into a degraded mode, likely "direct law" due to the ADIRS being tripped off line.
They were at a failry high altitude, possibly close to max altitude for that weight which would have seen them in an area where there was little buffett margin both high and low speed. With the ADIRS tripped off line they would have lost primary flight instruments, would have had an ELAC fault and would have been operating in "direct law" which would result in the loss of all of airbus' flight control protections.
Operating in direct law at altitude in severe turbulence would make things very easy to overcontrol in a situation that was quite frankly out of control.
In the end, why did they find themselves in this thunderstorm. Who was at the controls? Was the Captain out of the cockpit on break? Which would have put the 3,000 releif pilot in one of the seats. In the end, a thunderstorm could bring a plane down, and no matter how skilled the two pilots are, they could easily lose control of the aircraft.
We will have to wait and see what the causal factors were that led this crew to fly a very capable, advanced jet into a large thunderstorm.
in lay-mans terms... what is the difference between alternate law and direct law? Does alternate still have some flight protection against stalls/over stressing and direct is as it sounds?
IIRC the ones from the twin towers were not but I am not sure about any of the others. Do correct me if I am wrong.
There seems to be lots of conflicting reports coming out as to whether or not the debris is that of AF447. Anyone any reliable sources on it yet? Or are we better waiting a while. I for one would be VERY suprised if it isnt.
Come with me, there's a place I want you to see, where the leaves are dark, I've got a hiding place in central park.
Rj777 From United States, joined Dec 2000, 907 posts, RR: 3 Reply 152, posted (6 months 2 weeks 2 days 5 hours ago) and read 28936 times:
Quoting SixtySeven (Reply 147): We will have to wait and see what the causal factors were that led this crew to fly a very capable, advanced jet into a large thunderstorm.
Ya know, CNN is making parallels to the titanic disaster. (difficulty of recovery). That almost makes this sound similar as well.. (crew's overconfidence in craft's ability).
Mavs------- Will---------- Hunt, Mavs Will Hunt! (UNOmaha Drum Cadence)
StasisLAX From United States, joined Jul 2007, 2174 posts, RR: 3 Reply 153, posted (6 months 2 weeks 2 days 5 hours ago) and read 29091 times:
Some interesting news from the Associate Press regarding the "black box" recovery efforts:
"Remotely controlled submersible crafts will have to be used to recover wreckage settling so far beneath the ocean's surface. France dispatched a research ship equipped with unmanned submarines that can explore as deeply as 19,600 feet (6,000 meters).
A U.S. Navy P-3C Orion surveillance plane - which can fly low over the ocean for 12 hours at a time and has radar and sonar designed to track submarines underwater - and a French AWACS radar plane are joining the operation. France also has three military patrol aircraft flying over the central Atlantic, two commercial ships reached the floating debris, and Brazilian navy ships were en route."
Experts have started that the black boxes will signal their location for 30 days, but the recorders themselves can last indefinitely underwater, even at extreme depths in salt water.
SixtySeven From Canada, joined Nov 2006, 221 posts, RR: 2 Reply 154, posted (6 months 2 weeks 2 days 5 hours ago) and read 28563 times:
I wouldn't say any crew I have ever been on could be called "overconfident" in terms of the actual aircrafts abilities to penetrate storms.
The crew themselves could easily be careless or nonchalant which could find themselves jetting towards a situation nobody could fly themselves out of.
I fly through the ITCZ all the time. You are always aware of the storms there mainly just by experience, they are ALWAYS there. But they are usually quite easy to deviate around if one uses his head. And also it's always at night and the cells are very active, you can see them hundreds of miles away.
The thing I always shake my head at is you can be clear of all the storms, but you are in light to moderate chop, and you look at the wind and it's dammed near calm.
Toulouse From Ireland, joined Apr 2005, 2673 posts, RR: 60 Reply 155, posted (6 months 2 weeks 2 days 5 hours ago) and read 28654 times:
AIRLINERS.NET CREW FORUM MODERATOR
Quoting Wexfordflyer (Reply 151): There seems to be lots of conflicting reports coming out as to whether or not the debris is that of AF447. Anyone any reliable sources on it yet? Or are we better waiting a while. I for one would be VERY suprised if it isnt.
Very conflicting indeed. Basically, what I'm hearing here in France this evening, is that so far everything the Brazilians claimed to have been pieces of AF447 and which the French Army has had an opportunity to verify (visually I believe) they have rejected that they are parts of AF447. At the same time, we are being informed of the "newer' pieces now being collected by the Brazilians, but these have yet to be verified. All very confusing. Can you imagine if what we've believed to be part of this flight for the past 24 hours or so isn't... we're bast to square one... So sad.
Edited for latest update here in France, which is now putting more emphasis on the fact that the Brazilians are now collecting pieces of debris which they are sure are part of AF447, yet news continues to highlight that what they were sure to be parts of the a/c on Wednesday are not.
One link (worry, it's in French and don't have time to translate, just copy and paste it into Google Translate if you don't speak French to get a rough idea).
Hardiwv From Netherlands, joined Oct 2004, 7581 posts, RR: 58 Reply 156, posted (6 months 2 weeks 2 days 5 hours ago) and read 28692 times:
Breaking news:
Brazilian media is now reporting headlines that the debris found and collected during today's operations are not related to AF A330.
