The Boeing AGM-69 SRAM (Short-Range Attack Missile) was an air-to-surface missile with a nuclear warhead. It had a range of up to , and was intended to allow US Air Force strategic bombers to penetrate Soviet airspace by neutralizing surface-to-air missile defenses.

The SRAM was designed to replace the older AGM-28 Hound Dog standoff missile which was tasked with the same basic role. The Hound Dog was a very large missile that could only be carried in pairs by the B-52, so some aircraft were tasked with suppressing Soviet missile and radar sites while others would carry on to strike their strategic targets. The SRAM was so much smaller that a number could be carried along with other weapons, allowing a single aircraft to blast a nuclear path through to its targets.

The SRAM entered service in 1972 and was carried by a number of aircraft, including the B-52, FB-111A, and the B-1B. In September 1980 a ground fire raised concerns about the safety of the warhead, and in 1990 they were temporarily removed from service while safety checks were carried out. These revealed a number of the missiles' rocket motors had developed cracks that could have resulted in them exploding when launched.

The SRAM was removed from service in 1993. The weapon was to be replaced by the AGM-131 SRAM II and the new W89 warhead, but the program was terminated at the end of the Cold War.

History

thumb|"SRAM: A Weapon For Strategic Bombers" (1970) - Official de-classified USAF AGM-69 SRAM information film-reel.

The Air Force had been considering the idea of a medium-range missile to attack air defense sites since the mid-1950s. This concept became more important with the Soviet introduction of the SA-2 missile, which presented a serious threat to the United States Air Force Strategic Air Command's (SAC) bomber fleet. The first attempt to address this role led to the GAM-67 Crossbow, which flew for the first time in 1956. However, the Crossbow's subsonic speed meant it could not get far enough ahead of the bomber to be useful. A supersonic development, the Longbow, was under development, but ultimately cancelled as well.

The role was finally filled by the AGM-28 Hound Dog, a much larger supersonic missile. The Hound Dog served the dual purpose of attacking defense sites as well as being a stand-off missile to use against strategic targets so that the bombers did not have to approach them. However, Hound Dog was so large that only two could be carried by a B-52, and only if it removed all other weapons. A more practical system specifically for the counter-defense role was highly desirable.

AGM-69A SRAM

thumb|left|An AGM-69A SRAM being loaded into a [[B-1B bomb bay in 1987.]]

The requirement for the weapon was issued by the Strategic Air Command in 1964, and the resultant AGM-69A SRAM contract was awarded to Boeing in 1966. After delays and technical flaws during testing, it was ordered into full production in 1971 and entered service in August 1972. It was carried by the B-52, FB-111A, and, for a very short period starting in 1986, by B-1Bs based at Dyess AFB in Texas. SRAMs were also carried by the B-1Bs based at Ellsworth AFB in South Dakota, Grand Forks AFB in North Dakota, and McConnell AFB in Kansas up until late 1993.

thumb|[[White Sands Missile Range Missile Park SRAM display.]]

SRAM had an inertial navigation system as well as a radar altimeter which enabled the missile to be launched in either a semi-ballistic or terrain-following flight path. The SRAM was also capable of performing one "major maneuver" during its flight which gave the missile the capability of reversing its course and attacking targets that were behind it, sometimes called an "over-the-shoulder" launch. The missile had a circular error probable (CEP) of about and a maximum range of . The SRAM carried the W69 warhead with an estimated yield of . A decade earlier in September 1980, a B-52H on alert status at Grand Forks AFB in northeastern North Dakota experienced a wing fire that burned for three hours, fanned by evening winds of . The wind direction was parallel to the fuselage, which likely had SRAMs in the main bay. Eight years later, weapons expert Roger Batzel testified to a closed U.S. Senate hearing that a change of wind direction could have led to a conventional explosion and a widespread scattering of radioactive plutonium.

The AGM-69A was retired in 1993 over growing concerns about the safety of its warhead and rocket motor. There were serious concerns about the solid rocket motor, when several motors suffered cracking of the propellant, thought to occur due to the hot/cold cycling year after year. Cracks in the propellant could cause catastrophic failure once ignited.

Specifications

  • Length: with tail fairing, without tail fairing
  • Diameter: .
  • Wing span: .
  • Launch weight: .
  • Maximum speed: Mach 3.5
  • Maximum range: depending on flight profile
  • Powerplant: 1 × Lockheed SR75-LP-1 two stage solid-fuel rocket motor
  • Guidance: General Precision/Kearfott KT-76 IMU and Stewart-Warner radar altimeter
  • CEP:
  • Warhead: W69 thermonuclear

References

General

  • Gunston, Bill (1979). Illustrated Encyclopedia of the World's Rockets & Missiles. London: Salamander Books.
  • Air University and the 42nd Air Base Wing
  • Strategic Air Command