PPRuNe Forums - View Single Post - AF 447 Thread No. 9
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Old 8th Jul 2012, 20:57
  #182 (permalink)  
RetiredF4
 
Join Date: Jun 2009
Location: Germany
Age: 71
Posts: 776
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BOAC
There seems to be some departure from 'actual' parameters in that sim (as expected), as you describe a pitch down below the horizon with full THS and power. 447 managed to hold a high nose attitude in that situation. How much stick effort was required to hold the nose down against the thrust couple? Full forward, half
@PJ2
I share that concern. PF achieved a higher pitch attitude and stalled at lower speeds, mainly due to the fact that some ND SS and or reducing th NU SS input led to some g- reduction below 1.0 g without effectively reducing the pitch rate (see the Nz graphs of the respective time frame). TOGA application at that point (2nd StallWarning) and SS NU input forced a further increase of pitch without solving the speed and AOA problem. Thus when the stall finallly occured, pitch was a lot higher and speed was slower than what you describe in your sim exercise. With the nose lower like that gods g (gravity for the nonflyers) works a lot earlier than it would have for AF447, and the speed would be back in flying parameters a lot quicker.
Presently on leave on my iphone, therefore no further comments on the report.

Last edited by RetiredF4; 8th Jul 2012 at 21:00.
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