Among the debris collected is a piece of wood which is used in the cargo compartment of airplanes but is has no identification with the AF A330. Brazil Air Force also said that the pieces collected will need to go through further analysis.
Antskip From Australia, joined Jan 2006, 838 posts, RR: 12 Reply 157, posted (6 months 2 weeks 2 days 5 hours ago) and read 28504 times:
"potentially faulty readings may have prompted the crew of the Air France flight to mistakenly boost thrust from the plane's two engines and increase speed as they went through what may have been extreme turbulence. As a result, the pilots may have inadvertently subjected the plane to increased structural stress, according to people familiar with the investigation" http://online.wsj.com.
(Wall Street Journal)
Toulouse From Ireland, joined Apr 2005, 2673 posts, RR: 60 Reply 158, posted (6 months 2 weeks 2 days 5 hours ago) and read 28299 times:
AIRLINERS.NET CREW FORUM MODERATOR
Quoting Hardiwv (Reply 156): Brazilian media is now reporting headlines that the debris found and collected during today's operations are not related to AF A330.
Oh God, well that puts a dampener on my last post just a minute or so before you with latest news from France.
Mcg From United States, joined Sep 2003, 164 posts, RR: 14 Reply 159, posted (6 months 2 weeks 2 days 5 hours ago) and read 28109 times:
[
Quoting GlobeEx (Reply 129): Well, I jump and say, do absolutely abandon the terrorism theory. But again I will give you an explanation. If you look at the ACARS messages the message indicating that you have a loss in cabin pressure is among the last. Please tell me about a bomb that manages to interfere with electronical systems and about 4 minutes later explodes and rips the aircraft apart. I haven't heard about a nuke that starts with an EMP and about 4 minutes later detonates
Hardiwv From Netherlands, joined Oct 2004, 7581 posts, RR: 58 Reply 161, posted (6 months 2 weeks 2 days 5 hours ago) and read 28072 times:
Quoting Toulouse (Reply 158): Oh God, well that puts a dampener on my last post just a minute or so before you with latest news from France
Quoting Hardiwv (Reply 156): Brazilian media is now reporting headlines that the debris found and collected during today's operations are not related to AF A330.
Quoting Hardiwv (Reply 156): Among the debris collected is a piece of wood which is used in the cargo compartment of airplanes but is has no identification with the AF A330. Brazil Air Force also said that the pieces collected will need to go through further analysis.
According to Brazil authorities the material collected today bears no identification wiht the AF 330. Of course, they need to submit material for further detailed analysis.
AF2323 From France, joined Aug 2007, 105 posts, RR: 0 Reply 163, posted (6 months 2 weeks 2 days 5 hours ago) and read 27919 times:
Quoting Toulouse (Reply 155): Very conflicting indeed. Basically, what I'm hearing here in France this evening, is that so far everything the Brazilians claimed to have been pieces of AF447 and which the French Army has had an opportunity to verify (visually I believe) they have rejected that they are parts of AF447.
My only source is internet, but here's what I found :
Quote: "The nature of the debris, the density, the position, make no doubt that we have the first material evidence that are linked to Air France 447," French military spokesman Christophe Prazuck said.
PPVRA From Brazil, joined Nov 2004, 6127 posts, RR: 48 Reply 164, posted (6 months 2 weeks 2 days 5 hours ago) and read 27696 times:
Quoting Toulouse (Reply 158):
Oh God, well that puts a dampener on my last post just a minute or so before you with latest news from France.
Don't get hung up on that quote, all they know at this point is that it isn't obvious the debris are from AF or from an A330. They are gonna have to look closer at them.
"If goods do not cross borders, soldiers will" - Frederic Bastiat
JSquared From United States, joined Sep 2006, 76 posts, RR: 0 Reply 165, posted (6 months 2 weeks 2 days 5 hours ago) and read 27775 times:
I’ve been following the threads about this accident form the beginning, and it still makes me sick to think about how a large modern jet like the A330 could be brought down for reasons we may never be able to determine with absolute certainty.
Obviously the black boxes should give a fair amount of insight into what happened, but given past accidents where the aircraft crashed into the ocean from altitude (TWA 800, Adam Air 574, Alaska 261, etc) and the little we currently know about this accident, what condition are the CVR and FDR expected to be in? I guess I’m mostly curious if they’re typically found attached to a part of the fuselage, or if they tend to separate during impact.
For that matter, does anybody have a diagram or picture of what they look like and where they’re located on the A330? I know that they’re in the tail section, but just curious as to where in particular.
Pihero From France, joined Jan 2005, 1884 posts, RR: 63 Reply 166, posted (6 months 2 weeks 2 days 5 hours ago) and read 27894 times:
WE have seen all on A.net : armchair aviators, 20,000 hour-experienced sim pilots and now self-appointed accident investigation experts !
I have seen everything, from 160mph winds to stick shakers on a 330,"coffin corner" at FL 350 five hours into the flight, flat spins à la Tupolev 154 and its T-tail (btw the exact term is "deep stall"), loss of load factor protection in ALT and pilots overstrssing their airframe and an ADIRU theory, the merit of which is that it contains the only documents pertaining to a fault in the aircraft but suits a lot of agendas that are better called "slightly biased".
