Airborne radio relay
Encyclopedia
Airborne radio relay is a technique employing aircraft fitted with radio relay stations for the purpose of increasing the range, flexibility, or physical security
of communications
systems.
One of the first uses of airborne radio relay was by the United States Army
's 1st Cavalry Division in the Battle of Ia Drang
during the Vietnam War
, which employed the technique to improve communications with commanders at headquarters. The action of war had shifted to the borders of Laos
and Cambodia
, where the hilly terrain made the monetary and human cost of seizing and holding high ground, and airlifting and installing radio relay equipment prohibitive. In 1968, the Department of the Army
provided four specially-equipped relay aircraft to the Division, which proved invaluable throughout the country, in particular, during the 1st Cavalry Division's relief of Khe Sanh
in 1968.
The use of airborne radio relay was a great success, although two problems arose during the Vietnam War. The first was the limitations of the aircraft used as relays. The 1st Cavalry Division had originally used C-7 Caribou
s as the relay aircraft, but when these planes were turned over to the Air Force
, the equipment was installed in single-engine Otter
aircraft, which were too underpowered to carry the heavy equipment required for relay. Eventually, the 1st Signal Brigade
was provided with six specially-equipped U-21
aircraft for use in relay operations. The second problem was that of radio frequency interference: the limited frequency spectrum in use for combat radios meant that relay aircraft often interfered with the communication of ground units when their frequencies were overridden by the airborne units. The Army eventually assigned certain frequencies for airborne relay only, although this further limited the frequencies available to ground units.
Security
Security is the degree of protection against danger, damage, loss, and crime. Security as a form of protection are structures and processes that provide or improve security as a condition. The Institute for Security and Open Methodologies in the OSSTMM 3 defines security as "a form of protection...
of communications
Telecommunication
Telecommunication is the transmission of information over significant distances to communicate. In earlier times, telecommunications involved the use of visual signals, such as beacons, smoke signals, semaphore telegraphs, signal flags, and optical heliographs, or audio messages via coded...
systems.
Use in Vietnam
United States Army
The United States Army is the main branch of the United States Armed Forces responsible for land-based military operations. It is the largest and oldest established branch of the U.S. military, and is one of seven U.S. uniformed services...
's 1st Cavalry Division in the Battle of Ia Drang
Battle of Ia Drang
The Battle of Ia Drang was the first major battle between the United States Army and the People's Army of Vietnam The Battle of Ia Drang was the first major battle between the United States Army and the People's Army of Vietnam (PAVN) The Battle of Ia Drang was the first major battle between the...
during the Vietnam War
Vietnam War
The Vietnam War was a Cold War-era military conflict that occurred in Vietnam, Laos, and Cambodia from 1 November 1955 to the fall of Saigon on 30 April 1975. This war followed the First Indochina War and was fought between North Vietnam, supported by its communist allies, and the government of...
, which employed the technique to improve communications with commanders at headquarters. The action of war had shifted to the borders of Laos
Laos
Laos Lao: ສາທາລະນະລັດ ປະຊາທິປະໄຕ ປະຊາຊົນລາວ Sathalanalat Paxathipatai Paxaxon Lao, officially the Lao People's Democratic Republic, is a landlocked country in Southeast Asia, bordered by Burma and China to the northwest, Vietnam to the east, Cambodia to the south and Thailand to the west...
and Cambodia
Cambodia
Cambodia , officially known as the Kingdom of Cambodia, is a country located in the southern portion of the Indochina Peninsula in Southeast Asia...
, where the hilly terrain made the monetary and human cost of seizing and holding high ground, and airlifting and installing radio relay equipment prohibitive. In 1968, the Department of the Army
United States Department of the Army
The Department of the Army is one of the three military departments within the Department of Defense of the United States of America. The Department of the Army is the Federal Government agency which the United States Army is organized within, and it is led by the Secretary of the Army who has...
provided four specially-equipped relay aircraft to the Division, which proved invaluable throughout the country, in particular, during the 1st Cavalry Division's relief of Khe Sanh
Khe Sanh
Khe Sanh is the district capital of Hướng Hoá District, Quảng Trị Province, Vietnam, located 63 km west of Đông Hà.Khe Sanh Combat Base was a United States Marine Corps outpost in South Vietnam used during the Vietnam War. The airstrip was built in September 1962...
in 1968.
The use of airborne radio relay was a great success, although two problems arose during the Vietnam War. The first was the limitations of the aircraft used as relays. The 1st Cavalry Division had originally used C-7 Caribou
De Havilland Canada DHC-4 Caribou
The de Havilland Canada DHC-4 Caribou is a Canadian-designed and produced specialized cargo aircraft with short takeoff and landing capability...
s as the relay aircraft, but when these planes were turned over to the Air Force
United States Air Force
The United States Air Force is the aerial warfare service branch of the United States Armed Forces and one of the American uniformed services. Initially part of the United States Army, the USAF was formed as a separate branch of the military on September 18, 1947 under the National Security Act of...
, the equipment was installed in single-engine Otter
De Havilland Canada DHC-3 Otter
The de Havilland Canada DHC-3 Otter is a single-engined, high-wing, propeller-driven, STOL aircraft developed by de Havilland Canada. It was conceived to be capable of performing the same roles as the earlier and highly successful Beaver, but was overall a larger aircraft.-Design and...
aircraft, which were too underpowered to carry the heavy equipment required for relay. Eventually, the 1st Signal Brigade
1st Signal Brigade (United States)
The 1st Signal Brigade is a military communications brigade of the United States Army subordinate to the Eighth United States Army and located at Yongsan Garrison in South Korea.-Vietnam War:...
was provided with six specially-equipped U-21
Beechcraft King Air
The Beechcraft King Air family is part of a line of twin-turboprop aircraft produced by the Beech Aircraft Corporation...
aircraft for use in relay operations. The second problem was that of radio frequency interference: the limited frequency spectrum in use for combat radios meant that relay aircraft often interfered with the communication of ground units when their frequencies were overridden by the airborne units. The Army eventually assigned certain frequencies for airborne relay only, although this further limited the frequencies available to ground units.