Upon graduating from military college in 1936 he applied for combat in Spain, joining a Spanish Republican Air Force fighter squadron in 1937.

[citation needed] At the end of 1941 69th Fighter Aviation Regiment received the LaGG-3 to replace the outdated I-16 and relocated to the Stalingrad area.

Shestakov eventually flew more than 450 missions during his career, took part in roughly 100 aerial combats and was credited with 18 solo plus nine shared shootdowns before being killed in action on 13 March 1944.

According to Lavrinenkov's book, Shestakov fought a private war with a well-known Stuka ace - a 'Kurt Renner', who was awarded 'the Golden Knight's Cross'.

Shestakov apparently tried to shoot him down during the first months of 1944, and reportedly searched for a Ju 87 with a viper painted along its fuselage, assuming that this conspicuous aircraft was flown by Renner/Rudel.