Airbus A320 crashed in Southern France

[mm_flynn]

Originally Posted by Easy Street

Would the cabin crew have expected any communication from the flight deck following a depressurisation? I can see a terrible image of all pax and cabin crew sitting there with their oxygen masks on, waiting for the aircraft to level off. At what point would anyone think to ask whether the flight deck crew were OK, and try to gain access to the cockpit?

Assuming for a minute the depressurisation/hypoxia scenario is correct, the flight path seems to have been exactly as the cabin crew would have expected, until they descended below 10,000 feet. So for a minute or two people may have thought 'we are getting close to the ground, why are we still descending?'. The FR24 flight path then suggests the aircraft levelled off c 3000 feet above the local terrain and then a minute later .... when the 350 knot aircraft intersected the rapidly rising terrain.

I would have thought the cabin crew would have been focusing on breathing, making sure the passengers didn't do anything dumb, and hoping to get warm soon for most of the descent and letting the flight crew get on with resolving whatever problems they were dealing with.

[Chris_Clark]

The Guardian reported this at 18:26:

Jouty said it was too early to give details of the cockpit recording. However, he said the information investigators had put together suggested the plane had not exploded and did not suffer a “classic decompression situation”

Voices heard on recorder from cockpit of Germanwings plane crash | World news | The Guardian

[Greasy Monkey]

If there was an explosive decompression, that descent took too long. The oxygen generator masks for the passengers would not have provided sufficient oxygen at sufficient pressure to keep them awake for that duration to get below 25,000'. At 38,000' you are really looking at pressure breathing apparatus if spending too much time up there.

I am amazed when I read of PJ crews, cruising at FL510 for example. Get a blowout up there you are a gonna. Period. Forget about the passengers, they will most likely be dead very quickly. End of.

From what I can find, it is the lower-left forward fuselage, I would assume as close to the flight deck as possible.

[cockpitvisit]

Originally Posted by ams6110

Very few suicides take 150+ innocent lives along with their own. It's literally is almost unthinkable and certainly exceedingly rare.

Suicides are not rare at all (compared with the overall frequency of fatal crashes in the cruise phase).

There were 3 pilot suicides with killed passengers in the last 20 years (EgyptAir 990, SilkAir 185, LAM 470).

Compare this with just 2 fatal mechanical failures during cruise flight in the same time period (China Airlines 611 and Helios 522).

[ironbutt57]

If the pilots were indeed incapacitated by hypoxia, is it possible that one or both could regain consciousness upon reaching lower altitudes?

Yes Navcant...entirely possible....

[Pontius Navigator]

Originally Posted by Navcant

If the pilots were indeed incapacitated by hypoxia, is it possible that one or both could regain consciousness upon reaching lower altitudes?

Asked and answered earlier. The short answer is maybe. The longer answer is it depends - fitness, time unconscious, time to regain useful consciousness.

[ECAM_Actions]

Germanwings crash investigators review cockpit recordings found on black box | World news | The Guardian

The Airbus A320 that ploughed into an Alpine mountain flew “right to the end”, the investigators said, and did not explode mid-flight. It also appeared not to have suffered a sudden drop in pressure.

Jouty said it was too early to give details of the cockpit recording. However, he said the information investigators had put together suggested the plane had not exploded and did not suffer a “classic decompression situation”.

Asked about the aircraft’s apparently controlled descent before it crashed, he added: “The path is compatible with the plane being controlled by pilots, except it’s hard to imagine that a pilot would send an aircraft into a mountain, and it’s compatible with an autopilot.”

He was unwilling to give any more information.

Rémi Jouty is a BEA spokesperson.

Make of that what you will.

[Lonewolf_50]

Originally Posted by roundsounds

Interestingly the Cirrus SR 22 has a feature whereby if there is no crew input to certain systems after a set period, the autopilot commences a descent to 10,000'

This might cause some trouble over certain mountain ranges ...
Vertical Speed:

1. AP executes 90degree left turn and pitch down.
2. Speed controlled near Mmo/Vmo and level off at 15,000'
3. EMER DESCENT annunciated on PFD

Fewer mountain ranges cause trouble with this.

