Author Topic: Boeing 737 crash.... 121 dead. (Read 2014 times)

mora · « **Reply #15 on:** August 14, 2005, 01:14:59 PM »

Some reports say that it might have flown for almost 2 hours without coms(coms lost shortly after take off at 10.30, crash at 12.20), so it might have been at cruising level and crashed after running out of fuel.

This looks alot like the Payne Stewart crash.

Toad · « **Reply #16 on:** August 14, 2005, 01:16:51 PM »

The NG has a different Quick-don oxygen system for the pilots. That's why I asked.

On the old 737's the Q/D hang by the side of the pilot's head and are connected to a big O2 bottle that has a manual shutoff valve on the bottle. IIRC. Been a few years since I flew those.

The NG's have a stowed inflatable Q/D harness in a box by each pilot's outboard knee. It's possible to turn off the O2 at the box on those IIRC.

In either case the O2 has to be on or the Q/D's are useless.

These things are designed for use during rapid decompression, so that's going to be a big question early on in this investigation.

mora · « **Reply #17 on:** August 14, 2005, 01:19:56 PM »

Quote

Originally posted by Toad
On the old 737's the Q/D hang by the side of the pilot's head and are connected to a big O2 bottle that has a manual shutoff valve on the bottle. IIRC. Been a few years since I flew those.

According to ppl at pprune it's a common practise to turn the shutoff valve to off on the ground and this might have played a part. Pure speculation of course.

Toad · « **Reply #18 on:** August 14, 2005, 01:27:16 PM »

And i think it's in the Co-pilot's preflight to make sure the valve is OPEN before engine start on the first flight of the day. Shouldn't be changed during the day unless maintenance is performed on the O2 system.

FiLtH · « **Reply #19 on:** August 14, 2005, 01:33:56 PM »

Remember that golfer that dies in the US a few years back? Sounds similar. They say that when you lose cabin pressure its not like a slow process of choking to death, where there is still some oxygen in your system. Its very quick they say.

soda72 · « **Reply #20 on:** August 14, 2005, 01:46:27 PM »

I read some where you have 15 to 30 secs before you pass out, if it happens above 30,000 ft...

culero · « **Reply #21 on:** August 14, 2005, 01:53:43 PM »

From Reuters

snips:

*******************************
"The pilot has turned blue," a passenger said in a mobile text message to his cousin, according to Greek television. "Cousin farewell, we're freezing."

"I saw many bodies scattered around, all of them wearing (oxygen) masks," one witness told Reuters.

Akrivos Tsolaki, head of the accident investigation committee, told reporters at the crash site the plane's two black boxes -- voice and data recorders -- had been located.

Greek Defense Ministry officials said 90 minutes elapsed between the alert first being raised at 10:30 a.m. and the plane crashing at 12:03 p.m.
*******************************

Relevant stuff, but the sum doesn't make sense to me.

culero

Russian · « **Reply #22 on:** August 14, 2005, 01:59:28 PM »

That doesnt makes sence then....if AC is flying at 10....then there shouldn't be a problem with oxygen, nor cold.

Dinger · « **Reply #23 on:** August 14, 2005, 02:19:45 PM »

Er, aircraft was listed for FL 340. If the crew passes out, the A/P flies to the last waypoint, which would be the hold outside of Athens. It probably stooged around for 1.5 hours at 10k before it ran out of fuel. The descent may have happened after everybody froze (-40C is darn cold, especially if you're dressed for 40C and flying somewhere at 35C)

Anyway, word on the street was that this particular aircraft had a recurring problem with contamination (oil) in one of the packs, and that it flew on one pack.

Gunslinger · « **Reply #24 on:** August 14, 2005, 02:51:34 PM »

My God what a horrible way to die.

mora · « **Reply #25 on:** August 14, 2005, 03:20:32 PM »

Quote

Originally posted by Dinger
Er, aircraft was listed for FL 340. If the crew passes out, the A/P flies to the last waypoint, which would be the hold outside of Athens. It probably stooged around for 1.5 hours at 10k before it ran out of fuel. The descent may have happened after everybody froze (-40C is darn cold, especially if you're dressed for 40C and flying somewhere at 35C)

What happens when the aircraft reaches the last programmed waypoint, does the ap go into HDG and ALT hold, or does it try to chase the last waypoint?

It may actually have been the lack of oxygen rather than cold which made the people unconsious, because the supply of oxygen lasts only a limited time. The Greek AF reported that they received visual communications from plane at first but it later stopped. No mention about the altitude this took place.

BUG_EAF322 · « **Reply #26 on:** August 14, 2005, 06:11:02 PM »

Very tragic.

Vulcan · « **Reply #27 on:** August 14, 2005, 06:11:49 PM »

Normally you can't see the pilots on a 737, so if the passengers saw a pilot with a blue face, it sounds like one of them came back to check, and probably passed out.

If the cockpit cabin door was secured the passengers were screwed, probably just sitting there freezing, on the O2 masks, waiting to die.

eagl · « **Reply #28 on:** August 14, 2005, 06:21:06 PM »

Damn shame there wasn't a military pilot onboard. We're trained to watch out for this sort of thing. Very odd that the crew didn't realize what was happening in time, but hypoxia is extremely insidious. A slow pressurization failure *could* progress slowly enough that they wouldn't realize it until it was too late, but there are supposed to be safeguards against such things.

I suspect the bottom line will be that as usual in any aviation endeavor, no matter how routine, complacency kills.

cpxxx · « **Reply #29 on:** August 14, 2005, 07:53:58 PM »

I agree Eagl, my brother who is an Engineer said he knew of an incident where the crew were unaware that they had not pressurised and were begining to become hypoxic. A flight attendant visited the cockpit three times complaining about the cold but wasn't taken seriously by the pilots due to the hypoxia. Being hypoxic can be like being drunk.

It was only on her third visit which coincided with the pax oxygen masks deploying automatically that they realised there was a problem. It's all guesswork but with a locked cockpit door the pilots could become incapaciitated without being aware there ever was a problem. Smokers would have passed out sooner than non smokers. Older pilots too would pass out sooner.

I suspect it's some kind of variation on this. The aircraft never pressurised and or the crew oxygen either failed or was never used.

If as someone says, that the aircraft was operating on one pack routinely then perhaps there was an issue with the other one. The brother pointed out that on the 737 the switches for the packs on the overhead operate opposite to the normal sense. ie down for off and up for on. He said it's not uncommon for pilots to switch off a pack when they mean to switch it on.

No doubt all will be revealed. If the text message was true and someone saw the pilot. Then the cockpit door was open. If so, how come no one gave him oxygen?