Hawker Siddeley Harrier as VTOL and STOL manoeuvres (where the traditional lift and control surfaces are useless) requiring skills and technical knowledge usually associated with helicopters. Most services demand great aptitude and extensive training for Harrier pilots, as well as experience in piloting both types of aircraft. Trainee pilots are often drawn from highly experienced and skilled helicopter pilots. In addition to normal flight controls, the Harrier has a lever for controlling the direction of the four vectoring nozzles. It is viewed by senior RAF officers as a significant design success, that to enable and control the aircraft's vertical flight required only a
British Aerospace Harrier II programme. In July 2008, Qinetiq was awarded a contract to perform upgrades and maintain the Harrier II fleet until 2018, which was the predicted out of service date for the type. The first squadrons to receive the Harrier II were based in Royal Air Force Germany, a standing force maintained to deter Soviet aggression against the West and, in the event of war, to carry out ground attacks. As the Harrier II had significantly greater range and survivability than its predecessor the Hawker Siddeley Harrier, a new emphasis was placed on interdiction operations. By the end of 1990, the Harrier