Fighter: The World's Greatest Aces and Their Planes'' by Edwards Park - Thomasson-Grant Inc. 1990 - Page 144 Even though its engine was rather low in power, the Zero had very low wing loading characteristics, a small turn radius, a top speed over 330 mph , and could climb better than any fighter used by the U.S. at that time, although it was poorly armored compared to U.S. aircraft.