Grumman TBF Avenger Specifications:
- Length: 40 ft. 11.5 in.
- Wingspan: 54 ft. 2 in.
- Height: 15 ft. 5 in.
- Wing Area: 490.02 sq. ft.
- Empty Weight: 10,545 lbs.
- Loaded Weight: 17,893 lbs.
- Crew: 3
- Power Plant: 1 × Wright R-2600-20 radial engine, 1,900 hp
- Range: 1,000 miles
- Max Speed: 275 mph
- Ceiling: 30,100 ft.
- Guns: 2 × 0.50 in. wing-mounted M2 Browning machine guns, 1 × 0.50 in. dorsal-turret mounted M2 Browning machine gun, 1 × 0.30 in. ventral-mounted M1919 Browning machine gun
- Bombs/Torpedo: 2,000 lbs. of bombs or 1 Mark 13 torpedo
TBF Avenger - Origins:
In 1939, the US Navy's Bureau of Aeronautics (BuAer) issued a request for proposals for a new torpedo/level bomber to replace the Douglas TBD Devastator. Though the TBD had only entered service in 1937, it was quickly being outclassed as aircraft development rapidly advanced. For the new aircraft, BuAer specified a crew of three (pilot, bombardier, and radio operator), each armed with a defensive weapon, as well as a dramatic increase in speed over the TBD and an ability to carry a Mark XIII torpedo or 2,000 lbs. of bombs. As the competition moved forward, Grumman and Chance Vought won contracts to build prototypes.
TBF Avenger Design & Development:
Beginning in 1940, Grumman commenced work on the XTBF-1. The development process largely proved to be unusually smooth. The only aspect that proved challenging was meeting a BuAer requirement that called for the rear-facing defensive gun to be mounted in a power turret. While the British had experimented with powered turrets in single engine aircraft, they had difficulties as the units were heavy and mechanical or hydraulic motors led to a slow traverse speed. To solve this issue, Grumman engineer Oscar Olsen was directed to design an electrically powered turret.
Pushing forward, Olsen encountered early problems as the electric motors would fail during violent maneuvers. To overcome this, he utilized small amplidyne motors, which could vary torque and speed rapidly, in his system. Installed in the prototype, his turret performed well and it was ordered into production without modification. Other defensive armaments included a forward-firing .50 cal. machine gun for the pilot and a flexible, ventrally-mounted .30 cal. machine gun which fired under the tail. To power the aircraft, Grumman used the Wright R-2600-8 Cyclone 14 driving a Hamilton-Standard variable pitch propeller.
Capable of 271 mph, the aircraft's overall design was largely the work of Grumman Assistant Chief Engineer Bob Hall. The XTBF-1's wings were square-tipped with an equal taper which, along with its fuselage shape, made the aircraft look like a scaled-up version of the F4F Wildcat. The prototype first flew on August 7, 1941. Testing proceeded and the US Navy designated the aircraft TBF Avenger on October 2. Initial testing went smoothly with the aircraft showing only a slight tendency to lateral instability. This was rectified in the second prototype with the addition of a fillet between the fuselage and tail.
Moving to Production:
This second prototype first flew on December 20, only thirteen days after the attack on Pearl Harbor. With the US now an active participant in World War II, BuAer placed an order for 286 TBF-1s on December 23. Production moved forward at Grumman's Bethpage, NY plant with the first units delivered in January 1942. Later that year, Grumman transitioned to the TBF-1C which incorporated two .50 cal. machine guns mounted in the wings as well as improved fuel capacity. Starting in 1942, Avenger production was shifted to the Eastern Aircraft Division of General Motors to allow Grumman to focus on the F6F Hellcat fighter.
Designated TBM-1, the Eastern-built Avengers began arriving in mid-1942. Though they had handed off building the Avenger, Grumman designed a final variant which entered production in mid-1944. Designated TBF/TBM-3, the aircraft possessed an improved power plant, under-wing racks for munitions or drop tanks, as well as four rocket rails. Through the course of the war, 9,837 TBF/TBMs were built with the -3 being the most numerous at around 4,600 units. With a maximum loaded weight of 17,873 lbs., the Avenger was the heaviest single-engine aircraft of the war, with only the Republic P-47 Thunderbolt coming close.
The first unit to receive the TBF was VT-8 at NAS Norfolk. A parallel squadron to the VT-8 then stationed aboard USS Hornet, the unit began familiarization with the aircraft in March 1942, but were quickly shifted west for use during upcoming operations. Arriving at Hawaii, a six-plane section of VT-8 was sent to ahead to Midway. This group took part in the Battle of Midway and lost five aircraft. Despite this inauspicious beginning, the Avenger's performance improved as US Navy torpedo squadrons transitioned to the aircraft.
The Avenger first saw use as part of an organized strike force at the Battle of the Eastern Solomons in August 1942. Though the battle was largely inconclusive, the aircraft acquitted itself well. As US carrier forces sustained losses in the Solomons Campaign, ship-less Avenger squadrons were based at Henderson Field on Guadalcanal. From here they aided in intercepting Japanese re-supply convoys known as the "Tokyo Express." On November 14, Avengers flying from Henderson Field sank the Japanese battleship Hiei which had been disabled during the Naval Battle of Guadalcanal.
Nicknamed the "Turkey" by its aircrews, the Avenger remained the US Navy's primary torpedo bomber for the remainder of the war. While seeing action in at key engagements such as the Battles of the Philippine Sea and Leyte Gulf, the Avenger also proved an effective submarine killer. During the course of the war, Avenger squadrons sank around 30 enemy submarines in the Atlantic and Pacific. As the Japanese fleet was reduced later in the war, the TBF/TBM's role began to diminish as the US Navy shifted to providing air support for operations ashore. These types of missions were more suited to the fleet's fighters and dive bombers such as the SB2C Helldiver.
During the war, the Avenger was also used by the Royal Navy's Fleet Air Arm. Though initially known as the TBF Tarpon, the RN soon switched to the name Avenger. Beginning in 1943, British squadrons began seeing service in the Pacific as well as conducting anti-submarine warfare missions over home waters. The aircraft was also provided to the Royal New Zealand Air Force which equipped four squadrons with the type during the conflict.
Retained by the US Navy after the war, the Avenger was adapted to several uses including electronic countermeasures, carrier onboard delivery, ship-to-shore communications, anti-submarine warfare, and airborne radar platform. In many cases, it remained in these roles into the 1950s when purpose-built aircraft began to arrive. Another key postwar user of the aircraft was the Royal Canadian Navy which used Avengers in various roles until 1960. A docile, easy to fly aircraft, Avengers also found widespread use in the civilian sector. While some were used in crop dusting roles, many Avengers found a second life as water bombers. Flown by both Canadian and American agencies, the aircraft was adapted for use in fighting forest fires. A few remain in use in this role.