The AGM-12 Bullpup is a short-range air-to-ground missile developed by Martin Marietta for the US Navy. It is among the earliest precision guided air-to-ground weapons and the first to be mass produced. It first saw operational use in 1959 on the A-4 Skyhawk, but soon found use on the A-6 Intruder, F-100 Super Sabre, F-105 Thunderchief, F-4 Phantom II, F-8 Crusader, and P-3 Orion in both Navy and US Air Force service, as well as NATO allies. The weapon was guided manually via a small joystick in the aircraft cockpit, which presented a number of problems and its ultimate accuracy was on the order of , greater than desired. In the 1960s it was increasingly supplanted by fully automatic weapons like the AGM-62 Walleye and AGM-65 Maverick.

History

ASM-N-7 Bullpup

Development of Bullpup began in 1953 when Korean War experience demonstrated the almost complete inability for conventional bombing to attack point land targets like bridges. There had been great experimentation during World War II on various guided weapons by many of the belligerents, including some operational use of radio control weapons by Germany and the US with varying degrees of success. These experiments mostly ended in the post-war era, especially as nuclear weapons made accuracy a less interesting problem to solve. This left little research into conventional weapons before Korean War started.

A contract tender for a new weapon was released in 1953 calling for a weapon armed with the AN-M57 or AN-M81 bomb and a maximum speed of Mach 2. The contract was won by Martin Marietta in April 1954 and the project was assigned the name ASM-N-7 Bullpup. The initial XASM-N-7 prototypes were powered by the Mark 8 Mod 1 solid propellant rocket motor made by Aerojet-General, which delivered about 38 kN of thrust for 2.5 seconds. The first test launches were carried out in June 1955.

The weapon was guided by the launch aircraft through the manual command to line of sight (MCLOS) method, with the pilot tracking the flight of the missile via two bright flares on the weapon's tail and making corrections using a small joystick in the cockpit. The position of the receiver antenna on the weapon meant that the aircraft had to continue flying in roughly the same direction as the missile in order for the signals to be received from the AN/ARW-73 transmitter, and due to the location of the cockpit on the aircraft, this generally meant the aircraft had to be in a dive toward the target throughout the approach.

Although the weapon did not meet its original requirements exactly, in that it carried only the M81 warhead and reached M1.8, development was otherwise straightforward. The weapon was officially put into service on 25 April 1959 on the A-4 Skyhawks aboard the USS Lexington. This was followed by fittings on the North American FJ-4 Fury and Sikorsky CH-34. Production versions were mostly built by Maxson Electronics.

GAM-79 White Lance, Bullpup A

The US Air Force was interested in the system as early as 1954, and in 1955 began development of their own version, known as White Lance. Desiring higher performance, White Lance was to use a liquid fuel rocket engine, the Thiokol LR44 which provides approximately 53.9 kN of thrust for 2 seconds. LR44 was originally intended for Sparrow III missile. It used storable hypergolic propellants: inhibited red fuming nitric acid as an oxidizer and MAF-1 as a fuel. MAF-1 is a mixture of 40.5% UDMH, 50.5% diethylenetriamine and 9% acetonitrile. Compared to solid rocket motor, liquid rocket engine provided increased impulse and smokeless exhaust, improving visibility for a pilot. Another change was to move to a newer radio control system, the AN/ARW-77, which allowed off-axis guiding so the aircraft could fly parallel to the target instead of straight at it, greatly increasing visibility and eliminating the need to dive directly at the target.

While they waited for GAM-79, the Air Force also purchased examples of the ASM-N-7, which they put into service under the name GAM-83 on the North American F-100 and Republic F-105. As the development of GAM-79 continued, the Navy also became interested in a liquid fuel engine and had Thiokol build another version, the LR58.

For training purposes, Martin produced a guidance system that could be fit to surplus High Velocity Aircraft Rockets, which entered service as the TASM-N-7/TGAM-83.

Bullpup B

thumb|[[Saab 35XD prototype fitted with a AGM-12B under its left wing]]

While development of the original versions was still ongoing, development of a significantly larger version, ASM-N-7b Bullpup B, began. This enlarged the warhead to and upgraded the motor to the LR62 with much higher thrust.

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  • Republic of China Air Force

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  • Turkish Air Force

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  • Royal Air Force
  • Royal Navy

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  • United States Air Force
  • United States Navy

See also

References

  • Designation Systems.Net website
  • Federation of American Scientists webpage