Roll Rate

Report No. 868 - National Advisory Committee for Aeronautics
Figure 47. - Variation with indicated airspeed of rolling velocity obtainable with 50-pound stick force. Altitude, 10,000 feet.

The wings of the British Spitfire fighter aircraft were elliptically shaped, except when they weren't. At some point they started clipping the wing tips which greatly upset the purists in the aesthetics department, but helped with the maneuverability.
    This was kind of nit. This report came out after the war. During the war they had much bigger issues with aircraft design.
    The N.A.C.A. (National Advisory Committee for Aeronautics) produced a boatload of reports, all of which are supposedly available online from NASA, but try as I might I couldn't get NASA's website to cough this one up. I had better luck with a British site, but only because I knew the year (1947). No surprise there since NASA's public face is their promotional / marketing arm, and what do taxpayers care about roll rate?