Later A300s incorporated other advanced features such as the Forward-Facing Crew Cockpit, which enabled a two-pilot flight crew to fly the aircraft alone without the need for a flight engineer, the functions of which were automated; this two-man cockpit concept was a world-first for a wide-body aircraft. Glass cockpit flight instrumentation, which used cathode ray tube (CRT) monitors to display flight, navigation, and warning information, along with fully digital dual autopilots and digital flight control computers for controlling the spoilers, flaps, and leading-edge slats, were also adopted upon later-built models. Additional composites were also made use of, such as carbon-fiber-reinforced polymer (CFRP), as well as their presence in an increasing proportion of the aircraft's components, including the spoilers, rudder, air brakes, and landing gear doors. Another feature of later aircraft were the addition of wingtip fences, which generated greater aerodynamic performance (first introduced on the A310-300).