Hawker Siddeley Harrier GR.1 / GR.1A

The Harrier GR.1 grew out of the Hawker P.1127 and Kestrel evaluation aircraft after the supersonic P.1154 was cancelled. Around 90 per cent of the Kestrel's airframe was redesigned: the GR.1 got the more powerful Pegasus 6 engine with four swivelling nozzles, new intakes with auxiliary blow-in doors, a larger wing and stronger landing gear. An order for 60 production aircraft followed in early 1967, and the first GR.1 flew on 28 December 1967.

The type entered RAF service on 1 April 1969, with No. 1 Squadron at RAF Wittering the first unit to convert. Squadrons followed at Wildenrath in RAF Germany from 1970, where the Harrier was meant to disperse to camouflaged rough sites and strike armoured columns rather than wait on vulnerable main bases. The GR.1A introduced the uprated Pegasus 10 (Mk 102); 17 were built new and 41 GR.1s were converted.

An early showcase came in May 1969, when two Harriers took part in the Daily Mail Transatlantic Air Race between London and New York using air-to-air refuelling; the journey from the Post Office Tower to the Empire State Building took 6 hours 11 minutes. The RAF later upgraded its GR.1/GR.1As to GR.3 standard.