The B43 was a

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

air-dropped

variable yield Variable yield, or dial-a-yield, is an option available on most modern nuclear weapons. It allows the operator to specify a weapon's yield, or explosive power, allowing a single design to be used in different situations. For example, the Mod-10 ...

thermonuclear weapon A thermonuclear weapon, fusion weapon or hydrogen bomb (H bomb) is a second-generation nuclear weapon design. Its greater sophistication affords it vastly greater destructive power than first-generation nuclear bombs, a more compact size, a lowe ...

used by a wide variety of

fighter bomber A fighter-bomber is a fighter aircraft that has been modified, or used primarily, as a light bomber or attack aircraft. It differs from bomber and attack aircraft primarily in its origins, as a fighter that has been adapted into other roles, wh ...

and

bomber aircraft A bomber is a military combat aircraft designed to attack ground and naval targets by dropping air-to-ground weaponry (such as bombs), launching torpedoes, or deploying air-launched cruise missiles. The first use of bombs dropped from an aircraf ...

. The B43 was developed from 1956 by

Los Alamos National Laboratory Los Alamos National Laboratory (often shortened as Los Alamos and LANL) is one of the sixteen research and development laboratories of the United States Department of Energy (DOE), located a short distance northwest of Santa Fe, New Mexico, ...

, entering production in 1959. It entered service in April 1961. Total production was 2,000 weapons, ending in 1965. Some variants were parachute-retarded and featured a

ribbon parachute A parachute is a device used to slow the motion of an object through an atmosphere by creating drag or, in a ram-air parachute, aerodynamic lift. A major application is to support people, for recreation or as a safety device for aviators, who ...

. The B43 was built in two variants, Mod 1 and Mod 2, each with five yield options. Depending on version, the B43 was in diameter, and length was between and . The various versions weighed between . It could be delivered at altitudes as low as , with fuzing options for airburst, ground burst, free fall, contact, or

laydown delivery Laydown delivery is a mode of delivery found in some nuclear gravity bombs: the bomb's descent to the target is slowed by parachute so that it lands on the ground without detonating. The bomb then detonates by timer some time later. Laydown deliver ...

. Explosive yield varied from 70

kiloton TNT equivalent is a convention for expressing energy, typically used to describe the energy released in an explosion. The is a unit of energy defined by that convention to be , which is the approximate energy released in the detonation of a t ...

s of

TNT Trinitrotoluene (), more commonly known as TNT, more specifically 2,4,6-trinitrotoluene, and by its preferred IUPAC name 2-methyl-1,3,5-trinitrobenzene, is a chemical compound with the formula C6H2(NO2)3CH3. TNT is occasionally used as a reagen ...

to 1

megaton Megaton may refer to: * A million tons * Megaton TNT equivalent, explosive energy equal to 4.184 petajoules * megatonne, a million tonnes, SI unit of mass Other uses * Olivier Megaton (born 1965), French film director, writer and editor * ''Me ...

of TNT. The B43 used the

Tsetse primary The Tsetse was a small American nuclear bomb developed in the 1950s that was used as the primary in several US thermonuclear bombs and as a small stand-alone weapon of its own. The Tsetse had a boosted composite core which used 2.25 kg Pu-239, 1.4 ...

design for its fission stage, as did several mid- and late-1950s designs. The B43 was one of four thermonuclear gravity bombs carried by Canadian

CF-104 The Canadair CF-104 Starfighter (CF-111, CL-90) is a modified version of the Lockheed F-104 Starfighter supersonic fighter aircraft built in Canada by Canadair under licence. It was primarily used as a ground attack aircraft, despite being des ...

jets while serving in Germany between June 1964 and 1972.

Delivery systems

Carrier aircraft included most

USAF The United States Air Force (USAF) is the air service branch of the United States Armed Forces, and is one of the eight uniformed services of the United States. Originally created on 1 August 1907, as a part of the United States Army Sign ...

