Eventhough the Germans had developed the Ruhrstahl X-4,
nothing has really been said about the other AAM developed to some degree during WW 2
The Hughs JB-3 Tiamat, was definitely a much better concept
and design than the X-4. Yet, there is little written on it.
The X-4 was a relatively small wire guided missile. It
had a top speed of about .9 mach (700 mph) and a range of about 3.5 miles (5.5 km). The pilot of the launching plane would
have to 'fly' it using a joystick placed on his insturment panel. This meant he had to keep the missile in sight, the target
in sight, and fly his own plane simultaneously while using this missile.
The JB-3 was also fairly small. It too had
a top speed of about .9 mach but its range was greater at about 9 miles. Guidance was provided by semi-active beam riding.
That is, the firing aircraft would lock its radar on the target and the missile would fly up the radar beam to the target.
beam riding was a far better and more practical means of guidance than a joy stick and wire feed like the X-4, it was only
practical from post war testing against non-maneuvering aircraft targets. Both missiles featured proximity fuses. The US version
used a standard VT type fuze that worked on the same principle as ones in shells and other weapons. The German one worked
on acoustic means. How practical that would have been was never determined but, it too was likely impractical leaving the
X-4 as an impact weapon.
Both missiles underwent some wartime testing. The X-4 was test fired from Ju 88 launch platforms
on a number of occasions. Several Fw 190 were fitted with the firing system but there is no evidence any were used operationally.
The JB-3 was test fired from ground platforms on a number of occasions using a booster rocket to get it aloft.
It was fired from an A-26 on several occasions, the first
being at Wendell Field, Utah, on August 6, 1945 and then a further three
more missiles were fired during the course of the next ten days to test the aerodynamic configuration of the missile
It is not known if any were actually fired using the guidance
system in full against a airborne target like a drone however.
The development of the air-to-air missile has seen a long
and often tumultuous history. From its first serious beginnings during World War II to the advanced, ramjet-powered weapons
undergoing testing today, the capability and effectiveness of the AAM has increased exponentially since the first pioneering
efforts. During the Cold War, the AAM played a key role in the defense of North America from the threat of Soviet bombers.
Supersonic interceptors entered and exited USAF service at various times, but all shared one common element: the Falcon missile.
Originally intended as a bomber-carried AAM for defense against fighter attack, the various Falcon missile variants enjoyed
a service career spanning nearly 50 years, leaving behind a legacy often forgotten by aviation history.
effect of airpower demonstrated in World War II led to the initiation of development programs for four AAMs by 1943. The goal
of these early AAM programs was interception of bombers; missile designs did not yet incorporate the necessary maneuverability
to make them effective anti-fighter weapons. In Germany, the Henschel Flugzeugwerke Hs.298 and Ruhrstahl X-4 both underwent
firing trials by the end of 1944, but neither weapon served in combat. England examined the Artemis missile project in the
The US Navy began developing the Gorgon AAM in July of
1943. Cdr. D. S. Fahrney first suggested the use of unpiloted aircraft for various roles, including bomber interception, in
1937. The USN attempted to begin development in 1940, but available propulsion systems were not adequate. By 1943, rocket
technology had matured to the point where it represented a viable propulsion option, and Gorgon was reborn. Gorgon survived
the war as an AAM concept, but found itself relegated to R&D status in the middle of 1946 as more advanced designs were
on the drawing board.
A fifth AAM program appeared in January of 1944. The USAAF tasked Hughes with developing a subsonic
missile capable of intercepting bombers under project MX-570. The resultant missile, designated JB-3 and referred to by Hughes
as the Tiamat, conducted its first test launch on 6 August 1945, the same day that Col. Paul Tibbets flew the B-29 Enola Gay
to Hiroshima. JB-3 was a large weapon for the time, weighing 625 pounds with a 100-pound warhead. The weapon featured a range
of up to nine miles, and employed an early form of SARH guidance. The JB-3 proved to be unsatisfactory in testing, cancellation
coming in September of 1946.
While none of the World War II-era programs survived to
see operational service, they did provide industry with a technological starting point to develop the first operational AAMs.
Work on the JB-3 established Hughes as one of the frontrunners in the AAM development circle, which would serve the company
well in the post-war years.
The first significant Western AAM program to emerge in
the post-war years had its origins in one of the USN’s last major World War II development programs, Project Bumblebee.
Because of the success of Japanese kamikaze attacks on the fleet, the USN initiated Project Bumblebee to develop a series
of SAM systems. In November of 1945, the USN contracted with MIT to develop the AAM-N-5 Meteor missile as a backstop against
the failure of Project Bumblebee. The contract called for the development of both an AAM and a SAM, although only the AAM
reached the hardware stage. Meteor began flight trials in July of 1948. While the USN cancelled the program in 1953 in favor
of more advanced designs, a recurring theme in early AAM development, it stands as the first AAM ever designed for use by
The USN’s second major post-war AAM program was the AAM-N-2 Sparrow I. Initially, the
USN contracted with Sperry in 1946 to develop a beam-riding guidance system for rockets, converting them into crude AAMs.
