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Old 25th Apr 2011, 18:41
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Pugachev Cobra
 
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Position Altitude and French report

It just occurred to me, have anyone in all the AF447 threads considered the possibility that the last ACARS position report was not at FL350? I read the ACARS sequence and it just contains lat/lon coordinates, no altitude information (nor track, heading, speed, etc.)

The aircraft could be well below that altitude, and AFAIK, at the LKP report, they could be in another heading, is that correct?

Now, maybe my math (and distances information) is wrong here, but from the crew position report at INTOL and their estimates to SALPU and ORARO, the groundspeed varies considerably to the LKP.

But, considering their last estimate 02:00 UTC at ORARO and the LKP at 02:10:34 UTC, their groundspeed was ~273 knots. Does that compute?

INTOL - SALPU (122nm - 13.25 mins elapsed): ~552 kts

SALPU - ORARO (122nm - 12 mins elapsed): ~610 kts

ORARO - LKP (~48.18nm - 10.57 mins elapsed): ~273.6 kts

Isn't it possible that at the position report the aircraft was turning back to Brazil or something different than flying the planned route, at a different altitude and speed?

About Svarin's observation, maybe something got lost from the french to english translation. Anyone here good in french?

The original french report explanation about the AFS occurrence:

Ce message ne peut pas être la trace d’un reset, ce qui exclut notamment la possibilité d’un arrêt manuel. Ce message pourrait être la conséquence d’une incohérence entre les deux chaînes internes du FMGEC (COM et MON). Une telle incohérence pourrait elle-même être la conséquence de valeurs erratiques des paramètres d’entrée. Quoi qu’il en soit, les seules conséquences d’un tel message ne peuvent être que le désengagement d’automatismes dont les messages cockpit effect associés ont déjà été émis à 2 h 10.
Le caractère « INTERMITTENT » signifie que l’anomalie a duré moins de 2,5 secondes.
I think Svarin made a point that the crew was alive, alert and well in the flight deck, by trying to reengage the autopilot.

However, for an automatic commanded pitch down (or up maybe), we have seen that the A330 doesn't need a connected Autopilot to command a abrupt pitchdown - read QF72 accident investigation..

Last edited by Pugachev Cobra; 25th Apr 2011 at 18:49. Reason: Added QF72 info
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