UGM-109 hits target on San Clemente Island 1986

An air burst or airburst is the detonation of an explosive device such as an

anti-personnel An anti-personnel weapon is a weapon primarily used to maim or kill infantry and other personnel not behind armor, as opposed to attacking structures or vehicles, or hunting game. The development of defensive fortification and combat vehicle ...

artillery shell A shell, in a military context, is a projectile whose payload contains an explosive, incendiary, or other chemical filling. Originally it was called a bombshell, but "shell" has come to be unambiguous in a military context. Modern usage ...

or a

nuclear weapon A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission (fission bomb) or a combination of fission and fusion reactions ( thermonuclear bomb), producing a nuclear explosion. Both bom ...

in the air instead of on contact with the ground or target. The principal military advantage of an air burst over a ground burst is that the energy from the explosion (as well as any shell fragments) is distributed more evenly over a wider area; however, the peak energy is lower at

ground zero In relation to nuclear explosions and other large bombs, ground zero (also called surface zero) is the point on the Earth's surface closest to a detonation. In the case of an explosion above the ground, ''ground zero'' is the point on the groun ...

History

Air burst artillery has a long history. The

shrapnel shell Shrapnel shells were anti-personnel artillery munitions which carried many individual bullets close to a target area and then ejected them to allow them to continue along the shell's trajectory and strike targets individually. They relied almo ...

was invented by

Henry Shrapnel Lieutenant General Henry Shrapnel (3 June 1761 – 13 March 1842) was a British Army officer whose name has entered the English language as the inventor of the shrapnel shell. Henry Shrapnel was born at Midway Manor in Bradford-on-Avon, Wiltshir ...

of the British Army in about 1780 to increase the effectiveness of

canister shot Canister shot is a kind of anti-personnel artillery ammunition. Canister shot has been used since the advent of gunpowder-firing artillery in Western armies. However, canister shot saw particularly frequent use on land and at sea in the various ...

. It was widely used by the time of the

War of 1812 The War of 1812 (18 June 1812 – 17 February 1815) was fought by the United States of America and its indigenous allies against the United Kingdom and its allies in British North America, with limited participation by Spain in Florida. It ...

and stayed in use until it was superseded during the First World War. Modern shells, though sometimes called "shrapnel shells", actually produce fragments and splinters, not shrapnel. Air bursts were used in the

First World War World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fig ...

to shower enemy positions and men with shrapnel balls to kill the largest possible number with a single burst. When infantry moved into deep trenches, shrapnel shells were rendered useless and high-explosive shells were used to attack field fortifications and troops in the open. The time fuses for the shells could be set to function on contact or in the air, or at a certain time after contact. Early

anti-aircraft warfare Anti-aircraft warfare, counter-air or air defence forces is the battlespace response to aerial warfare, defined by NATO as "all measures designed to nullify or reduce the effectiveness of hostile air action".AAP-6 It includes surface based ...

used time fuses to function when they reached the estimated altitude of the target. During

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the World War II by country, vast majority of the world's countries—including all of the great power ...

a "

proximity fuze A proximity fuze (or fuse) is a fuze that detonates an explosive device automatically when the distance to the target becomes smaller than a predetermined value. Proximity fuzes are designed for targets such as planes, missiles, ships at sea, an ...

" was developed for antiaircraft use, controlled by a

doppler radar A Doppler radar is a specialized radar that uses the Doppler effect to produce velocity data about objects at a distance. It does this by bouncing a microwave signal off a desired target and analyzing how the object's motion has altered the fr ...

device within the shell that caused it to explode when near the target. The idea was later adapted for use against ground targets. During the

Vietnam War The Vietnam War (also known by #Names, other names) was a conflict in Vietnam, Laos, and Cambodia from 1 November 1955 to the fall of Saigon on 30 April 1975. It was the second of the Indochina Wars and was officially fought between North Vie ...

