Grumman Avenger Mk.II (TBM-1c)

At the beginning of WWII the Royal Navy's aviators were forced to fly such antediluvian types as the Swordfish and Sea Gladiator as a direct result of the pedestrian approach of of the naval staff to the operational requirements of the Fleet Air Arm. Fortunately for the Allied cause, this lack of enterprise had not been emulated in the USA, where audacity had been displayed in no small measure by aircraft manufacturers in their efforts to meet more far-sighted shipboard combat aircraft requirements. Outstanding among the companies that had created a new generation of carrier-based airplanes being the Grumman Aircraft Engineering Corporation of Bethpage. It was to this Long Island based company that the British Fleet Air Arm was to contract an immense debt for boosting the service's morale at a time when it was very much the poor cousin to the RAF in the matter of front-line aircraft. It was not simply the fact that British naval aviation was restored to the first division by this company's aircraft but Grumman gave the Fleet Air Arm an insight into how purpose-built naval airplanes could really perform, reorienting much of the naval staff thinking on operational requirements in the process.

Grumman received the order for two examples of the XTBF-1 on April 8, 1940. This was a mid-wing cantilever design with a crew of three. Externally, it looked like Grumman's F4F Wildcat, but with a bigger belly. The TBF was designed from the start with folding wings. The folding mechanism was patterned after that developed for the Martlet II and F4F-4 Wildcat. Armament consisted of one synchronized "50 caliber" (12.7mm) Browning machine gun in the upper engine cowling firing through the propeller, another 50 caliber weapon firing from a small electrically powered turret at the aft end of the long canopy, and a ventral flexible 30 caliber (7.62mm) machine gun firing rearwards from a position just aft of the long weapons bay. The weapons bay was large enough to hold four 500-pound bombs, or one 22.4-inch 2,000 pound Mark 13 torpedo. Provision was made for carrying the Norden bombsight, but Avenger pilots found this to be less accurate than other aiming techniques.

The prototype flew on August 7, 1941. The designation TBF-1B applied to 402 aircraft built for the Royal Navy, which the British initially called Tarpon T.R. Mark I, but later called Avenger T.R. Mark I. British Avengers were sometimes modified to British specification by Blackburn Aircraft. The most noticeable modifications made by Blackburn were the bulged windows fitted to the radioman's station on the sides of the aircraft and also included the installation of British oxygen systems and gunsights. The TBF-1C deleted the nose-mounted machine gun and, instead, mounted one 50 caliber weapon in each wing. This variant was plumbed to carry up to 391 gallons of additional fuel in auxiliary fuel tanks. Grumman built 764 of this model, while GM built 2,332 of their virtually identical TBM-1C.

In the Atlantic, the Avenger was the obvious choice for use aboard British and American escort carriers in screening convoys and hunting down U-boats. Avengers would sight surfaced U-boats, and swoop down on them in a glide bombing approach, releasing multiple 250-pound, 325-pound, or (most often) 500-pound depth bombs. If the U-boat put up accurate flak, the Avenger pilot might choose to circle out of range and wait for other aircraft to assist. Grumman Wildcat fighters, with either four or six heavy machine guns, were often effective at subduing the U-boat's flak battery so that the Avengers could more safely make their attacks. Later the Avenger's arsenal included rockets for use on surfaced U-boats and, after mid-1943, a super-secret antisubmarine homing torpedo known as the Mark 24 Fido (also called Zombie). Various versions of the Avenger were fitted with radar for finding submarines or surface ships, with sonobuoys to track submerged submarines, and with flares and searchlights for illuminating potential targets at night. Avengers were known to carry combinations of these devices, such as two 500-pound depth bombs, one Fido, radar, flares, and sonobuoys.

American escort carrier air groups sank, or assisted in sinking, 35 submarines in the Atlantic. Most, perhaps all, of these kills must have been made by Avengers. To this total must be added the achievements of British Avengers. Additionally, Avengers flew antisubmarine patrols from land bases, and laid mines.

In all, 9,839 Avengers were assembled, including 2,293 TBFs built by Grumman and 7,546 TBMs built by Eastern Aircraft (General Motors). After the war, they faded from service more gradually than most aircraft of the era, serving useful roles into mid-1950s.

GB Planes and Specifications