Years (many!) since I was "in the business", but I wonder if anyone else noticed in the pictures of the debris (http://www.pprune.org/rumours-news/5...ml#post9383765 - post 907) that nothing out of the clothing, belongings, aircraft parts, etc, seemed to be burned or scorched?

Perhaps the debris so far located (or photographed for public consumption) was from the opposite end of the aircraft from where the presumed fire started, and break-up separated those parts from the fire, - or can an inference be drawn, or at least postulated?

TBH I suspect no two decompressions are the same, especially the rate of pressure change, the associated temperature drop and I guess also relative humidity will play a part in misting.

I can certainly can remember there being white mist back in the days of being subject to rapid decompressions as part of altitude chamber runs...

mover265...interesting that you say that you had no misting in your event, as that was also my experience in a 747 depressurisation.

Perhaps that's because, in the hypobaric chamber, you start off with sea level air which may be more humid than that at high altitude.
I've never had a rapid decompression in an aircraft but there was misting in the hypoxia run.

Well in theory it is, and certainly has it's uses on smaller types, especially high performance types, especially if you load it up...... However whether it is an appropriate, sensible or "good" manoeuvre to employ on a transport category aircraft at night is another matter...and might be "interesting", if not impossible, with functioning FBW.

Basil - good point, thanks.

Progressive flight control system failure and Avionics Smoke ?
 

From the NY Times
¨ First, there was a problem with the autoflight control computer. The jet would have been flying near its maximum speed and elevation at that time. That is the most efficient way for jetliners to fly, and it is safe, but pilots prefer to rely on autopilot systems in those conditions because if they were to ever lose control of the plane, it could be hard to regain, Mr. Mann said. The last message had to do with the spoiler elevator controller, which essentially controls the flaps responsible for pitch and roll control. The computer controlling these failed as well.

“It looks to me like you have a progressive flight control system failure,” Mr. Mann said. It is over the course of two minutes, which might have seemed like an eternity on that plane, but is relatively fast.This is also the moment that the plane left Greek airspace, and at 2:29:40 a.m., Greek controllers lost the aircraft’s trace, just inside Egyptian airspace, about halfway between Crete and Egypt.

Around this time, the plane made a 90-degree turn to the left and then a full circle to the right, dropping precipitously to 15,000 feet from 37,000 and then plunging again to 9,000 feet before it disappeared from radar.


The crew never gave any indication of a technical problem or other difficulties on board, even during the final, fatal minutes when the plane itself was transmitting data indicating a catastrophic failure.

One former crash investigator said that radar evidence pointing to a series of sharp maneuvers in the moments before radar contact was lost suggested that the plane was almost certainly not under the control of the pilots. Whatever upset the Airbus was so sudden and violent that it could not be compensated for by the plane’s automated safety systems.

“In my mind, this basically opens two axes of possibility: either a sudden technical problem or some kind of illicit or terrorist act,” said the expert, Alain Bouillard, a former chief investigator for the French Bureau of Investigations and Analyses.¨

AF447 ACARS
 

Many more ACARS maintenance messages were issued by AF447.

Considerable speculation swirled around these messages until recovery of the CVR and FDR which showed a thoroughly different scenario to the many that had previously been theorized.

At present we have a few puzzle pieces and many more to recover.

The final sequence of ACMS messages transmitted via ACARS was

ANTI ICE R WINDOW
R SLIDING WINDOW SENSOR
SMOKE LAVATORY SMOKE
AVIONICS SMOKE
R FIXED WINDOW SENSOR
AUTO FLT FCU 2 FAULT
F/CTL SEC 3 FAULT

I was considering the sequence of the faults/messages and the absence of some others and ignoring the AVIONICS SMOKE ECAM, it would lead one to suspect an avionics bay event that led to some kind of fire.

Following LAND ASAP in the QRH's SMOKE/FUMES/AVNCS SMOKE procedure, the next action states 'IF PERCEPTIBLE SMOKE APPLY IMMEDIATELY: '. The use of the word perceptible there is because in the case of AVIONICS smoke crew will likely smell the smoke before any ECAM warning is displayed. . The AVIONICS SMOKE detector is very slow to actually trigger an ECAM. I'm even suspecting the Lav smoke detector picked up smoke before the avionics detectors did.

