Fourth Air Force

A numbered air force that during World War II handled air defense of the western United States and today is a component of Air Force Reserve Command. Its CONUS air-defense mission was largely transferred to the Western Air Defense Force around 1949, after which it concentrated on training Reserve and Air National Guard personnel. There is no well-documented record of Fourth Air Force running UFO investigations; early Air Force study of unidentified objects was centralized under Air Materiel Command (ATIC) and Air Defense Command.

Historically involved in the air defense of the western U.S. and the early investigation of regional UFO sightings during the Cold War.