Now, the moderators will be facing a drastic decision : whether to leave the forum as it is and risk the ridicule of the whole aviation community or to do something to restrict the uninformed BS that's plaguing this site...(that decision has already been made on other sites).
We all have to ask ourselves a simple question : Why is it that most of the respected pilots and engineers have left this thread ? Where are PhilSquares, Zeke, Bellerophon, TYdscanuck, OldAeroGuy, pilotaydin... and many more ? (see tech-ops, they're still alive !)
The answer will be about professionalism, a decent attitude towards the dead occupants of that airplane and their relatives and friends...and a refusal to speculate when we have basically nothing to bese a theory on. Have you noticed the number of brand new or low-contributing posters since the accident ?
This is turning into a ghoulish feast and I won't have anything more to do with it...
...until some real fact emerges...
and I have a feeling that won't be very soon.
757GB From Uruguay, joined Feb 2009, 355 posts, RR: 1 Reply 167, posted (6 months 2 weeks 2 days 5 hours ago) and read 27420 times:
Quoting PPVRA (Reply 164): Don't get hung up on that quote, all they know at this point is that it isn't obvious the debris are from AF or from an A330. They are gonna have to look closer at them.
You beat me to it. I was reading the article in Portuguese but I'm a little rusty on it
What it says is very different from saying that the parts do not belong to the airplane.
They could not confirm it, but that doesn't prove the opposite.
747MegaTop From United States, joined May 2007, 62 posts, RR: 0 Reply 168, posted (6 months 2 weeks 2 days 5 hours ago) and read 27401 times:
What are the chances (meaning..does it happen) of lightning strike happening at cruise altitude..at 35000feet in the case of AF 447? If that is possible then it definitely throws open the the door to the possibility of a rare combination of A) in flight fire due to lightning strike and B) decompression due to hole blown by lightning strike. Both these occurrences have happened in the past as evidenced below in 2 separate incidents (and am sure many more) -
On November 29, 2000, about 1753 eastern standard time, a McDonnell Douglas
DC-9-82 (MD-80), N3507A, operated by American Airlines as flight 1683, was struck by
lightning and experienced an in-flight fire that began shortly after takeoff from Reagan National
Airport in Washington, D.C.5 The flight crew performed an emergency landing and ordered a
passenger evacuation at Dulles International Airport. The airplane sustained minor damage.
None of the 2 pilots, 3 flight attendants, or 61 passengers were injured.
Fellow A.netters, any thoughts? For some reason an in flight fire seems to be a strong contender here in AF 447's case. The source of the in flight fire could be anybody's guess - short circuit, explosion, lightning induced fire etc. Hopefully recovered debris and hopefully recovered bodies will shed some light to support or eliminate an in-flight fire theory on further analysis.
LongHaul67 From Norway, joined Jan 2007, 187 posts, RR: 1 Reply 169, posted (6 months 2 weeks 2 days 5 hours ago) and read 27149 times:
Quoting Canoecarrier (Reply 126): So where is all this data going to be stored? With the airline or an agency? With the thousands of commercial airline flights each day the amount of data could be quite significant. The transmission of the data to a remote facility would likely also be subject to atmospheric interference, sunspots, etc.
Cost of data storage today is next to nothing. Take a look at how Youtube can store enormous amounts of data - for free.
In addition it is easy to apply rules which will let you delete data the minute the aircraft touches down or is turned around.
This is only meant to increase efficiency and reduce lead-time wrt the initial phase of the investigation. The physical FDR will still be in use.
But real time transfer of FDR data will mean that in those cases where the FDR is not recovered or destroyed this might actually be all you've got.
SpeedbirdA380 From United Kingdom, joined Jul 2008, 493 posts, RR: 2 Reply 171, posted (6 months 2 weeks 2 days 4 hours ago) and read 26126 times:
Quoting YWG747 (Reply 160):
This coming just hours after an article saying the craft may have stalled and crashed....
I don't know what to believe anymore....
I always give it a week or two before after something like this happens before I start taking info I read in the press seriously. After every crash of this scale there is always a mass tirade of specualtion and misinformation.
I remeber when the BA T7 crashed. We had reports the plane had insufficient fuel,then there was a conspiracy theory that a terrorist group caused the crash as the British PM was flying out of Heathrow at the same time....
Speculation is fine...just dont believe it!
"I stand Corrected" said the man in the Orthopedic shoe's.
Storage may not be the problem but transmission most certainly would be. YouTube sends and receives information via the internet. What people are suggesting here would require separate channels similar to radio frequencies aircraft currently use for voice/data communication. With the thousands of flights a day it would require thousands of separate frequencies.
757GB From Uruguay, joined Feb 2009, 355 posts, RR: 1 Reply 173, posted (6 months 2 weeks 2 days 4 hours ago) and read 25697 times:
Quoting SpeedbirdA380 (Reply 171): I always give it a week or two before after something like this happens before I start taking info I read in the press seriously. After every crash of this scale there is always a mass tirade of specualtion and misinformation.
