The son of the Reverend Thomas William Longfield, he was born at High Halstow in Kent, and was educated at Aldenham School.[1] Upon leaving Aldenham, Longfield enlisted in the Royal Air Force as a pilot officer in February 1929,[2] with confirmation in the rank in March 1930.[3] He was promoted to the rank of flying officer in August 1930.[4] He made his debut in first-class cricket for the Royal Air Force cricket team against the Army at The Oval in 1931;[5] he claimed both of his first-class wickets in this match, dismissing Alexander Wilkinson and Adrian Gore.[6] He made a second first-class appearance the following year in a repeat of the 1931 fixture.[5]
He was transferred to the class A reserve in February 1934,[7] with a further transfer to the C class in December 1934.[8] He was transferred back to the A class in December 1935,[9] He was promoted to the rank of flight lieutenant in January 1938.[10] Serving during the Second World War, Longfield was promoted to the rank of squadron leader in December 1940.[11]
He was promoted to the temporary rank of wing commander in September 1942, with seniority antedated to March 1942,[12] and was placed in command of 105 Squadron,[1] which had the distinction of being the first squadron to fly the Mosquito fighter-bomber. On 26 February 1943, he took off from RAF Marham for an attack on Rennes in occupied France.[1] While engaging the target, Longfield made a navigational error and collided with another Mosquito in the squadron. Longfield and his navigator, Flight Lieutenant Ralph Frederick Mills, were both killed,[1] along with the crew of the Mosquito he collided with, piloted by Flight Officer Spencer Griffith Kimmel of the Royal Canadian Air Force.[13] His replacement as commanding officer of 105 Squadron, Wing Commander John William Deacon, was killed the following day in a training accident in Norfolk.[13]
Longfield was buried at Rennes Eastern Communal Cemetery.[1] His brother, Tom Longfield, was also a first-class cricketer.