Analog avionics began to be introduced, replacing older "steam-gauge" cockpit instrumentation. Enhancements to improve the aerodynamic performance of third-generation fighters included flight control surfaces such as canards, powered slats, and blown flaps. A number of technologies would be tried for Vertical/Short Takeoff and Landing, but thrust vectoring would be successful on the Harrier jump jet.The F-4 Phantom II was one of the most advanced 3rd generation fighter jets and was the only plane to fly as a Blue angel and a Thunderbird.[citation needed]