That's a wise attitude. I have to admit it's hard though. We all want so much to know what happened that a lot of times we can't help it. You end up losing a lot of energy if you take everything seriously and analyze each piece of news. It can sure be overwhelming in cases like this one.
Antskip From Australia, joined Jan 2006, 838 posts, RR: 12 Reply 174, posted (6 months 2 weeks 2 days 4 hours ago) and read 25235 times:
Quoting YWG747 (Reply 160): This coming just hours after an article saying the craft may have stalled and crashed....
I don't know what to believe anymore....
My thoughts also - opposites - though both scenarios suggest faulty speed - too little (causing stall) or too much (causing breakup). Interesting that the Wall Street Journal article indicates the cause of the latter could have been faulty readings of airspeed (indicating an airspeed slower than real) - ie increased speed to avoid a stall, when actual speed was actually higher than the reading...
I have encuntered similar conditions in sailing boats - both in turbulent water current conditions and in turbulent wind conditions - massive changes in water/air speed at the same time as huge changes in water/air direction, causing the sailing boat's air foils (sails) and water foils (centreboard/keel and rudder) to widely move between effectivity and a stall, causing huge contradictory loads and flows on both sets of foils and onto the boat itself - sometimes causing capsize / even reversal in the water / (air and water) stalling oscillating with dramatic changes of speed, excessive acceleration causing the hull to dive into the water rather than sail across it - these are wide oscillations in boundary conditions...and in boundary conditions the skipper can find themselves limited in ability to intervene
ChrisK2 From Germany, joined Mar 2009, 30 posts, RR: 0 Reply 175, posted (6 months 2 weeks 2 days 4 hours ago) and read 25171 times:
Hello,
Quoting Pihero (Reply 166): Now, the moderators will be facing a drastic decision : whether to leave the forum as it is and risk the ridicule of the whole aviation community or to do something to restrict the uninformed BS that's plaguing this site...(that decision has already been made on other sites).
Well, when you suggest some action (like, moderators taking action to forcibly lower the "noise" on a forum), the question is: Will it improve things, or will it make things worse?
And I'm not necessarily talking about "will it increase or decrease the quality of discussion in this particular thread?". Because, I'm quite confident, if you force people only to post facts, solid stuff, based on first-hand knowledge - well, the quality of this thread will become quite a lot better. No doubt. Although, at the same time, we'll be able to make do with 1 post per day or so.
But would it make the overall picture better? You know, I think it's a great thing when people post about Flight Data Recorders beaming the "last four minutes" of the plane via satellite to somebody who's recording it (just paraphrasing) and when then people can *correct* this here. It's great to see people quote BS from the media, and then be able to state here that it's BS, and explain why. I think, this thread does serve the purpose to be able to dispell a lot a rumours, false conclusions, whatever.
I think one shouldn't leave every kind of reporting and speculation (and speculation it is, can't be more right now) to the media! That would be much worse.
Quote: We all have to ask ourselves a simple question : Why is it that most of the respected pilots and engineers have left this thread ? Where are PhilSquares, Zeke, Bellerophon, TYdscanuck, OldAeroGuy, pilotaydin... and many more ? (see tech-ops, they're still alive !)
Well, I guess many of them will just be saying "OMG, there's so much BS reported in the media, let's have a look at a.net forums". And next they'll say OMG, lots of BS discussed on the forums as well, over and over again. I can see there's a sense of resignation.
But don't resign! Resigning means leaving the job of explaining and "educating" to the mass media!
The worse alternative, I think.
This is a very typical post-accident thread. I've seen others, and they weren't "better" when it comes to exact information and non-speculation.
But closing it or enforcing tougher rules would not make the world a better place. I can see, and I can appreciate, that not every knowledgable person wants to be a teacher. Or a kindergarten employee, if you prefer. So if you don't feel like teaching - no problem. No offense. But weren't it for a thread like this one, where people - yes - ask a lot of stupid questions and can get corrected over them, none of us who's not so much "in the know", including myself, would have any chance to see how much BS we are fed most of the time by the mainstream media. And I think there is a value in that.
Thanks to everybody here who takes the time to explain. And no offense to anybody who doesn't feel (any more) to do it - I know teaching can be a headache, and dispelling rumours and BS even more so.
BAViscount From United Kingdom (England), joined Mar 2004, 1781 posts, RR: 3 Reply 176, posted (6 months 2 weeks 2 days 4 hours ago) and read 25403 times:
Quoting Pihero (Reply 166): This is turning into a ghoulish feast and I won't have anything more to do with it...
...until some real fact emerges...
and I have a feeling that won't be very soon.
Agreed. I can't believe that this topic has got to "Part 10" - yes, it's one of the most tragic accidents of recent times, but once you get past the replies that are passing on latest news and/or condolences, it's just getting boring and tedious. The only reason I keep looking is in the hope that there may be some more official news that might help clear up what happened, but generally this topic is getting out of hand.
Ladies & gentlemen this is Captain Tobias Wilcock welcoming you aboard Coconut Airways flight 372 to Bridgetown Barbados
Bramble From , joined Dec 1969, posts, RR: Reply 177, posted (6 months 2 weeks 2 days 4 hours ago) and read 25298 times:
Quoting YWG747 (Reply 160): This coming just hours after an article saying the craft may have stalled and crashed....
