The X-31 VECTOR aircraft has performed the first extremely short take-off and landing (ESTOL) approaches to a virtual runway 5,000ft (1,525m) above ground at the NAS Patuxent River, Maryland. Such approaches are being explored for aircraft carrier operations and are due to culminate next year in ESTOL landings on a runway. Landing approaches to the virtual runway are planned at up to a 45° angle of attack, whereas the angle of attack for real landings will be limited to 24° for safety reasons, in case of a failure of the thrust vectoring system. VECTOR, which is a joint venture between the US Navy, German defence procurement agency BWB, EADS and Boeing, is also being used as a testbed for an EADS-developed flush air-data system.
Source: Flight International