USN The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage of ...

and

USMC The United States Marine Corps (USMC), also referred to as the United States Marines, is the maritime land force service branch of the United States Armed Forces responsible for conducting expeditionary and amphibious operations through co ...

fighters, bombers and attack aircraft, including the

A-3 Skywarrior The Douglas A-3 Skywarrior is a jet-powered strategic bomber that was developed and produced by the Douglas Aircraft Company. It was designed by Douglas on behalf of the United States Navy, which sought a carrier-capable strategic bomber. Duri ...

A-4 Skyhawk The Douglas A-4 Skyhawk is a single-seat subsonic carrier-capable light attack aircraft developed for the United States Navy and United States Marine Corps in the early 1950s. The delta-winged, single turbojet engined Skyhawk was designed a ...

A-5 Vigilante The North American A-5 Vigilante was an American carrier-based supersonic bomber designed and built by North American Aviation (NAA) for the United States Navy. Prior to 1962 unification of Navy and Air Force designations, it was designated t ...

A-6 Intruder The Grumman A-6 Intruder is an American twinjet all-weather attack aircraft developed and manufactured by American aircraft company Grumman Aerospace and operated by the U.S. Navy and U.S. Marine Corps. It was designed in response to a 1957 ...

A-7 Corsair II The LTV A-7 Corsair II is an American carrier-capable subsonic light attack aircraft designed and manufactured by Ling-Temco-Vought (LTV). The A-7 was developed during the early 1960s as replacement for the Douglas A-4 Skyhawk. Its design was ...

B-47 Stratojet The Boeing B-47 Stratojet (Boeing company designation Model 450) is a retired American long-range, six-engined, turbojet-powered strategic bomber designed to fly at high subsonic speed and at high altitude to avoid enemy interceptor aircraft ...

B-52 Stratofortress The Boeing B-52 Stratofortress is an American long-range, subsonic, jet-powered strategic bomber. The B-52 was designed and built by Boeing, which has continued to provide support and upgrades. It has been operated by the United States Air ...

B-58A Hustler The Convair B-58 Hustler, designed and produced by American aircraft manufacturer Convair, was the first operational bomber capable of Mach 2 flight. The B-58 was developed during the 1950s for the United States Air Force (USAF) Strategic Air ...

F-100 Super Sabre The North American F-100 Super Sabre is an American supersonic jet fighter aircraft that served with the United States Air Force (USAF) from 1954 to 1971 and with the Air National Guard (ANG) until 1979. The first of the Century Series of ...

F-105 Thunderchief The Republic F-105 Thunderchief is an American supersonic fighter-bomber that served with the United States Air Force from 1958 to 1984. Capable of Mach 2, it conducted the majority of strike bombing missions during the early years of the Viet ...

F-4 Phantom II The McDonnell Douglas F-4 Phantom II is an American tandem two-seat, twin-engine, all-weather, long-range supersonic jet interceptor and fighter-bomber originally developed by McDonnell Aircraft for the United States Navy.Swanborough and Bow ...

F-104 Starfighter The Lockheed F-104 Starfighter is an American single-engine, supersonic air superiority fighter which was extensively deployed as a fighter-bomber during the Cold War. Created as a day fighter by Lockheed as one of the "Century Series" of fi ...

FB-111A The General Dynamics F-111 Aardvark is a retired supersonic, medium-range, multirole combat aircraft. Production variants of the F-111 had roles that included ground attack (e.g. interdiction), strategic bombing (including nuclear weapons c ...

strategic bomber variant,

F-15E Strike Eagle The McDonnell Douglas (now Boeing) F-15E Strike Eagle is an American all-weather multirole strike fighter derived from the McDonnell Douglas F-15 Eagle. The F-15E was designed in the 1980s for long-range, high-speed interdiction without rely ...

F-16 Fighting Falcon The General Dynamics F-16 Fighting Falcon is a single-engine multirole fighter aircraft originally developed by General Dynamics for the United States Air Force (USAF). Designed as an air superiority day fighter, it evolved into a successful ...

and the

F/A-18 Hornet The McDonnell Douglas F/A-18 Hornet is an all-weather, twinjet, twin-engine, supersonic aircraft, supersonic, carrier-based aircraft, carrier-capable, Multirole combat aircraft, multirole combat aircraft, designed as both a Fighter aircraft, ...

