<human>:  When did the A-1 Skyraider enter service?
<bot>: The A-1 Skyraider was first flown in 1944, but didn’t enter service until 1946. It was designed to be a high-altitude interceptor aircraft, and was used during World War II. It was used in combat by the US Navy and US Marine Corps. The A-1 Skyraider was also used by the US Air Force for training pilots, and was retired in 1974.