Hawker Siddeley Harrier single lever added in the cockpit. For horizontal flight, the nozzles are directed rearwards by shifting the lever to the forward position; for short or vertical takeoffs and landings, the lever is pulled back to point the nozzles downwards. The Harrier has two control elements not found in conventional fixed-wing aircraft: the thrust vector and the reaction control system. The thrust vector refers to the slant of the four engine nozzles and can be set between 0° (horizontal, pointing directly backwards) and 98° (pointing down and slightly forwards). The 90° vector is normally deployed for VTOL manoeuvring. The reaction control
Hawker Harrier February , the first of the competitors for the two specifications to fly. The Harrier was a two-seat biplane with single-bay wings powered by a geared Bristol Jupiter VIII radial engine. It was armed with one .303 in (7.7 mm) Vickers machine gun and one .303 in (7.7 mm) Lewis gun carrying a maximum of 1,000 lb (454 kg) of bombs. The prototype Harrier was tested at the Aeroplane and Armament Experimental Establishment (A & AEE) at Martlesham Heath in November 1927, where, while it met the requirements of Specification 23/25 and had satisfactory handling, the geared engine meant that