Moderators: jsumali2, richierich, ua900, PanAm_DC10, hOMSaR

 
ACEregular
Posts: 578
Joined: Mon Aug 11, 2003 8:00 am

RE: Helios 737 Discussion, Part 3

Wed Aug 17, 2005 6:17 pm

It just seems odd that this aircraft was involved in an incident landing in Larnaca late last year, whereby some occupants had passed out. I think if the FO wanted to off himself he would have gone down the same route as maybe the Silk Air 737, after all its a lot less inticate.
 
We're Nuts
Posts: 4723
Joined: Sun Jun 04, 2000 6:12 am

RE: Helios 737 Discussion, Part 3

Wed Aug 17, 2005 6:24 pm

Quoting Kesflyer (Reply 148):
Could this have been some sort of suicide by the Co-Pilot, killing the Captain and then releasing some sort of poisonous gas onboard the aircraft.

Remember Occam's Razor! Of two equivalent theories or explanations, all other things being equal, the simpler one is to be preferred.
Dear moderators: No.
 
vfw614
Posts: 3830
Joined: Mon Dec 10, 2001 12:34 am

RE: Helios 737 Discussion, Part 3

Wed Aug 17, 2005 6:50 pm

1. Where is the body of the Captain ? It cannot disappear if they have found 120 corpses reasonably intact and I am sure by now they have turned every stone at the crash site.

2. Where is the CVR ? How can it break open on impact and make the contents disappear ?

3. How did the aircraft manange to loose 34.000ft while apparently gliding from the Kea hold to the crash site which is a mere 50nm ?

4. Why was the body of a F/A found in the cockpit but not the CPT and not the F/A who allegedly had flight training ?

5. How difficult would it be for a F/A with pilot training to communicate with the ground - the radio was obvioulsy set on ATH frequency, so he would only have needed to pick it up from the F/O ?

6. If the aircraft ran out of fuel while on autopilot, would it indeed glide to the ground because the AP is disengaged automatically or would it stall ? Would the AP disengage when the first engine stops running - it seems very unlikely that both engines flame out at the very same moment ? If not, could the AP keep the aircraft on track and at altitude with just one engine running ? If all answers are no, would this indicate that the descent was initiated by someone in the cockpit who manually disengaged the AP and also allowed the aircraft to loose that much altitude form the Kea hold to the crash site ?

7. If so, did the aircraft fly a straight routing from the Kea hold or was there some manoeuvring by the F/A ? It seems to be an interesting coincident that the aircraft more less descended alongside the coastline from the Kea hold and crashed very near the coast. Could this be an indication that it was deliberately flown in that direction to be as close as possible to the coast but to remain over water. With the aircraft flying a holding pattern over the open sea, the likelihood that it glides to the - under the given circumstances - best possible direction without any input is very remote.
 
noelg
Posts: 2313
Joined: Fri Apr 26, 2002 11:39 pm

RE: Helios 737 Discussion, Part 3

Wed Aug 17, 2005 7:53 pm

If the captain was slumped over the controls, this would disengage the autopilot if there was enough pressure.

Is it true that the wreckage was spread over a very wide area? If so then surely an aircraft hitting a mountain would generally be relatively compact crash site, a break up in flight would result in a wider area.

My belief (with others on here by the look of it) is that the F-16 pilots shot the aircraft down to avoid it going down in a built up area or causing a danger to others, with good reason. However the Greeks aren't going to admit it as it would open them up to a lot of criticism.

I honestly don't think the Greek authorities will be as open as they could be with this, and hope there is a third party investigation into this (neither the Greeks or Cypriots), it's the only way to get a neutral view of it. What evidence is there to show that what the pilots/Greek authorities are saying is true? Nothing as it is all in pieces (and the CVR has mysteriously been damaged beyond repair now as well). We are relying solely on word of mouth from the Greeks.

Sorry if I have my cynicism hat on here, but something isn't right here.

Noel.
 
iakobos
Posts: 3255
Joined: Wed Aug 06, 2003 6:22 pm

RE: Helios 737 Discussion, Part 3

Wed Aug 17, 2005 8:42 pm

Quoting Vfw614 (Reply 152):
1. Where is the body of the Captain ? It cannot disappear if they have found 120 corpses reasonably intact and I am sure by now they have turned every stone at the crash site.

As of yesterday evening, 2 (perhaps 3 ?) corpses had not been found, including the German captian.
Of the recovered 119 (118 ?) corpses (many are not in one piece !), a rather large number are unidentifiable and DNA will have to be used.

