Looking at Gottingen 535 airfoil data: There is data point for C.P. (Center of pressure?) at 92% of chord from leading edge at -6 deg, and the C.P. curve is extended to -150% of chord from leading edge. So how is the center of pressure not on the wing, off in space so to speak, or what does that mean. If my flapperon is for example at 90% from leading edge seems like that is a lot of lift/force on the flapperon and fabric portion of the wing when at negative angles of attack, without even talking about gust loading.