In 1977, the Air Force sent the F-111F aircraft from Mountain Home to the 48th Tactical Fighter Wing at RAF Lakenheath, England, to modernize its European forces. In return, the 366th Fighter Wing, located in Mountain Home AFB, Idaho, received F-111A aircraft from Nellis AFB, Nevada, where they equipped the 389th and 391st Squadrons.
The F-111A 'Aardvark' was an all-weather attack aircraft, capable of low-level penetration of enemy defenses to deliver ordnance on the target. The F-111 featured variable-geometry wings, an internal weapons bay and a cockpit with side-by-side seating. The cockpit was part of an escape crew capsule.[36] The wing sweep varied between 16 degrees and 72.5 degrees (full forward to full sweep). The wing included leading edge slats and double slotted flaps over its full length. The F-111 used a three-point landing gear arrangement, with a two-wheel nose gear and two single-wheel main landing gear units. The landing gear door for the main gear, which was positioned in the center of the fuselage, also served as a speed brake in flight. Most F-111 variants included a terrain-following radar system connected to the autopilot. The aircraft was powered by two Pratt & Whitney TF30 afterburning turbofan engines.