I don't know what to believe anymore....
I think the media is over speculating about the cause of this tragedy. They need infomation and will interview anyone with an opinion.
So far we have theories based on ACARS messages. Thats is. Until the authorities find evidence on debris or get good results form the FDR/CVR we are left in a void of speculation.
Richierich From United States, joined Nov 2000, 3260 posts, RR: 8 Reply 178, posted (6 months 2 weeks 2 days 4 hours ago) and read 25150 times:
Quoting Pihero (Reply 166): WE have seen all on A.net : armchair aviators, 20,000 hour-experienced sim pilots and now self-appointed accident investigation experts !
I have seen everything, from 160mph winds to stick shakers on a 330,"coffin corner" at FL 350 five hours into the flight, flat spins à la Tupolev 154 and its T-tail (btw the exact term is "deep stall"), loss of load factor protection in ALT and pilots overstrssing their airframe and an ADIRU theory, the merit of which is that it contains the only documents pertaining to a fault in the aircraft but suits a lot of agendas that are better called "slightly biased".
That's correct - this mystery has brought out every possible explanation known to man although I'm still waiting for the "collision with an alien craft". Second that, I think this has been mentioned too!
Quoting Pihero (Reply 166): Where are PhilSquares, Zeke, Bellerophon, TYdscanuck, OldAeroGuy, pilotaydin... and many more ? (see tech-ops, they're still alive !)
ThrottleHold From South Africa, joined Jul 2006, 472 posts, RR: 0 Reply 179, posted (6 months 2 weeks 2 days 4 hours ago) and read 25170 times:
Quoting SixtySeven (Reply 147): The airbus with it's fly by wire flight controls likely were sent into a degraded mode, likely "direct law" due to the ADIRS being tripped off line.
An ADR 1 + 2 + 3 Fault results in Alternate Law.
Quoting SixtySeven (Reply 147): With the ADIRS tripped off line they would have lost primary flight instruments, would have had an ELAC fault
The A330 does not have ELAC's. It has PRIM's and SEC's.
Quoting Adam42185 (Reply 150): in lay-mans terms... what is the difference between alternate law and direct law? Does alternate still have some flight protection against stalls/over stressing and direct is as it sounds?
From the A330 FCOM:
Alternate Law.....
ALTN LAW 1
PITCH CONTROL
Ground mode:
Identical to normal law ground mode.
Flight mode:
Flight law is a load factor demand law, similar to normal law, with limited pitch rate feedback and gains, depending on speed and configuration.
Flare mode:
Flare law is identical to normal flare law.
LATERAL CONTROL
Lateral control is similar to normal law, except that alterations of positive spiral static stability will not occur due to the loss of high AOA and high speed protection.
PROTECTIONS
Low speed stability:
At low speed, a nose down demand is introduced in reference to IAS, instead of angle of attack, and alternate law changes to direct law. It is available, whatever the slats/flaps configuration, and it is active from about 5 knots up to about 10 knots above the stall warning speed, depending on the aircraft's weight and slats/flaps configuration. A gentle progressive nose down signal is introduced, which tends to keep the speed from falling below these values. The pilot can override this demand.
Bank angle compensation is provided.
In addition, audio stall warning (crickets + "STALL" synthetic voice message) is activated at an appropriate margin from the stall condition.
The PFD speed scale is modified to show a black/red barber pole below the stall warning.
V prot and V max are replaced by Vsw (stall warning speed).
The Alpha Floor protection is inoperative.
High speed stability
Above VMO/MMO a nose up demand is introduced to avoid an excessive increase in speed.
The pilot can override this demand.
The high speed protection symbol (VMO + 4) disappears.
In addition, the overspeed warning (VMO + 4 or MMO + 0.006) remains available.
Pitch attitude protection lost.
-------------------------------------------------------------------------------------------------------------------------------
ALTN LAW 2
PITCH CONTROL
Identical to ALT 1 law.
LATERAL CONTROL
Roll direct law:
Provides a direct stick-to-surface position relationship. The gains are automatically set according to the slats/flaps configuration.
The maximum roll rate is approximately 20 to 25° / second, depending on the speed and configuration.
Spoilers 2, 3 and 6 are inhibited, except in case of some additional failures affecting the lateral control.
Yaw alternate law:
The dutch roll damping function is available, and damper authority is limited to ± 4° rudder (CONF 0) and ± 15° (other configuration).
Turn coordination is also provided, except in CONF 0.
PROTECTIONS
Identical to protections in ALT 1, except that :
There is no bank angle protection in ALT 2 law.
In case of failure of 2 ADRs, there is no low speed stability.
In case of failure of 3 ADRs, there is no high speed stability.
An abnormal attitude law in pitch and roll is provided, if the aircraft is in flight and in any of these conditions :
Pitch attitude > 50° nose up or 30° nose down
Bank angle > 125 °
Angle of attack > 30° or < - 10°
Speed > 440 knots or < 60 knots
Mach > 0.96 or < 0.1
The law in pitch is the alternate law without protection (except load factor protection) and without auto trim. In roll, it is a full authority direct law with yaw alternate.
After recovery, the flight controls laws are:
In pitch : Alternate law.
