M117 bomb
Encyclopedia
General-purpose bomb
A general-purpose bomb is an air-dropped bomb intended as a compromise between blast damage, penetration, and fragmentation in explosive effect.-Characteristics:...
used by United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
military forces. It dates back to the time of the Korean War
Korean War
The Korean War was a conventional war between South Korea, supported by the United Nations, and North Korea, supported by the People's Republic of China , with military material aid from the Soviet Union...
of the early 1950s. Although it has a nominal weight of 750 lb (343 kg), its actual weight, depending on fuze
Fuze
Fuze Beverage, commercially referred to as just Fuze , is a manufacturer of teas and non-carbonated fruit drinks enriched with vitamins. Currently the brand consists of five vitamin-infused lines: Slenderize, Refresh, Tea, Defensify, and Vitalize...
and retardation options, is around 820 lb (373 kg). Its explosive content is typically 403 lb (183 kg) of Minol 2 or Tritonal
Tritonal
Tritonal is a mixture of 80% TNT and 20% aluminium powder, used in several types of ordnance such as air-dropped bombs. The aluminium improves the total heat output and hence impulse of the TNT - the length of time during which the blast wave is positive...
. It can also be configured with a low-drag tail fin for medium and high-altitude deliveries.
History
In the 1950s through the early 1970s the M117 was a standard aircraft weapon, carried by the F-100 Super SabreF-100 Super Sabre
The North American F-100 Super Sabre was a supersonic jet fighter aircraft that served with the United States Air Force from 1954 to 1971 and with the Air National Guard until 1979. The first of the Century Series collection of USAF jet fighters, it was the first USAF fighter capable of...
, F-104 Starfighter
F-104 Starfighter
The Lockheed F-104 Starfighter is a single-engine, high-performance, supersonic interceptor aircraft originally developed for the United States Air Force by Lockheed. One of the Century Series of aircraft, it served with the USAF from 1958 until 1969, and continued with Air National Guard units...
, F-105 Thunderchief
F-105 Thunderchief
The Republic F-105 Thunderchief, was a supersonic fighter-bomber used by the United States Air Force. The Mach 2 capable F-105 conducted the majority of strike bombing missions during the early years of the Vietnam War; it has the dubious distinction of being the only US aircraft to have been...
, F-111
General Dynamics F-111
The General Dynamics F-111 "Aardvark" was a medium-range interdictor and tactical strike aircraft that also filled the roles of strategic bomber, reconnaissance, and electronic warfare in its various versions. Developed in the 1960s by General Dynamics, it first entered service in 1967 with the...
, and F-4 Phantom.
The M117 series was used extensively during the Vietnam War, and B-52G Stratofortress aircraft dropped 44,600 M117 and M117R bombs during Operation Desert Storm.
At present it is used only by the B-52 Stratofortress
B-52 Stratofortress
The Boeing B-52 Stratofortress is a long-range, subsonic, jet-powered strategic bomber operated by the United States Air Force since the 1950s. The B-52 was designed and built by Boeing, who have continued to provide maintainence and upgrades to the aircraft in service...
, tactical aircraft now tend to use the Mark 80-series bombs (particularly the Mark 82 (500 lb) bomb or Mark 84 (2,000 lb) bomb and their guided equivalents).
Variants
M117RThe M117R (R - Retarded) uses a special fin assembly providing either high-drag or low-drag release options. For low altitude deliveries, the tail assembly opens four large drag plates which rapidly slow the bomb and allow the aircraft to escape its blast.
MAU-103/MAU-91
The M117Rs that are fitted with tail units, are the MAU-103 low drag tail and the MAU-91 high drag tail, respectively.
M117D
The M117D (D - Destructor) looks similar to the M117R but uses a magnetic influence fuze, which enables the bomb to function as an mine. The M117D is released in a high-drag configuration for ground implant or shallow water mining. It detonates when an object passing near the bomb triggers the fuze.
