ST27 Quote:
The aircraft pitched up steeply and decelerated from cruise speed to a virtual standstill in the first 30 seconds or so
There is no way an a/c at 38000 ft is going to decelerate fron Mach 0.82 to a virtual standstill in 30s. Imagine the forces on the flightcrew: why would they proceed? If they try, it'll stall well before the standstill.
The BEA report simply doesn't contain much information. Don't read too much into it.
I was exaggerating somewhat, since the previous poster had suggested a constant deceleration throughout the incident, and that the ride might have seemed like horizontal flight.
The BEA report states that the IAS near the top of the ballistic path was 185 kts (about mach .59), and suggested that this was an accurate speed, since the indications on two instruments coincided.
Some simple physics calculations can be made to confirm that, given that when the aircraft started the episode, it was flying in level flight and at constant speed. As a rough assumption, it can be assumed that the energy needed to climb 3,000 feet will all come by bleeding off the energy of the forward motion of the aircraft.
The calculation suggests that they would have lost about 260 kts as a result of the climb, ignoring the effect of the TOGA power that was applied for a while during the climb. That puts us pretty close to the 185 kts that was recorded. So overall, they would have dropped from mach .82 to about mach .59 in about 30 seconds.
Perceived vertical acceleration would have been something like +1.5g near the start of the climb, and +0.5 g over the top. That certainly would have been noticed by both passengers and crew.