25.08.1916 Famous Russian ace E.N.Kruten' shot down his first German aircraft. During the WW1 he claimed 7 victories (+2 unconfirmed). Nieuport 17/21/23/24/25/27
25.08.1937 ANT-51 (renamed Su-2) first flight. Sukhoi Su-2
25.08.1959 Tupolev Tu-121 unmanned attack supersonic aircraft first flight. It was the prototype of Tu-123 'Hawk'.