Russian Plane Crash

[Anomalocaris]

If the plane was largely intact and its engines functioning normally When for whatever reason it suddenly climb from cruising speed and altitude to the point of stalling, then the plane would likely Experience large gain in altitude before the actual stall.

That's hardly possible with airbus systems in good working order. A 320 pilot once demonstrated to me what he could and couldn't do without the systems stepping on the brakes. A climb to a stall is virtually impossible, even if all the systems are disabled. Unless something took care of the safeties before that.

I said the aircraft was intact, not necescarily in good working order.

But in fact it is possible for out of safety envelope condition to happen even if the Airbus was mostly in good working order, as we saw with the air France Airbus A340 that pancaked into the Atlantic, and whose wreckage too 2 years to find, it is entirely possible for the fly by wire system on the Airbus to be fooled by an external air pressure sensor malfunction, leading to software commands that would destroy the aircraft.   The Airbus relies on differential readings from an array of external air pressure sensors to deduce the speed and attitude of the aircraft.   Failure of any one of these could cause the control system to detect of dangerous situation that does not in fact exist, and strenuously attempt to correct the dangerous situation, and in the process put the aircraft into a different dangerous situation which it could not detect.  What is more, Airbus uses a full authority fly by wire system.  Which means the fly by wire system would override any pilot input it judged to be dangerous.  So when the fly by wire system is confused by malfunctioning sensors and doing all it can to mitigate the danger which is in fact not there,  it is actually impossible for the pilot to override the FBW system and restore sanity.

In fact, one of the first Airbus A320s, same model as crashed aircraft here, also overrode pilot corrections and flew the plane right into the ground in front of spectators in 1989 because another sensor malfunction causing the computer to become confused over what the plane is actually doing.

But in this case, I think the aircraft is already catastrophically damaged when it deviated from cruise altitude and speed.

My guess is either a bomb, or explosive decompression had already either shattered major portion of the fuselage, or severed all control wiring. Because bombs tend to leave readily detectable evidence on the wreckages, my money is on explosive decompression causing massive structural damage. Perhaps the rear pressure bulkhead at the aft end of the passenger cabin blew out.

This aircraft sustained major damage by striking its tail on the runway during a landing early in its life. This could well have damaged the rear pressure bulkhead. If the repair was not properly conducted, the bulkhead may well fail after a number of pressure cycles. If that bulkhead blows out in flight, it could severe the plane's tail, or at least compromise all the control wiring to the plane's empennage.