During the 1950s the US became aware of developments regarding the Soviet Union's surface-to-air missiles (SAMs), notably at large installations being constructed around Moscow. At the time the entire nuclear deterrent of the United States was based on manned strategic bombers, both with the U.S. Air Force and the U.S. Navy, and the deployment of large numbers of SAMs placed this force at some risk of being rendered ineffective. One solution to this problem is to extend the range of the bomb, either through glide bomb techniques, or more practically, by mounting them in a short-to-medium-range missile.
The Air Force's solution to this problem was the introduction of stand-off missiles. Since the Soviet air-defenses were static and easy to spot from aerial reconnaissance or satellite reconnaissance photos, the plan was to use a long-range cruise missile to attack these air-defense bases before the bombers got into range of them. The SA-2 Guideline missile had a maximum range of about 30 kilometers at that time, but since the bombers would be approaching the sites, their own guided missiles would have to be launched well-before it entered this SAM range. If the American missile was to be used to attack enemy air bases as well, an extended range of several hundred kilometers would be needed. A missile with these capabilities was called for in General Operational Requirement 148, which was released on March 15, 1956, known as WS-131B. GOR 148 called for a supersonic air-to-surface cruise missile with a weight of not more than 5,700 kilograms (12,500 lb) (fully fueled and armed) to be carried in pairs by the B-52 Stratofortress. Each B-52 would carry two of the missiles, one under each wing, on a pylon located between the B-52's fuselage and its inboard pair of engines.
Both Chance Vought and North American Aviation submitted GAM-77 proposals to the USAF in July 1957, and both based on their earlier work on long-range ground-launched cruise missiles. Vought's submission was for an air-launched version of the Regulus missile, developed for the US Navy, while North American's was adapted from their Navaho missile. On August 21, 1957, North American Aviation was awarded a contract to develop Weapon System 131B, which included the Hound Dog missile.
The importance of Hound Dog in penetrating the Soviet air-defense system was later described by Senator John F. Kennedy in a speech to the American Legion convention in Miami, Florida, on October 18, 1960: "We must take immediate steps to protect our present nuclear striking force from surprise attack. Today, more than 90 percent of our retaliatory capacity is made up of aircraft and missiles which have fixed, un-protectable bases whose location is known to the Russians. We can only do this by providing SAC with the capability of maintaining a continuous airborne alert, and by pressing projects such as the Hound Dog air-ground missile, which will enable manned bombers to penetrate Soviet defenses with their weapons".
The Hound Dog missile's airframe was an adaptation of technology developed in the SM-64 Navaho missile, adapted for launching from the B-52. The Hound Dog's design was based on that of the Navaho G-38 missile, which featured small delta wings and forward canards.
A Pratt & Whitney J52-P-3 turbojet propelled the Hound Dog, instead of Navaho's ramjet engine. The J52 engine was located in a pod located beneath the rear fuselage, giving it an appearance similar to the Lockheed X-7 high-speed experimental drone. The J52-P-3 used in the Hound Dog, unlike J52's installed in aircraft like the A-4 Skyhawk or the A-6 Intruder, was optimized to run at maximum power during the missile's flight. As a result, the Hound Dog's version of the J52 had a short operating lifetime of only six hours. However, in combat, the Hound Dog was expected to self-destruct in less than six hours.
A derivative of the Navaho's NAA Autonetics Division N-6 inertial navigation system (INS), the N5G, was used in the Hound Dog. A Kollsman Instruments Co. star tracker located in the B-52's pylon was used to correct inertial navigation system orientation errors with celestial observations while the Hound Dog was being carried by the B-52. The INS could also be used to determine the bomber's position after the initial calibration and "leveling" process, which took about 90 minutes. The Hound Dog had a circular error probable (CEP) of 3.5 kilometres (2.2 mi), which was acceptable for a weapon equipped with a nuclear warhead.
The thermonuclear warhead carried by the Hound Dog was the W28 Class D. The W28 warhead could be preset to yield an explosive power of between 70 kilotons and 1.45 megatons. Detonation of the Hound Dog's W28 warhead could be programmed to occur on impact (ground burst) or air burst at a preset altitude. An air burst would have been used against a large area, soft target. A surface impact would have been used against a hard target such as a missile site or command and control center.
The Hound Dog could be launched from the B-52 Stratofortress at high altitudes or low altitudes, but not below 1,500 metres (5,000 ft) in altitude. Initially, three different flight profiles for the Hound Dog were available for selection by the commander and the bombardier of the bomber (though other options were added later):High-altitude attack: The Hound Dog would have flown at a high altitude (up to 17,000 metres (56,000 ft) depending on the amount of jet fuel on board the missile) all the way to the immediate area of its target, then diving to its nuclear warhead's preset detonation altitude.