Quoting Vfw614 (Reply 152):
3. How did the aircraft manange to loose 34.000ft while apparently gliding from the Kea hold to the crash site which is a mere 50nm ?

Kea island to crash site is 37-38nm.

Quoting Vfw614 (Reply 152):
7. If so, did the aircraft fly a straight routing from the Kea hold or was there some manoeuvring by the F/A ? It seems to be an interesting coincident that the aircraft more less descended alongside the coastline from the Kea hold and crashed very near the coast. Could this be an indication that it was deliberately flown in that direction to be as close as possible to the coast but to remain over water. With the aircraft flying a holding pattern over the open sea, the likelihood that it glides to the - under the given circumstances - best possible direction without any input is very remote.

The a/c came from the E or ESE.
It did not pass over or close to Marathon, which is 4.5 nm S from the crash site, and would obviously be seen or/and heard.

Quoting Noelg (Reply 153):
I honestly don't think the Greek authorities will be as open as they could be with this, and hope there is a third party investigation into this (neither the Greeks or Cypriots), it's the only way to get a neutral view of it. What evidence is there to show that what the pilots/Greek authorities are saying is true? Nothing as it is all in pieces (and the CVR has mysteriously been damaged beyond repair now as well). We are relying solely on word of mouth from the Greeks.

I honestly think the opposite...and I am not Greek.
The media might speculate otherwise but the modern history of the Hellenic CAA shows they are following a very honest path. (the Aerosweet Yak-42, HAF C-130 and Greek State Falcon crashes of recent years are examples)
Boeing obviously is also playing its role in the investigation.
 
tockeyhockey
Posts: 882
Joined: Fri Feb 04, 2005 10:57 pm

RE: Helios 737 Discussion, Part 3

Wed Aug 17, 2005 9:41 pm

this conversation leads me to the next logical question, one that may be best answered in tech-ops, but i'll let it fly here anyway:

is there any way that a depressurization of either the sudden or the slow leak variety can have an effect on the control surfaces or the aircraft, and/or on the controls in the cockpit?

it seems to me that there must have been two accidents on this flight -- one that caused the depressurization and one that stopped the pilots/flight attendants from initiating the emergency decent.

can anyone think of an event that would cause both a depressurization and a loss of flight controls? and explosion in the cockpit? what?
 
mandala499
Posts: 6593
Joined: Wed Aug 29, 2001 8:47 pm

RE: Helios 737 Discussion, Part 3

Wed Aug 17, 2005 10:38 pm

Turkish ATC reported the 737 transmitting transponder code 7700 - an emergency, not the hijack code.

7700 after 7500 means "situation deteriorating. Help"

Though I don't think it's sabotage.

Is it not procedure that during a decompression, *both* pilots be in the cockpit (so one acts as redundant to the other), and an emergency descent is initiated immediately? Even if the cockpit O2 system was faulty (which seems more likely a maintenance issue with the airline than a "technical problem" with the airplane), where was the captain? Presumably he went to check on something - why did he not come back? Even in an explosive decompression (which there's so far no real evidence of), eventually a person would be able to make their way back up through the cabin to the cockpit. We do know that the cabin oxygen masks had deployed, so if the pilot was back there, he'd have been able to breathe that way and make his way back up to the cockpit over a period of several minutes

Time of useful Conscience:
40,000 feet 15 seconds
35,000 feet 30 seconds
30,000 feet 45 seconds
28,000 feet 01 minutes
25,000 feet 02 minutes
22,000 feet 05 minutes
*Assuming idle and lack of activity. More active/adrenalin, the less TUC u have.


Just a guess... but...

0 seconds Explosive Decomp cabin alt alert already on.
3 seconds pilots realize the problem.
6 seconds masks donned.
10 seconds Pilot selected lower altitude and selected FL CH and interrupted by them realizing the O2 isn't working.
12 seconds Capt. decides to leave seat to look for O2 in cabin... in the chaos crew forgot speedbrakes. "U descend the plane, I'll look for O2" scenario.
17 seconds new alt selected to 14,000 or 10,000 Captain now left the cockpit.
20 seconds shock effect of seeing cabin in decomp wears off.
23 seconds he's in the front galley asks for POB...
30 seconds, time ran out before he got the POB.