This program morphed into a new AAM with the incorporation of an airframe designed by Douglas capable of containing a larger
rocket motor and the necessary guidance equipment. Sparrow I had a protracted development period, with the first intercept
occurring in December of 1952. The weapon reached IOC in 1956, but did not remain in use very long. 2,000 missiles were produced,
and the weapon had a range of 5 miles.
With Sparrow having its genesis in beam-riding rockets,
the USN initiated a dedicated AAM program in 1947. A contract was awarded to Martin to develop the AAM-N-4 Oriole missile,
with the goal of fielding a weapon employing active radar homing (ARH) to a range of up to 25 miles. Difficulties with the
guidance system led to Oriole’s cancellation in 1948, although the airframe returned as a test article in 1950, serving
in that status until 1955. The missile appearing as the test article featured a range reduced to 5 miles, indicating that
an operational variant would not have met the initial range requirement.
By the end of 1946, the USAAF had issued numerous AAM
development contracts. The USAAF sought two categories of missiles: those launched by bombers for self-defense against fighters,
and those launched by fighters to intercept bombers. The sole bomber-launched AAM development program at the time was the
General Electric MX-802, codenamed Dragonfly. Fighter-launched AAM projects included the Ryan MX-799, the Kellogg MX-800,
and the Bendix MX-801. The Hughes MX-798 project represented a continuation of the MX-570 program, albeit with a new design
under the auspices of a generalized AAM research program.
The USAAF cancelled the majority of its AAM programs
before production or testing of hardware occurred, primarily due to budgetary constraints. By March of 1947, the MX-570, MX-798,
and MX-801 no longer remained active. By July of the same year, the USAAF cancelled the MX-800 and reduced the MX-801 to a
guidance system study. The newly formed USAF eliminated the MX-802 and the MX-800 study by March of 1948.
USAAF AAM to reach the hardware stage was Ryan’s MX-799. The Firebird missile, eventually designated AAM-A-1, employed
midcourse command and terminal SARH guidance. An operator directed the missile during midcourse command guidance. Intended
for use against bombers, Firebird was subsonic. The first test launch occurred in October of 1947. Earlier in 1947, Ryan initiated
studies for a proposed supersonic follow-on program, which lasted until March of 1948.
Ultimately, the subsonic speed of the Firebird, coupled
with the midcourse command guidance restricting it to daytime, clear-weather use, led to the program’s cancellation
in April of 1949. Firebird’s demise, alongside the cancellation of numerous missile projects in the post-war years,
left the USAF with a single AAM program.
Hughes JB-3 Tiamat
The JB-3 Tiamat subsonic air-to-air missile program
began in January 1944 under project MX-570. Prime contractor was Hughes who developed the Tiamat with the assistance
of the NACA. JB-3 prototypes were initially launched from the ground with the aid of a booster and then from A-26 Invader
aircraft. The JB-3 was propelled by a dual-thrust (boost/sustain) solid-fueled rocket motor and had three comparatively large
wings with control surfaces for stability and control. The Tiamat used a semi-active radar seeker and the warhead was triggered
by a proximity fuze.
Testing and development of the JB-3 continued until after
World War II, but in late 1946 or early 1947, the program was eventually terminated. By that time, more promising air-to-air
missile projects had been started, notably the AAM-A-1 Firebird and AAM-A-2/F-98/GAR-1 Falcon.
In 1946 the USAAF awarded study contracts for several types
of guided air-to-air missiles. These included project MX-799, which was assigned to Ryan Aeronautical, and which called for
a fighter-launched subsonic AAM for use against bombers. In 1947, Ryan was awarded a development contract under project MX-799
for the AAM-A-1 Firebird missile, the first really viable air-to-air missile project of the U.S. Air Force. The first launch
of an XAAM-A-1 prototype occurred in October 1947.
NBS/McDonnell AUM-N-6 Puffin
The Puffin was part of the Kingfisher family of guided
anti-ship/anti-submarine weapons, which was developed under the prime contract of the National Bureau of Standards (NBS).
Originally begun as Kingfisher F in February 1947, it was redesignated in September that year as AUM-6 (AUM-N-6
from early 1948) Puffin. The development of Puffin was subcontracted by the NBS to McDonnell, and flight tests of XAUM-N-6
prototypes occurred in the 1948/49 time frame.
