AZON (or Azon), from "

azimuth An azimuth (; from ar, اَلسُّمُوت, as-sumūt, the directions) is an angular measurement in a spherical coordinate system. More specifically, it is the horizontal angle from a cardinal direction, most commonly north. Mathematical ...

only", was one of the world's first guided weapons, deployed by the Allies and contemporary with the German

Fritz X Fritz X was the most common name for a German guided anti-ship glide bomb used during World War II. ''Fritz X'' was the world's first precision guided weapon deployed in combat and the first to sink a ship in combat. ''Fritz X'' was a nickname us ...

. Officially designated VB-1 ("Vertical Bomb 1"), it was invented by Major Henry J. Rand and Thomas J. O'Donnell during the latter stages of

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 vast majority of the world's countries—including all of the great powers—forming two opposing ...

as the answer to the difficult problem of destroying the narrow wooden bridges that supported much of the

Burma Railway The Burma Railway, also known as the Siam–Burma Railway, Thai–Burma Railway and similar names, or as the Death Railway, is a railway between Ban Pong, Thailand and Thanbyuzayat, Burma (now called Myanmar). It was built from 1940 to 1943 ...

. AZON was essentially a general-purpose AN-M65 bomb with a quadrilateral 4-fin style radio controlled tail fin design as part of a "tail package" to give the desired guidance capability, allowing adjustment of the vertical trajectory in the

yaw axis An aircraft in flight is free to rotate in three dimensions: '' yaw'', nose left or right about an axis running up and down; ''pitch'', nose up or down about an axis running from wing to wing; and ''roll'', rotation about an axis running from ...

, giving the Azon unit a lateral steering capability (meaning it could only steer left and right, and could not alter its pitch or rate of fall). This lack of any pitch control meant that the bombardier still had to accurately release it with a bombsight to ensure it could not fall short of or beyond the target. The "tail package" bolted onto the standard bomb warhead, in place of the usual sheet-metal fixed fins; this concept was an early iteration of a now common method of making modern guided bombs (such as the

JDAM The Joint Direct Attack Munition (JDAM) is a guidance kit that converts unguided bombs, or "dumb bombs", into all-weather precision-guided munitions. JDAM-equipped bombs are guided by an integrated inertial guidance system coupled to a Global Po ...

, the

Paveway Paveway is a series of laser-guided bombs (LGBs). ''Pave'' or PAVE is sometimes used as an acronym for ''precision avionics vectoring equipment''; literally, electronics for controlling the speed and direction of aircraft. Laser guidance is ...

family, the

KAB-500L The KAB-500L is a laser-guided bomb developed by the Soviet Air Force, entering service in 1975. It remains in service with the CIS and post-Soviet Russian Air Force. The KAB-500L is a standard FAB-500 general-purpose bomb, which has a nomin ...

, etc.): making the guidance and control units as separate pieces that attach to the tail and/or nose of a standard "

iron bomb An unguided bomb, also known as a free-fall bomb, gravity bomb, dumb bomb, or iron bomb, is a conventional or nuclear Aerial bomb, aircraft-delivered bomb that does not contain a guidance system and hence simply follows a Ballistics, ballistic tr ...

", making it into a guided weapon. There were gyroscopes mounted in the bomb's added tail package that made it an Azon unit, to autonomously stabilize it in the roll axis via operating a pair of ailerons, and a radio control system to operate the proportional-control rudders, to directly control the bomb's direction of lateral aim, with the antennas for the tail-mounted receiver unit built into the diagonal support struts of the tail surface assembly. The bomb's receiver and control system were powered by a battery which had around three minutes of battery life. The entire setup in the added "tail package" was sufficient to guide the weapon from a 5,000-foot (1,500 m) drop height to the target. Situated on the tail of the bomb was a 600,000-

candela The candela ( or ; symbol: cd) is the unit of luminous intensity in the International System of Units (SI). It measures luminous power per unit solid angle emitted by a light source in a particular direction. Luminous intensity is analogous t ...

flare A flare, also sometimes called a fusée, fusee, or bengala in some Latin-speaking countries, is a type of pyrotechnic that produces a bright light or intense heat without an explosion. Flares are used for distress signaling, illumination, ...

which also left behind a noticeable smoke trail, to enable the bombardier to observe and control it from the control

aircraft An aircraft is a vehicle that is able to fly by gaining support from the air. It counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engine ...

. When used in combat, it was dropped from a modified Consolidated B-24 Liberator, with earlier development test drops of the Azon in the United States sometimes using the B-17 Flying Fortress as the platform. Some ten crews, of the

458th Bombardment Group 458th may refer to: *458th Air Expeditionary Group The 458th Air Expeditionary Group is a provisional United States Air Force unit assigned to United States Air Forces in Europe to activate or inactivate as needed. The most recent known activa ...

, based at

RAF Horsham St Faith RAF Horsham St Faith is a former Royal Air Force station near Norwich, Norfolk, England which was operational from 1939 to 1963. It was then developed as Norwich International Airport. RAF Bomber Command use The airfield was first developed ...

, were trained to drop the device for use in the

European theater The European theatre of World War II was one of the two main theatres of combat during World War II. It saw heavy fighting across Europe for almost six years, starting with Germany's invasion of Poland on 1 September 1939 and ending with the ...

. The ability to only control the path of the bomb in the azimuth direction, made AZON bombs most suitable for long and narrow targets, such as bridges or railways. A disadvantage of using an AZON bomb was that after a bomb was dropped the bomber could not break way immediately because the bombardier had to keep the bomb in view so he could guide it. The bombardier used a BC-1156 joystick control to adjust the course left or right. The directional commands were sent to the guidance package via a special-purpose radio system. The 493rd Bomb Squadron also dropped Azon bombs in Burma in early 1945 from similarly-modified B-24s, based at

Pandaveswar Airfield Pandaveswar Airfield is a former wartime United States Army Air Forces airfield in India used during the Burma Campaign 1944-1945. It is now abandoned. History Pandaveswar was a major Tenth Air Force combat airfield, hosting numerous groups betwe ...

, India, with considerable success, fulfilling the designers' original purpose for the ordnance.

Azon operations

References

External links

NMUSAF page about the Azon ordnanceOfficial 1943 USAAF film describing the AZON bomb
* ttp://www.ausairpower.net/WW2-PGMs.html The Dawn of the Smart Bombbr>Guided weapons of World War II
* ttps://www.youtube.com/watch?v=raeNrPq1K6s Video account of AZON Use Against the Burma Railway bridgesbr>WW II video of AZON Bomb Drop over BurmaAnother video of AZONs in action over Burma
{{Authority control World War II weapons of the United States World War II aerial bombs of the United States Guided bombs of the United States Weapons and ammunition introduced in 1944

Azon operations

See also

References

External links