From Wikipedia: The F-4 Phantom was designed as a fleet defense fighter for the U.S. Navy, and first entered service in 1960. By 1963, it had been adopted by the U.S. Air Force for the fighter-bomber role. When production ended in 1981, 5,195 Phantom IIs had been built, making it the most numerous American supersonic military aircraft. Until the advent of the F-15 Eagle, the F-4 also held a record for the longest continuous production with a run of 24 years. Innovations in the F-4 included an advanced pulse-doppler radar and extensive use of titanium in its airframe. Despite the imposing dimensions and a maximum takeoff weight of over 60,000 pounds (27,000 kg), the F-4 had a top speed of Mach 2.23 and an initial climb of over 41,000 ft per minute (210 m/s). Shortly after its introduction, the Phantom set 15 world records, including an absolute speed record of 1,606.342 mph (2,585.086 km/h), and an absolute altitude record of 98,557 ft (30,040 m). Although set in 1959?1962, five of the speed records were not broken until 1975 when the F-15 Eagle came into service. The F-4 could carry up to 18,650 pounds (8,480 kg) of weapons on nine external hardpoints, including air-to-air and air-to-ground missiles, and unguided, guided, and nuclear bombs. Since the F-8 Crusader was to be used for close combat, the F-4 was designed, like other interceptors of the day, without an internal cannon; In a dogfight, the RIO or WSO (commonly called "backseater" or "pitter") assisted in spotting opposing fighters, visually as well as on radar. It became the primary fighter-bomber of both the Navy and Air Force by the end of the Vietnam War. Due to its distinctive appearance and widespread service with United States military and its allies, the F-4 is one of the best-known icons of the Cold War. It served in the Vietnam War and Arab?Israeli conflicts, with American F-4 crews achieving 277 aerial victories in South East Asia and completing countless ground attack sorties. The F-4 Phantom has the distinction of being the last United States fighter to attain ace status in the 20th century. During the Vietnam War, the USAF had one pilot and two WSOs, and the USN one pilot and one RIO, become aces in air-to-air combat. It was also a capable tactical reconnaissance and Wild Weasel (suppression of enemy air defenses) platform, seeing action as late as 1991, during Operation Desert Storm. The F-4 Phantom II was also the only aircraft used by both of the USA's flight demonstration teams. The USAF Thunderbirds (F-4E) and the USN Blue Angels (F-4J) both switched to the Phantom for the 1969 season; the Thunderbirds flew it for five seasons, the Blue Angels for six. 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. The Phantom would be replaced by the F-15 Eagle and F-16 Fighting Falcon in the U.S. Air Force. In the U.S. Navy, it would be replaced by the F-14 Tomcat and the F/A-18 Hornet which revived the concept of a dual-role attack fighter.