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
McDonnell Douglas AV-8B Harrier II of funds for a replacement aircraft. Following the decommissioning of "Príncipe de Asturias" in February 2013, the sole naval platform from which Spanish Harrier IIs can operate is the amphibious assault ship . During its service with the USMC, the Harrier has had an accident rate three times that of the Corps' F/A-18s. , approximately 110 aircraft have been damaged beyond repair since the type entered service in 1985, the first accident occurring in March that year. The "Los Angeles Times" reported in 2003 that the Harrier family had the highest rate of major accidents among military aircraft in service