The AAM-N-3 Sparrow II was unique in that it had a fully active radar guidance system. This combined both a radar transmitter and receiver in the missile, making it unnecessary for the pilot to keep the aircraft aimed at the target after firing the missile, unlike Semi-active radar homing (SARH) missiles which require continuous radar-assisted guidance throughout flight. This allowed the aircraft that fired the AAM-N-3 to turn away, prosecute other targets, and/or escape from potential retaliatory missiles fired by the enemy aircraft during the time it takes for the Sparrow to reach its target. Despite the significant advantages of this design over SARH guidance, all subsequent models of the Sparrow use semi-active radar homing.