Posted for Walter Atkinson <walter@advancedpilot.com>:

 Lowering flaps results in a weaker wing due to the movement of the center of
lift aft.  Don't lower flaps.
 
 walter
 
 
 On Aug 26, 2005, at 11:35 AM, Robert Overmars wrote:
 
 Saluti tutti,
  
 Perhaps those pilots contemplating extending flaps in the case of inadvertent
penetration of thunderstorms should read FAR 23.345  (a) (1) (2)appended
below.
  
 Martin Hollman writes in M.A.D. vol I, "...A limit load factor of 0.5 x n1 is
used at Vf. This condition gives us the maximum twisting load on the wing....
Twisting causes high in-plane shear stress and together with twisting
generates high rear spar loads"  (n1 is the positive manoeuvre limit load
factor)
  
 Never having penetrated one of those nasty thunderies I still can't help but
think that compromising the aircraft G load limit, the gust design
strength, and restricting the aircraft speed envelope  to Vf at a time when
the maximum strength/gust response/speed may well be needed is just not a good
idea. Test piloting the ultimate flap system or wing strength at such a time
could really spoil your day.