Meanwhile, cockpit door locked and F/A are trained to wait until it is safe to move about and "assess" situation. But the F/O is already unconscious.
Now if the speedbrakes were not deployed then those without mask might be dead by the time the aircraft reaches FL100. At FL100 it is still cold up there. Given the fact that it's summer, the pax could have suffered from the cold due to light clothing.

The above is just a wild guess with assumption that FL100 was selected but with no speedbrakes, but it could be any altitude... higher or lower.

The slow decomp. is likely too, it has happened here and the F/A went to the flight deck to find 2 semi conscious pilots (cabin alt alerter failed in cockpit)... However, in this case, it's a tech failure in that the cabin alerter did not raise the alarm... they're set at 10,000ft, not 14,000ft.

That still doesn't explain how the flight attendant apparently got up and made it into the cockpit. Why was she apparently the only person awake? How did she stay awake, or why was she the only one to regain consciousness?

Cabin crew uses the pax O2 system. Many of them could be awake for a long time but again, it might take a while for the F/As to realise that the F/O was also dead.

If some were blue and others were not....something doesn't jive.
The jive is that different people react to decompression differently and has different TUCs depending on their stress and activity level. Plus cockpit crew use O2 bottle, cabin crew use Pax Oxy until below FL140, then they use POB to support their activity.

Take an unpressurized cessna twin to FL100 and get the pax to do push ups and U'll see how different reactions are...

Would a jet in the process of running out of fuel be enough of a reason to knock itself out of cruise control and slam itself into a mountain?

If the flight attendants were the persons seen in the cockpit by the F16 crew I wonder why they did not use the radio to communicate with ATC? I am curious why anyone conscious enough to be trying to control the plane did not speak on the radio.

Try hypoxia induced manual intervention... now if the reports of pax & F/A trying to rescue the plane, add hypoxia and proximity to yoke PTT and yoke A/P Disengage buttons... U get the results.

and also in this report, they found the Voice-Recorde, but the recorder was EMPTY inside!!!! Thats getting strange more and more

If that's true then the lawyers will have a feast, and Helios will be history before the trial starts!

1. The CVR box was already empty when the 737 started
==> Q: Is it possible / allowed to start withOUT CVR in operation?


Yes, ask the MX guys how to do it if you dare!  Smile It is possible for a COMPANY to do this, but they must be nutcases to do it... Some have probably done this... but I certainly hope that Helios isn't one of them!

just my 2 cents...

Mandala499
When losing situational awareness, pray Cumulus Granitus isn't nearby !
 
ltbewr
Posts: 15021
Joined: Thu Jan 29, 2004 1:24 pm

RE: Helios 737 Discussion, Part 3

Wed Aug 17, 2005 10:55 pm

I would assume that the Greek aviation authorities have jurisdiction to investigate this crash. Besides the French aviation authorities being consulted to review the CVR and other recorders, what other EC or other countries will be consulted to assist in this investigation? Will the USA's NTSB also participate in this as involved an USA made (Boeing) aircraft?
 
User avatar
N328KF
Posts: 5946
Joined: Tue May 25, 2004 3:50 am

RE: Helios 737 Discussion, Part 3

Wed Aug 17, 2005 11:02 pm

Boeing has said that it did not sign off on MX certification in 2004, as was previously thought:

http://seattletimes.nwsource.com/htm...ogy/2002442821_boeinggreece17.html
“In the age of information, ignorance is a choice.”
-Donny Miller
 
NAV20
Posts: 8453
Joined: Thu Nov 27, 2003 3:25 pm

RE: Helios 737 Discussion, Part 3

Wed Aug 17, 2005 11:09 pm

Some good points in there, Mandala499. Two points to add:-

1. It's unlikely that the two FAs knew the full situation at first. It would have taken time for them to piece it together and decide to try to take over the controls. And even then they'd have had problems getting into the cockpit, they maybe had to spend time breaking the security door open.

2. They very possibly did communicate with the ground. But if those communications contained any evidence of the problem maybe being caused by negligence or malfeasance on the part of the operating company, the authorities would not release details at this stage.
"Once you have flown, you will walk the earth with your eyes turned skywards.." - Leonardo da Vinci
 
iakobos
Posts: 3255
Joined: Wed Aug 06, 2003 6:22 pm

RE: Helios 737 Discussion, Part 3

Thu Aug 18, 2005 1:10 am

Quoting LTBEWR (Reply 157):
Will the USA's NTSB also participate in this as involved an USA made (Boeing) aircraft?

There is a 4-person team from the NTSB including the person who was in charge of the Payne/Learjet investigation. (Mr Brenzon ?)

