For most of its history, the USAF Air Demonstration Squadron (USAF ADS), better known as the Thunderbirds, had flown front-line fighter aircraft, having been part of TAC since they moved to Nellis AFB, Nevada in the mid-1950s. In 1969, the team switched aircraft from the F-100 Super Sabre to the F-4 Phantom II. However, due to the 1973 oil crisis, the team only flew six air shows and was grounded for some time. In 1974, the Thuunderbirds switched to the more economical T-38 Talon advanced jet trainer. The rationale for the change to a trainer was purely economical in an era of post-Vietnam fiscal austerity, since five T-38s used the same amount of fuel needed for one F-4 Phantom II. The switch to the T-38 also saw an alteration of the team's flight routine to exhibit the aircraft's maneuverability in tight turns.