AGM-28 Hound Dog

In the 1950s, the appearance of the first anti-aircraft missile systems significantly complicated the use of conventional, free-falling bombs against enemy targets. The United States, which deployed more than 200 MIM-3 Nike Ajax air defense batteries in 1953-1958 to cover the country's territory, feared that the USSR could implement a similar program ^[5] , thereby significantly weakening the combat potential of American strategic aviation.

The solution to the problem could be missiles launched from strategic bombers with nuclear warheads. Faster, less noticeable and much cheaper, such missiles could effectively break through the enemy’s air defense. Launched from a sufficient distance, they allowed the bomber himself to avoid entering dense air defense sectors.

In 1956, GOR 148 ( General Operational Requirement 148 ) requirements were formulated for an air-based cruise missile with a range of several hundred kilometers. Such a missile would have to have a mass of not more than 5700 kg in order to enable the suspension of a pair of missiles under the wings of a B-52 bomber. Chance Vought and North American Aviation firms proposed their projects for the competition: the first - a modernized SSM-N-9 Regulus II ship cruise missile upgraded for air launch, the second - a new missile based on the Navajo intercontinental cruise missile. As a result, the second project was chosen to continue the work.

The AGM-28 “Hound Dog” cruise missile was developed with the active involvement of developments on the Navajo intercontinental cruise missile. Like the prototype, it had a narrow cigar-shaped fuselage, about 12.95 meters long. The plumage was performed according to the “duck” scheme, horizontal stabilizers were in the bow, and vertical ones were in the tail. Wingspan 3.71 meters.

The rocket was propelled by a Pratt & Whitney J52-P-3 turbojet engine located under the fuselage, with a thrust of 33 kilonewtons. The engine was specially modified for continuous operation at maximum power, which is why its resource was limited to only 6 hours. However, since the flight duration of the rocket was less than half an hour, the low engine life did not matter. The engine provided the rocket with a speed of the order of M = 2.1 at a distance of 1263 km.

An interesting feature of the rocket was that it could be used as a launch booster when a heavily loaded bomber took off. The spent fuel was then replenished in flight directly from the carrier tanks.

In the front of the rocket was a thermonuclear warhead of type B28 , the power of which could be set to values ​​from 60 kt to 1.45 Mt. At the maximum setting, the warhead provided an area of ​​extensive damage from overpressure of the shock wave above 5 psi - with a radius of 7.4 km and effective exposure to light radiation in a radius of up to 14.1 km.

The missile was guided using the N5G inertial navigation system (development of the N-6 system developed for Navajo). To clarify the position of the rocket at the time of launch, the Kolsman astrocorrection system KS-120 mounted on the bomber’s pylon was used. The bomber and missile continuously exchanged navigation information, which made it possible to guarantee the absence of errors. The missile’s probable circular deflection was about 3.2 km, which was considered acceptable when using a megaton warhead.

AGM-28 missiles were launched from the board of the specially equipped B-52G / H missile carrier. Two rockets were suspended under the wings of a bomber on special pylons. The launch of missiles could be carried out from any height, not less than 1200 meters.

The missile had three flight modes:

• High-altitude attack - a rocket made an entire flight at an altitude of 17,000 meters or more and then dive to the target.
• Low altitude attack - a rocket flew at an altitude of about 1,500 meters. At the same time, the radius of action was reduced to 640 kilometers (due to increased air resistance), but the missile was less noticeable for enemy radars. Since the missile followed the target in a straight line and could not go around the bumps in the terrain, when starting in this mode it was necessary to make sure that there were no obstacles more than 1000 meters high on the proposed launch track.
• Low-altitude radar attack - a rocket flew at an altitude of 900 to 30 meters above the surface, guided by a radar altimeter. Only the GAM-77A modification could carry out such a flight. The rocket could not go around the bumps of the relief except by jumping through them with a vertical jump.
• Dodging attack - the rocket flew from the launch point to a pre-programmed position, then turned and rushed toward the target. Such a maneuver was to mislead the enemy fighters regarding the purpose of the attack, and allow the missile to slip through.

On later rocket models, various design solutions were used to improve their characteristics. So, the KS-120 astrocorrection system on the bomber’s pylon was replaced by the new KS-140, built directly into the rocket itself. The AGM-28 tested EPR reduction systems and, accordingly, reducing the missile detection radius by enemy radars.

In 1971, a modification of the rocket was tested with the TERCOM radar map orientation system , which was an early version of the system used in the future on the BGM-109 Tomahawk . It was assumed that TERCOM will allow the rocket to fly at very low altitudes, bypassing the terrain roughnesses embedded in its computer. The tests were successful, and the TERCOM missiles, for which the designation AGM-28C were reserved, were never received. The reason was the low fitness of the supersonic missile for flights at altitudes of 30-50 meters: because of the high speed, the missile control system did not have time to respond to obstacles.

In 1972, a strategic anti-radar missile based on the AGM-28 was also developed. Equipped with a passive radar seeker, it was intended to destroy the enemy’s radar from a long distance, but although it successfully passed the tests, it was not entered service.

The number of missiles AGM-28 "Hound Dog" in service, by years:

• B-77 - designation used in the mid-1950s in the process of developing a rocket ^[6]
• XGAM-77 - 25 prototype missiles
• GAM-77 (since 1963 - AGM-28A) - 697 serial missiles
• GAM-77A (since 1963 - AGM-28B) - 452 improved missiles equipped with a built-in astro-correction system and a radar altimeter.
• AGM-28C is a version of a missile with a TERCOM system for flying at very low altitudes. Not adopted.

• Length: 12.95 m
• Diameter: 0.71 m
• Swipe: 3.7 m
• Starting weight: 4350-4600 kg
• Maximum speed: 2.1 M
• Range: ~ 1100 km
• Ceiling: 16800 m
• CVO: 1850 m
• Warhead: Nuclear Mk.28 Mod.1 or Mk.28 Mod.2
  • Warhead power:
    • 0.07-1.45 Mt
  • Warhead mass: 750-790 kg
• Guidance System: Astroinertial
• Engine: Turbojet engine Pratt & Whitney J52-P-3
  • Thrust DN: 33 kN

• X-20

• Werrell, Kenneth P. The Evolution of the Cruise Missile. - Maxwell Air Force Base, Alabama: Air University Press, 1985 .-- 289 p.
• Gibson, James N. Nuclear Weapons of the United States: An Illustrated History. - Atglen, Pennsylvania: Schiffer Publishing Ltd., 1996 .-- 240 p. - (Schiffer Military History). - ISBN 0-7643-0063-6 .

• AGM-28 Hound Dog Aviation Encyclopedia " Corner of the Sky "
• Andreas Parsch. North American GAM-77 / AGM-28 Hound Dog (English) . Directory of US Military Rockets and Missiles . Website Designation-Systems.net (2002). Date of treatment January 3, 2011. Archived March 1, 2012.