The Cessna O-1 Bird Dog is a liaison and observation aircraft that first flew on December 14, 1949, and entered service in 1950 as the L-19 in the Korean War.

The U.S. Army was searching for an aircraft that could fly over enemy locations to collect information related to artillery fire target locations and distances, as well as perform liaison duties, and preferably be constructed of all metal, as the fabric-covered liaison aircraft used during World War II (primarily Stinson and Piper products) had short service lives.

[citation needed] The Army held a competition in April 1950 for the contract, with contenders from Cessna, Piper, Taylorcraft, and Temco.

The prototype Cessna 305 (registration N41694) first flew on 14 December 1949, and it now resides in the Spirit of Flight Center in Erie, Colorado.

[3][4] The USMC issued a requirement for a larger and faster version, prompting Cessna to adapt Cessna 180 wings and a more powerful 260 hp (190 kW) Continental O-470-2 engine to the aircraft, which was designated OE-2; 27 of these improved aircraft were delivered, but the sharp price increase dissuaded the USMC from future orders.

The winning entry, submitted by Jack A. Swayze, an industrial photographer, was selected by a U.S. Army board.

[citation needed] The United States Department of Defense (DOD) ordered 3,200 L-19s that were built between 1950 and 1959, entering both the U.S. Army and Marine Corps inventories.

[1] With the adoption of the 1962 United States Tri-Service aircraft designation system, the Army L-19 and Marine Corps OE were redesignated as the O-1 Bird Dog, and soon entered the Vietnam War.

Because of its short takeoff and landing (STOL) and low altitude/low airspeed capabilities, the O-1 also later found its way into USAF service as a Forward Air Controller (FAC) aircraft for vectoring faster fighter and attack aircraft and supporting combat search-and-rescue operations recovering downed aircrews.

[10] Two O-1 Bird Dogs were loaned to the Australian Army's 161 Reconnaissance Flight operating out of Nui Dat in Phuoc Tuy Province.

Another Bird Dog was built by this unit's maintenance crew, using aircraft sections salvaged from dumps around Vietnam.

In United States Service, it was mostly replaced by the O-2 Skymaster and OV-10 Bronco, although it lingered in many roles due to unique advantages.

American television personality and actor Ed McMahon was a Marine Corps aviator who piloted an OE during the Korean War, flying 85 combat missions and earning six Air Medals in 1953.

[16] Captain Hilliard A. Wilbanks, USAF, posthumously received the Medal of Honor for sacrificing his life on February 24, 1967, while supporting an ARVN Ranger Battalion at Di Linh, near Da Lat, South Vietnam.

After evading enemy ground fire, Major Bung-Ly headed out to sea and spotted the aircraft carrier Midway.

These are mostly historical (not current) list of operators: Data from Jane's All The World's Aircraft 1962–63[45]General characteristics Performance