AIM-54 Phoenix

The AIM-54A achieved its initial operational capability in 1974 with the introduction of the F-14A Tomcat. The Phoenix uses either an Aerojet Mk 60 or Rocketdyne Flexadyne Mk 47 long-burn-time solid-fuel rocket motor, semi-active radar midcourse guidance, active radar terminal guidance, and a impact or proximity fused 132 pound high explosive warhead. The missile is capable of Mach 5.0 at high altitudes and has a range in excess of 100 miles. At low altitudes, the AIM-54 is limited to Mach 3.8 by aerodynamic heating considerations.

After launch, the Phoenix can use three dif­ferent types of guidance – autopilot, semi active radar homing, or fully-active radar hom­ing. For long-range shots, the missile general­ly flies a pre-programmed route immediately after launch under autopilot control. At mid- course, the nose-mounted radar seeker takes over, operating in semi-active mode, homing in on radar waves reflected off the target from the Tomcat’s AN/AWG-9 or AN/APG-71 radar. Once it gets within about 14 miles of the tar­get, the Phoenix’s own radar takes over for the final run in to the target, and the missile oper­ates in fully-active radar homing mode.

At this time the missile is completely inde­pendent of its launching aircraft, and becomes ‘fire-and-forget’. Some reports have suggested the existence of a ‘flyout’ mode in which the missile can be launched at heavily- jammed targets upon which the F-14 radar is unable to achieve a lock. In such a mode, the missile flies most of the way to the target under autopilot control, switching over to its built-in seeker for the final approach.

Several performance modifications were incorporated into AiM-54As both during and after production. The Reject Image Device (RID) offered improved capabilities against low altitude targets over water, and was incor­porated during production of later missiles. The Extended Active Gate (EAG) improved the missile’s resistance to certain ECM threats, and was also a production feature of later mis­siles. The High Altitude Performance (HAP) modification improved performance against very high-altitude and high-speed targets. This feature was added to late production mis­siles, and was also retrofitted to some earlier missiles. A modification to the warhead, des­ignated Mk 11 Mod 3 EA, improved the war­head lethality against small targets, and was a retrofit item only.

The Phoenix missile is 13 feet long, 15 inches in diameter, has a 3 foot wing span, and weighs 1,008 pounds (AIM-54A) or 985 pounds (AIM-54C). There are two production versions of the Phoenix: the initial AIM-54A which was phased out of production in 1980 after 2,566 had been built; and the follow-on AIM-54C with improved ECCM capability and reliability. An AIM-54B version was to substi­tute sheet metal wings for the difficult to man­ufacture honeycomb ones of the AIM-54A, along with other detail improvements to ease production and maintenance. This version never reached production due to budgetary considerations and the subsequent introduc­tion of the AIM-54C.

Development of the improved AIM-54C missile was undertaken in October 1976 with Hughes delivering the first engineering devel­opment models in August 1979. An increased emphasis was placed on the missile after the Iranian revolution to minimize the usefulness of any information about the AIM-54A that might have fallen into Soviet hands. Pilot pro­duction of 30 rounds for fleet evaluation began in early 1981 and the first production missile was delivered on 27th October 1981.

The AIM-54C featured a new DSU-28C proximity fuse, a new digital electronics unit, inertial navigation reference system, and a solid-state receiver-transmitter. The Navy had a stated requirement for 3,467 of the missiles, to be produced at a peak production rate of 60 per month at a total cost of $4.1 billion.

Quality control problems at Hughes Tucson plant caused the Navy to suspend acceptance of AIM-54Cs on 22nd July 1984, but these were subsequently resolved and deliveries resumed later that year.

The AIM-54C ECCM/Sealed missile provides two major improvements over the early AIM-54C: enhanced electronic counter-coun- termeasures (ECCM) capability and the elimi­nation of the liquid cooling oil. The missile’s external appearance remains unchanged. This version of the Phoenix is also known as the AIM-54C+, and made its first flight on 14th August 1990. The F-14D is not equipped with the cooling oil system. The older missiles physically fit on the F-14D, but there are some flight restrictions In order to minimize the effects of aerodynamic heating since the air­craft cannot cool the missiles in flight.