The F-100A officially entered USAF service on 27 September 1954, with the 479th Fighter Wing at George AFB, California. By 10 November 1954, the F-100As suffered six major accidents due to flight instability, structural failures, and hydraulic system failures, prompting the air force to ground the entire fleet until February 1955. The 479th finally became operational in September 1955. Due to ongoing problems, the air force began phasing out the F-100A in 1958, with the last aircraft leaving active duty in 1961. By that time, 47 aircraft had been lost in major accidents. Escalating tension due to construction of the Berlin Wall in August 1961 forced the USAF to recall the F-100As into active service in early 1962. The aircraft was finally retired in 1970.