The XAUM-N-6 was basically a lightweight homing torpedo
in a simple airframe with straight wings, a V-type tailplane, a pulsejet for propulsion, and a radar seeker. After launch
from medium altitude, the missile would drop to about 60 m (200 ft) and home on the target (a surface ship or a surfaced submarine)
using its active radar homing guidance system. Shortly before the target was reached, the torpedo would drop into the water
for its terminal run on the target vessel.
The AUM-N-6 program was short-lived, though, and development
was halted in October 1949.
Martin ASM-N-5 Gorgon V
(and other NAMU Gorgon variants)
Above is a press shot taken on 18th March 1950 of a USAF A-26
with a Gorgon V underneath its Starboar wing.
Martin ASM-N-5 Gorgon V
other NAMU Gorgon variants)
Between 1943 and 1953, the U.S. Navy's Bureau of Aeronautics (BuAer)
developed a whole family of guided missiles under the Gorgon name. The Gorgon project resulted in numerous different vehicles
with a bewildering list of designations (some Gorgon variants were (re-)designated four times within about two years). To
write a useful historical summary of the whole Gorgon program, and to put the various variants in context with each other,
all Gorgon missiles are discussed in this article.
As early as 1937, U.S. Navy Cdr D.S. Fahrney proposed to develop an
unmanned "drone" aircraft for a variety of tasks, including ground attack and the interception of bomber formations. In mid-1940,
the BuAer began to tentatively design what was then called an "aerial torpedo", but then available piston engine technolgy
resulted in an aircraft with far too low performance to be useful. The project re-emerged in May 1943 when the new rocket
and turbojet propulsion began to show promise for missile applications, and in July 1943, the Gorgon developmant program was
formally begun. The Gorgon missiles were designed and built by the NAMU (Naval Aircraft Modification Unit), which became the
NADS (Naval Air Development Station) in 1947 and finally the NADC (Naval Air Development Center) in 1949.
Gorgon was to be a light (300 kg (660 lb)) air-launched missile using
a small (9.5 in) Westinghouse turbojet for a speed of up to 820 km/h (510 mph). The primary mission was to be the interception
of large aircraft (i.e. bombers or transports), with a secondary ground-attack capability. The proposed guidance options included
TV/command guidance (where the missile was controlled by an operator using the picture of a TV camera in the missile nose),
radar homing, or a simple heat (infrared) seeker. For the air-to-air mission, the missile would be equipped with both a proximity
and a contact fuze. However, it seems that the problems of air-to-air missile guidance were a bit underestimated at that time,
because initial Gorgon development focused on airframe and propulsion. Accordingly, in late 1943 alternative airframe configurations
were proposed, the Gorgon II with canards, and the Gorgon III with conventional layout. Both configurations were to be tested
with rocket, turbojet and pulsejet propulsion, indicated by suffix letters "A", "B" and "C", respectively (e.g. Gorgon IIC
would be the pulsejet-powered canard airframe). In late 1943, 25 missiles each of Gorgon II and Gorgon III type were ordered
to be used as test and evaluation vehicles. This order was later amended and changed, and by April 1945 had arrived at 21
Gorgon IIA, 4 Gorgon IIB, 34 Gorgon IIIA, 16 Gorgon IIIB and 20 Gorgon IIIC.
No turbojet variants (Gorgon IIB and Gorgon IIIB) were actually built,
because no suitable flight-rated engine was available at that time. The other Gorgon II/III variants were actually built,
although the Gorgon IIIC ended up with a rocket instead of a pulsejet propulsion system. Initially, all variants were indeed
developed (and designated) as tactical missiles with either anti-aircraft or ground-attack missions. However, a March 1945
live test of a TV/command-guided air-to-air Gorgon IIA failed miserably, because there was effectively no way an operator
could manually steer the rather sluggish missile to an interception point when closing speeds reach 1300 km/h (800 mph). Because
the other proposed guidance methods were also immature and/or unsuitable, the whole Gorgon program was reoriented in mid-1946
to a research and development effort, and all Gorgon variants then in existance were redesignated as test vehicles. For an
overview of the numerous designations, which the Gorgon II/III missiles received between 1945 and 1948.
Some of the Gorgons used as research vehicles were modified with a
parachute recovery system.
The Gorgon IIA, of which 21 were built, was powered by a Reaction Motors
CML2N liquid-propellant rocket engine. Unpowered flight tests began in early 1945, followed by the first powered launches
in March that year. While launching and flying characteristics were generally satisfactory, the same could not be said about
the guidance system. The missile used the radio command guidance system with a TV camera in the nose, but as said in the previous
paragraph, this was unsuitable for air-to-air applications. Intially designated as KA2N-1 anti-aircraft missile in
October 1945, Gorgon IIA was redesignated as KU2N-1 control test vehicle in 1946. In September 1947 and early 1948,
the KU2N-1 was redesignated as CTV-4 and CTV-N-4, respectively.