Quoting NAV20 (Reply 159):
2. They very possibly did communicate with the ground. But if those communications contained any evidence of the problem maybe being caused by negligence or malfeasance on the part of the operating company, the authorities would not release details at this stage.

ATC does not give a damn about companys' wrongdoings, they care about planes-passengers and how to get them on the ground.

IF the "person" at the commands was indeed a f/a with a CPL (and I imply he must have been reasonably aware of this 737 basic controls), and a sufficient degree of mental/physical capacity, AND he could communicate, it makes no doubt in my mind that the outcome would have been very different.
 
AMSSFO
Posts: 912
Joined: Wed Feb 02, 2005 8:42 am

RE: Helios 737 Discussion, Part 3

Thu Aug 18, 2005 3:56 am

Quoting Vfw614 (Reply 152):
How did the aircraft manange to loose 34.000ft while apparently gliding from the Kea hold to the crash site which is a mere 50nm ?



Quoting Vfw614 (Reply 152):
If so, did the aircraft fly a straight routing from the Kea hold or was there some manoeuvring by the F/A ?

Cover-up theories are always nice isn't it? Some of your assumptions are not based on the facts as known:
Why do you assume that the plane followed a straight path? It was reported that it maid repeatedly right turns. It is most likely, although not confirmed as far as I know, that it circled for a considerable amount of time until running out of fuel OR until the FA accidentally disconnected the auto pilot (probably under influence of hypoxia. he or she probably didn'y really think clear).
Besides, it is not really a straight path from Larnaca via Kea to Grammatikos, where the plane crashed.
I do not know from wich direction the plane was overflying Grammatikos.

Quoting Vfw614 (Reply 152):
the radio was obvioulsy set on ATH frequency, so he would only have needed to pick it up from the F/O ?

Why do you assume that the pilots set ATH frequency. At the time the plane entered the Greek airspace, ATC couln't get into contact with the plane, suggesting that the pilots were already incapable before entering the Greek airspace. Most likely they never changed their frequency from the Turkish to ATH.

Quoting Mandala499 (Reply 156):
The above is just a wild guess with assumption that FL100 was selected but with no speedbrakes, but it could be any altitude... higher or lower.

It was reported that the F16s intercepted the plane at FL340, almost an hour after ATC failed to establish contact. Seems to me enough time to descent.

10:37 Aircraft enters Athens FIR, but fails to establish contact.
11:05 Two F-16 fighter planes take off from Nea Anchialos, Greece.
11:18 Fighter pilots see co-pilot slumped unconscious on the aircraft's instrument panel, oxygen masks deployed.
12:04 Aircraft crashes near Grammatiko.
 
DAYflyer
Posts: 3546
Joined: Wed Sep 08, 2004 9:35 pm

RE: Helios 737 Discussion, Part 3

Thu Aug 18, 2005 4:02 am

Pilots Union said there are too many contradictions in stories of flight:

UK Pilots Group: Cypriot Plane Crash Details "Don't Add Up"



Wednesday August 17, 12:01 PM EDT

LONDON (AP)--The U.K. pilots' union on Wednesday urged Greek authorities to quickly release preliminary findings on the cause of the Cypriot plane crash that killed 121 people, and said some of the details about the flight's last minutes "just don't add up."

The Helios Airways flight crashed Sunday, killing everyone on the plane. Greek authorities are investigating whether something may have caused most of the passengers and crew to lose consciousness, and if someone other than the pilot and copilot may have tried to fly the aircraft in the moments before it crashed.

Authorities are also investigating reports that the Boeing (BA) 737-300 had suffered technical problems in the past. Initial theories had pointed to a catastrophic loss of air pressure, which starved the crew and passengers of oxygen.



There have been several apparently conflicting reports and a number of statements that just don't add up," Captain Mervyn Granshaw, head of the British Airline Pilots' Association said in a statement.

"There is a concern in our industry to learn, as quickly as possible, what happened.... If there is too much delay, the speculation will increase."

Granshaw didn't specify which reports conflicted and what their sources were. But he mentioned what the pilots of two Greek air force jets said they saw in the Cypriot airliner's cockpit when they flew alongside after the plane lost radio contact.

The fighter pilots reported seeing the copilot slumped over in the cockpit, apparently unconscious, and said the pilot wasn't in his seat. They said they later saw two unidentified people in the cockpit, possibly trying to regain control of the aircraft.

Greek authorities have refused to release more details while the investigation is going on.

