andy l wrote on 9/24/2020 5:20 PM:
On Thursday, 24 September 2020 at 23:47:32 UTC+1, Eric Greenwell wrote:
Dan Daly wrote on 9/24/2020 2:59 PM:
I can imagine why the cockpit load would be reduced, but have no idea why it would
The maximum cockpit load can have 3 conditions - the all-up weight, the forward c of g limit, and the maximum weight of non-lifting parts
The last of these is related to the bending loads of the wing. Perhaps if the wingtip is made a bit heavier this relieves bending slightly and the max cockpit load might increase, depending on the other limits.
Admittedly this is speculation and could be ill-founded.
Winglets increase the lift of the outer end of the wing. This shift in wing lift
distribution increases the bending moment on the spars; reducing the cockpit load
could compensate for the increased bending moment. I'm guessing the winglet weight
is not enough to prevent the increase. I'm basing this on retrofitting relatively
heavy winglets to my ASH26E, and noticing in flight that the wing tips were higher
than before. I confirmed the extra bend using before and after pictures taken from
But, I don't know why they did reduce the cockpit load, so I hope someone will
find out and tell us.
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"