until 1971. An XV-5B can be seen on display at the United States Army Aviation Museum, Fort Rucker, Alabama. Although the program was cancelled, the ducted fan concept had been judged successful and several follow up programs were proposed. The ducted fans were considered very quiet for their time, and were capable of operating from standard surface materials. Other VTOL aircraft often require protective mats to avoid damaging ground surfaces with their exhaust. This is not a problem with the much cooler exhaust from ducted fans. Variants XV-5A Two aircraft built in the initial build standard. XV-5B The second XV-5A re-built after a fatal crash with improved controls, fixed wide-track undercarriage and up-rated lift/propulsion systems. Specifications (XV-5) (performance estimated) See also References Notes Bibliography External links V/STOL: The First Half-Century. Augmented power plant for hover Partial specifications Immenschuh, William T. V/STOL by Vertifan Flight International, October 1964 "600-m.p.h. Vertifan Jet Can Hover Like a Copter." Popular Science, September 1966, pp. 69–73. XV-5 photos and drawings at San Diego Air & Space Museum Archives Lift-fan aircraft – Lessons learned from XV-5 flight experience Gerdes, Ronald M. (SYRE; NASA, Ames Research Center, Moffett Field, CA) AIAA-1993-4838 IN:AIAA International Powered Lift Conference, Santa Clara, CA, 1–3 Dec 1993, Technical Papers (A94-16426 02–05), Washington, American Institute of Aeronautics and Astronautics, 1993 Why not put lift fans in the wings? Dr. Raymond L. Puffer, Air Force Flight Center historian VZ-11 - VTOL Lift from Fans in the Wings a 1962 Flight article Test flight video on youtube XV-05 V-5 Vertifan Twinjets Lift fan Cancelled military aircraft projects of the United States Aircraft first flown in 1964 Low-wing aircraft T-tail aircraft