The AIM-7 Sparrow is a radar-guided, air-to-air missile with a high-explosive warhead. The versatile Sparrow has all-weather, all-altitude operational capability and can attack high-performance aircraft and missiles from any direction. It had been the major medium range air-to-air missile of U.S. fighters until the introduction of the AIM-120 AMRAAM.
The AIM-7F featured vast improvements over previous version of the missile. These improvements included a new dual-thrust (boost/sustain) rocket motor (usually a Hercules MK 58, but sometimes an Aerojet MK 65), which greatly increased the missile's range and a completely new solid-state electronic guidance and control system (GCS), designated AN/DSQ-35, which was also compatible with modern pulse-doppler radars. The smaller GCS permitted the use of a larger MK 71 warhead in the new WAU-10/B warhead section.
The main new feature of the AIM-7M was the new inverse monopulse seeker for look-down/shoot-down capability in a new WGU-6/B (later WGU-23/B) guidance section. The monopulse seeker improves missile performance in low-altitude and ECM environments. Other new features of the AIM-7M are a digital computer (with software in EEPROM modules reprogrammable on the ground), an autopilot, and an active fuze. The autopilot enables the AIM-7M to fly optimized trajectories, with target illumination necessary only for mid-course and terminal guidance. The AIM-7M also has a new WDU-27/B blast-fragmentation warhead in a WAU-17/B warhead section.
The AIM-7P is an improved AIM-7M. It features improved guidance electronics and on-board computer, has a new radar fuze, and has an uplink to the autopilot for mid-course guidance updates. The AIM-7P improves Sparrow performance especially against small and/or low-flying targets.
The final Sparrow variant was the AIM-7R. It was an improved AIM-7P Block II with a new dual mode (Radar/IR) seeker developed under the MHIP (Missile Homing Improvement Program) to improve the terminal phase performance. It also had a considerably improved on-board computer for the higher processing requirements of active terminal homing. Although it was initially planned to upgrade many AIM/RIM-7M/P rounds to AIM/RIM-7R standard, the -7R program was cancelled because of high costs after the evaluation phase was completed.