In roll : Direct law with yaw alternate law.
To control the aircraft during a temporary complete loss of electrical power.
PITCH
Pitch mechanical control is achieved through the THS, using manual trim control.
«MAN PITCH TRIM ONLY» is displayed in red on the PFDs.
LATERAL
The Backup Control Module (BCM) computer provides yaw damping and direct rudder command with pedals. This computer includes its own electrical generator, supplied by the B or Y hydraulic system.
Ikramerica From United States, joined May 2005, 18493 posts, RR: 60 Reply 180, posted (6 months 2 weeks 2 days 4 hours ago) and read 24859 times:
Quoting Richierich (Reply 178): That's correct - this mystery has brought out every possible explanation known to man although I'm still waiting for the "collision with an alien craft". Second that, I think this has been mentioned too!
That's what mysteries do.
But it's educational, because people learn what is and isn't possible from the limited data points by asking questions and getting answers.
What's wrong with that exactly?
I've yet to read anyone claim they KNOW what happened, or try to blame on thing or another, at least in this thread.
There's another thread where the safety of twins is called into question by an expert despite no evidence this accident was ETOPS related. THAT's irresponsible...
Of all the things to worry about... the Wookie has no pants.
Micstatic From United States, joined Jul 2001, 574 posts, RR: 1 Reply 181, posted (6 months 2 weeks 2 days 4 hours ago) and read 24593 times:
Quoting Ikramerica (Reply 180): But it's educational, because people learn what is and isn't possible from the limited data points by asking questions and getting answers.
Amen. I think dialog is the reason we are all on a.net
Thank you very much for the detail. I have to admit I saved it in my notes because I really want to read it slowly and understand it when I get some time. It's been a long day...
Quoting Ikramerica (Reply 180): But it's educational, because people learn what is and isn't possible from the limited data points by asking questions and getting answers.
Exactly my thoughts. I've learned so much by reading this type of thread on Anet. Thanks to all who have the patience and take the time to explain.
Trystero From Portugal, joined Oct 2008, 163 posts, RR: 0 Reply 184, posted (6 months 2 weeks 2 days 3 hours ago) and read 24010 times:
Quoting Pihero (Reply 166): WE have seen all on A.net : armchair aviators, 20,000 hour-experienced sim pilots and now self-appointed accident investigation experts !
Is this a forum for experts only or for enthusiasts? If it's pilots only, I'm out of here! You may know a lot more, but previous cases showed us that very well informed members with highly structured, and totally possible theories ended up as wrong as we " the armchair whatever".
You want facts, wait for them.
KBUF From United States, joined Apr 2005, 194 posts, RR: 0 Reply 185, posted (6 months 2 weeks 2 days 3 hours ago) and read 23801 times:
Brazil Recovers first AF447 debris
FERNANDO DE NORONHA, Brazil – A Brazilian helicopter crew recovered the first wreckage from Air France Flight 447 on Thursday, pulling a cargo pallet from the sea. No sign of human remains have been spotted, and Air France has told families that the jetliner broke apart, killing all 228 people on board.
Two buoys — standard emergency equipment on planes — also were recovered from the Atlantic Ocean about 340 miles (550 kilometers) northeast of Brazil's northern Fernando de Noronha islands by the helicopter crew, which was working off a Brazilian navy ship.
Air France's CEO Pierre-Henri Gourgeon told family members at a private meeting that the Airbus A330 disintegrated, either in the air or when it slammed into the ocean and there were no survivors, according to Guillaume Denoix de Saint-Marc, a grief counselor who was asked by Paris prosecutors to help counsel relatives.
Soldiers at Fernando de Noronha's airport, where any recovered human remains would be taken, unloaded body bags and a refrigerator truck on Thursday from a military plane.
Flight 447 disappeared en route from Rio de Janeiro to Paris on Sunday night, the deadliest crash in Air France history and the world's worst commercial air accident since 2001.
BMIFlyer From United Kingdom (England), joined Feb 2004, 8170 posts, RR: 71 Reply 186, posted (6 months 2 weeks 2 days 3 hours ago) and read 23792 times:
Last minutes of doomed plane
"Doomed Air France Flight 447's last terrifying few minutes in the air have already been pieced together by accident investigators."
PPVRA From Brazil, joined Nov 2004, 6127 posts, RR: 48 Reply 187, posted (6 months 2 weeks 2 days 3 hours ago) and read 23341 times:
Quoting KBUF (Reply 185): Air France's CEO Pierre-Henri Gourgeon told family members at a private meeting that the Airbus A330 disintegrated, either in the air or when it slammed into the ocean and there were no survivors, according to Guillaume Denoix de Saint-Marc, a grief counselor who was asked by Paris prosecutors to help counsel relatives.
I find it hard to believe that the plane disintegrated anywhere when there's so little evidence floating around. Maybe there's more somewhere, we just missed the area, but so far this explanation isn't making much sense to me.
