slats11 wrote:-
I wonder what the vertical descent rate really was. I think we will do better to estimate velocity and calculate a probable acceleration rather than the other way round.
I posted something similar a few pages back -
- On 22 October 1963 a BAC 1-11 G-ASHG entered a deep stall during a prototype test flight. The aircraft descended from FL180 to the ground over Cricklade, Wiltshire in 80 seconds - 13,500 fpm [133 knots]. Horizontal velocity at impact was effectively nil, as the aircraft belly-flopped and burned in-situ.
Post #2067 was a rehash of an earlier post and had both the vertical and horizontal velocity components doubled. I'm not happy with those velocities and believe that 75KT and 13,500 fpm is probably closer to the mark.
There has been speculation in this thread that AF447 stalled a number of times during its descent, which could explain the nominal FL350 to terra oceania time of 5 minutes. This assumption of a stall(s) has developed as a result of discussion around a "Pollution Spot" located at 2°43.5'N 30°30.5'W by satellite radar imaging some 30 hours after the LKP time.
Bearfoil
From BEA Interim Report #1:-
- The tail fin was damaged during its recovery and transport but the photographs available made it possible to identify the damage that was not the result of the accident. The middle and rear fasteners with the related fragments of the fuselage hoop frames were present in the fin base. The distortions of the frames showed that they broke during a forward motion with a slight twisting component towards the left.
- Observations of the tail fin and on the parts from the passenger (galley, toilet door, crew rest module) showed that the airplane had likely struck the surface of the water in a straight line, with a high rate [of] vertical acceleration.
Underline is mine.
mm43