Roberto:--

   What a startling and chilling observation!  It brought to mind some almost forgotten memories, especially after Skip Slater mentioned slats.  Some of you may recall back in 1980 or thereabouts a DC-10 lost an engine - literally, it departed the aircraft - on takeoff at O'Hare. As was the noise abatement custom the airplane climbed out steeply, but the departing engine severed the hydraulic lines to the slats on that wing and they retracted. The effect of closing the slat is to move the stall point back down the curve in Roberto's graph to a lower angle of attack. The result was that one wing stalled while the other was still flying; the aircraft rolled over and dived into the ground. The least asymmetry or  possibly even surface roughness on the L.IV wing could, at the stall point, put it into the same situation as with one slat extended, the other retracted.

   I'm not building a L.IV, but if I were I wouldn't take this observation lightly.

               Charles Keller



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