Chris Scott;
thanks for replying, I’m pleased someone is interested in my little exercise.
Originally Posted by Chris Scott; #674
it's interesting that they seem to have derived Alpha (AoA) from their stated equation:
" alpha = pitch - fpa "
The equation is correct as long as fpa is defined relative to the air mass. In this case: it is assumed that the airmass does not move vertically: sin(fpa)=vsi/TAS
I was under the impression that a direct reading of AoA would be recorded elsewhere; either on the DFDR or (...)
The DFDR traces in the ATSB report include AoA, but the scale chosen to show the ‘spikes’ is too small to read a real AoA value. Therefore I integrated vertical acceleration to obtain vsi, and from that AoA.
Who produced the graph, I wonder?
The graph was produced by MS EXCEL from data read manually from the DFDR traces provided in the ATSB 1st Interim Report on the accident, with some help from BOAC and PJ2.
regards,
HN39