The Eastern TBM-1 Avenger was the first version of that aircraft produced by the Eastern Aircraft Division of General Motors, and was produced in larger numbers than the Grumman TBF-1.
A great deal of effort went into getting the Avenger (and Wildcat) into production with General Motors. After the American entry into the Second World War General Motors stopped car production at all five of its large automobile factories, and began to look for contracts to produce aircraft spare parts. The Navy and Grumman had a more ambitious idea, instead wanted to open production lines for complete aircraft in the unused factories. Three of the five factories would be used to produce parts and sub-assemblies for the Wildcat and Avenger, while GM's Lindon, New Jersey factory would produce the completed FM-1 Wildcats and their Trenton, New Jersey would produce the TBM-1 Avenger. The newly created aircraft manufacturer became the Eastern Aircraft Division of GM.
Eastern were given ten full sets of Avenger sub-assemblies and a number of aircraft built with Parker-Kalon (PK) fasteners instead of rivets. These could be removed and replaced at will, allowing the sample aircraft to be repeated dismantled and assembled.
After the first meetings in the spring of 1942 a production contract was signed on 23 March 1942. The first complete TBM-1, built from Grumman-built sub-assemblies, was delivered in November 1942, followed by two more in December. Early in 1943 Eastern began to assemble aircraft constructed from their own assemblies, and thirty-one aircraft were delivered in March 1943. After that production built rapidly, to 75 in June, 100 in July, 215 in November 1943 and peaking at 400 in March 1945. The last Grumman Avengers were built in December 1943, leaving Eastern as the sole producer for the last two years of the war.
Between November 1942 and the end of the war Eastern built a total of 7,546 Avengers, three quarters of the total. Of these aircraft 550 were TBM-1s and 2,332 were TBM-1Cs, for a total of 2,882 aircraft.
The first 550 aircraft off the line were exact copies of the TBF-1, designated TBM-1, and with same .30in gun in cowling. They were followed by 2,332 TBM-1Cs which were identical to the Grumman TBF-1C. 334 -1Cs entered Fleet Air Arm service as the Tarpon II/ Avenger II.
The TBM-1 Avenger was identical to the Grumman built TBF-1. The two types could be told apart by some of the internal paint colours, with Eastern not using Grumman's own colours, otherwise only the Bureau Numbers separated them.
The TBM-1C was identical to the TBF-1C, armed with two .50in machine guns in the wing in place of the .30in gun in the cowling of the TBM-1.
The TBM-1CP was a photographic reconnaissance aircraft equipped with a trimetrogen camera, capable of taking panoramic pictures that spread from horizon to horizon in a single frame.
The TBM-1D was a night bomber produced by installed an ASD-1 (airborne search radar) set on a standard TBM-1 or -1C. The radar was carried in a pod mounted on the leading edge of the right wing. Those aircraft converted from -1Cs had their wing guns removed, while other guns were sometimes removed to save weight. The -1D was used as a control aircraft for night fighters, for airborne early warning duties and on anti-submarine patrols.
A small number of TBM-1s were given extra radar equipment and the designation TBM-1E.
The TBM-1J was modified for Arctic conditions, gaining de-icer boots on all leading edges and extra heaters. BuNo.06031 was converted to this standard.
The TBM-1L carried a retractable searchlight in the bomb-bay and was used for anti-submarine warfare and air-sea rescue duties.
Designation given to a small number of photo-reconnaissance conversions of the -1 or -1C.