Nice find!
Originally Posted by
sandiego89
Interesting that the laminar flow wing did indeed work, but had to be kept super clean.
They'd discovered that with the P-51's best-we-can-do-in-1940 laminar wing, to a lesser degree of laminar purity. It had to be kept scrupulously clean to have any effect otherwise it became turbulent earlier on the chord. The wind tunnel laminar flow remained until 60% of chord which was very very good, but in service it was somewhat less. But still well beyond a traditional aerofoil's 20%.
With the X-21 but the problem just seems to have scaled proportionally.