I disagree with kwh that such over-automation is needed. Additional complexity for what value that cannot otherwise be mitigated? Further this point, the recent concerns over Normal Law Alpha Protect taking control from pilots (due to a malfunction) reminds us that with every feature like this you put in, you induce the potential for yet another novel failure mode.

Fix one perceived problem and raise another that you won't discover ... until it happens, perhaps in flight.

Further a point ia raised a bit earlier:

Task saturation/task focus.
Whatever went wrong at altitude, there is the potential, as with AF 447 and the recent Indonesian accident, that the two pilots were consumed with the first two prime directives of flying -- aviate navigate -- (and part of aviate being get plane in control and fix / trouble shoot what's wrong with it) that their task loading did not get to the communicate/squawk change step. While in those two cases upset looks to have been the core problem, and in this case not, that doesn't mean that a serious malfunction didn't occur that wholly occupied the attention of the flight deck crew.

If you go back about ten pages and re read the strange case of the leaking fluid that sickened the captain and the FO in the terminal environment ... a rare but nasty malfunction.

[SAMPUBLIUS]

Regarding possible cockpit window issues

this link may help

When Windshields Fail | Business Aviation content from Aviation Week

[BigFrank]

@aterpster

"He's doing his job. The CVR is probably in Paris by now, being carefully disassembled, properly set up in a specially equipped sound proof room, then preferably having a full CVR team present to listen to the recorder.

That's the way it's done at the NTSB. I resume the French follow a very similar protocol."

As one who is not professional in the airline world I find this confusing.

The implication of what you write is that the initial process of listening to which the Head of BEA (as I understand the gentleman's rôle) alluded in his press conference took place in less than optimum conditions and away from the main base.

Yet I understood, perhaps wrongly, that the device was delivered to the main base at 9:45 am and that the press conference took place there some 7+ hours later.

Edit:
Based on a doubt raised by a recent post on here which describes M Jouty as a BEA spokesperson, I found press reports on-line from last year which confirm my understanding that he is in fact the Head of BEA.

[DozyWannabe]

Originally Posted by BigFrank

I stand by my observation that his failure to listen to the cockpit recording is very striking.

The BEA is an organisation of many people, including specialists in flight recorder data recovery and interpretation - there's no need for the head of the organisation to personally involve themselves in that kind of work.

[MrSnuggles]

ECAM_ACTIONS

Thankyou for providing the parts about pressurisation. I didn't really catch that. I did hear him talk about the flight path though, and due to helpful people here on Pprune understood that he wouldn't comment on the question on what was heard on the CVR during the descent period before the crash.

[bsieker]

The FR24 flight path then suggests the aircraft levelled off c 3000 feet above the local terrain and then a minute later .... when the 350 knot aircraft intersected the rapidly rising terrain.

No, that additional minute is almost certainly an extrapolation artifact to hide temporary loss of realtime data and provide smooth animation of the little airplanes symbols on the FR24 website. If you download the raw data, it ends in a descent and there is no levelling off.

[fizz57]

And if my understanding is correct and they listened to the recording under the best conditions available, why was the boss not interested in listening in to such a crucial piece of evidence at the earliest possible opportunity?

As has already been described, there is a lot of work to be done between "listening" to a recording and issuing an annotated transcript. At the very least, timelines have to be established, unclear and noisy words deciphered, and decisions taken on what to omit out of respect for the dead and their relatives.

Knowing that he was going to face the press, I personally am certain that "the boss" did not listen to the recording, and deliberately so. I am equally personally certain that he has a pretty good idea of the contents, and that these will be released when the job is complete.

[2Planks]

And is the language in cockpit one that the BEA head would understand? In an emergency situation would you revert to your language of birth, aviation English or a mixture. Surely as a professional investigator he would wait for a native speaker to interpret the language used and its idiosyncrasies.
IIRC with the Spanair Madrid accident - it took quite a while to come up with an accurate translation - despite much rubbish being talked on here when an audio file was released.

[NigelOnDraft]

If you are right about the need to listen elsewhere in optimum conditions, why did these operatives handle such a delicate and central component of the investigation in less than optimum conditions?

And if my understanding is correct and they listened to the recording under the best conditions available, why was the boss not interested in listening in to such a crucial piece of evidence at the earliest possible opportunity?