(I had some initial speculations this might be an EFB issue (window mounted (iPad plugged into an 400 HZ f/d supply or some such other jerry rigged setup), which flared up and caused the WHC faults. Back in the day, prior to AIRBUS introducing the new LITHIUM PED FIRE procedure, some recommended moving the smoking device to the FWD LAV))

So while I'm inclined to think this is the result of some issue with, or upstream of, WHC 1 (or 2) and that the subsequent faults are probably related to the spreading fire, what I don't understand with that scenario is why there were so few ECAMS included in the ACMS ACARS msg. Surely there would have at least been a record of a ANTI ICE WNDSHIELD ECAM if that were the case?

@Oldchina
 

I meant to say "not" survivable. Good catch.

oldchina



The issue of controllability has to do with the reverser efflux effect on control surfaces at specific speed configurations.

Deployment at altitude is quite different than early climb

fire onboard
 

Kittiara

Think Swissair 111

Kittiara
or UPS 6 out of Dubai. If you haven't read those accident reports, then you should before making comments like that

Given a scenario of uncontrollable fire on board,the best fire extinguisher at hand was 37,000' below them....Any recovered flight deck parts could play a major part in the puzzle...and possibly answer the question as to why no distress call was given.....The Egyptair 777 came to my mind too..
All guessing...aren't we!!!!!!

ACARS, particularly their sequence in time, may be hard to understand from their very few lines displayed on screen, without their full headers, and sequential relations between them, including how they are supposed to be triggered (e.g. with or without delay, priority order, class, etc.).

Since we had AF447 ACARS discussed to death, we should be aware of that ACARS are designed to report "system fault" (and related message). Taken independently a "system fault" can cover quite a lot of events. First, it's hard to figure out the sequence of those events simply at looking at ACARS order, and next, it's hard to figure out what caused the fault to be reported without other data from the maintenance computer.

Nonetheless, ACARS are telling us that between take off and the end of the report :
1. this flight was uneventfull (system wise) until 00.26
2. events took place at cruise (6)
3. ACARS stopped at 00.29, hence 3-4 minutes of reporting.

Next, out of the ACARS report between 00.26 & 00.29, only "SMOKE" looks serious enough for causing the end of ACARS transmission 3-4 minutes later ; excepted from it, those ACARS are telling us that none of the aircraft vital system (and airframe) was actually compromised up to the end of transmission... because nothing else was reported than three minor "faults" up to 00.29. Whatever caused the loss happened after.

Also, whatever caused the smoke to be detected at the first place won't be read from ACARS only ; nothing can tell us if a system "faulting" is the cause or the consequence of a SMOKE event without any further data. So far, all we can do is to think about what action would take the crew while displayed "SMOKE" in lavatory then avionics :
http://takata1940.free.fr/1_smoke_source.jpg

Whilst it seems the acars msg has been confirmed, has it been confirmed that these were the total of the messages ? Given the subsequent flight path, is it plausible that the ap was still engaged, and if not, would an acars msg on disconnect be expected?SLF, so pls don't be too harsh.

ACARS might end transmittng following action of the crew after an "Avionics Smoke" ECAM is tiggered.
if ELEC EMER CONFIG is applied, ACARS should not be powered anymore as far as I can tell.

http://takata1940.free.fr/2_smoke.jpg

Speculations
 

I think one of the important pieces to this event is the time it took to go from FL370 to 15,000 feet.

I think I saw in some earlier post that radar showed this to be a rather short time. A shorter time that an emergency descent would take.

Maybe someone here can refresh that information.

I would think a cabin, avionics bay, or lav fire would allow time for some emergency call.

I know they may have been in a poor ATC communication area, but maybe another aircraft on the frequency would have heard them.

Forgive my ignorance, but I see only "hours and minutes" recorded in the times of these events. Are seconds within minutes not displayed?

Given the above - can we know if these events occur simultaneously and simply appear in the order they do so in this list by some accident of software logic - oris their order on the list absolutely defined by the order in which they occurred?

Also....without "seconds" how can we know the events of minute 26 and minute 27 did not actually occur within seconds of one another....?

Would this information be available to aircrew handling a sequence of errors and therefore allow them to perhaps make a causal link between errors?

I am not involved in the air industry at all, but I do handle systems where error reporting allows me to trace a causal event through real time error reporting.

I haven't seen any timed data from the radar source anywhere. Only the manoeuvers were described, but it's way too vague at this point. No com reported is somewhat a clue about the situation of the crew by itself. One can imagine a fast pace of events taking place in a very short time.

conjecture
 

With Avionics Smoke, Lavatory smoke, and SEC 3.