Granshaw said if there was a sudden loss of air pressure, pilots and passengers would be affected similarly.

The passengers "may have managed to get on their oxygen masks, but it seems inconceivable that they would have walked up to the cockpit, seen the pilots, wrestled with the controls," Granshaw said.

He said allowing speculation to continue "wouldn't help the relatives, or our industry."

The pilots' union represents more than 8,000 U.K. pilots and flight engineers. Granshaw didn't immediately return a phone call seeking further comment.

(END) Dow Jones Newswires
One Nation Under God
 
mrocktor
Posts: 1391
Joined: Mon Jan 24, 2005 12:57 am

RE: Helios 737 Discussion, Part 3

Thu Aug 18, 2005 4:19 am

Quoting Vfw614 (Reply 149):
- both know that the chance of survival for them and consequently for all passengers is close to zero as it takes longer to get down to breathable air than one is able to survive without O2

No, it takes longer to reach ~15.000ft than one is able to remain conscious, it is perfectly possible to survive the descent without oxygen. Of course the crew should remain conscious during the descent but even that is not strictly necessary if they manage to punch in 10.000ft and flgiht level change in the autopilot.

Quoting Mandala499 (Reply 156):

Your theory doesn't match the facts. The aircraft was intercepted at cruise altitude, a long time after the cabin must have depressurized. No emergency descent was performed.

mrocktor
 
iakobos
Posts: 3255
Joined: Wed Aug 06, 2003 6:22 pm

RE: Helios 737 Discussion, Part 3

Thu Aug 18, 2005 4:21 am

The descent, from FL340 up to the time of impact, took 24 minutes.
The a/c was indeed spiralling (clockwise ?)

One theory is that there was loss of pressurization
(after a preliminary and possibly similar problem had occured during the climb to cruise level)

masks deployed in the cabin

the Captain went to the cabin (to investigate or take an emergency O2 bottle)

the F/O either had no O2 in the cockpit or did not done his mask quickly enough

Quoting AMSSFO (Reply 161):

10:37 Aircraft enters Athens FIR, but fails to establish contact.

Impossible. STA was 10:45
Must have been after 09:30 but before 10:00
 
qwerty
Posts: 383
Joined: Sat Mar 17, 2001 7:31 am

RE: Helios 737 Discussion, Part 3

Thu Aug 18, 2005 4:26 am

Quoting Vfw614 (Reply 149):
OK, let's get this straight: Your assumption is that
- the pilots find out that they are not on O2
- they decide both to stay in the cockpit instead of one getting O2 for both from the cabin and the other initiating the emergency descent (which he, for whatever reason, does not do or is unable to do),
- both know that the chance of survival for them and consequently for all passengers is close to zero as it takes longer to get down to breathable air than one is able to survive without O2

You're thinking about what you would logically do. What a pilot would do is very different. THEY FLY THE PLANE FIRST.

Crew would have preflighted the cockpit O2, they would have trusted it. Trusting it, even if truly bad, was long enough to avoid the problem. That said, if they realized they did not have O2 afterall, they would not have gone to look for good air until finding a way to get the plane lower without them. Every pilot knows how to do this quickly and it would have been done. The plane would have had no chance of staying at the flight level it was found by Greek military.

The pilots either failed to put on O2 or something else happened. Either way, they would have been buckled in. A pilot may have been out of his seat, I grant that, but being out of the seat would have not been because of an emergency, it would have been prior to it. But this flight was so short that a lav visit would likely not have been in order nor would a pilot have wanted to get up just to get up.

Quoting Vfw614 (Reply 152):
6. If the aircraft ran out of fuel while on autopilot, would it indeed glide to the ground because the AP is disengaged automatically or would it stall ?

Without pilot input, as the fuel got close to low, each feeding off its own wing tank, it would be possible for a wing to tip over and spiral the plane down without burning all reserves in both tanks. Not likely, but it could happen. It will be best if they can find the yokes in good condition and get prints off them. I'd like to know who touched the sticks. I don't believe the reports of F/A in the cabin trying to fly simply because the same source that would confirm this, the F16s, would have mentioned that this person, or persons other than the pilots, would have made visual contact with them to at least signal a problem.

Quoting Noelg (Reply 153):
My belief (with others on here by the look of it) is that the F-16 pilots shot the aircraft down to avoid it going down in a built up area or causing a danger to others, with good reason

That's total crap. If there was a hint of this, you'd need to find two crashed engines in totally different condition.
 