. The

B-1B Lancer The Rockwell B-1 Lancer is a supersonic variable-sweep wing, heavy bomber used by the United States Air Force. It is commonly called the "Bone" (from "B-One"). It is one of three strategic bombers serving in the U.S. Air Force fleet along with ...

was also intended to carry the B43, though it remains unclear whether this particular aircraft was ever type-approved to carry the B43 prior to the B-1's reassignment to conventional strike roles. The B43 was also supplied for delivery by

Royal Air Force The Royal Air Force (RAF) is the United Kingdom's air and space force. It was formed towards the end of the First World War on 1 April 1918, becoming the first independent air force in the world, by regrouping the Royal Flying Corps (RFC) and ...

Canberra Canberra ( ) is the capital city of Australia. Founded following the federation of the colonies of Australia as the seat of government for the new nation, it is Australia's largest inland city and the eighth-largest city overall. The ci ...

and

Valiant Valiant may refer to: People * James Valiant (1884–1917), English cricketer * The Valiant Brothers, a professional wrestling tag team of storyline brothers ** Jerry Valiant, a ring name of professional wrestler John Hill (1941-2010) ** Jimmy ...

aircraft assigned to NATO under the command of SACEUR.

Broken Arrow

The B43 was never used in combat, but it was involved in a

nuclear accident A nuclear and radiation accident is defined by the International Atomic Energy Agency (IAEA) as "an event that has led to significant consequences to people, the environment or the facility. Examples include lethal effects to individuals, lar ...

when an

A-4E Skyhawk The Douglas A-4 Skyhawk is a single-seat subsonic carrier-capable light attack aircraft developed for the United States Navy and United States Marine Corps in the early 1950s. The delta-winged, single turbojet engined Skyhawk was designed a ...

, BuNo ''151022'', of the

USS Ticonderoga (CVA-14) USS ''Ticonderoga'' (CV/CVA/CVS-14) was one of 24 s built during World War II for the United States Navy. The ship was the fourth US Navy ship to bear the name, and was named after the capture of Fort Ticonderoga in the American Revolutionary W ...

(from Attack Squadron VA-56), was lost off the coast of

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...

on 5 December 1965 when it rolled off an elevator, in of water in the Pacific Ocean, from

Kikai Island is one of the Satsunan Islands, classed with the Amami archipelago between Kyūshū and Okinawa. The island, in area, has a population of approximately 7,657 persons. Administratively the island forms the town of Kikai, Kagoshima Prefectur ...

Kagoshima Prefecture is a prefecture of Japan located on the island of Kyushu and the Ryukyu Islands. Kagoshima Prefecture has a population of 1,599,779 (1 January 2020) and has a geographic area of 9,187 km2 (3,547 sq mi). Kagoshima Prefecture borders Kumamoto P ...

. The Skyhawk was being rolled out of the number 2 hangar bay, onto the number 2 elevator, when it continued over the edge and was lost. Neither the pilot LTJG

D. M. Webster The 1965 Philippine Sea A-4 crash was a United States military nuclear incident terminology#Broken Arrow, Broken Arrow incident in which a United States Navy Douglas A-4E Skyhawk attack aircraft carrying a nuclear weapon fell into the sea off Jap ...

, airframe, nor the bomb were ever recovered. No public mention was made of the incident at the time and it would not come to light until a 1989

US DoD The United States Department of Defense (DoD, USDOD or DOD) is an executive branch department of the federal government charged with coordinating and supervising all agencies and functions of the government directly related to national secur ...

report revealed that one of these one-megaton bomb (which had recently been retired from service and replaced) had gone missing. Japan then asked for details of the incident.Washington, D.C.: Washington Post, "''Japan Asks Details On Lost H-Bomb''", Wednesday, 10 May 1989, page A-35.

Withdrawn

The B43 was phased out in the 1980s, and the last B43 weapons were retired in 1991 in favor of the newer B61 and B83 weapons.

References

External links

Allbombs.html data page at nuclearweaponarchive.orgVideo showing shipboard handling procedures for the B43 bomb
{{United States nuclear devices Cold War aerial bombs of the United States Nuclear bombs of the United States Military equipment introduced in the 1960s

Delivery systems

Broken Arrow

Withdrawn

See also

References

External links