Airborne radio relay is a technique employing aircraft fitted with

radio relay Radio stations that cannot communicate directly due to distance, terrain or other difficulties sometimes use an intermediate radio relay station to relay the signals. A radio relay receives weak signals and retransmits them, often in a different di ...

stations for the purpose of increasing the range, flexibility, or physical security of

communications Communication is commonly defined as the transmission of information. Its precise definition is disputed and there are disagreements about whether Intention, unintentional or failed transmissions are included and whether communication not onl ...

systems. The aircraft may be manned or

unmanned aerial vehicle An unmanned aerial vehicle (UAV) or unmanned aircraft system (UAS), commonly known as a drone, is an aircraft with no human pilot, crew, or passengers onboard, but rather is controlled remotely or is autonomous.De Gruyter Handbook of Dron ...

Use in Vietnam

One of the first uses of airborne radio relay was by the

United States Army The United States Army (USA) is the primary Land warfare, land service branch of the United States Department of Defense. It is designated as the Army of the United States in the United States Constitution.Article II, section 2, clause 1 of th ...

's 1st Cavalry Division in the Battle of Ia Drang during the

Vietnam War The Vietnam War (1 November 1955 – 30 April 1975) was an armed conflict in Vietnam, Laos, and Cambodia fought between North Vietnam (Democratic Republic of Vietnam) and South Vietnam (Republic of Vietnam) and their allies. North Vietnam w ...

, which employed the technique to improve communications with commanders at headquarters. The action of war had shifted to the borders of

Laos Laos, officially the Lao People's Democratic Republic (LPDR), is the only landlocked country in Southeast Asia. It is bordered by Myanmar and China to the northwest, Vietnam to the east, Cambodia to the southeast, and Thailand to the west and ...

and

Cambodia Cambodia, officially the Kingdom of Cambodia, is a country in Southeast Asia on the Mainland Southeast Asia, Indochinese Peninsula. It is bordered by Thailand to the northwest, Laos to the north, and Vietnam to the east, and has a coastline ...

, 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 Caribous as the relay aircraft, but when these planes were turned over to the

Air Force An air force in the broadest sense is the national military branch that primarily conducts aerial warfare. More specifically, it is the branch of a nation's armed services that is responsible for aerial warfare as distinct from an army aviati ...

, the equipment was installed in single-engine

Otter Otters are carnivorous mammals in the subfamily Lutrinae. The 13 extant otter species are all semiaquatic, aquatic, or marine. Lutrinae is a branch of the Mustelidae family, which includes weasels, badgers, mink, and wolverines, among ...

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.

References

{{DEFAULTSORT:Airborne Radio Relay Telecommunications techniques Aviation communications

Use in Vietnam

See also

References