PPRuNe Forums - View Single Post - AF447 final crew conversation - Thread No. 1
Old 28th Oct 2011, 13:57
  #488 (permalink)  
BOAC
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It seems that all those 'obsessed' with the 'horrendous 0g plunge' of 447 as it stalled do not understand what happened. The a/c was lifted up to the altitude and pitch angle where its wings could not support its weight. It probably then settled very gently and 'mushed' downwards gathering vertical speed. Look at two parts of the FDR

1) 'Normal acceleration' and
2) 'Vertical speed'

1) hardly showed a divergence from 1g
2) shows a change from Vs=0 (level at 38,000') to 10,000fpm after around 40 seconds. That is 0 to 10,000/60 fps =166fps after 40 seconds. Using basic laws of motion, the acceleration works out at 166/45fps/s = 4.15fps/s. Since '1g' is 32fps/s you have a change of around 1/8th of a g during the 'acceleration' downwards. Barely noticeable in amongst everything else that was going on. Less than you probably get walking down stairs..

Can we put this Oozlum back in its cage now please?.
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