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Old 12th Nov 2015, 08:33
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safetypee
 
Join Date: Dec 2002
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Memory fades, but there were significant differences between the 700 and 800 wings. The latter had a ‘high-speed’ outer section and a reverse-profile aileron. Although both retained the inboard section stall-breaker strips, there were differences in vortex generator number and location; the 800 also had ‘underwing’ vortilons.

The 125 stall characteristics were often challenging, particularly if wingtip panels were slightly misaligned or with gaps between the TKS strip / leading edge panel and the wing ahead of the aileron (800’s had laser drilled leading edges?).
The stall breakers would require fine tuning if moved, but any error did not primarily cause roll problems, more likely with the stall speed and stick push relationship.

The stall characteristics of a well set up aircraft were generally benign, but some were sensitive to lat / dir trim condition. Stalls were never flown with the autopilot or yaw damper engaged which could lead to interesting results (also there were differences between avionic vendors).
A mis-set aircraft would in general not ‘flick’, but often suffered a rapid wing drop more likely due to aileron ‘snatch’, including movement the rams-horn control sufficient to break a lightly help grip or rap the knuckles of a free hand.

Did this aircraft have wing tip extensions?
AFAIR the type designer never approved winglets – the Hatfield design view was that they would only improve a bad wing – "Hatfield does not design bad wings" (although latterly the Airbus wing had ‘winglets’).
Winglet stall certification appears to be subject to localised approval – FAA, which could be via a DER where I suspect that the extent of any investigation of stall characteristics was limited by test instrumentation and safety devices; - any one able to clarify this?

Did the aircraft descend through an icing layer?
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