When I said "I think" I was very humble...

Regarding winglets I am an "expert" (definition of an expert is someone that
have read what other have don :-)
Peter Masak did a great pioneer work on effective winglets. result was
winglets that didn't decrease performance at high speed as the large earlier
winglets.

Winglets make the wing act like it was of greater span, the improvement is
larger then if the wing was lengthened the amount of the winglets height.
And the increase in bending moment is smaller then the longer wing will
produce.

Winglets and longer wings reduce the induced drag (that come from the work
of producing lift) that work is harder at low indicated speed, =slow speed
at low altitude, low indicated speed at high altitude and getting there.

So even an "high speed" jetliner will be helped by using winglets, it spend
a long time at high weight climbing to economical cruising altitude, there
it cruise at low indicated speed (what pilot see) or more correct low
dynamic pressure.

Ok, no one here on RAH build jet liner, some fly them, and some build high
performance aeroplanes that have the capability to cruise at high altitude,
other aeroplanes can benefit from improvements of winglets too, if you fly
very long distances and want most economic, you would like to cruise near
(high side of) speed for best L/D ( at alt it will still go fast) here
winglets will help a lot.
other situations is to improve take off and climb and roll stability AND
roll rate, better aileron efficiency.

In this case Dick want more stability on a ? small big M ? plane, with
winglets he get a wing that "think" that the dihedral is grater then it is,
and improve the short wings low speed performance. don correct it would not
hurt cruise performance.

Jan in ME
www.jcpropellerdesign.com
Propeller and Performance software


"Morgans" skrev i meddelandet
...

"Jan Carlsson" wrote in message
...
Dick,

I think that winglets would improve roll stability, and L/D, climb
performance and high alt. performance.

Jan Carlsson

At the speeds we fly, winglets do little to nothing. They only become
useful at higher speeds.
--
Jim in NC