, air bursting shells were used to great effect to defend bases. This tactic was known as "Killer Junior" when referring to 105 mm or 155 mm shells, and "Killer Senior" when employed with larger

howitzer A howitzer () is a long-ranged weapon, falling between a cannon (also known as an Artillery, artillery gun in the United States), which fires shells at flat trajectories, and a Mortar (weapon), mortar, which fires at high angles of ascent and de ...

s. Some anti-personnel bounding mines such as Germany's World War II " Bouncing Betty" fire a

grenade A grenade is an explosive weapon typically thrown by hand (also called hand grenade), but can also refer to a shell (explosive projectile) shot from the muzzle of a rifle (as a rifle grenade) or a grenade launcher. A modern hand grenade g ...

into the air, which detonates at waist level, increasing the blast

radius In classical geometry, a radius ( : radii) of a circle or sphere is any of the line segments from its center to its perimeter, and in more modern usage, it is also their length. The name comes from the latin ''radius'', meaning ray but also the ...

and harm inflicted by detonation, shock wave, and flying splinters. A relatively recent example of airburst munitions is the VOG-25P "jumping" 40 mm caseless grenade, which contains a secondary charge to launch it up to 1.5 meters above its point of impact before the main charge detonates. Another recent development are computer programmable air burst grenades with

fire control system A fire-control system (FCS) is a number of components working together, usually a gun data computer, a Director (military), director, and radar, which is designed to assist a ranged weapon system to target, track, and hit a target. It performs ...

Grenade launcher A grenade launcher is a weapon that fires a specially-designed large-caliber projectile, often with an explosive, smoke or gas warhead. Today, the term generally refers to a class of dedicated firearms firing unitary grenade cartridges. The m ...

s using this technology include the

XM29 The XM29 OICW (''Objective Individual Combat Weapon'') was a series of prototypes of a new type of assault rifle that fired 20 mm HE airbursting projectiles. The prototypes were developed as part of the Objective Individual Combat Weapon ...

, XM307, PAPOP, Mk 47 Striker, XM25,

Barrett XM109 The Barrett XM109 is a prototype anti materiel sniper rifle, chambered for 25 × 59 mm grenade rounds and developed by Barrett Firearms Manufacturing. It was designed in accordance with a requirement set out in 1994, and is capable of defeating ...

, K11,

QTS-11 The Type 11, () designated as QTS-11, is an air burst grenade launcher integrated with the QBZ-03 assault rifle in service of Chinese military since 2015. Reporting on the weapon as early as February 2011 initially identified the weapon as the ZH ...

, Norinco LG5 / QLU-11 and Multi Caliber Individual Weapon System. Orbital ATK developed air burst rounds for

autocannon An autocannon, automatic cannon or machine cannon is a fully automatic gun that is capable of rapid-firing large-caliber ( or more) armour-piercing, explosive or incendiary shells, as opposed to the smaller-caliber kinetic projectiles (bulle ...

Nuclear weapons

The air burst is usually above the

hypocenter In seismology, a hypocenter or hypocentre () is the point of origin of an earthquake or a subsurface nuclear explosion. A synonym is the focus of an earthquake. Earthquakes An earthquake's hypocenter is the position where the strain energy ...

to allow the

shockwave In physics, a shock wave (also spelled shockwave), or shock, is a type of propagating disturbance that moves faster than the local speed of sound in the medium. Like an ordinary wave, a shock wave carries energy and can propagate through a me ...

of the

fission Fission, a splitting of something into two or more parts, may refer to: * Fission (biology), the division of a single entity into two or more parts and the regeneration of those parts into separate entities resembling the original * Nuclear fissio ...

or fusion driven explosion to bounce off the ground and back into itself, combining two wave fronts and creating a shockwave that is more forceful than the one resulting from a detonation at ground level. This " mach stem" only occurs near ground level, exists around the entire perimeter of the expanding wave front near ground level, and is similar in shape to the letter Y when viewed from the side (see sliced view). Airbursting also minimizes

fallout Nuclear fallout is the residual radioactive material propelled into the upper atmosphere following a nuclear blast, so called because it "falls out" of the sky after the explosion and the shock wave has passed. It commonly refers to the radioa ...

by keeping the fireball from touching the ground, limiting the amount of debris that is vaporized and drawn up in the radioactive debris cloud. For the Hiroshima bomb, an air burst above the ground was chosen "to achieve maximum blast effects, and to minimize residual radiation on the ground as it was hoped U.S. troops would soon occupy the city". Some nuclear weapons have a contact preclusion fuzing feature to prevent the backup contact fuze from detonating the weapon if the air burst fuzing fails.