Because it is a serial process:

1. Receive and document the CVR condition
2. Determine how to dismantle the CVR given it's condition
3. Technically treat the CVR innards with the highest level of care, and with minimum risk, attempt to extract data
4. In the event you get data, preserve and document that data (backups, file characteristics)
5. Using a copy of the data, check it is readable / valid data i.e. not blank or corrupt
6. Preliminary assessment of the data - timings, matching to other data, clear / easy to interpret output
7. Process of establishing formal transcript

The above is a guess, but I got the impression we are somewhere about 3 from the bottom. When we get second from bottom, there will be political and commercial implications of releasing the info.

Much as we on pPrune might like some "hot info", we have no right to it, and the BEA will not be concerned about our wishes. Their priority is not to establish what happened (that comes later), but if there are immediate safety implications for other aircraft?

[MrSnuggles]

I understand all precautions and different interpretations that you must go through to decipher a CVR.

What I do not understand is why the question if anything was heard from the CVR during the descent was dodged. The answer to that would be at least some sort of clue. Was there voices - yes? - no?

[Denti]

And is the language in cockpit one that the BEA head would understand? In an emergency situation would you revert to your language of birth, aviation English or a mixture. Surely as a professional investigator he would wait for a native speaker to interpret the language used and its idiosyncrasies.

The german BFU has three investigators in france to take part in the investigation. I guess one pretty big part will be the voice recordings. I guess the official flightdeck languages at lufthansa are german and english, with all the checklist and procedures in english, the more relaxed personal talk in german. At least that is how the german competitor handles it. ATC of course is always in english.

[SoaringXc]

I have experience in pressurizing and depressurizing transport aircraft on the ground (done for the purpose of locating structural defects). We would pressurize to about 20% over normal in-flight differential pressure using two large road works compressors.

For safety we devised several means of depressurizing rapidly. Our main method used a purpose built valve installed into a modified over-wing exit door, while our backup was through the toilet cleaning valves. Typical times for reducing from maximum in-flight differential pressure to sea level were on the order of 30 seconds for a 707 size aircraft.

During the development process the owner once had several technicians inside the aircraft. They reported that the depressurization process was a “wild ride”, in which they could not see or hear anything. It was so disorienting that they were unable to concentrate on their duties. And this was done at about 20C, not at -40C.

If D-AIPX experienced such a rapid depressurization at FL380, I can easily understand why the pilots might not have been able to put on their O2 masks before they lost consciousness!

[Rananim]

Folks, as former check airman on the 747-400, as SOP I would command a "simulated" RD in cruise to the crew who I was giving an IOE or check ride to.

Results would blow your mind ---- most "effed up" big time. So, I would leave the cockpit, tell them to bone up on procedures, and I'll be baaaack and run the exercise again.

Some didn't even know how to do a rapid RD properly, some couldn't even get the mask out of holder, some hadn't ever experience this exercise before, some did not know how to preflight the system, some didn't know where the sanitary wipes were, some didn't know how to re-install the mask after use.

It's your life and your pax lives ---- get smart and make the time to do it right.

John Galt

This was posted yesterday and subsequently ridiculed by at least one.Yet they are very wise words and may well be pertinent.It is difficult to get right and the simulator can not reproduce the physiological effects of a decompression.No civilian pilot has seen the inside of a decompression chamber.Many pilots may only know the sequence of the drill and not fully understand what it entails in real life(explosive=ear/lung/cavity trauma).
The subtle failure to pressurize has been discounted due ECAM warnings and I am sure that well-trained Lufthansa pilots can cope with rapid depressurization(valve/pack failure) but what about explosive?Not so easy.

The drill should be memorized and repeatedly performed so it can be done with a blindfold.Self protection should be achieved within 5 seconds(glasses/headsets can be obstacles).Establishing comms(vital because its a coordinated drill)can be tricky and the traps explained and trained until right(SPKR vol,is there a boom/mask switchover).Familiarity with the mask and its operation is so important;the pre-flight test and what to watch for,the NORM/100 and when to use each,how to select/de-select EMRG with mask on(must be practiced repeatedly),how to ensure the door is closed after drill to enable normal comms etc.Many operators are woefully deficient in their focus on such a vital drill and instead choose to focus on SOPs which have never saved anyones life.Airmanship first.Always.