I don't get it. So all pilots left the cockpit after go around? If not, why nobody answered ATC? Can 747, even relatively light, sustain 120 knots (130mph) or is it just pure media imagination? What do you guys think?
Doug_Or From United States of America, joined Mar 2000, 3160 posts, RR: 4 Reply 2, posted (8 years 2 months 1 week 3 days 7 hours ago) and read 13885 times:
Did you read the article? The autopilot disconnected and the pilots didn't know it.
PolAir From United States of America, joined May 2001, 893 posts, RR: 2 Reply 3, posted (8 years 2 months 1 week 3 days 7 hours ago) and read 13870 times:
Did not read this closely. Crew was in the cockpit. However, didnt they feel steep climb/loss of speed? I assume visibility was poor.
OzGlobal From France, joined Nov 2004, 2596 posts, RR: 4 Reply 4, posted (8 years 2 months 1 week 3 days 7 hours ago) and read 13854 times:
This happened four months ago from memory. The article is dated, if you look carefully, 14/10/2004. Today's date is being automatically displayed on the webpage.
[Edited 2005-03-14 02:36:11]
When all's said and done, there'll be more said than done.
DLKAPA From , joined Dec 1969, posts, RR: Reply 5, posted (8 years 2 months 1 week 3 days 7 hours ago) and read 13831 times:
The article also said that the aircraft was doing 120 knots (130mph) in a 30* Roll and because of the roll AVOIDED the stall. That's physically impossible, the roll would cause the wing to be less efficient in lifting the plane (hence why when you turn an aircraft in flight you also pull back on the yoke to give it a slightly noze-high angle of attack), thus the airplane would have fallen to the ground in a nice sliding corkscrew action.
Ok, so maybe it's possible for an empty 747 to be doing 120kts in flight, provided it's the phase of flight known as "Flare" and the thing is inches above a runway, but comeon, a 747 loaded with 350 pax doing a 30* bank at 120kts, no way!
Doug_Or From United States of America, joined Mar 2000, 3160 posts, RR: 4 Reply 6, posted (8 years 2 months 1 week 3 days 7 hours ago) and read 13785 times:
DLKAPA, Chill! My response was written when there were no replies. I was reacting to the question about the crew not being in the cockpit.
However, if you enter a roll , like you say, you need to apply an up elevator input. Otherwise the nose drops. Since the pilots didn't apply any backpreasure, the nose did drop and so the angle of attack was reduced.
DLKAPA From , joined Dec 1969, posts, RR: Reply 7, posted (8 years 2 months 1 week 3 days 6 hours ago) and read 13530 times:
Quoting Doug_Or (Reply 6): However, if you enter a roll , like you say, you need to apply an up elevator input. Otherwise the nose drops. Since the pilots didn't apply any backpreasure, the nose did drop and so the angle of attack was reduced.
True, but according to the article, the noze didn't drop until at or near 120kts airspeed. I'm pretty sure a 747 flying with a decent pax load will stall well before that.
727EMflyer From United States of America, joined Mar 2005, 547 posts, RR: 0 Reply 9, posted (8 years 2 months 1 week 3 days 5 hours ago) and read 13237 times:
Keep in mind this story is coming to us via the media... the most often flamed contributor at a.net. I would guess the 130 MPH quoted speed was groundspeed. Given all the variables like wind and angle of climb, the aircraft could have been in much better shape airspeed wise. Either way if the course the plane took is anywhere close to that shown in the articles graphic, shame shame shame on the flightcrew. When did crew stop being pilots and start being mere "airplane operators?"
FriendlySkies From United States of America, joined Aug 2004, 4004 posts, RR: 6 Reply 10, posted (8 years 2 months 1 week 3 days 5 hours ago) and read 13173 times:
Quoting 727EMflyer (Reply 9): I would guess the 130 MPH quoted speed was groundspeed.
Not to be nit-picky, but isn't groundspeed usually HIGHER than airspeed?
DLKAPA From , joined Dec 1969, posts, RR: Reply 11, posted (8 years 2 months 1 week 3 days 4 hours ago) and read 13077 times:
Quoting FriendlySkies (Reply 10): Not to be nit-picky, but isn't groundspeed usually HIGHER than airspeed?
Depends on the winds. Airspeed is really a measurement of Ram Air Pressure into the aircraft's Pitot tubes, so if there is a strong headwind, the measurement of the rate at which the aircraft cuts through the air will be higher. The airspeed will always be higher than the groundspeed in the event of a headwind.
