Originally Posted by
TripleBravo
Lost in Saigon:
I would very much argue this to be a climb, i. e. pressure loss. If it would be a descent, there had two independent computers to be failed *and* a source of overpressure to be present (aircraft descent, increased bleed air pressure), because the outflow valves would have to be stuck in their present position or being closed. But still to be verified, agreed.
I disagree with your assessment. Nothing would have had to fail as you describe.
Even if there was no failure of any system at all you would still get a "advisory regarding cabin vertical speed" once the aircraft descended in a dive below the pressure altitude of the cabin (6000-8000 feet)
You would have "caught the cabin" in descent resulting in a very high descent rate for the cabin.
The fact that the "advisory regarding cabin vertical speed" was the last message sent prior to impact tends to support my theory.
Does it not?