As long as the elevators produces a force downwards, the low pressure side
is on top. This is typically the case for speeds higher than best L/D.
For speeds closer to stall speed, the elevator produces lift, and the low
pressure side is on the bottom.
For an optimum design, the elevator produces no force at all (except
drag...) at the speed of best L/D. But then, not all designs are optimum...

Bert

wrote in message
...
On May 20, 6:39 am, Ed Winchester wrote:
nimbusgb wrote:
On May 20, 2:25 am, "Bob Salvo" wrote:

It seems to me that Mylar may only be necessary on the top of the
stab/elevator, since the top surface is the high pressure side. Has
anyone
tried this?

The top side is the low pressure side Bob!

I don't think so, as the tail of just about every airplane or glider has
a download. That's how they achieve stability. So it's backward at the
tail, the top surface is indeed the high-pressure side.

Just to add to this "pressure" discussion, my elevator has a shape
similar to the trailing edge of my wing. The top-side is convex, and
the bottom-side is concave. Wouldn't that be a clue as to where the
high and low pressure areas are? I would think the convex side is the
low-pressure side, which is on top.


Dave


P.S. Any other thoughts on using mylars and safety tape on the
elevator gap?