In order for the Tornado to perform well as a low-level supersonic strike aircraft, it was considered necessary for it to possess good high-speed and low-speed flight characteristics. To achieve high-speed performance, a swept-wing or delta-wing planform is typically adopted, but these wing designs are inefficient at low speeds. To operate at both high and low speeds with great effectiveness, the Tornado uses a variable-sweep wing. This approach had been adopted by earlier aircraft, such as the American General Dynamics F-111 Aardvark strike fighter, and the Soviet Mikoyan-Gurevich MiG-23 fighter. The F-111 has many similarities with the smaller Tornado; however, the Tornado differs in being a multi-role aircraft with more advanced onboard systems and avionics. The Tornado features a tandem-seat cockpit, crewed by a pilot and a navigator/weapons officer; both electromechanical and electro-optical controls are used to fly the aircraft and manage its systems. An array of dials and switches are mounted on either side of a centrally placed CRT monitor, controlling the navigational, communications, and weapons-control computers. BAE Systems developed the Tornado Advanced Radar Display Information System (TARDIS), a 32.5-centimetre (12.8 in) multi-function display, to replace the rear cockpit's Combined Radar and Projected Map Display; the RAF began installing TARDIS on the GR4 fleet in 2004.