MS804

[kraznyi_oktjabr]

Originally Posted by Catfish

There was that Air France Flight from South America. Ice had rendered all tachometer devices useless, and the autopilot tried to counter with the data it received. When the jet lost altitude it gave positive elevator control and the nose went up until stalling.
The pilots did not know what was going on and were not able to switch from automatic to manual steering. A stall, drop and circling could be a hint for a similar technical failure.
Just saying.

There are three major errors in your narrative:
1) When autopilot does not get sufficient data to fly safely it disconnects. That happened on Air France Flight 447.

2) Change between flight control laws is automated process not manual one. However ff person knows what he or she is doing it can be intentionally triggered by shutting down some of flight control computers.

3) At time of the accident plane's captain was off duty. First officer was in captain's seat with second officer in FO's. When troubles started first officer tried to correct situation. However second officer was applying constant nost up command in his side stick which caused the orignal stall situation and as it overrode all first officer's control inputs also ensured first officer could not correct situation. However I do not know if first officer's intended actions were appropriate or not.

Air France Flight 447 crash was due pilot error with mechanical malfunction (frozen pitot tubes) and user interface design (presentation of information and lack of feedback via side stick controllers) playing secondary role. Procedures exist for flying aircraft without accurate speed information but those were not followed.

(Air France 447 and Air Transat 236 were used as examples in user interface design course when speaking about user interface design in safety critical applications.)

[Skybird]

The probabilities seem to shift in favour of a cable fire or something like that as an explanation scenario. Board systems should have rang alarm over problems with the heating system on the toilets.

[Von Due]

According to BBC, there are unconfirmed (officially, that is) reports of smoke detection coming from, among other areas, the avionics bay. Fire is seriously bad news. Fire in the avionics bay ups the bad bit by a lot.

Pure speculations here: If there was a fire in the avionics bay, that could possibly explain why no mayday call was heard as monitoring systems, radio and transponders could be affected by this. A fire seems like a very likely candidate at this point but still, nothing is for sure yet. As for possible causes, that is a complete unknown at this point.

[Jimbuna]

Images of some of the debris:

http://www.bbc.co.uk/news/world-middle-east-36349882

[Von Due]

Update

Black box signal detected
http://www.bbc.com/news/world-middle-east-36427053

Now as soon as they can recover it, theories can give way for answers.

[Oberon]

The Egyptian investigation committee has said that the Cockpit Voice Recorder has been recovered from the sea.

https://twitter.com/AP/status/743430423192141824

[Aktungbby]

Originally Posted by Aktungbby

Inasmuch as the 'dog is not barking'; no organization is taking 'credit' for a terrorist operation. That is not their usual modus operendi.

“received information from three independent channels”, that ACARS (Aircraft Communications Addressing and Reporting System) received the following messages from the aircraft: 00:26Z 3044 ANTI ICE R WINDOW
00:26Z 561200 R SLIDING WINDOW SENSOR
00:26Z 2600 SMOKE LAVATORY SMOKE
00:27Z 2600 AVIONICS SMOKE
00:28Z 561100 R FIXED WINDOW SENSOR
00:29Z 2200 AUTO FLT FCU 2 FAULT
00:29Z 2700 F/CTL SEC 3 FAULT
The timestamps refer to GMT and point to the alerts being received in the minutes before the flight dropped off radar screens.

Still no claim by a terrorist group "in contrast to a quick claim by Isis after a Russian plane exploded over Egypt in November." Avionics fire appears likeliest at present....