AF447

[Hyperveloce]

Vertical rate at impact

There are known past cases of losses of control with very high vertical rates: 20 000 fpm, 30 000 fpm, even more (>40 000 fpm) before a mid air break up occured. In the Adams Air case, involved in a 60° high dive, the structural integrity of the airframe was compromised at ~475 kts, under a vertical load factor exceeding +3G (over 40 000 fpm). Those irrecoverable dives lead to short scenarii (<1min30sec: compatible with ACARS being emitted more than 3mn after the multiple FLRs and AP disengagement ?), very high impact speed and incidence angles, very small debris and no body to recover as such. Looking to the debris as shown by the BEA report (more spec. the big furnitures/Galley G2), knowing that the Airbus was in "ligne de vol" when it impacted on its belly (or on its tail, with a slight pich up), knowing that the 30 bodies recovered by the Ventose Frigate were all in a relatively good overall state (with their clothes), it seems difficult to think that the impact occured in such a way (with such high vertical rates). If we need a longuer scenario (>3mn), maybe we have to assume that the control initially lost at high altitude was somewhat regained but either not enough, or overcorrected ? and that the max. vertical rate at the impact did not exceed 10 000 fpm ?
Jeff