operational task being surveillance patrols, but the RAAF maintained an intensive training regime and undertook combined exercises with other Allied forces. On 23 June, No. 77 Squadron made what was expected to be its last flight before rotating back to Australia. Korean War Spence and his family were about to go on holiday before returning to Australia when, on 25 June 1950, No. 77 Squadron was placed on standby for action in the Korean War, which had just broken out. The unit was specifically requested by General Douglas MacArthur, commander of United Nations (UN) forces. No. 77 Squadron flew its initial escort and patrol sorties from Iwakuni on 2 July, becoming the first non-American UN unit to go into action. That day, Spence took eight Mustangs on an escort mission for United States Air Force (USAF) B-26 Invaders attacking a bridge south of Seoul. Families still living at Iwakuni, pending their repatriation from what had become an operational theatre, could watch the Mustangs depart for missions over Korea. A friendly fire incident occurred on 3 July 1950, when No. 77 Squadron attacked a train full of US and South Korean troops on the main highway between Suwon and Pyongtaek, inflicting many casualties, twenty-nine of them fatal. Before the mission, Spence had raised concerns that the North Koreans could not have penetrated so far south, but was assured by USAF controllers that the target was correct. The incident was widely reported in American newspapers but a public statement by Lieutenant General George E. Stratemeyer, commander of the US Far East Air Force, cleared the RAAF of blame. Spence was recommended for the US Air Medal for "meritorious service" in operations from 25 June to 15 July. His increasingly heavy taskload included diplomatic duties and public relations, as well as squadron administration and many combat sorties. No. 77 Squadron did not encounter enemy aircraft in the opening phase of the war, but often faced intense ground fire. During July and August 1950, equipped with bombs, rockets and napalm, the Mustangs supported UN troops retreating before the North Korean advance. According to the official history of the Air Force in 1946–1971, the squadron's part in the Battle of Pusan Perimeter earned recognition "not only for the RAAF but also Australia at the highest political levels in the United States". On 15 August, Prime Minister Robert Menzies presented the Gloucester Cup to No. 77