"If goods do not cross borders, soldiers will" - Frederic Bastiat
QFMel From Australia, joined Jun 2009, 79 posts, RR: 0 Reply 188, posted (6 months 2 weeks 2 days 3 hours ago) and read 22756 times:
Quoting Gniou (Reply 67):
Quoting 747MegaTop (Reply 54):
Black Box recovery - I really hope that the black boxes are recovered. Given the fact that deep sea submersibles have reached Mariana Trench ...the deepest known part of the world's oceans..there is hope. Given the fact that as recently as May 31st "Nereus" dived and sampled sediments from the Mariana Trench at a depth of 10,902 meters (6.8 miles) we all have reason to be optimistic (agreed that the conditions are extremely difficult for locating and retrieving the black boxes). Here are a couple of articles that make interesting reading and increases our optimism of the black boxes being retrieved
So I understand that once balck boxes are located, it's technically possible to retrieve them with such submersible (or other types mentioned in other posts).
But as for identifying the location ... I would tend to think that it's not too complex given that these black boxes spend signals for the next 30 days ? I am not a specialist, but it would sound to me not too complicated task if they can track their signal ... unless they were destroyed.
Main issue remains locating it, recovery likely to be less problematic; though that's not to say less time consuming.
Quoting MarSciGuy (Reply 66):
My guess would be either the Porquoi Pas or some of the other vessels in the area so equipped will fully survey the area using multibeam, probably sidescan, and maybe another more novel type of sonar firstly before dispatching the submersibles (unmanned and manned).
Perhaps a SURTASS vessel could be sent to find the boxes if they're having trouble hearing the pinging bacuse of the depth and layers.
As has been suggested in previous threads, deploying a surface vessel with a towed array certainly couldn't hurt.
Yeah, they had the same account on ABC Nightline last night. Scary stuff! It kind makes me wonder: if the computer on the Qantas jet was acting on bad information, how accurate was the text-ed info sent on the AF a/c? Just a thought...
Ah, Summer, Fenway Park, Boston Red Sox and Beer.....
QFMel From Australia, joined Jun 2009, 79 posts, RR: 0 Reply 191, posted (6 months 2 weeks 2 days 3 hours ago) and read 22693 times:
Quoting Pihero (Reply 166):
The answer will be about professionalism, a decent attitude towards the dead occupants of that airplane and their relatives and friends...and a refusal to speculate when we have basically nothing to bese a theory on. Have you noticed the number of brand new or low-contributing posters since the accident ?
I couldn't agree more with the tone of your post.
My first post on this site was a few threads back and I said pretty much the same thing. I've tried to restrict myself to certain aspects of the recovery of the FDR/CVR for this reason- I'm not going to pretend I have knowledge beyond certain very specific areas, nor wed myself to a theory I've decided accounts for what's happened.
LTBEWR From United States, joined Jan 2004, 9396 posts, RR: 7 Reply 192, posted (6 months 2 weeks 2 days 3 hours ago) and read 22313 times:
Quoting PPVRA (Reply 187): I find it hard to believe that the plane disintegrated anywhere when there's so little evidence floating around. Maybe there's more somewhere, we just missed the area, but so far this explanation isn't making much sense to me.
Part of such a belief is to in part be honest, not putting out false hope. It may also suggest that the people on this flight didn't suffer, probably died quickly from decompression. It could also be a way for AF to try to deflect some possible liability in this matter, to defect it to an 'act of God' beyond their control.
EMA747 From United Kingdom, joined Jun 2006, 912 posts, RR: 2 Reply 195, posted (6 months 2 weeks 2 days 2 hours ago) and read 22169 times:
Quoting Pihero (Reply 166): User currently offlinePihero From France, joined Jan 2005, 1722 posts, RR: 43
Reply 166, posted Thu Jun 4 2009 22:55:41 your local time (1 hour 49 minutes 22 secs ago) and read 4684 times:
Please point me to where it says we cannot discuss this topic, because I can't see it.
I am sure there is a pilots only forum somewhere so why not just go there? Your post has a real feel of snobbery about it and I don't think we need that attitude. You are a pilot and have so much real world knowledge and that's good for you but.....the rest of us are trying to get find out what went on whilst also having to learn about how these complex machines are operated/designed. If this requires posting some questions that seem stupid to you then so be it.
Rant over.
Failing doesn’t make you a failure. Giving up and refusing to try again does!
ComeAndGo From United States, joined Mar 2005, 825 posts, RR: 0 Reply 196, posted (6 months 2 weeks 2 days 2 hours ago) and read 22062 times:
Quoting Readytotaxi (Reply 59): I was wondering what percentage of of the population think that there is total radar coverage on the globe, would they be shocked at the gaps out there?
Radar in itself is essentially useless. It's old technology nothing more. Merchant vessel show up on radar screens. Most of the information used by ATC comes from the transponder. If GPS was added to the transponder info, no radar would needed anymore. All you'll need is a bunch of receiving stations and one big network of computers to sync all the information of all flying aircraft all at once.
TUNisia From United States, joined Aug 2004, 1756 posts, RR: 8 Reply 197, posted (6 months 2 weeks 2 days 2 hours ago) and read 21680 times:
Quoting EMA747 (Reply 195): Please point me to where it says we cannot discuss this topic, because I can't see it.
I am sure there is a pilots only forum somewhere so why not just go there? Your post has a real feel of snobbery about it and I don't think we need that attitude. You are a pilot and have so much real world knowledge and that's good for you but.....the rest of us are trying to get find out what went on whilst also having to learn about how these complex machines are operated/designed. If this requires posting some questions that seem stupid to you then so be it.
