Not thrust in the same way as a propulsion system,
but winglets generally do produce a lift vector that
has a spanwise and a chordwise component. Since the
flowfield at the wingtip is angled inward, the winglet
has an incidence angle that is slightly outward-facing
-- while still producing a positive angle of attack
(look at your winglets from straight ahead to see that
this is true). This means that the 'lift' produced
by the winglet is directed mostly inwards towards the
fuselage, but also forwards.

I don't know what lift coefficients winglets fly at,
but I suspect the actual magnitude of the 'thrust'
is very small.

9B

At 19:54 28 November 2003, Bob Salvo wrote:
Anyone?
Bob