Steve,

Perhaps my ignorance of this plane and its wing is showing. You're right, for a thin wing, filling in the lower surface would approximately half the camber. Good point.

I would not want to unduly obfuscate the issue by starting off on a lecture about terminology. What I tried to do was get to the point that I could give my best answer to japan's question, which is that more camber gives lower drag at low speed, less camber give lower drag at high speed, but that it is mean line camber for which this statement is true.

Thickness, as opposed to maximum thickness, is the thickness at each point along the chord. This is why I should have used the term thickness distribution, and been a bit more clear.

I try to be as clear and simple as possible without missing the correct essence of the issue. I reckon that if I sometimes end up with more detail than some want, they can always ignore or ask for clarification ( how was that for some English English? ).

banktoturn