On 10 April 1959, Northrop test flew the N-156 prototype, which was first developed into the T-38 supersonic lightweight twin-jet trainer for USAF pilot training and then modified into the F-5 light tactical fighter. The first true model of the F-5 "Freedom Fighter" was flown on July 30, 1959, and deliveries to the Tactical Air Command for instructing foreign pilots began in April 1964. The F-5B two place combat trainer version first flew in February 1964, with 134 in final production. In 1966-67, a USAF squadron under the code name Skoshi Tiger flew F-5As during combat missions in southeast Asia for operational evaluation purposes. More than 2,000 F-5 aircraft have been procured by the USAF for use by Allied nations. The F-5B on display was officially assigned as a test bed for structural testing and was never completely fitted for flight operations. It is painted to represent a USAF F-5B "Tiger II" single seat fighter aircraft in operations during 1966-67. This aerospace vehicle, serial number 73-1630, is part of the USAF Heritage Program Collection.