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
Harrier Jump Jet to proceed with ordering a modified derivative of the P.1127/Kestrel for service, which was designated as the Harrier GR.1. The "Hawker Siddeley Harrier GR.1/GR.3" and the "AV-8A Harrier" were the first generation of the Harrier series, the first operational close-support and reconnaissance attack aircraft with vertical/short takeoff and landing (V/STOL) capabilities. These were developed directly from the Hawker P.1127 prototype and the Kestrel evaluation aircraft. On 18 April 1969, the Harrier GR.1 officially entered service with the RAF when the Harrier Conversion Unit at RAF Wittering received its first aircraft. The United States Marine Corps (USMC) also chose to procure