AMSSFO
Posts: 912
Joined: Wed Feb 02, 2005 8:42 am

RE: Helios 737 Discussion, Part 3

Thu Aug 18, 2005 5:16 am

Quoting Iakobos (Reply 164):
Quoting AMSSFO (Reply 161):

10:37 Aircraft enters Athens FIR, but fails to establish contact.

Impossible. STA was 10:45
Must have been after 09:30 but before 10:00

At first sight that's true. But you already put forward a possible explanation in another thread:

Quoting Iakobos (Reply 19):
Some time was lost (I assume) when the plane levelled off at FL140 (120 ?) to "check a problem", then resumed its climb to FL340.
It seems plausible (time and FIR-wise) that the 7700 transponder code was initiated during that climb, which could imply the pilots could have been incapacitated before reaching cruise level, and, at best climb speed, which I assume would have been kept all the way after having levelled off at 340.
This could explain the late arrival on Kea (some 40 minutes), better than someone "in control" flying in circles for that long.
 
Bobster2
Posts: 1523
Joined: Mon Jan 17, 2005 3:04 am

RE: Helios 737 Discussion, Part 3

Thu Aug 18, 2005 5:17 am

Quoting Vfw614 (Reply 152):
. Where is the body of the Captain ? It cannot disappear if they have found 120 corpses reasonably intact and I am sure by now they have turned every stone at the crash site.

A news report today said there was a badly burned body in the cockpit and it might turn out to be the captain. If this is true, why was this information not released earlier? So I'm not sure if I believe anything in the news right now.
"I tell you this, no eternal reward will forgive us now for wasting the dawn." Jim Morrison
 
We're Nuts
Posts: 4723
Joined: Sun Jun 04, 2000 6:12 am

RE: Helios 737 Discussion, Part 3

Thu Aug 18, 2005 5:24 am

I don't know about in other countries, but in America emergency squawk codes are very rarely used. They are reserved for if the pilot cannot contact ATC for whatever reason. If this flight squawked 7700, it would have been a last-ditch effort by someone to notify controllers of the problem. But maybe procedures are different elsewhere...?
Dear moderators: No.
 
mandala499
Posts: 6593
Joined: Wed Aug 29, 2001 8:47 pm

RE: Helios 737 Discussion, Part 3

Thu Aug 18, 2005 4:31 pm

NAV20,

1. It's unlikely that the two FAs knew the full situation at first. It would have taken time for them to piece it together and decide to try to take over the controls. And even then they'd have had problems getting into the cockpit, they maybe had to spend time breaking the security door open.

That is correct, the cabin crew manual on explosive decompression would be mask on, sit down, hang on, instruct pax to use mask if automatic announcer fail... then after flight deck signalled it is safe, go and get POB and move around.

In this case, it must have taken some time until they realised something was wrong. Their job is to look after pax safety. They may have had to ensure the pax were on the masks first... as in all of them... then they realised something's not right upfront... Unfortunately, using POB at high altitude is less effective because it is not designed to work at those altitudes.

AMSSFO,
If it was intercepted at FL340, then simple they failed to descend the aircraft... But now I dunno who descended the plane...

mrocktor,
Your theory doesn't match the facts. The aircraft was intercepted at cruise altitude, a long time after the cabin must have depressurized. No emergency descent was performed.

Which part of the theory? If someone can produce a timeline of the F16 interception, and the Flight Profile timeline of the 733 then perhaps a better theory can be constructed...

If no descent was done then this makes the possible theories more interesting.

Of course the crew should remain conscious during the descent but even that is not strictly necessary if they manage to punch in 10.000ft and flgiht level change in the autopilot.

Well, the procedure is: O2, punch the new alt, FL CH, Speedbrakes, manual assist descent if required... The Boeing manual states that level off must be monitored, or if manual descent, commence level off much earlier (can't remember the number given) than a normal descent.

Some airlines would have minor differences... ie: punch 10,000 or MSA before commencing descent then adjust speed selection, and some requires significantly lower flight level, commence descent, and then adjust level off altitude and speed selection...

Should they remain conscious, ideally yes, the plane doesn't cruise at 10,000 well with speedbrakes selected.

Mandala499
When losing situational awareness, pray Cumulus Granitus isn't nearby !
 
mrocktor
Posts: 1391
Joined: Mon Jan 24, 2005 12:57 am

RE: Helios 737 Discussion, Part 3

Thu Aug 18, 2005 9:54 pm

Quoting Qwerty (Reply 165):
The plane would have had no chance of staying at the flight level it was found by Greek military.

