My reading of the reports so far (the genuine ones) is that the RadAlt malfunctioned at or before 2000' when the GPWS warning was issued. I think by 500'; or so the a/c was well into decayed speed and near stall and had been without 'normal' power for around 100 seconds, although normally some of that time would be expected to be throttles closed anyway as it slows up with flap and gear extension. The situation was therefore masked. I can understand how this developed that far. Missing the 'RETARD caption is easy and 'green arrows' tell you nothing at that point. What I cannot understand is the lack of monitoring thereafter. Apart from PF being aware of what the a/c is doing, PNF's job is primarily to monitor. A TC as PNF has an even greater demand on him/her and I would expect to be even more attentive. Then there is the 'recovery' itself. Apparently wrong and muddled. I would expect strong calls of 'SPEED' from my PNF, rising in tempo and volume until I hear 'I HAVE CONTROL!'. I have lost the plot now on the height at which the stall warning occurred, but with the power available a recovery would certainly have been possible had it been flown correctly.
Hetfield - lawyers aside, the aviation doctrine revolves around 'Fail' as a finite situation. Fluctuating or wrongly reading do not necessarily constitute a 'failure' in terms of warnings or software interaction, and as someone else has pointed out, A/T and RadAlt #1 are NOT needed for a successful A/P B approach. Also a manual approach can be flown by the LHS with those 'failures' if desired.
Last edited by BOAC; 5th Mar 2009 at 19:10.