Airbus A320 crashed in Southern France

[henra]

Originally Posted by ia1166

There are many other possibilities. Some more likely than this one.

If you are referring to OEB48: Rather unlikely.
For multiple reasons.
Besides what @Lonewolf mentioned:
1. They were in cruise. Freezing would have occcured earlier in all likelyhood.
2. This problem is mostly relevant in climb. In climb Mach number will increase with altitude, thus critical AoA will reduce. At the same time the AoA will increase with decreasing CAS. Therefore with a probe frozen at a constant angle the system will try to correct for increasing Mach. In cruise Mach won't change significantly and Alpha_prot won't usually be reached (especially since there was no significant weather reportde in the area). Only at Alpha_prot and at the same time significantly increasing Mach number the chain described in the Bulletin will be triggered.
Edit: So in summary for this to apply here you need: No freezing in climb, then freezing in cruise, flying at Alpha_Prot, Mach number increasing. And all at the same time and while flying at ~280kts (Alpha_prot @1g should kick in around 170 - 180 kts, so you would have a margin of about 2,4g).
/Edit
3. They had 8 minutes time to:
pull two CB's or
change heading towards lower terrain or
communicate their problems or
select 7700.
Nothing of those happened.
Not saying it is necessarily decompression but Occam's razor has a hard time with the scenario described in the OEB.

[oceancrosser]

Originally Posted by Bleve

The 2008 Qantas event is informative. When cruising at 29 000' (cabin altitude 3 700') an oxygen bottle exploded creating a 3 square metre hole in the fuselage. One second later the A/P disconnected and the aircraft pitched nose UP. Three seconds later the cabin altitude reached 10 000'. Pilots put on oxy masks and established communications with each other. At 22 seconds descent was initiated (thrust to idle/ speed brakes extended). At approx 40 seconds the uncommanded climb was reversed and and the descent established, maximum cabin of 25 900' occurred at about this time. The mean rate of descent was about 3 000 fpm and the cabin altitude was about about 3000' below the aircraft's altitude during the descent.

The key points are that at 29 000' and with a 3 sq m hole, cabin altitude reached 10 000' within 3" and 26 000' within 40". With idle thrust, speed brakes extended snd IAS at the cruise IAS, descent rate was ~ 3 000 fpm.

I could see an event where the crew oxygen bottle blew out leading to something like this. Explosive decompression, pilots without oxygen. Not an Airbus pilot, where is the oxy bottle on the A320?

[Fafnir_stolberg]

The toxicity of oxygen is a problem when (mostly ill) lungs are exposed to high concentrations of oxygen> 50% for a long time (days). Oxygen radicals are supposed to do structural damage to the alveolar membranes. Another problem of breathing of 100 % oxygen are atelectasis (collapsed areas of the lung due to complete resorption of oxygen in absence of nitrogen). A continous flow, providing an positive endspiratory pressure, solves the problem.Conclusion: If an pilot is alone in the cockpit in dangerous hights, he would be wise to wear a mask, breathing 40 % of oxygen, thus changing his hypoxia tolerance from seconds to minutes. Hygenical problems shouldn`t be a problem in the times of single use devices. By the way- every fire brigade can show you how to keep reusable masks hygienically clean.

[SAMPUBLIUS]

re O2 effects

Tigger said

Between 10,000 and 15,000 ft the ability to perform skilled tasks such as aircraft control and navigation are impaired

I've been at 14K feet on Mount Rainier. The above description is accurate, especially when happening almost instantaneously. While climbing from 10,000 feet for 6 to 8 hours allows one to sort of acclimate- most first timers( like myself years ago ) start to have a hard time doing all but the most simple tasks-or concentrating. While one would think you would be gasping for breath above 12K or so, you do NOT notice that effect other than the exertion issue which **seems** to be moderate. IMHO- those who think they can remember a multi step procedure under more severe cases ( above 25 to 30 K feet for example ) are simply kidding themselves. Any such response will probably be from " memory' - muscle memory- or similar. Which requires practice, practice, practice. I'm sure a condensation ( moisture smoke) filled cockpit does not help ..

[pavlik1]

black box

to me the container with the memory is intact.

[Mozella]

Agreed. Over the ocean auto descent after pressurisation failure might be useful but in busy European & US skies a plummet without some sort of ATC clearance could lead to more serious consequences. A mid-air would clearly be more hazardous than temporary hypoxia for some passengers.

I'll have to disagree. A study done some years ago concluded that, strictly from a statistical point of view, mid-air collisions would occur at a lower rate if pilots flew at random altitudes and directions completely uncontrolled. In other words, the sky is a big place.

Yes, a midair will ruin your day, no argument there. But if you turn off course, it's so freakishly unlikely that it's hardly worth considering. Can anyone reference a single midair resulting from an airline pilot doing what he felt was necessary during a serious emergency?