Bingo.

Quoting Mandala499 (Reply 169):
Should they remain conscious, ideally yes, the plane doesn't cruise at 10,000 well with speedbrakes selected

Of course, but after a couple minutes at 10.000ft the crew would regain consciousness and proceed with the flight.

The crew was incapacitated before they reacted to the decompression at all.

mrocktor
 
mandala499
Posts: 6593
Joined: Wed Aug 29, 2001 8:47 pm

RE: Helios 737 Discussion, Part 3

Fri Aug 19, 2005 2:53 pm

Of course, but after a couple minutes at 10.000ft the crew would regain consciousness and proceed with the flight.

If they're not brain dead by then...

In the case of the aircraft being found at FL340 by the F16s, then that would throw out most of my theory.

Mandala499
When losing situational awareness, pray Cumulus Granitus isn't nearby !
 
NAV20
Posts: 8453
Joined: Thu Nov 27, 2003 3:25 pm

RE: Helios 737 Discussion, Part 3

Fri Aug 19, 2005 3:19 pm

Just thinking aloud - but maybe it wasn't a decompression at all?

There had been reports of the crew of that aeroplane complaining of cold on previous flights. Anyone know in detail how the heating works on an airliner? All I know that it is achieved by bleeding hot air from the engine exhausts. Presumably the hot air is then passed through a heat exchanger, which in turn heats up recycled cabin air?

If the heat exchanger sprang a leak, could this result in exhaust fumes being fed into the cabin and/or flight deck? So might we be looking at a case of carbon monoxide poisoning, rather than oxygen starvation?
"Once you have flown, you will walk the earth with your eyes turned skywards.." - Leonardo da Vinci
 
User avatar
HAWK21M
Posts: 30067
Joined: Fri Jan 05, 2001 10:05 pm

RE: Helios 737 Discussion, Part 3

Fri Aug 19, 2005 5:07 pm

Quoting NAV20 (Reply 172):
If the heat exchanger sprang a leak, could this result in exhaust fumes being fed into the cabin and/or flight deck? So might we be looking at a case of carbon monoxide poisoning, rather than oxygen starvation?

Bleed is extracted frm the Bypass air & not Exhaust side.There is a recirculating fan available too.
Why has Gas poisoning been eliminated.
regds
MEL
I may not win often, but I damn well never lose!!! ;)
 
qwerty
Posts: 383
Joined: Sat Mar 17, 2001 7:31 am

RE: Helios 737 Discussion, Part 3

Fri Aug 19, 2005 5:48 pm

Quoting HAWK21M (Reply 173):
Bleed is extracted frm the Bypass air & not Exhaust side.There is a recirculating fan available too.
Why has Gas poisoning been eliminated.
regds
MEL

Well I don't think anything has been eliminated, except some of my ideas by others who have their own storylines.

Do you mean gas from an outside source intentionally put into the cabin or cockpit? As in malicious? Perhaps but I think that's remote since bodies with masks on lead me toward a pressurization problem as the incapacitator since mask only drop when cabin atmosphere is 14,000. If masks have been manually activated, that would have been done for the benefit of the cabin by a pilot breathing pressurized O2 who assumed something like this scenario. So pilot would have been fine because of the breathing system he was on.

If you mean gas otherwise from abnormal aircraft performance like packs causing fumes/smoke/bad air (overfilled hydraulics, etc.)? Wouldn't this likely have been discovered on the ground I think or very early after startup?
 
NAV20
Posts: 8453
Joined: Thu Nov 27, 2003 3:25 pm

RE: Helios 737 Discussion, Part 3

Sat Aug 20, 2005 12:49 am

Quite a comprehensive article here. Says that the investigators have almost ruled out decompression/oxygen starvation and are thinking about some form of poisoning, whether by carbon monoxide or something else:-

"Hellenic Radio reported yesterday that Greece's chief medical examiner, Filippos Kotsaftis, had "almost ruled out" the possibility that passengers had been exposed to a sudden decompression or subzero temperatures. Some of the strongest supporting evidence was dismissed as a publicity stunt, after a Cyprus man admitted in court yesterday that he had invented his story of a passenger sending a mobile phone text message that "the pilot has turned blue and we're freezing to death".

"The hypothesis that the plane's air supply had been contaminated will be tested in toxicology reports due in 10 days. Urine samples had been extracted from the dead co-pilot and a flight attendant for testing.