Rant over.
WELL SAID! It's the holier than thou crowd that really gets under my skin.
This is an AVIATION FORUM, of course people are going to debate and share ideas as to what might have happened.
"Someday the sun is going to shine down on me in some faraway place." - Mahalia Jackson
This report from Flightglobal says that confirmation has not been made yet, however there is other debris seen from aircraft which has not been recovered yet. Merchant ships in the area have now continued their voyage, so it's up to Navy vessels to continue recovery operations.
I get the feeling that it will all be confirmed, we just need to give it time.
"Doomed Air France Flight 447's last terrifying few minutes in the air have already been pieced together by accident investigators."
See this is the type of crap people should be complaining about. That article reads as if it's pure fact!
Quoting ThrottleHold (Reply 190):
Screenshots of AF447 ACARS Mx messages. Print format means that the first message received is at the bottom of the lists.
Does: "NAV ADR DISAGREE" have anything to do with the procedure documented in the EASA AD regarding the QF 330 incident? (Sorry I don't have the EASA document handy, but that is standing out to me...)
Also (I have no idea the formatting of ACARS messages): the IR2 fault line, is that saying that IR2 failed or is IR2 the only IRU still functioning correctly?
I don't care what you think of my opinion. It's my opinion, so have a nice day :)
AlitaliaMD11 From Spain, joined Dec 2003, 4068 posts, RR: 20 Reply 201, posted (6 months 2 weeks 2 days 2 hours ago) and read 21483 times:
Quoting 757GB (Reply 198): This report from Flightglobal says that confirmation has not been made yet, however there is other debris seen from aircraft which has not been recovered yet. Merchant ships in the area have now continued their voyage, so it's up to Navy vessels to continue recovery operations.
I get the feeling that it will all be confirmed, we just need to give it time.
According to the link EZEIA posted, the cargo pallet retrieved from the water was made of wood and not of aluminum which is 'not the material of normal airplane cargo pallets'. Although the A330 could very well have been carrying some sort of cargo in a wooden pallet.
The BBC is now reporting as one of its latest headlines:
"LATEST:Debris recovered in the Atlantic is not from Air France jet, says Brazilian air force official"
ThrottleHold From South Africa, joined Jul 2006, 472 posts, RR: 0 Reply 202, posted (6 months 2 weeks 2 days 2 hours ago) and read 21300 times:
Quoting Osiris30 (Reply 199): Does: "NAV ADR DISAGREE" have anything to do with the procedure documented in the EASA AD regarding the QF 330 incident?
Possibly, I don't have that AD to hand, but here's the FCOM procedure.....
This caution is triggered by the PRIMs, when they only use 2 ADRs, and these 2 ADRs disagree. This may occur, when :
One ADR has already been selected OFF by the pilot, or One ADR has been eliminated by the PRIM, without any caution, because it deviated from the others.
-AIR SPD X CHECK
Check airspeed information on both PFDs, and on the standby airspeed indicator.
-IF NO SPD DISAGREE :
AOA DISCREPANCY
-IF SPD DISAGREE :
ADR CHECK PROC APPLY
Refer to the associated procedure.
F/CTL ALTN LAW (PROT LOST)
Note : Following an ADR DISAGREE, detected by the PRIMs, ALTN law is latched. Resetting the PRIMs by using the pushbutton does not allow normal law recovery.
Refer to the associated procedure.
-MAX SPEED 330/.82
Quoting Osiris30 (Reply 199): Also (I have no idea the formatting of ACARS messages): the IR2 fault line, is that saying that IR2 failed or is IR2 the only IRU still functioning correctly?
From the print-out, I'm not sure either. However, there is also a NAV TCAS FAULT warning which will appear due to an IR1 fault, but not with an IR2 or IR3 fault. This, as along with the PRIM 1 and SEC 1 faults would lead me to believe that IR1 and IR3 had faulted leaving only IR2 in operation.
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In about three minutes in my case, twenty seconds in Pihero's...
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From Puerto Rico, joined Apr 2005, 738 posts, 
From Barbados, joined Sep 2006, 3134 posts, 
From Italy, joined Mar 2005, 400 posts, 
From Netherlands Antilles, joined May 2001, 5791 posts, 
From South Africa, joined Jul 2006, 472 posts, 
It was my last 757 for a few years, too). But *could* this eventually lead to a problem?
, 442 posts, 
From Ireland, joined Jun 2009, 206 posts, 
From Indonesia, joined Aug 2001, 4569 posts, 
From Finland, joined Oct 2007, 1604 posts, 
From French Southern Territories, joined Feb 2007, 4799 posts, 
From Iceland, joined Jan 2005, 2617 posts, 
From Netherlands, joined Oct 2004, 7581 posts, 
From Uruguay, joined Feb 2009, 355 posts, .gif){kind=small}
From United Kingdom (England), joined Mar 2004, 1781 posts, 
From , joined Dec 1969, posts, 
From Argentina, joined Aug 2004, 4081 posts, 
From Angola, joined May 2007, 3 posts, 
From Spain, joined Dec 2003, 4068 posts,