Generally, one way to think about a headwind is "Free Airspeed." If you are rolling down a runway with a 30kt headwind, you can lift off the runway going 30kts slower than your normal takeoff speed with no headwind. The same works for landing, as it's much easier to make a soft touchdown with the same 30kt headwind (provided it's an almost direct headwind), because you are again travelling 30kts slower than normal touchdown speed.
PhilSquares From , joined Dec 1969, posts, RR: Reply 12, posted (8 years 2 months 1 week 3 days 4 hours ago) and read 13033 times:
Sorry to be a nay sayer, but airspeed really doesn't have a lot to do with stalls. What is relevant is the angle of attack. I can have 0 angle of attack on an airplane and 0 airspeed and I am not in a stalled condition.
I can assure you depending on the flap configuration, with full thrust and 130 mph (kias more likely) the airplane probably flying fine.
Remember this incident is really very old news. It was on PPRUNE for a while and I am sure if you want search the archives on there you will probably get a better idea of what happened.
DLKAPA From , joined Dec 1969, posts, RR: Reply 13, posted (8 years 2 months 1 week 3 days 4 hours ago) and read 13008 times:
Quoting PhilSquares (Reply 12): I can have 0 angle of attack on an airplane and 0 airspeed and I am not in a stalled condition.
When you're sitting on the ground parked, yes. I find it very hard to believe that any airplane in flight could be at 0 angle of attack and have 0 airspeed while not being in a stalled condition.
Doug_Or From United States of America, joined Mar 2000, 3160 posts, RR: 4 Reply 14, posted (8 years 2 months 1 week 3 days 4 hours ago) and read 12959 times:
Quoting DLKAPA (Reply 13): I find it very hard to believe that any airplane in flight could be at 0 angle of attack and have 0 airspeed while not being in a stalled condition
Well you'll just have to work on that. Stall is caused by one thing- angle of attack. In normal 1 g flight, angle of attack needs to increased as airspeed decreases, just as AoA must be increased when weight is increased. However, when in less than 1 G flight- like, I don't know- when the nose is coming down, the AoA @ a given airspeed will be lower, and therefore further from stalling.
RE: Airspeed vs ground speed, there are two basic kinds of airspeed indicated (IAS, the ram preasure you talked about) and true airspeed (TAS, the actaul speed of the aircraft moving through the air). Statisticaly, TAS will on average be average be faster that ground speed, becasue more than half of the potential wind vecotors result in a reduction in groundspeed. However, as altitude increases, IAS goes down @ a given TAS, and therefore will most likely be less than GS.
GoBoeing From United States of America, joined Jun 2000, 2630 posts, RR: 12 Reply 15, posted (8 years 2 months 1 week 3 days 4 hours ago) and read 12949 times:
Quoting DLKAPA (Reply 13): I find it very hard to believe that any airplane in flight could be at 0 angle of attack and have 0 airspeed while not being in a stalled condition.
PhilSquares From , joined Dec 1969, posts, RR: Reply 16, posted (8 years 2 months 1 week 3 days 4 hours ago) and read 12933 times:
DKKAPA,
What happens when you "unload" an airplane?
The angle of attack approaches 0. The wings are producing no lift, so you have no induced drag. All your thrust is being converted to potential energy.
When I flew fighters you tried to do all your maneuvering in the vertical. It's the best way to conserve/make energy. It was not uncommon to go vertical, unload and have your airspeed bleed down to 0. When I was a T-38 instructor, you tried to teach energy management and that was a great demo to go to mil power and unload and watch the airspeed go to 0 and the angle of attack go to 0.
707437 From United States of America, joined Nov 2003, 152 posts, RR: 1 Reply 18, posted (8 years 2 months 1 week 3 days 2 hours ago) and read 12759 times:
No load means you need no lift to maintain altitude so no problem right?
So as long as your momentum is holding the airplane up who even needs a wing anyway. . .
But realistically when the lift is slightly less than the weight of the aircraft you've got a controlled mild descent.
But when these numbers diverge seriously. . . Then the flow separates across the airfoil and game over.
PhilSquares From , joined Dec 1969, posts, RR: Reply 19, posted (8 years 2 months 1 week 3 days 2 hours ago) and read 12687 times:
The reason the wings are producing no lift is you are in a 0G, or close to it, environment. So as the g-load approaches 0 the demand for lift on the wings decreases (read angle of attack). Conversely, a 60 degree bank level turn, will give you a 2 G load. Now you have to have back pressure on the stick (yoke) to increase your angle of attack. If you add no power, you will lose airspeed, and have a greater need for back pressure. Now you are increasing the angle of attack to produce the same amount of lift at a lower airspeed. I have felt buffet on the airframe at over 500 KIAS while maneuvering. Why? Because I was approaching the Max AOA. Now you have an accelerated stall.
Hope that helps. If not just ask here or send me an email.
