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 Siddeley Harrier to replace the first generation of Harrier jets already in service; all the above variants of the Harrier have mainly been retired with the Harrier II taking their place in the RAF, USMC and FAA. In the 1970s the United Kingdom considered two options for replacing their existing Harriers: joining McDonnell Douglas (MDD) in developing the BAE Harrier II, or the independent development of a "Big Wing" Harrier. This proposal would have increased the wing area from , allowing for significant increases in weapons load and internal fuel reserves. The option of cooperation with MDD was chosen in 1982 over