The Country Party's coalition with the UAP had lapsed following Menzies' elevation to the prime ministership. In March 1940, Menzies and Cameron agreed to resume the coalition, providing an opportunity for five Country Party members to be added to the ministry. Cameron somewhat unexpectedly nominated Fadden as a Country Party representative, and he was appointed as an assistant minister to the Treasurer (Percy Spender) and the Minister for Supply and Development (Frederick Stewart). In August 1940, Fadden narrowly escaped being killed in the Canberra air disaster, which claimed the lives of three government ministers and the Chief of the General Staff. He was scheduled to be aboard the flight, which was transporting the ministers back to Canberra after a cabinet meeting in Melbourne, but instead took an overnight train. He traded places with Richard Elford (James Fairbairn's private secretary), who had wanted to stay in Melbourne to celebrate a wedding anniversary; both Elford and Fairbairn were among those killed. After the crash, Fadden replaced Fairbairn as Minister for Air and Minister for Civil Aviation; he also continued as assistant minister to the Treasurer.