Old 28th Jul 2010, 16:49
  #92 (permalink)  
BOAC
Per Ardua ad Astraeus
 
Join Date: Mar 2000
Location: UK
Posts: 18,584
Forgetting 'aerodynamics' and concentrating instead on 'stability and control', there appear to be two major contributors to recent 'underslung' accidents/incidents involving near or complete LOC following an unintentional low-speed 'event'.

1) The way that a/c flight systems are allowed to automatically continue trimming tailplanes below normal flying speeds without some form of warning to crews that this is happening

2) A failure to recognise and handle the resulting excessive pitch and low speeds following the application of recovery power.

As I and others have said over the last few years, historically initial and recurrent training has 'compartmentalised' stalling and unusual attitude recovery ie "now we will look at stalls and recoveries" and "next session we will look at nose-high low-speed recoveries". Those of us who have air-tested down to the stall know that you always STOP trimming at xkts above the stall speed so you do not get the excessive nose-up couple. We are now arriving increasingly at events where the a/c has done exactly the opposite and crews are not ready for it. With the increasing ratios of those pilots in the industry who have not got much real experience of unusual attitudes, it is apparent, to me anyway, that 'stall' recoveries MUST now lead straight into the nose-high low-speed recoveries as an exercise, meaning that I would suggest allowing trimming right down to stick shake. Recovery from these conditions is indeed simple if you are prepared for it and take the correct actions.
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