AGM-28 Hound Dog
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The North American AGM-28 Hound Dog was the first air-launched nuclear stand-off missile deployed by the United States.
Development
The development of the nuclear stand-off missile was initiated by the USAF in 1956. Initially known as Weapon System 131B, it was intended to give Strategic Air Command heavy bombers the ability to attack Soviet targets from outside enemy airspace. The first powered flight of the prototype missile, designated XGAM-77, was made in April 1959. The missile's engine, airframe, and warhead were straightforward adaptations of existing technology, so the weapon's development period was quite short, and the production GAM-77 entered operational service in December 1959. It received the popular name Hound Dog, apparently inspired by the contemporary hit song by Elvis Presley.Hound Dog was essentially an unpiloted jet airplane with small delta wings and forward canards. It was powered by a single Pratt & Whitney J-52-P-3 turbojet in a ventral pod beneath the rear fuselage, with 7,500 lbf (33 kN) thrust. It used inertial navigation for guidance, with heading updates provided by astro-trackers mounted in the launch pylon. The W28 warhead (the same as the B28 nuclear bomb) had an explosive yield of 1.1 megatons. The missile's maximum range was about 700 miles (1,100 km).
The Hound Dog was carried by B-52 Stratofortress bombers; the B-52D, B-52G and B-52H were fitted with provision for the large underwing pylons to launch the weapons, each bomber normally carrying one under each wing. The Hound Dog's fuel tanks, interestingly, could be topped up from the B-52's own fuel supply, and before launch its engines could be used as auxiliary booster engines for the bomber. The missile's inertial navigation system (INS) could be used as a backup system for determining the aircraft's position after the initial calibration and "leveling" which took a minimum of 90 minutes.
The GAM-77 was subsequently upgraded to GAM-77A standard, with improved astro-trackers now mounted in the missile, rather than the pylon, a radar altimeter, and larger fuel capacity. The upgrade made possible several different altitude profiles, such as high altitude launch/high altitude cruise (high/high) or high altitude launch/high altitude cruise followed by a descent to terrain following cruise (high/high/low). Other options were high/low, low/high, low/low and low/high/low.
In June 1963 the GAM-77 and GAM-77A were redesignated AGM-28A and AGM-28B, respectively. An updated AGM-28C, with improved guidance, was proposed in the early 1970s, but never built.
A total of about 700 Hound Dogs were produced. They were intended to be replaced by the AGM-48 Skybolt, which did not enter service. The last Hound Dogs were retired in 1976.
Specifications
- Length: 12.95 m (42 ft 6 in)
- Wingspan: 3.66 m (12 ft)
- Diameter: 0.71 m (28 in)
- Launch weight: 4,500 kg (10,000 lb)
- Speed: Mach 2.1
- Ceiling: 16,800 m (55,000 ft)
- Maximum range: 1,100 km (700 miles)
- Guidance: inertial with astro-tracker heading correction
- CEP: 13,000 feet
- Warhead: W-28 thermonuclear (1.1 MT)
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