The highest flutter speeds were found in the vicinity of the angle of zero aerodynamic moment and the flutter speed increased considerably in this region with decreasing pressure. Over the rest of the pitch range, the flutter speeds were much lower and varied little with pressure.

A rapid method for estimating the downwash behind swept-wing airplanes is presented. The basic assumption is that of a flat horizontal sheet of vortices trailing behind the wing. The integrations for the downwash are handled in a manner similar to both Multhopp's and Weissinger's approximate integrations in their span-loading calculations. The principal effects of rolling-up of the wake are treated as corrections to the flat-sheet wake. A simple approximate correction for the effect of the fuselage is applied. The agreement with available experimental data taken behind airplane models is good. Computing forms are included together with charts of pertinent functions, so as to enable simple direct application.

February issue includes Appendix entitled Directory of United States Government periodicals and subscription publications; September issue includes List of depository libraries; June and December issues include semiannual index.