The F-4 Phantom is a tandem-seat fighter-bomber designed as a carrier-based interceptor to fill the U.S. Navy's fleet defense fighter role. Innovations in the F-4 included an advanced pulse-doppler radar and extensive use of titanium in its airframe. The F-4's nine external hardpoints have a capability of up to 18,650 pounds of weapons, including air-to-air and air-to-ground missiles, and unguided, guided, and nuclear bombs. The baseline performance of a Mach 2-class fighter with long range and a bomber-sized payload would be the template for the next generation of large and light/middle-weight fighters optimized for daylight air combat.
(Wikipedia)