The Avenger AS Mk.4 was the British designation given a version of the TBM-3S anti-submarine warfare aircraft that served with the Fleet Air Arm from 1953.
The standard TBM-3S had the turret removed and a radar operator's position installed. A longer canopy was installed, although with a number of metal panels. The -3S carried its own radar, but normally operated alongside the TBM-3W radar early warning aircraft.
The British Avenger AS Mk.4 differed in that it was designed to operate without the -3W. As on the American aircraft the turret was removed, but the new canopy was glazed along its full length. A surface search radar was carried in a radome mounted below the forward fuselage, with most of the radar equipment in the front of the bomb bay.
The AS Mk.4 served with seven Fleet Air Arm squadrons during the 1950s (Nos.814, 815, 824, 831, 1830, 1841 and 1844), and the last aircraft, serving with No.831 Electronic Counter-Measure Squadron remained in use until the early 1960s.