The Gnat was designed by W.E.W. Petter as a development of the private venture Folland Midge, and first flew in 1955. Its design allowed its construction without specialised tools by countries not highly industrialised. Although never used as a fighter by the Royal Air Force (RAF), the Gnat T.1 trainer variant was widely used. The Gnat became well known as the aircraft of the RAF’s Red Arrows aerobatic team.
The Gnat was exported to Finland, Yugoslavia and India. The Indian Air Force became the largest operator and eventually manufactured the aircraft under licence. India then developed the HAL Ajeet, a modified and improved variant.
The Gnat was the creation of WEW “Teddy” Petter, a British aircraft designer formerly of Westland Aircraft and English Electric. Designed to meet the 1952 Operational Requirement OR.303 calling for a lightweight fighter, Petter believed that a small, simple fighter would offer the advantages of low purchase and operational costs. New lightweight turbojet engines that were being developed enabled the concept to take shape. Petter’s first design resulted in the Folland Midge private venture, which however had only a short lifespan, but served as a proof-of-concept design. It failed to interest the RAF as a combat aircraft, but they encouraged the development of a similar aircraft for training purposes.
The first prototype Gnat was built as a private venture project by Folland, but subsequently six further aircraft were ordered by the British Ministry of Supply for evaluation. The Folland prototype, serial number G-39-2, first flew on 18 July 1955 from Boscombe Down.
Although the evaluation by the British brought no orders for the lightweight fighter, orders were placed by Finland, Yugoslavia and a large order from India which included licence for production by Hindustan Aeronautics Limited. Although the Gnat’s development is considered a factor which motivated the Mutual Weapons Development Team to issue a NATO requirement for a low level light fighter, the Gnat itself was not evaluated in the competition, which was won by the Fiat G.91. However, the Gnat was evaluated in 1958 by the Royal Air Force as a replacement for the de Havilland Venom, as well as other light fighters such as the BAC Jet Provost, the Hawker Hunter was the eventual winner of the fly-off competition.