The squadron later received Wellingtons and Smith flew them operationally in the first two months of the war. After further postings he joined No 264 Squadron at Kirton-in-Lindsay, equipped with Defiants, as ‘A’ Flight commander, on 11 September 1940.
In December, Smith was promoted to Squadron Leader and joined No 221 Squadron at Birchham Newton, Norfolk as a Flight Commander. He carried out the first Coastal Command Wellington attack on a U-boat in the Atlantic in May 1941.
Smith went to a staff job at HQ No 18 Group in October 1941. A year later he took command of No 248 Squadron at Talbenny, flying Beaufighters on long-range fighter patrols between the UK and Gibraltar. From February 1944 to July 1945 he was part of the RAF Delegation in Washington DC. He commanded a Mosquito Wing in France.
Post-war RAF appointments included serving at the British High Commission in Delhi with the British Delegation to the United Nations in New York during the Korean War and at the embassy in Budapest, Hungary. He was also Deputy OC at RAF Acklington. He retired on 1 January 1961, as a Wing Commander, retaining the rank of Group Captain.
Smith then worked for the Scottish Office, specialising in the development of rural businesses. He was a Deputy Lieutenant for Morayshire.
Smith changed his name to Montagu-Smith after the Second World War. He died on 19 January 2014.
