Concurrently with the development of the Sparrow I, in 1951, Raytheon began work on the semi-active radar homing version of Sparrow family of missiles, the AAM-N-6 Sparrow III.
The first of these weapons entered United States Navy service in 1958.

The AAM-N-6a was similar to the -6, but used a new Thiokol liquid-fuel rocket engine for improved performance.
It also included changes to the guidance electronics to make it effective at higher closing speeds.
The -6a was also selected to arm the Air Force's F-110A Spectre (F-4 Phantom) fighters in 1962, known to them as the AIM-101.
It entered production in 1959, with 7500 being built.

Another upgrade reverted to a Rocketdyne solid-fuel motor for the AAM-N-6b, which started production in 1963.
The new motor significantly increased maximum range to 35 kilometres (22 mi) for head-on attacks.

During this year the Air Force and Navy agreed on standardized naming conventions for their missiles.
The Sparrows became the AIM-7 series.
The original Sparrow I and aborted Sparrow II became the AIM-7A and AIM-7B, despite both being out of service.
The -6, -6a, and -6B became the AIM-7C, AIM-7D, and AIM-7E respectively.

25,000 AIM-7Es were produced, and saw extensive use during the Vietnam War, where its performance was generally considered disappointing.
The mixed results were a combination of reliability problems (exacerbated by the tropical climate), limited pilot training in fighter-to-fighter combat, and restrictive rules of engagement that generally prohibited BVR (beyond visual range) engagements.
The Pₖ (kill probability) of the AIM-7E was less than 10%; US fighter pilots shot down 59 aircraft out of the 612 Sparrows fired.
Of the 612 AIM-7D/E/E-2 missiles fired, 97 (or 15.8%) hit their targets, resulting in 56 (or 9.2%) kills.
Two kills were obtained beyond visual range.

In 1969 an improved version, the E-2, was introduced with clipped wings and various changes to the fuzing.
Considered a "dogfight Sparrow", the AIM-7E-2 was intended to be used at shorter ranges where the missile was still travelling at high speeds, and in the head-on aspect, making it much more useful in the visual limitations imposed on the engagements.
Even so, its kill rate was only 13% in combat, leading to a practice of ripple-firing all four at once in hopes of increasing kill probability.
Its worst tendency was that of detonating prematurely, approximately a thousand feet in front of the launching aircraft, but it also had many motor failures, erratic flights, and fuzing problems.
An E-3 version included additional changes to the fuzing, and an E-4 featured a modified seeker for use with the F-14 Tomcat.
Concurrently with the development of the Sparrow I, in 1951, Raytheon began work on the semi-active radar homing version of Sparrow family of missiles, the AAM-N-6 Sparrow III. The first of these weapons entered United States Navy service in 1958.
The AAM-N-6a was similar to the -6, but used a new Thiokol liquid-fuel rocket engine for improved performance. It also included changes to the guidance electronics to make it effective at higher closing speeds. The -6a was also selected to arm the Air Force's F-110A Spectre (F-4 Phantom) fighters in 1962, known to them as the AIM-101. It entered production in 1959, with 7500 being built.
Another upgrade reverted to a Rocketdyne solid-fuel motor for the AAM-N-6b, which started production in 1963. The new motor significantly increased maximum range to 35 kilometres (22 mi) for head-on attacks.
During this year the Air Force and Navy agreed on standardized naming conventions for their missiles. The Sparrows became the AIM-7 series. The original Sparrow I and aborted Sparrow II became the AIM-7A and AIM-7B, despite both being out of service. The -6, -6a, and -6B became the AIM-7C, AIM-7D, and AIM-7E respectively.
25,000 AIM-7Es were produced, and saw extensive use during the Vietnam War, where its performance was generally considered disappointing. The mixed results were a combination of reliability problems (exacerbated by the tropical climate), limited pilot training in fighter-to-fighter combat, and restrictive rules of engagement that generally prohibited BVR (beyond visual range) engagements. The Pₖ (kill probability) of the AIM-7E was less than 10%; US fighter pilots shot down 59 aircraft out of the 612 Sparrows fired. Of the 612 AIM-7D/E/E-2 missiles fired, 97 (or 15.8%) hit their targets, resulting in 56 (or 9.2%) kills. Two kills were obtained beyond visual range.
In 1969 an improved version, the E-2, was introduced with clipped wings and various changes to the fuzing. Considered a "dogfight Sparrow", the AIM-7E-2 was intended to be used at shorter ranges where the missile was still travelling at high speeds, and in the head-on aspect, making it much more useful in the visual limitations imposed on the engagements. Even so, its kill rate was only 13% in combat, leading to a practice of ripple-firing all four at once in hopes of increasing kill probability. Its worst tendency was that of detonating prematurely, approximately a thousand feet in front of the launching aircraft, but it also had many motor failures, erratic flights, and fuzing problems. An E-3 version included additional changes to the fuzing, and an E-4 featured a modified seeker for use with the F-14 Tomcat.
AIM-7 Sparrow