The relation of unrelated ( or related ) failures avionics smoke, lavatory smoke and a SEC 3 fault is disturbing and perturbing.
What if the cockpit filled up with smoke ?

The avionics smoke checklist is not easy, and in my opinion should be trained more often, it the real world it does not happen as in the simulator.
I could understand the crew being too busy ( aviating ) to make a radio call.

The possibility of a Electrical fire comes to mind?

Then how does this lead to the appearance that they lost control of the airplane ?
The investigators have their work cut out for them, and the results will take a while to come out.

As we see how conclusions were jumped too immediately. Once again, the experts who know the most at this point will say the least, until the facts come out.

Do Egyptair have an EFB on the 320? The FO's one right next to the two faulty windows?

"It would be infantile and churlish to engage in any form of speculation about the cause(s) of this crash, until relevant evidence and information from FDR and CVR has been gathered and analysed in the coming days and weeks" said no media organisation, aviation pundit or Monday morning quarterback ever.............!!

What I take away is the small number of alerts over a 3-minute period means a bomb was less likely to be at the origin of this disaster than an avionics bay fire-- that could have been an in-air mirror of the 777 MS incident at Cairo Airport.

more...

http://takata1940.free.fr/3_smoke.jpg

http://takata1940.free.fr/4_smoke.jpg

http://takata1940.free.fr/5_smoke.jpg

I don't believe there is anything other than
1 - the last clean data item from FR24 is at 0:29:33
2 - Greek ATC say the lost primary radar contact at 00:30 (implied descending through 9 or 10 thousand feet).

There is no data other than the Greek defence Minister's statement that the aircraft made the manoeuvres attributed. The slick graphics are AFAIK all made up by the media outlets. The time frame between everything OK and claimed loss of radar contact is too short for ATC radar to have reliably detected the claimed heading changes. This would not be the first time a defence official attributed more information to the radar returns than appropriate (this happened both with the Brazil mid air collision and MH17).

I feel that particular comment is being given massively excessive weight and will likely prove to be a red herring.

The most likely scenario is everything progessed normally up to 0:26z and then by 0:29:33 there was fully developed catastrophe that resulted in the failure of all/most systems and the subsequent loss of the aircraft. Determine the sequence of events in leading to the catastrophe will need a few more days items to clarify.

One item, that is in the hands of the investigators, is the time stamped radar data. This will indicate if there really were 'controlled' turns or just an uncontrolled aircraft or fragments of aircraft tumbling down.

The claimed timeline would indicate a slightly negative g descent coupled with a 4-6 g set of turns sustained for about 30-50 seconds (for a net positive 3.5-6 g load). I would believe no sane A320 pilot would choose to initiate that kind of maneuver. However, it would be totally consistent with free falling debris.

Of course if the Greeks really lost radar contact at 0:35, then there would be plenty of time for pilot controlled maneuvers. But we don't have the data and will need to wait for it to be published.

and so for ACARS VHF receivers, if at FL150 or FL90, meaning additional - most probably generated - messages, 'were gone with the wind'...so last resort the DFDR it seems.

was checking AIP Greece, lowest control limit (airway floor) for UN132 is 7000 FT.

From the fault messages observed I would suspect a explosive device in the fwd galley area carts/cannisters. The explosion has breached the RHS of the aircraft causing the windshield heat controller, flight warning computer/air data fault, avionics smoke and in turn lav smoke faults. The explosion in that area also behind the flight deck circuit breaker panels 121VU etc ... very sad 😢

How many watts is that window deicing system? If you were to look at cockpit items that could possibly cause a fire, a window heater would be near the top of the list. High current next to condensation and vibration is a really good way to cause a fire, as many boaters have discovered.

Contrary to popular belief, circuit breakers do not protect you from fires. They protect you from one condition that can cause a fire but they do nothing to save you from a loose connection that heats up and melts the insulation. If there was resistance in the heating circuit the window would not get to temperature and the thermostat would keep calling for more heat, and the loose connection would keep getting hotter. I'm sure it is not that simple or it would happen more often, but I suspect we are about to learn a lot more about window deicing systems.

The three messages related to the RH window are telling us something.

But you're missing the most important and obvious message? There is no "Cabin Pressure" message, right? At FL370 any breach of the pressure hull is going to bring a cacophony of warnings and messages. But there are none. And those would be well before any smoke messages if your bomb scenario were true.

