The Gloster F.5/34 is one of many intriguing “what-if” fighter aircraft that aviation historians and enthusiasts still discuss today.     First flying in 1936, the initial prototype was modelled as a monoplane development of Gloster’s Gladiator biplane fighter, which was just then about to enter service with the Royal Air Force.     Such an evolution was natural. This course had already been followed by the Hawker company when they developed their famous Hurricane fighter, which was evolved from the Fury. Like the Hurricane, the F.5 was a major update on its biplane...