The F-111C is a high speed, all-weather attack aircraft capable of low-level penetration of enemy defences to deliver its ordnance. The F-111C features variable geometry wings, an internal weapons bay and a cockpit with side by side seating. The cockpit is part of a crew escape module. The wing sweep varies between 16 degrees and 72.5 degrees (full forward to full sweep). The airframe is made up mostly of aluminium alloys with steel, titanium and other materials used throughout the aircraft. The F-111C has a terrain-following radar system connected to the autopilot giving it the ability to fly at low level in all weather conditions and is powered by two Pratt & Whitney TF30 afterburning turbofan engines.