Hawker Siddeley P.1127 GR.1" designation. The Harrier went on to become a successful aircraft in British service, and was exported to several nations, often seeing usage as a carrier-based aircraft. The P.1127/Kestrel was an experimental V/STOL aircraft, which served as the forerunner for the production of the Hawker Siddeley Harrier and the wider Harrier Jump Jet family. It served to demonstrate an entirely original technique of flight, as well as to trial a brand new type of engine in the form of the Pegasus turbofan engine. Despite this, the aircraft employed a principally conventional structure which, according to Mason, lent itself favourably to
British Aerospace Sea Harrier and were inducted the same year. Ten more Sea Harriers were purchased in November 1985; eventually a total of 30 Harriers were procured, 25 for operational use and the remainder as dual-seat trainer aircraft. Until the 1990s, significant portions of pilot training was carried out in Britain due to limited aircraft availability. The introduction of the Sea Harrier allowed for the retirement of India's previous carrier fighter aircraft, the Hawker Sea Hawk, as well as for the Navy's aircraft carrier, INS "Vikrant" (ex-HMS "Hercules"), to be extensively modernised between 1987 and 1989. India has operated Sea Harriers from both the