In article ,
Newps wrote:

A 7 knot direct tailwind is trivial.


I just checked a couple of my Cessna POHs.... for the 1981 172P and the
1980 Cutlass RG. In both in notes for takeoff or landing distances that
you should "increases the distance by 10% for each 2 knots of tailwind".

I don't consider 35% as trivial. Of course, that may only apply to those
two models of aircraft.

--
Dale L. Falk

There is nothing - absolutely nothing - half so much worth doing
as simply messing around with airplanes.

http://home.gci.net/~sncdfalk/flying.html