"The poison theory - possibly by carbon monoxide or toxic fumes from passenger baggage - might explain why the co-pilot was slumped over the controls of the stricken jet when he should have been sucking oxygen from the emergency tank stowed beneath his seat."


http://www.theaustralian.news.com.au.../0,5744,16317739%255E23349,00.html
"Once you have flown, you will walk the earth with your eyes turned skywards.." - Leonardo da Vinci
 
We're Nuts
Posts: 4723
Joined: Sun Jun 04, 2000 6:12 am

RE: Helios 737 Discussion, Part 3

Sat Aug 20, 2005 4:20 am

Quoting Qwerty (Reply 174):
If masks have been manually activated, that would have been done for the benefit of the cabin by a pilot breathing pressurized O2 who assumed something like this scenario.

Don't the cabin masks mix ambient air into the flow by design? It wouldn't take much CO, or some more lethal mix, before each breath proved deadly.
Dear moderators: No.
 
JAM747
Posts: 524
Joined: Thu Feb 03, 2005 12:17 am

RE: Helios 737 Discussion, Part 3

Sat Aug 20, 2005 4:32 am

Quoting NAV20 (Reply 172):
If the heat exchanger sprang a leak, could this result in exhaust fumes being fed into the cabin and/or flight deck? So might we be looking at a case of carbon monoxide poisoning, rather than oxygen starvation?

just saw this info regarding the investigation of fumes and possible causes of death
http://www.aero-news.net/index.cfm?C...dc7f2-0dad-4082-9872-05610532e01a&
 
User avatar
HAWK21M
Posts: 30067
Joined: Fri Jan 05, 2001 10:05 pm

RE: Helios 737 Discussion, Part 3

Sat Aug 20, 2005 7:11 pm

Quoting Qwerty (Reply 174):
Do you mean gas from an outside source intentionally put into the cabin or cockpit? As in malicious? Perhaps but I think that's remote since bodies with masks on lead me toward a pressurization problem as the incapacitator since mask only drop when cabin atmosphere is 14,000. If masks have been manually activated, that would have been done for the benefit of the cabin by a pilot breathing pressurized O2 who assumed something like this scenario. So pilot would have been fine because of the breathing system he was on

Qwerty...Not ruling out any other possibility but.
I mean Terrorist attack.
In case the leak of gas was near the Cabin area near cockpit compounded by INOP Crew O2.
Examining the Pax medically would probably tell.
Since We Mx B737s.This is one confusing Discussion at Work for the last few days.
Very Mysterious.
regds
MEL
I may not win often, but I damn well never lose!!! ;)
 
highflyer9790
Posts: 1189
Joined: Thu Jul 07, 2005 1:21 am

RE: Helios 737 Discussion, Part 3

Sat Aug 20, 2005 10:33 pm

I was A few miles away when from it when it crashed. As I was swimming i saw the F-16s going to escort it...of course, at the time i didn't know what i was witnessing.

ps- I was on vacation there and had no internet access..which means no A.net!!  banghead  so I haven't posted in a few weeks
121
 
MerlinIIIB
Posts: 99
Joined: Sat Aug 20, 2005 7:32 pm

RE: Helios 737 Discussion, Part 3

Wed Aug 31, 2005 5:04 am

Given proper landing configuration (flap settings, trim etc), would it be feasible to ditch a 737 by the use of autopilot and autothrottle only, achieving a "better than poor" survival probability? What is the optimal IAS and rate of decent in such a scenario?

Who is online

Popular Searches On Airliners.net

Top Photos of Last:   24 Hours  •  48 Hours  •  7 Days  •  30 Days  •  180 Days  •  365 Days  •  All Time

Military Aircraft Every type from fighters to helicopters from air forces around the globe

Classic Airliners Props and jets from the good old days

Flight Decks Views from inside the cockpit

Aircraft Cabins Passenger cabin shots showing seat arrangements as well as cargo aircraft interior

Cargo Aircraft Pictures of great freighter aircraft

Government Aircraft Aircraft flying government officials

Helicopters Our large helicopter section. Both military and civil versions

Blimps / Airships Everything from the Goodyear blimp to the Zeppelin

Night Photos Beautiful shots taken while the sun is below the horizon

Accidents Accident, incident and crash related photos

Air to Air Photos taken by airborne photographers of airborne aircraft

Special Paint Schemes Aircraft painted in beautiful and original liveries

Airport Overviews Airport overviews from the air or ground

Tails and Winglets Tail and Winglet closeups with beautiful airline logos