Grumman TBF Avenger
Grumman's first torpedo bomber was the heaviest single-engine aircraft of World War II, and only the USAAF's P-47 Thunderbolt came close to equalling it in maximum loaded weight among all single-engined fighters, only being some 400 lb (181 kg) lighter than the TBF, by the end of World War II. The Avenger was the first design to feature a new wing-folding mechanism created by Grumman, intended to maximize storage space on an aircraft carrier; the F4F-4 and later models of Wildcat received a similar folding wing and the F6F Hellcat (both designed by Grumman) employed this mechanism as well. The engine used was the Wright R-2600-20 (which produced 1,900 hp/1,417 kW).
There were three crew members: pilot, turret gunner and radioman/bombardier/ventral gunner. One .30 caliber machine gun was mounted in the nose, a .50 caliber (12.7 mm) gun was mounted right next to the turret gunner's head in a rear-facing electrically powered turret, and a single .30 caliber hand-fired machine gun mounted ventrally (under the tail), which was used to defend against enemy fighters attacking from below and to the rear. This gun was fired by the radioman/bombardier while standing up and bending over in the belly of the tail section, though he usually sat on a folding bench facing forward to operate the radio and to sight in bombing runs. Later models of the TBF/TBM dispensed with the nose-mounted gun for one .50 caliber gun in each wing per pilots' requests for better forward firepower and increased strafing ability.
There was only one set of controls on the aircraft, and no access to the pilot's position from the rest of the aircraft. The radio equipment was massive, especially by today's standards, and filled the whole glass canopy to the rear of the pilot. The radios were accessible for repair through a "tunnel" along the right hand side. Any Avengers that are still flying today usually have an additional rear-mounted seat in place of the radios, which increases crew to four.