MC-1
The M117 was the basis of the MC-1 chemical warfare bomb
MC-1 bomb
The MC-1 bomb was the first U.S. non-clustered air-dropped chemical munition. The MC-1 was first produced in 1959 and carried the nerve agent sarin.-History:...
, which had the body cavity filled with sarin
Sarin
Sarin, or GB, is an organophosphorus compound with the formula [2CHO]CH3PF. It is a colorless, odorless liquid, which is used as a chemical weapon. It has been classified as a weapon of mass destruction in UN Resolution 687...
nerve gas. The MC-1 was never used by the U.S. in combat and was eliminated from the U.S. stockpile in June, 2006..
M117 General Purpose Bomb
The M117 is a free-fall, unguided, general purpose [GP] 750-pound bomb. Its usual fuzes are the mechanical M904 (nose) and M905 (tail), or the mechanical FMU-54 (tail). The M117 is employed in several configurations.The basic M117 dates from the Korean War and uses a low-drag tail fin for medium and high-altitude deliveries.
The M117R (Retarded) uses a special fin assembly providing either high-drag or low-drag release options. For low altitude deliveries, the tail assembly opens four large drag plates which rapidly slow the bomb and allow the aircraft to escape its blast.
The M117D (Destructor) is similar to the M117R but uses a magnetic influence fuze which enables the bomb to function as a mine. The M117D is released in a high-drag configuration for ground implant or shallow water mining. It detonates when an object passing near the bomb triggers the fuze.
The M117 series was used extensively during the Vietnam War, and B-52G aircraft dropped thousands of tons of M117 and M117R bombs during Operation Desert Storm. The B-52s dropped virtually all of the M117 bombs during Desert Storm.
With the receipt of a contract in 1995 to perform demilitarization on 750-pound Tritonal filled bombs, Crane Army Ammunition Activity designed and developed a process that allows the explosive material to be removed through the nose of the bomb skin, eliminating the need for a separate facility to remove the base of the bomb.
The traditional approach to the demilitarization of a 750-pound Tritonal-filled bomb at Crane Army Ammunition Activity (CAAA) or any other government facility was open detonation or manual extraction by cutting off the base of the bomb and steam- or autoclave-out the explosive material. There were several drawbacks to both methods. With open detonation, neither the explosive nor the metallic container could be recovered, the emissions required extensive tracking and reporting to the proper authorities, and weather conditions determined the work schedule. The second method required the base of the bomb to be removed with a power metal bomb saw. The operator would have to set up the operation at one facility and then move to a remote facility to view the actual cutting process by video transmission. The resultant residue in the water from this cutting procedure also required purification.
CAAA did not have the facility for the treatment of the water nor a bomb saw. It is estimated that such a facility would cost $500,000. With the receipt of a contract in 1995 to perform demilitarization on 750-pound Tritonal filled bombs, CAAA designed and developed a conduit cutting tool that is inserted into the nose cavity liner and manually cuts the swaged tubing. This approach is done by removing the nose fuze wall liner, and using a high-pressure waterjet nozzle to remove the tar nose pad. The bomb is then placed nose first into an autoclave explosive collection system to melt out the Tritonal explosive material under controlled heat and pressure procedures. The explosive is then pumped to a holding vacuum to bring the moisture content down to an acceptable level where it is transported to a conveyor belt for additional cooling prior to packaging for shipment. This extraction method allows the explosive and the metal bomb skin to be recycled commercially, with the option of retaining small donor quantities of Tritonal explosives for use in other open detonation applications at CAAA. Secondly, the handling of the explosive articles is reduced by 50%, and has shown a four to six times faster turnaround in the meltout operation over steam wand applications.
Since the introduction of the Autoclave Bomb Meltout System in 1996, more than nine million pounds of Tritonal explosive and 8.75 million pounds of steel have been recovered from 24,497 bombs. This process has also been adopted by other facilities within the Army commands that perform demilitarization.