Tactics

In conventional warfare, air bursts are used primarily against

infantry Infantry is a military specialization which engages in ground combat on foot. Infantry generally consists of light infantry, mountain infantry, motorized infantry & mechanized infantry, airborne infantry, air assault infantry, and m ...

in the open or unarmored targets, as the resulting fragments cover a large area but will not penetrate armor or field fortifications. In

nuclear warfare Nuclear warfare, also known as atomic warfare, is a theoretical military conflict or prepared political strategy that deploys nuclear weaponry. Nuclear weapons are weapons of mass destruction; in contrast to conventional warfare, nucle ...

, air bursts are used against soft targets (i.e. lacking the hardened construction required to survive overpressure from a nuclear explosion) such as cities in

countervalue In military doctrine, countervalue is the targeting of an opponent's assets that are of value but not actually a military threat, such as cities and civilian populations. Counterforce is the targeting of an opponent's military forces and facilitie ...

targeting, or airfields, radar systems and mobile ICBMs in

counterforce In nuclear strategy, a counterforce target is one that has a military value, such as a launch silo for intercontinental ballistic missiles, an airbase at which nuclear-armed bombers are stationed, a homeport for ballistic missile submarines, or a ...

targeting.

Killer Junior and Senior

Killer Junior and Killer Senior are techniques of employing

artillery Artillery is a class of heavy military ranged weapons that launch munitions far beyond the range and power of infantry firearms. Early artillery development focused on the ability to breach defensive walls and fortifications during sieg ...

direct fire Direct fire or line-of-sight fire refers to firing of a ranged weapon whose projectile is launched directly at a target within the line-of-sight of the user. The firing weapon must have a sighting device and an unobstructed view to the target, ...

air bursts, first developed during the

. The technique involves a

firing a high explosive (HE) shell using a mechanical time–super quick (MTSQ)

artillery fuze An artillery fuze or fuse is the type of munition fuze used with artillery munitions, typically projectiles fired by guns (field, anti-aircraft, coast and naval), howitzers and mortars. A fuze is a device that initiates an explosive function in ...

set to cause an airburst over a target in very close proximity to the firing gun's position. Set properly, the shell would detonate approximately above the ground at ranges of 200 to 1,000 meters. The term Killer Junior was applied to this technique when used with 105 mm or 155 mm howitzers, and the term Killer Senior applied to its use with the M115 203 mm (8-inch) howitzer. The term "Killer" came from the call-sign of the battery which developed the technique. The technique was later perfected by Lieutenant Colonel Robert Dean, commander of the 1st Battalion,

8th Field Artillery Regiment The 8th Field Artillery Regiment is a field artillery regiment of the United States Army first formed in 1916. The regiment served in World War I, World War II, and Korea, and regimental units have served in Vietnam, Honduras, Panama, Operation De ...

, of the 25th Infantry Division Artillery. Killers Junior and Senior were developed as alternatives to the

Beehive A beehive is an enclosed structure in which some honey bee species of the subgenus ''Apis'' live and raise their young. Though the word ''beehive'' is commonly used to describe the nest of any bee colony, scientific and professional literature ...

flechette A flechette ( ) is a pointed steel projectile with a vaned tail for stable flight. The name comes from French , "little arrow" or "dart", and sometimes retains the acute accent in English: fléchette. They have been used as ballistic weapons sinc ...

rounds previously used against nearby enemy troops. The advantage of the Killer techniques over Beehive is that the airburst projects fragments in all directions, and is able to wound enemies crawling or lying in

defilade Enfilade and defilade are concepts in military tactics used to describe a military formation's exposure to enemy fire. A formation or position is "in enfilade" if weapon fire can be directed along its longest axis. A unit or position is "in de ...

, whereas the flechettes of a Beehive round would simply fly harmlessly over a low target.

References

{{Reflist Aerial warfare strategy Aerial bombing Weapon operation

History

Nuclear weapons

Tactics

Killer Junior and Senior

See also

References