The HAL Ajeet (; IAST: Ajīt, invincible or unconquerable) was a jet-powered fighter aircraft developed and manufactured by Indian aerospace manufacturer Hindustan Aeronautics Limited (HAL). It was operated by the Indian Air Force (IAF) between 1977 and 1991.
The Ajeet is a derivative of the British Folland Gnat light fighter aircraft. The Gnat, which had been procured in large numbers for the IAF and produced under license by HAL, had acquitted itself favourably during its Indian service, including in active combat roles during multiple conflicts with Pakistan, including the Indo-Pakistani War of 1965 and the Indo-Pakistani War of 1971. As such, the IAF had a positive attitude towards the type, despite observing shortcomings in maintainability and some subsystems. Thus, during 1972, the service issued a requirement calling for the development of an upgraded and more capable variant of the Gnat, leading to the development of the Ajeet by HAL.
In the design phase of the Ajeet, HAL redesigned several aspects of the aircraft while seeking to improve both the reliability and effectiveness of several subsystems, such as the avionics and hydraulic systems. The adoption of a wet wing expanded the fighter's internal fuel capacity and freed-up several underwing hardpoints for other purposes, effectively increasing both the range and payload capability of the aircraft. On 6 March 1975, the first of two Ajeet prototypes, producing via the conversion of the final two licence-produced Gnat fighters, conducted its maiden flight. The satisfactory performance of these prototypes contributed to the issuing of a production order for the Ajeet. On 30 September 1976, the first production aircraft performed its maiden flight. Introduced to service during the following year, the Ajeet had a relatively brief and unremarkable service life, equipping only a single IAF squadron and being withdrawn from service during 1991.
Development
Background
During the 1950s, the government of India had come to an agreement with the United Kingdom to procure a large number of Folland Gnat fighters, a light combat-capable jet-propelled aircraft, for the Indian Air Force (IAF). In addition to the acquisition of British-built Gnats, the type was also manufactured under a licensing arrangement in India by aviation company Hindustan Aeronautics Limited (HAL). During its production run, in excess of 200 aircraft were constructed by HAL for the IAF; as much as 85 per cent of the airframe and 60 per cent of the engine were domestically produced. During 1958, the first Gnat fighter was accepted by the IAF into squadron service.
During its service life with the IAF, the Gnat proved to be relatively successful when deployed for active combat missions. The type was used in both the Indo-Pakistani War of 1965 and the follow-up Indo-Pakistani War of 1971 against neighbouring Pakistan. Operationally, it was used to conduct both low-level air superiority missions and to perform short range ground attack runs. Due to its effectiveness against Pakistani fighters, such the North American F-86 Sabre, the type was given the moniker of Sabre Slayer. The Gnat was ultimately operated by the IAF for several decades up until its retirement during the 1980s.
According to aviation author Pushpindar Chopra, the design of the Gnat had both positive and negative attributes; while being inexpensive to construct and to operate, several of the onboard systems had been allegedly prone to low levels of reliability, particularly the control system of the aircraft, while some aspects had proved to be difficult to maintain. The reliability issues had been a known contributing factor to several accidents which had resulted in the total loss of individual Gnats and the deaths of several pilots.
Programme launch
Accordingly, while the Gnat had been determined to be effective as a combat aircraft, it was also viewed that there was room for improvement on the design of its subsystems. During 1972, the IAF therefore issued a formal requirement, calling for the development and production of an improved model of the Gnat. Although the original revision of the requirement had called for the type to be produced to function as an interceptor, it was subsequently modified to incorporate a secondary ground-attack role for the new model as well. According to a report by the Public Accounts Committee of the Indian Parliament, the IAF officials tasks with overseeing the programme lacked realistic concepts of what was involved in the development process nor firm ideas on what the aircraft was required for.