A tail warning radar, sometimes TW for short, was a short-lived class of aircraft-mounted

radar Radar is a detection system that uses radio waves to determine the distance ('' ranging''), angle, and radial velocity of objects relative to the site. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, we ...

systems used to provide warning of another aircraft approaching from the rear. They were mostly used on

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 ...

bomber 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 air ...

s, starting with the Monica system fit to

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) an ...

(RAF)

heavy bomber Heavy bombers are bomber aircraft capable of delivering the largest payload of air-to-ground weaponry (usually bombs) and longest range (takeoff to landing) of their era. Archetypal heavy bombers have therefore usually been among the larges ...

s starting in June 1942. The set was also produced in the US as the AN/APS-13, but used primarily on late-war fighter aircraft like the Republic P-47 and

North American P-51 The North American Aviation P-51 Mustang is an American long-range, single-seat fighter and fighter-bomber used during World War II and the Korean War, among other conflicts. The Mustang was designed in April 1940 by a team headed by James ...

. These had to be withdrawn over Europe in 1944 when it was learned the ''Luftwaffe'' was homing in on their signals using the

Flensburg radar detector The FuG 227 ''Flensburg'' was a German passive radar receiver developed by Siemens & Halske and introduced into service in early 1944. It used wing and tail-mounted dipole antennae and was sensitive to the mid- VHF band frequencies of 170–220 M ...

. A small number were then transferred to RAF de Havilland Mosquito night fighters to attract the German fighters, and when one was seen approaching the Mosquito would perform a controlled 360 degree turn that would result in the German aircraft in front of the Mosquito and centered in their radar. During the same time, the ''Luftwaffe'' began adding additional rearward-pointing antennas to their

night fighter A night fighter (also known as all-weather fighter or all-weather interceptor for a period of time after the Second World War) is a fighter aircraft adapted for use at night or in other times of bad visibility. Night fighters began to be used i ...

s as an ad-hoc tail warning radar to provide some protection from these dreaded "

Serrate Serration is a saw-like appearance or a row of sharp or tooth-like projections. A serrated cutting edge has many small points of contact with the material being cut. By having less contact area than a smooth blade or other edge, the applied p ...

" intruder flights. Dedicated tail warning radars were used for a relatively short time, from late-WWII through the 1950s. After that time, the increasing speeds of aircraft and the ability to shoot from off-axis angles using air-to-air missiles eroded their usefulness. One of the last major uses was the

Red Steer Red Steer, also known as ARI 5919 and ARI 5952 depending on the version, was a tail warning radar used on the British V bomber force. Built by EKCO, it was developed from the experimental AI.20 radar for the English Electric Lightning. The Light ...

system on the V bombers, a long-range system that was used to help the electronics warfare officer properly time the use of jammers and chaff. Today, similar tasks are generally provided by passive receiver systems that listen for the signals from the

interceptor aircraft An interceptor aircraft, or simply interceptor, is a type of fighter aircraft designed specifically for the defensive interception role against an attacking enemy aircraft, particularly bombers and reconnaissance aircraft. Aircraft that are c ...

's radars; such systems do not provide range information but are still useful while not giving off any signals of their own. These systems also have the advantage of working against air and ground radars, which became important as the main anti-aircraft threat moved to surface-to-air missiles (SAMs). A new class of tail warning radars emerged in the 1980s, primarily as a counter to SAM fire. The AN/ALQ-153 was used on the

Boeing B-52 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 ...

G and H and

Rockwell B-1 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 ...

B aircraft and saw action during the

Gulf War The Gulf War was a 1990–1991 armed campaign waged by a Coalition of the Gulf War, 35-country military coalition in response to the Iraqi invasion of Kuwait. Spearheaded by the United States, the coalition's efforts against Ba'athist Iraq, ...

. The Automatic Gun Laying Turret used on

Avro Lancaster bombers combined tail warning with

gun laying A gun is a ranged weapon designed to use a shooting tube (gun barrel) to launch projectiles. The projectiles are typically solid, but can also be pressurized liquid (e.g. in water guns/cannons, spray guns for painting or pressure washi ...

. Systems like these were found on many post-war bomber designs and are generally regarded as a separate class.

References

Bibliography

* {{cite book , first=Maurice , last=Rubin , title= Radar: The Electronic Eye , publisher=Chemical Publishing Company , date=1963 , url=https://books.google.com/books?id=wxR5AAAAIAAJ , page=291 , isbn=9780820600871 Aircraft radars Military radars