The Gorgon IIC was of similar canard layout as the Gorgon IIA, but
was powered by a single 14 in. pulsejet instead. It was originally planned as a ship-to-shore bombardment missile, and accordingly
designated KGN-1 in October 1945. At one time, in April 1945, the production of several hundred Gorgon IICs for the
expected invasion of Japan had been planned, but these plans were cancelled after the end of the war. The missile could be
ground-launched from a sled or catapult with the assistance of a solid-propellant rocket booster with 4.0 kN (900 lb) thrust.
The Gorgon IIC had a significantly longer range than the Gorgon IIA at a maximum speed of about 725 km/h (450 mph). However,
like the rest of the early Gorgon vehicles, it became a pure test vehicle in late 1946, and was then known as KUN-1.
It was used to test homing devices, control systems and a variety of other equipment related to guided missile development.
The Gorgon IIC was finally redesignated as CTV-2 in September 1947, and as CTV-N-2 in early 1948. In 1950, a
CTV-N-2 tested an active radar seeker against ship targets.
There was also a Gorgon target drone version very similar to the Gorgon
IIC. Eight examples of this drone were built, and designated as TD3N-1 and (after March 1946) KD2N-1. The RTV-N-15
Pollux is also described as a test vehicle of Gorgon IIC configuration, and it's possible that it used auxiliary rocket propulsion
in addition to its pulsejet. The RTV-N-15 was probably used as a general research vehicle for a short time around 1950/51.
The liquid-fueled rocket-powered KA3N-1 Gorgon IIIA (the engine
was the same Reaction Motors CML2N type as in the Gorgon IIA) was of conventional layout, and was intended as an air-to-air
missile for long range patrol aircraft. It was equipped with TV/radio-command guidance, a homing device (of unspecified type),
a radio proximity fuze, and a 116 kg (257 lb) fragmentation warhead. Introduced in 1945, it was downgraded to control test
vehicle status in mid-1946 (designated KU3N-1), and was used to test various guided missile components. A total of
34 Gorgon IIIAs were built, and the final two designations of this missile were CTV-6 and CTV-N-6.
Although originally planned to be pulsejet-powered, the Gorgon IIIC
emerged as very similar to the Gorgon IIIA. The primary difference was the use of two CML2N liquid-fueled rocket engines instead
of only one as in the IIIA. The missile was successively designated KA3N-2, KU3N-2, RTV-4 and RTV-N-4.
12 Gorgon IIICs were built, and were used by NACA for high-speed (high subsonic regime) research and by the U.S. Navy for
performance and stability tests.
Although the Gorgon IIIB tactical missile was cancelled very early
during the Gorgon program, a derivative was tested as the TD2N-1 (later KDN-1) air-launched target drone. It
was a vehicle very similar in layout to the Gorgon IIIA/IIIC, but powered by a Westinghouse 9.5 in. turbojet. Drop tests began
in June 1945, and the first successful powered flight occurred in August 1945. Because of difficulties with the engine, the
TD2N/KDN program was cancelled in March 1946 after only nine drones had been delivered.
In May 1945, the U.S. Navy began the Gorgon IV program. This missile,
contracted to Martin, was originally planned to be a ramjet-powered air-to-surface missile with an active radar seeker. It
was relegated to propulsion test vehicle status in 1946, and successively designated KUM-1, PTV-2 and PTV-N-2.
It had slightly swept wings and an underslung Marquardt XRJ30-MA (model C-20-85C) ramjet. Free flight tests of KUM-1/PTV-2
vehicles began in July 1947, and the first successful high-speed flight occurred in November that year. The Gorgon IV's ramjet
was designed for a maximum speed of Mach 0.85. The PTV-N-2 flight test program was terminated in December 1949, and the few
remaining Gorgon IV vehicles were used up as KDM-1 Plover target drones. A total of 19 PTV-N-2/KDM-1 missiles were
The last of the Gorgon series was the Martin ASM-N-5 Gorgon
V, begun around 1950 as an unpowered air-to-ground chemical warfare derivative of the PTV-N-2 Gorgon IV. The latter's ramjet
was to be replaced by an Edo X14A aerosol generator, and the missile was to be equipped with an autopilot and a radio altimeter.
The Gorgon V was to be dropped from about 10700 m (35000 ft), diving at a shallow angle at a speed of Mach 0.95 to an altitude
of 30-150 m (100-500 ft), where a spray run of 9-20 km (5-11 nm) range would begin, covering a 9 km (5 nm) wide area. However,
the ASM-N-5 was cancelled in 1953, and it is not clear whether any XASM-N-5 vehicles were actually built and flown.