Low-altitude attack: The Hound Dog would have flown at a low altitude – below 1,500 metres (5,000 ft) (air-pressure altitude) to its target where its nuclear warhead would have detonated. In this mode of operation, the Hound Dog had a shortened range of about 640 kilometres (400 mi) when this flight profile was used. The missile would not carry out terrain following in this flight profile. No major terrain obstructions could exist at the preset altitude along the missile's flight path.
Low-altitude attack: The GAM-77B (later AGM-28B) could fly a low radar altitude, from 914 to 30 metres (3,000 to 100 ft) above the ground. As mentioned above in the GAM-77A model description, this shortened range. However, the improvement of "flying in the weeds", was such that the missile could be flown down in ground clutter (radar) thus nearly invisible to radar detection. Eventually, all A model GAM-77s were given this modification as well.
A dogleg attack: The Hound Dog would have flown along a designated heading (at either high or low altitudes) to a preset location. At that location the missile would have turned left or right and then proceeded to its target. The intention of this maneuver was to attempt to draw defensive fighter planes away from the missile's target.
The first air-drop test of a dummy Hound Dog was carried out in November 1958. 52 GAM-77A missiles were launched for testing and training purposes between 23 April 1959 and 30 August 1965. Hound Dog launches occurred at Cape Canaveral Air Force Station, at Eglin Air Force Base, Florida, and at the White Sands Missile Range, New Mexico.
The Hound Dog missile's development was completed in only 30 months. North American received a production contract to build Hound Dogs on 16 October 1958. The first production Hound Dog missile was then delivered to the Air Force on 21 December 1959. 722 Hound Dog missiles were produced by North American Aviation before its production of them ended in March 1963.
In May 1961, an improved Hound Dog missile was test-flown for the first time. This upgrade incorporated improvements to reduce its radar cross-section. The Hound Dog already had a low head-on radar cross-section because of its highly swept delta wings. This low radar cross-section was lowered further by replacing its nose cap, its engine intake spike, its engine duct with new radar-absorbent material components that scattered or absorbed radar energy. It has been reported that these radar cross-section improvements were removed as Hound Dogs were withdrawn from service.
The GAM-77A version of the GAM-77 also included a new Kollsman Instruments KS-140 star tracker that was integrated with the N-6 inertial navigation system. This unit replaced the star tracker that had been located in the B-52's wing pylon. The fuel capacity of the GAM-77A was increased during this upgrade. A radar altimeter was added to the missile to provide (vertical) terrain-following radar capability to the Hound Dog. 428 Hound Dog missiles were upgraded to the GAM-77A configuration by North American.
66 GAM-77A Hound Dog missiles were launched for testing and training up through April 1973.
In June 1963 the GAM-77 and GAM-77A were re-designated AGM-28A and AGM-28B, respectively.
In 1971, a Hound Dog missile was test-flown with a newly developed Terrain Contour Matching (TERCOM) navigation system. Reportedly, the designation AGM-28C was reserved for this version of the Hound Dog if development had been continued. While a Hound Dog with TERCOM was never deployed, this technology, with much better electronics and digital computers, was later used in both the Air Force's Air Launched Cruise Missile and the Navy's Tomahawk (missile).
In 1972, the Bendix Corporation was awarded a contract to develop an anti-radiation missile passive radar seeker to guide the Hound Dog missile to antennas transmitting radar signals. A Hound Dog with this radar seeker was test-flown in 1973, but never mass-produced.
On December 21, 1959, General Thomas S. Power, the Commander in Chief of the U.S. Air Force's Strategic Air Command (SAC), formally accepted the first production Hound Dog missile. Just two months later in February, SAC test-launched its first unarmed Hound Dog at Eglin Air Force Base.
In July 1960, the Hound Dog reached initial operational capability with the first B-52 unit. The Hound Dog was used on airborne alert for the first time in January 1962. In 1962, SAC activated missile maintenance squadrons to provide maintenance for both the Hound Dog and the ADM-20 Quail decoy missile. Full operational capability was achieved in August 1963 when 29 B-52 bomber wings were operational with the Hound Dog.
In 1960, SAC developed procedures so that the B-52 could use the Hound Dog's J52 engine for additional thrust while the missile was located on the bomber's two pylons. This helped heavily laden B-52s fly away from their airbases faster, before enemy nuclear weapons obliterated them. The Hound Dog could then be refueled from the B-52's wing fuel tanks.
One Hound Dog missile crashed near the town of Samson, Alabama, when it failed to self-destruct after a test launch from Eglin Air Force Base, Florida. In 1962, a Hound Dog was accidentally dropped to the ground during an underwing systems check.
