If I recall correctly, Dick Johnson tested Sam Fly's Ventus 2 with oil flow
and found that the mylar alone did not prevent cross flow from bottom to
top. He removed the ailerons and installed S-seals and stopped the flow. As
I further vaguely recall, this did only a little for the performance! There
was considerable data scatter.

Does anyone know of any hard data that shows, one way or the other, if the
mylars are effective?

Hartley Falbaum
ASW27B "KF" USA

wrote in message
oups.com...

the Mylar would
seem to me to be every bit as likely to trip the airflow as the
Teflon
tape. Second, the point behind external tape (or internal seals) is
to
prevent airflow through the gap. Are properly fitted Mylar seals
actually going to prevent this flow? Would it make sense to use
Teflon
tape to seal the gap, then put Mylar over the tape?

Thanks,
Marc


I have seen it done this way (mylar & tape) Just have come to the
conclusion it isn't necessary. I fit foam rubber in the flap well to
seal any cross-flow at each end of flap and aileron, then the mylar
comes over this area and prevents any air from entering.

I believe the big bug-aboo with tape only is the leading edge starts to
come loose and this = some real drag on that wing.
JJ