In an airliner suffering decompression, if you do everything correctly, the pilots are still in serious danger as long as they are at an altitude above which they can operate without supplemental oxygen. If it were me, I'd be on my way to a lower altitude immediately.

Waiting for ATC clearance during ANY very serious emergency was NOT in my bag of tricks back when I was flying over the North Atlantic and Europe. I suspect more people have died by turning control of their aircraft over to ATC than have died by doing what was necessary during a genuine emergency and then telling ATC about it later.

[pbeardmore]

NYT

Speaking on the French radio station RTL, Interior Minister Bernard Cazeneuve said on Wednesday that terrorism was “not a privileged hypothesis at the moment,” but that no theories had been definitively excluded. Mr. Cazeneuve said the size of the area over which debris was scattered suggested that the aircraft had not exploded in the air but rather had disintegrated on impact.

He said that the plane’s cockpit voice recorder, the first black box that was recovered, was damaged, but that investigators expected to be able to recover the conversations stored on its memory chip.

But as of early afternoon, a senior official involved in the investigation said analysts had so far been unsuccessful in retrieving any information from the cockpit voice recorder.

[MrSnuggles]

After looking on a few photos of the crash site, I believe there were some kind of post impact fire. The hillsides are blackened and in one picture you can see a small spruce all black. It seems the soil layer was very thin and it is unlikely that the aircraft would have made a large crater. A dent would be more in line with what the photos tell.

My sympathies goes out for all that lost dear ones and for the rescue crew. I can't imagine the awful awful task they have, picking pieces of humans from the ground. If anybody knows how to help the helpers, I wouldn't think twice to volunteer!

[Cagedh]

Live speech from Hollande, Merkel and Rajoy.
https://www.youtube.com/watch?v=1ZYZG8Yybgw

[carma1958]

CVR and FDR

What pictures are these on CNN of the CVR and FDR??? These units have old corrosion on them. In my opinion these 2 units have been damaged quite a while ago.

[MrSnuggles]

Here is a good picture of the charred mountainside. If you look closely you can see burnt trees. The unharmed terrain is beige-brown with the affected parts being black.



Picture taken from https://www.flickr.com/photos/minist...7649223170784/

[elkinsoto]

One black box found

Hollande said only one "black box" was found...

[ATSMAN]

I was an ATC instructor, with tuition including ATC handling of all types of aircraft emergencies. In the event of explosive decompression we'd expect the pilot to turn off track, initiate a descent and only then..set the emergency sqk and communicate. With TCAS, turning off track may not be immediately necessary!

[ZeBedie]

Is there any data from ACARS?

[Cagedh]

quote from press conference: useful information gas been retrieved from CVR

[RHRHRTTG]

Food for thought, the "bulkhead" separating the cockpit from the rest of the cabin is obviously not designed as part of the pressure cell. If the door has been beefed up sufficiently to prevent an aggressor entering the cockpit and should it remain (or try to remain) in place during a rapid decompression via the cockpit area then the parts that will not remain in place will be the toilet and galley backwalls. Seeing that the O˛ masks are situated slightly to the rear of the crew and are accessable via a small cover door that has to be raised in order to gain access which could be prevented by debris from the backwall failure. If the main cabin evacuates via the cockpit there will be massive movement in this area. Lets hope the CVR and FDR throw some light on this tragedy

[wiggy]

...and one of the main priorities now is finding the FDR......

[auldlassie]

BEA press conference lastest

From the Guardian - Recordings successfully extracted from cockpit voice recorders

As the press conference ends, Reuters reports that the French air accident investigator, BEA, says it has successfully extracted recordings from the cockpit voice recorder of the downed Germanwings Jet, contradicting the New York Times report from earlier.

And for elkinsoto - At the briefing, the Hollande said that the “envelope of the second black box has been found, unfortunately not the black box itself”. He said the search goes on for that.

The BEA press conference is about to start.

[Velhurstairport]

French media reports fdr housing found but not actual fdr

The Les Echos live app won't let me copy and paste but is reporting that the envelope of the FDR has been recovered but not the actual FDR.

Also that the CVR has been exploited.

[jkstark]

Originally Posted by dicks-airbus

From avherald

According to Finnish CAA in Finnish newpaper Helsingin Sanomat, the CVR has revealed crew was unconscious in the start of descent.

So looks like Helios 2.

Actually, the article states that they were *probably* unconscious - essentially they are speculating just as much as everybody else at this time. They do mention that some data has been recovered from the FDR, and state that the assumption is that the crew was unconscious based on the lack of communication as evidenced by the CVR. They go on to speculate that the unconsciousness may have been due to hypoxia, and then on to how pressurization may have failed - ie. a puncture or a failure of the pressurization system.