Boeing 737 crash.... 121 dead.

[Gunslinger]

Originally posted by cpxxx

Then the cockpit door was open. If so, how come no one gave him oxygen?

or attempted to land the plane?  No one on board has any aviation experience?  I thought even flight attendents knew the most basics of flight.


EDIT:

using AP and ILS could this plane have landed itself if somone "threw the right switches" so to speak?

[Toad]

The cabin altitude warning horn will sound when the cabin altitude exceeds 10,000ft. It sounds like the take-off config warning horn and can be inhibited by pressing the ALT HORN CUTOUT button. The pax oxygen masks will not drop until 14,000ft cabin altitude.

In short, neither pilot should have been incapacitated before the warning horn sounded since it sounds at 10k.

This is going to be an interesting one.

Typically in a slow depressurization, if the Cabin Pressurization warning sounded at 10k, the pilots would have donned the QD O2 masks until they regained pressure. If it looked like they would not be able to regain pressure before exceeding a cabin alt of 14K, they would have initiated an emergency descent.

So far it appears they did not use the QD O2 and they didn't inform ATC of a problem and request a descent.

Lots more to learn here.

[Vulcan]

Originally posted by cpxxx
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?

The way I'd read it is the pilot went back to the main cabin to check what was happening and collapsed, remember the F-16s saw the co-pilot slumped over the controls but no sign of the pilot.  Those cockpit doors swing shut on a spring iirc, so no one would have been able to reaccess to cockpit except the stewards maybe?

Having watched all the air investigation stuff I can on Discovery (  ) I can imagine the pressurisation alarm being overlooked if a whole pile of air con unit alarms were going off as well. A lot of situations like this always seem to be about information overload.

The question would be what were the cabin crew doing that they couldn't give aid to the pilot, or re-enter the cockpit? If I was a passenger and saw the pilot collapsed I certainly wouldn't sit there twiddling my thumbs.

[Toad]

Originally posted by Vulcan
I can imagine the pressurisation alarm being overlooked if a whole pile of air con unit alarms were going off as well.

 

It's a really loud horn and the silence button is on the pressurization panel itself.

[Vulcan]

How does the air con unit tie into the cabin pressurisation unit and what other sorts alarms could the air con unit generate?

[Toad]

Basically, the Air Conditioning packs provide the pressurization air.

It's a great system with a lot of redundancy. You'll note on the pressure controller that there is an  "Auto" function of the knob, a "Standby" function and a "Manual" function which can be powered either by AC or DC power, so you can run it off generator or battery power.

To lose pressurization because of a total controller failure would be rare.  It could happen but there are lots of options to control outflow.

Inflow is also redundant. There are two AC packs, although flight (with some restrictions) is allowed with one inop. They should not have gone to FL340 with one pack inop prior to T/O. Had a pack failed at FL340, they should have descended to FL250 max IIRC. It's been a while since I was in the books.

A/C Schematic


If they were running with one pack already inop, there's two main lights there to watch.

One is the "Duct Overheat", especially if the pax were complaining of cold. You can dump in heat too rapidly and trip the pack due to a duct overheat. This is usually easy to reset, however, and it cools to reset temp pretty quickly.

The other two are related; the bleed trip and the pack trip. If you get a bleed trip, pack trip is almost simultaneous. You can get a pack trip without a bleed trip. Either of these can be difficult to reset or, in some cases, not resettable in flight.

Nonetheless, the Cabin Alt Horn is the key. Assuming they had two packs since they went to FL340, their cabin alt was probably around 7k in normal cruise. If they lost pressure slowly, the horn would have went off at 10k Cabin Alt, they should have donned the O2 masks and either controlled the cabin or initiated an Emergency Descent.

If they lost pressure suddenly or had a very high rate of climb in the cabin alt, they should have got the horn at 10K, donned masks and initiated an Emergency Descent. The Pax O2 masks would drop at Cabin Alt 14k. A 737 with gear and boards out should be able to get 5+K rate of descent without overspeeding, so figure about 4 minutes to get down to a "breathable" altitude. Shouldn't have been a problem. US airlines practice the ED in the sim at least once a year.

So A/C problems in and of themselves should not have caused this accident simply because there is a "Auot Fail/ Unscheduled Pressurization Change checklist and an Emergency Descent checklist procedures that should be very familiar to the pilots.

To see a representative 737 Pressurization and ED checklist put " 6-3 AUTO FAIL / UNSCHEDULED PRESSURIZATION CHANGE " into Google. It's PDF but won't come up unless you select HTML. Can't link to it anyway.

[Sparks]

My guess as armchair unqualified accident investigator is a sudden decompression at altitude (bulkhead failure or freight door loss) - pilots O2 bottle turned off - captain tries to go aft for portable bottle and collapses in cockpit doorway - plane continues on AP untill out of fuel. Pax oxygen masks drop out on an auto switch which is why they were found with masks on.

A tragic accident - my thoughts are with all the families left.

[Fishu]

"Greek officials said after contact with the plane was lost, air force pilots found it flying above the Euboea peninsula with the pilots slumped in the cabin.

When they returned for a second look they saw two people trying to take control of the plane, but it was unclear if they were crew members or passengers, a Greek government spokesman said."


Sparks,

I don't think it went down without fuel, because it hit a mountain side and the tail stabilizers are still pretty much in one piece.
In the pictures there are no big craters visible and the parts are scattered over a long narrow area, indicating that the plane has crashed at a shallow angle.
Also the parts look to be scattered from downhill to uphill.

[mora]

If the plane hasn't been circling it wouldn't have run out of fuel so near to it's destination.

[culero]

Two different news sources (Reuters and the Daily Telegraph) are now quoting un-named sources in the Greek defense ministry as saying the bodies recovered were "frozen solid".

I can't see that happening unless whatever happened did so at high alt and persisted for a long time before the plane descended to 10K.

culero

[Meatwad]

Thats just some plain scary stuff

[Vulcan]

Unless the passengers did manage to get it off auto and descended into the mountain (perhaps lost control).

[mora]

Now they are reporting that the fighters saw a person wrestling with the controls. That would indeed disconnect the autopilot.

[Fishu]

Apparently people were still alive at the time of the crash.
Of the pilots at least co-pilot was.
However he could been unconcious.
the body of a flight attendant was found from the cockpit.

Apparently there was no flight simulator players onboard, who could've had a sufficient knowledge to bring down the plane relatively safely.

[Edbert1]

Originally posted by Fishu
Apparently there was no flight simulator players onboard, who could've had a sufficient knowledge to bring down the plane relatively safely.

Many of us could have done just that, or had a high probability of doing so.

Give me full access to a certified pilot of whatever aircraft I was in via the radio and i can almost guarantee a safe (maybe rough) landing. Hard to know exactly what flap/throttle settings and airspeed at each point in the glide slope you should be at, even with ILS.