In May 1962, operation "Silk Hat" was conducted at Eglin Air Force Base. During this exercise, a Hound Dog test launch was conducted before an audience of national and international dignitaries headed by President John F. Kennedy and Vice-President Lyndon B. Johnson.
On September 22, 1966, Secretary of Defense Robert McNamara recommended retiring all of the remaining Hound Dog missiles, within a few years. The Hound Dogs would be retained pending the outcome of the Terrain Contour Matching (TERCOM) guidance system development program. Secretary McNamara's recommendation was not acted upon, and the Hound Dog remained in service.
After thirteen years of service with the Air Force, the last Hound Dog missile was removed from alert deployment on June 30, 1975. The Hound Dog missiles were kept in dead storage for a number of years. The last Hound Dog was retired for scrapping on June 15, 1978, from the 42nd Bomb Wing at Loring Air Force Base, Maine.
No Hound Dog missile was ever used in combat, since it was strictly a weapon for nuclear warfare.
The number of Hound Dog missiles in service, by year:B-77 — Redesignated GAM-77 prior to production.
XGAM-77 — 25 prototype missiles produced
GAM-77 — 697 missiles produced.
GAM-77A — 452 missiles upgraded from GAM-77 to GAM-77A configuration.
AGM-28A — The GAM-77 was redesignated the AGM-28A in June 1963
AGM-28B — The GAM-77A was redesignated the AGM-28B in June 1963
AGM-28C — Proposed Hound Dog that would have been equipped with a TERCOM guidance system.
United States Air Force
All of the surviving missiles are located in the contiguous United StatesAGM-28 S/N 60-2176 located at the Eighth Air Force Museum, Barksdale Air Force Base, Bossier City, Louisiana
AGM-28 located at the Aerospace Museum of California, former McClellan Air Force Base, Sacramento, California
AGM-28 S/N 33792 located at the Air Force Space & Missile Museum, Cape Canaveral Air Force Station, Florida
AGM-28 S/N 62-0003 located at the Castle Air Museum, former Castle Air Force Base, Atwater, California
AGM-28 S/N 60-2192 located at the Dyess Linear Air Park, Dyess Air Force Base, Texas
AGM-28 marked as S/N 59-2794, located at the Air Force Armament Museum, Eglin Air Force Base, Florida
AGM-28 located at Grand Forks Air Force Base, North Dakota
AGM-28 located at the Joe Davies Heritage Airpark, Air Force Plant 42, Palmdale, California
AGM-28 located at Mars Hill Town Park, Mars Hill, North Carolina
AGM-28 S/N 61-2206 located at Minot Air Force Base, North Dakota
AGM-28 S/N 60-2141 located at the National Atomic Museum, adjacent to Kirtland Air Force Base, Albuquerque, New Mexico
AGM-28 S/N 62-0007 located at the National Museum of the United States Air Force, Wright-Patterson Air Force Base, Dayton, Ohio. It was transferred to the museum in 1975.
AGM-28 S/N 60-505 located at the New England Air Museum, Windsor Locks, Connecticut
AGM-28 S/N 59-2796 located at the Octave Chanute Aerospace Museum, former Chanute Air Force Base, Rantoul, Illinois
AGM-28 S/N 59-2866 located at the Pima Air & Space Museum, adjacent to Davis-Monthan Air Force Base, Tucson, Arizona
AGM-28 S/N 60-2092 located at the Pima Air & Space Museum, adjacent to Davis-Monthan Air Force Base, Tucson, Arizona
AGM-28 located at the Pratt & Whitney Engine Museum and Hangar, East Hartford, Connecticut
AGM-28 located at Veterans Park in Presque Isle, Maine
AGM-28 S/N 61-2148 located at the Museum of Aviation, Robins Air Force Base, Georgia
AGM-28 S/N 59-2791 located at the South Dakota Air and Space Museum, Ellsworth Air Force Base, Rapid City, South Dakota
AGM-28 S/N 60-2110 located at the U.S. Space and Rocket Center, Huntsville, Alabama
AGM-28 located at the Strategic Air and Space Museum, adjacent to Offutt Air Force Base, Omaha, Nebraska
AGM-28 located at the American Legion in Tecumseh, Oklahoma
XGAM-77 located at the Travis Air Museum, Travis Air Force Base, California
AGM-28 S/N 59-2847 located at the Veterans Home of Wyoming in Buffalo, Wyoming
AGM-28 located at the White Sands Missile Range Missile Park, New Mexico
AGM-28 S/N 60-2971 located at the Wings of Eagles Discovery Center, Horseheads, New York
Where it received the name Hound Dog has been the source of argument for decades. In recent years however people have given credit to fans in the Air Force of Elvis Presley's version of "Hound Dog".