|The prototype TBF was designed in 1940 by Bill Schwendler of Grumman Aircraft. It first flew on August 1, 1941. The TBF was primarily designed to replace the obsolete Douglas TBD Devastator.
Once accepted by the Navy, Grumman built 2,291 TBFs before General Motors, Eastern Aircraft Division, began building them under license from Grumman. These identical aircraft were designated as TBMs with GM building 7,546 for a type total of 9,837.
Early models of both the TBF and TBM had Wright R-2600-8 engines developing only 1700 hp. Later production saw increases in power up to 1900 hp with the Wright R-2600-20 engine. TBM-3s, with nearly 4,000 being built, had the more powerful engines. This required more cooling, the oil cooler was moved to the lower engine cowl lip and four more cowl flaps were added to each side. These changes and the removal of the 30 caliber ventral "stinger" gun are the primary visual differences between early and later model Avengers.
The TBF/TBM carries 2,000 lbs. of munitions. It could carry one 2,000 lb torpedo; four 500 lb bombs or depth charges, twenty 100 lb bombs, rockets, mines or an auxiliary fuel tank of 275 gallons.
At first the TBF-1 TBM had a .30 cal gun mounted on the cowl, a 30 cal ventral gun (stinger) and a .50 cal turret gun. In 1943 the cowl gun was replaced by two .50 cal guns in the wings and the ventral "stinger" was removed.
The first torpedo's were the Mark 13 models with poor performance having to be dropped at less than 100 mph and 100 ft. In 1943 the Mark 13-IA (ringtail) torpedo was deployed and could be dropped from a speed of up to 280 mph and 800 ft. Various techniques were used by different squadrons and pilots.
Bombs were dropped by the pilot, either in a cluster or, using the "intervalometer" (set by the radioman) in a four-bomb stick. The pilot usually entered a 30 to 45 degree dive to about 500 ft elevation before releasing the bombs. A four-bomb stick, spaced 60 to 75 ft apart was used on maneuvering ships.
TBF/TBM Avenger In Battle
Avengers are mostly known for their successes in the Pacific Theater attacking Japanese naval ships and land bases. TBMs flew from CVE escort and CV fast attack carriers as well as from U.S. held land bases. The Pacific Theater was a carrier war with TBM'S, SBD's and SB2C's sinking enemy ships and destroying their island bases.
In the North Atlantic, TBMs are credited with stopping the German submarine "wolfpacks". Deployed on CVEs, each with 20 to 28 TBMs, they accompanied convoys of allied ships. They could fly submarine patrols all day and night attacking German subs with machine guns, rockets, depth charges and bombs.
The last 24 TBMs were delivered to the Navy in August 1945. TBM were retired from US. Navy active service in June 1954