Now, if you change your device to something incendiary... maybe?

- GY

Uhhh IF a rapid decompression caused by whatever means- then due to later recording of ACARS- a cabin altitude or similar differential pressure sensor alarm would be expected to appear in the next few 2 or 3 minutes. Since there is no such- the decompression scenario seems to be near zero probibility !!

@Takata
 

Wonder on basis of chklsts you provided whether, whatever the cause (small explosion not excluded), fltcrew as per prescribed drills did shed the AC BUS1 by shutting down GEN1, while the GEN2 driven electrical system was compromised, and may have hampered transfer to AC ESS FEED. May well explain the transponder going down too around 02:30, like everything electrical on board, including ability to communicate or to get transponder setting 7700 effectively through.
In addition, this is of course still to be confirmed, if I understood it well from the Greek defence ministers' report, the manoeuvres of MS804 (90° left, followed by 360° right, rapidly descending) took place between 02:27 and 02:29. Never mind the FR24 report that A/C maintained heading and altitude until 02:30, which is likely to be based on extrapolation.
Regards

@ MM Flynn
 

"I don't believe there is anything other than
1 - the last clean data item from FR24 is at 0:29:33
2 - Greek ATC say the lost primary radar contact at 00:30 (implied descending through 9 or 10 thousand feet)."


I realize these time stamps may not be coordinated, but if I am reading this correctly.....they went from FL370 to 9 or 10,000 feet in 27 seconds?

What about to 370 to Zero in no time?
When will all you armchair 'experts' stop bullsh1ting and wait for a sensible answer

It's a rumor network
 

Lots of people here just want to ask questions and form opinions.

That's one of the purposes of this forum.

Agreed, we should wait for answers, however, they may never come with the Egyptians in charge of the investigation.

Thankyou Old Boeing Driver- I have never heard of his feature, it certainly is not a feature of any aircraft I have flown, ie, A380 or -400

Auto Descent
 

The Airbus family don't have a feature of commencing an automatic descent incase of a decompression. The 787 doesn't even have this feature. I couldn't speak for the A350 though.

Greek ATC radar
 

What I should like to know is when the Greek ATC lost MS804 from its secondary radar maybe a useful indication to the state of the aircraft.

When an aircraft dies.
The confounding elements and those that distinguish this particular loss, is the aircraft`s so far known behaviour in its dying throes. So far the link between its trajectories, both in the lateral and vertical planes and its electronic emissions, do not present any previously fitting or comparable pattern.
It will be sometime before any substantive evidence emerges which may assist in formulating any reasonable speculation as to the circumstance(s) which may have led to its demise.

@Rwy In Sight

was covered by two MSSRs, Rhodes and Karpathos. According to the AIP Greece these
radars 'see' from ~7000 ( for KUMBI area I believe at least FL100 ) up.

when - aircraft/radar target reached that floor - was according to HCAA statement at 00:29:40 Z.

Interesting till now, they did not say, if they called immediately after aircraft departed assigned altitude or if the call was just for UIR handover and then they realized it was descending.

The FR24 raw data gives every appearance of being actual ADSB messages from the aircraft, the projected data (which is not included in the raw data, but is used in the online display of aircraft tracks) is flagged as such. It is also completely consistent in time with the statements from Greek ATC. It would be amazing if the final facts don't show the aircraft in straight and level flight until 0:29:33 +- 2 seconds. What then happened will probably only be deduced from analysis of the radar data and wreckage.

The ACARS message are interesting, but the only thing that seems to fit is a 'fire' that then caused a sudden and catastrophic loss of power (so no more data) and then loss of control/integrity (resulting in the rapid descent - probably closer to a fall).

The descent timing based on the available statements appears to be close to what one would expect from a free fall, although the lack of clarity on the radar time makes this only a rough calculation.

Ps
The HCAA statement on the loss of 'radar signal' is ambiguous in that it probably meant the SSR return, but might have meant the primary return due to the descent going below the radar horizon. The various claims of turns and specific levels the aircraft descended through imply A - the SSR/ADSB data was being sent, B - there was some height finding radar (normally military) data, C - it is just noise that is not actually fact,

I think C is most probable, but that there is a time when the primary target disappeared, which is later than 00;29;40, but not clear if it is 20 seconds 1 minute or 3 minutes after this.