The American Civil War marked the first use of aerial reconnaissance by the U.S. Army in the form of balloons. The U.S. Army’s balloon corps – created in 1861 – observed the battlefield from tethered balloons and reported via telegraphs. Throughout the war, observers provided a steady stream of reports, enabling unit commanders to obtain an aerial view of their area of operations, track enemy dispositions, map approaches to objectives and direct artillery fire onto hostile troop concentrations. They provided Union commanders with early warning of the Confederate attacks and tracked battle developments. Union balloons forced the Confederates to divert time, energy and personnel in an effort to cloak their activities from aerial observation.1
The trench warfare of World War I precluded traditional ground reconnaissance by cavalry, which could not penetrate hostile defenses to locate artillery positions and key defensive concentrations. Consequently, this role fell to aircraft able to fly over the battlefield and observe enemy dispositions in depth. In most major offensives, reconnaissance flights sought to identify enemy positions and artillery batteries, photograph key locations, direct artillery fire and conduct battle-damage assessments. As one author noted, “The accuracy and timeliness of the intelligence they gathered changed the nature of warfare, and the devastating artillery barrages they orchestrated from high above the battlefield accounted for more casualties than any other weapon system of the Great War. Simply put, the reconnaissance aircrew was the most lethal killing machine of World War I.”2
World War II witnessed the growing sophistication and integration of aerial reconnaissance and ground operations. Aerial photography provided a sensing of the terrain upon which operations would occur and supplemented ground intelligence of enemy dispositions. In Italy, observation planes organic to most ground formations directed artillery fire, conducted route reconnaissance, tracked enemy movements, identified German demolitions and strong points and provided advance warning of antitank traps. They also helped determine assembly areas and bivouac points, while their simple presence discouraged German artillery and mortars from firing and disclosing their position.3
During the Vietnam conflict, integrated operations by air and ground cavalry often proved the most effective means of finding and eliminating insurgents. Air-cavalry helicopters formed an aerial screen, spotting hostile forces and directing friendly ground troops into contact. Air cavalry also interdicted enemy troops and fixed them in place until ground forces arrived to eliminate them. The 11th ACR relied on its organic air cavalry to conduct much of its reconnaissance in difficult terrain. The helicopters rapidly covered large areas and inserted air-mobile rifle platoons to conduct dismounted sweeps of select locations or bunker complexes. Air cavalry helped identify enemy infiltration trails and track them to base camps, which became targets for attack by ground forces. Air cavalry bore responsibility for verifying reports of enemy activity. Once confirmed, further reconnaissance occurred and the air cavalry sought to force an enemy reaction, sometimes through the insertion of air-mobile infantry, while ground forces moved to contact.4
1“Balloons in the American Civil War,” Harper’s Weekly on the American Civil War, Internet article accessed May 12, 2014, at http://www.civilwar.com/weapons/observation-balloons.htm; “Civil War Ballooning: Interesting Facts and Frequently Asked Questions,” Internet article accessed May 12, 2014, at http://www.civilwar.org/education/history/civil-war-ballooning/civil-war-ballooning.html; James L. Green, “Civil War Ballooning During the Seven Days Campaign,” Internet article accessed May 13, 2014, at http://www.civilwar.org/education/history/civil-war-ballooning/ballooning-during-the-seven.html.
2Unikoski, Ari, “The War in the Air – Observation and Reconnaissance,” FirstWorldWar.com, Internet article accessed May 13, 2014, at http://www.firstworldwar.com/airwar/observation.htm; Kostka, Del, “Air Reconnaissance in World War One,” MilitaryHistoryOnline.com, Internet article accessed May 13, 2014, at http://www.militaryhistoryonline.com/wwi/articles/airreconinwwi.aspx.
3Cameron, Robert S., Mobility, Shock and Firepower: the Emergence of the U.S. Army’s Armor Branch, 1917-1945, Washington, DC: Center of Military History, 2008; historical section, Army Ground Forces, Study No. 35, “Army Ground Forces and the Air-Ground Battle Team Including Organic Light Aviation,” 1948; US. Army Ground Forces Observer Board, “Report of Observers: Mediterranean Theater of Operations,” Vol. III, September 1944.
4See Neufeld, Jacob, and Watson, George M. Jr., editors, Coalition Air Warfare in the Korean War 1950-1953, Washington, DC: U.S. Air Force History and Museums Program, 2005, especially John Patrick Finnegan, “The Intelligence War in Korea: An Army Perspective,” retired U.S. Marine Corps MAJ Patrick C. Roe, “The Ghost Armies of Manchuria” and Samuel Dickens, “USAF Reconnaissance During the Korean War”; Schafer, Elizabeth, “Helicopters in the Korean War,” included in The Korean War: An Encyclopedia; Hiller OH-23 (Model UH-12) Light Utility Helicopter, Internet article accessed May 15, 2014, at http://www.militaryfactory.com/aircraft/detail.asp?aircraft_id=1090.