Ex RCAF 21160 / CAF 133160. It was sold to the Skyfox Corporation 14 January 1983 as N221SF and was converted as their prototype Skyfox with two pod mounted Garrett TFE731-3A turbofans and first flew at Mojave, California 21 August 1983. The company was taken over by the Boeing Military Aircraft Company in 1986 but no more aircraft were converted. Portugal was interested in purchasing 20 conversion kits but with no other interest the project was abandoned. The Skyfox was noted stored at the Rogue Valley International Airport, Medford, Oregon without engines in June 2008.