Oly720man From United Kingdom, joined exactly 9 years ago today! , 6183 posts, RR: 11 Reply 21, posted (8 years 2 months 1 week 2 days 23 hours ago) and read 11673 times:
Interesting caption on the little graphic..... "Near miss for Britons on Cathay Pacific flight to Hong Kong."
Were the other nationalities perfectly safe then??
Man City p3 w3 d0 l0 f4 a0 P9 - hey it may never happen again!
MEA-707 From Netherlands, joined Nov 1999, 4117 posts, RR: 37 Reply 22, posted (8 years 2 months 1 week 2 days 20 hours ago) and read 10100 times:
Yeah, that's a hilarious caption, typically the UK tabloid, like that the Britons on board make the story connect more to their reader base, they presume the reader might otherwise raised his shoulder "who cares about some shaded eyed people in some bamboo airplane"
nobody has ever died from hard work, but why take the risk?
DAYflyer From United States of America, joined Sep 2004, 3807 posts, RR: 4 Reply 23, posted (8 years 2 months 1 week 2 days 18 hours ago) and read 8861 times:
Quoting DLKAPA (Reply 5): The article also said that the aircraft was doing 120 knots (130mph) in a 30* Roll and because of the roll AVOIDED the stall. That's physically impossible, the roll would cause the wing to be less efficient in lifting the plane (hence why when you turn an aircraft in flight you also pull back on the yoke to give it a slightly noze-high angle of attack), thus the airplane would have fallen to the ground in a nice sliding corkscrew action.
Ok, so maybe it's possible for an empty 747 to be doing 120kts in flight, provided it's the phase of flight known as "Flare" and the thing is inches above a runway, but comeon, a 747 loaded with 350 pax doing a 30* bank at 120kts, no way!
I believe in a dirty configuration it must maintain a minimum of 140 knots to remain airborne.
PhilSquares From , joined Dec 1969, posts, RR: Reply 24, posted (8 years 2 months 1 week 2 days 18 hours ago) and read 8812 times:
Quoting DAYflyer (Reply 23): I believe in a dirty configuration it must maintain a minimum of 140 knots to remain airborne.
Believe me, it will continue to fly well below the 140 Knots you mention!!!! Again, it's not speed, but angle of attack.
25 DLKAPA: Nope! Last night after reading this thread I decided to test this theory in a fully loaded 744 in flightsim. I did a touch and go and pulled the plan
26 B742: Lucky escape there! I was at Kai Tak when the China Airlines 747 overran the runway, not a pretty sight! Good job we didn't have another HKG disaster!
27 Powerofpi: I wonder if they retracted the flaps like they were supposed to. Once I was on a 737 and we did a go-around. I know it's not a 747, but I was pretty a
28 Doug_Or: It might be possible they had partialy retracted the flaps. I don't know anything about 747 automation (or lack there of), but in the Boeing I'm famil
29 Rootsgirl: Did you read the post? Start your own post about rolls etc and someone answer the question. It involves the crew in the flight deck. Ignoring the ques
30 DLKAPA: Neither is coming into a thread 30 replies in and trying to tell us what the topic should be.
31 Stealthpilot: The article also mentioned that the aircraft had a pitch (not bank) of 28 degrees. That seems scarier than a 30 bank!! Does anyone know the critical a
32 BuckFifty: This makes me really wonder what the hell the pilots were doing up there because obviously you don't leave full flaps in on a go around. Who was respo
33 VEEREF: Actually we'll be seeing this headline again on a regular basis some time in the future when pilots are removed from aviation...........
34 VEEREF: The scary part of this event, assuming the numbers are correct, is the degree to which the crew lost situational awareness of what mode they were oper
35 LAPA_SAAB340: Hi Stealth One detail you have to be careful about is that angle of attack is not the same thing as pitch angle - it is not affected by where the nose
36 Stealthpilot: LAPA_SAAB = Correct you are, the angle of attack is the angle to the relative wind Nevertheless, what is the critical angle? -Nikhil
37 PhilSquares: There is no angle of attack indicator on the 744. In addition, it would depend on other factors such as gross wight and g loading (bank angle). Howeve
38 Airlinelover: Most passengers disembarked without realising they had been so near to disaster. Until now.. That's crazy.. Pilots must have been wasted or something.
39 PhilSquares: I am amazed at all the experts on this forum. If there are so many experts, why has no one suggested an autopilot malfunction? No, that couldn't happe
40 DLKAPA: They did, hence very few members of this forum will ever find their way into a cockpit
41 Doug_Or: "but I can land in MSFS9, so anytime anything goes wrong anywhere its becuause they are incometpant and should be fired"
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