The Vickers FB (Fighting Biplane) 5, also known as the “Gunbus”, was the world’s first fighter aircraft. It was in 1912 that Vickers began addressing the concept of an aircraft designed solely to destroy other aircraft. Designer Archibald Lowe’s first attempt, the experimental FB1, crashed on its maiden flight in early 1913 but development continued with further versions culminating in the FB5 which first flew on 17 July 1914.
Powered by a Gnome Monosoupape 9-cylinder rotary engine generating 100 hp, the FB5 was of the ’pusher’ layout with a gunner position forward of the pilot. Armament comprised a single Lewis .303in drum-fed machine gun. The aircraft entered RFC service with No 6 Squadron in November 1914 and several other squadrons on the Western Front each received one or two machines during the early months of 1915. However, it was No 11 Squadron that became the first true fighter squadron in the history of flying when, equipped entirely with FB5s, it deployed to France on 15 July 2015. And it was an action on 7 November 1915 by a No 11 Squadron crew that led to the award of a Victoria Cross to 2nd Lieutenant Gilbert Stuart Martin Insall who, along with his gunner, First Class Air Mechanic T. H. Donald, destroyed an German Aviatik machine and then, after being shot down by ground fire, repaired their machine and returned to base.
Although its forward firing gun was a great advantage in early combat, the FB5 was hampered by an unreliable engine and did not have sufficient speed, rate of climb nor ceiling to fully exploit its intended role. By the end of 1915 it was outclassed by German machines and was finally withdrawn from the Western Front in mid-1916, thereafter to be used as a trainer.
Eleven RFC squadrons were equipped with the FB5 and it was also operated by France and Denmark. A total of 224 aircraft were built. Whilst no FB5s survive, a replica built by British Aircraft Corporation apprentices from original drawings flew between 1966 and 1968 before being handed over to the RAFMuseum where it is now on display.