Farm Gate was the codename for the US Air Force military operation to train and support South Vietnamese Air Force personnel. It was authorized by President John F Kennedy in October 1961. The 4400th Combat Crew Training Squadron, code named "Jungle Jim," flew from their home base at Eglin AFB to South East Asia. In order to train the VNAF men, the Americans used older aircraft in support of the type of conflict they were facing. South Vietnamese crews were trained to fly the T-28 Trojan, C-47 Dakota and B-26 Invader.
Although their job was to train and advise South Vietnamese, the US pilots also flew undercover combat missions to support ground troops during Operation Farm Gate. This was authorized by the US Joint Chief of Staff. With this order, U.S. Air Force pilots were given the go-ahead to undertake combat missions against the Viet Cong as long as at least one Vietnamese national was carried on board the strike aircraft for training purposes. In the event an aircraft did get shot down in hostile territory, the presence of an Asian crewman would be enough to dodge any accusations of Geneva Accord violations. Nevertheless, after the escalation of the war as a result of the Gulf of Tonkin Incident, the Farm Gate detachment was no longer required to fly under South Vietnamese colors. Their aircraft began carrying full US markings and the detachment became known as the 1st Air Commando Squadron.