The standard torpedo of the US Naval Air Corps Bliss-Lewitt Mk.13 was unreliable, had low underwater speed (33 knots or 61 km/h) and had to be released at a very low aircraft speed (204 km/h) and altitude (15 m), which resulted in high combat losses and poor efficiency. Therefore, after the Midway Battle up to mid-1944 Avengers were mostly used as bombers and support battle crafts for the US Marine Corps operations. Still, there was a case in November of 1942 when TBF-1 destroyed the Japanese Hien battleship, already damaged by the US ship artillery.

TBF-1C on take-off, the summer of 1944. Notice the catapult cable and the HVAR missile guides. (taken from [5], p. 14).	TBF-1 dashboard
TBM-3 on board of Block Island, late 1944 (preparation for Okinawa battle). Notice the folded wing pods. (taken from [5], p. 66).	Our days. Restored TBF-3E, standard camouflage for spring of 1942.

With the development of Mk.13-1A torpedo in the summer of 1944, Avenger got back to its role of a torpedo bomber. The 182-kg TNT war head was changed for a 272 kg one with a more potent Torpex explosive charge. The torpedo was equipped with an extra ring stabilizer. Other modifications were made which allowed for a bomb to be dropped at high speeds (up to 518 km/h), and at altitudes up to 240 m. The efficiency of attacks drastically increased. For example, in June of 1944 Avengers sank the Japanese Hiyo carrier. In the Leyte Bay Battle (the central part of Philippines), the large-scale marine operation of 1944, Avengers made 19 precise torpedo hits destroying Musasi, which, having 67 tons displacement, was one of the two major battle ships of the Second World War,. Its twin, Yamato, a one-time flagship of Admiral Yamamoto, was sank in the Okinawa Battle on April 7, 1945. Avengers took part in its destruction, feeding its underwater part with a dozen of torpedoes. Avengers could boast with a kind of record: 6 Japanese transport ships sunk in one day, and 98 enemy aircraft downed in the air fights. Pilots appreciated the simplicity of handling and the deck landing of the aircraft, its durable chassis and high damage resistance.

Avenger preparing for a take-off	Avenger attempting a take-off

The Americans like to recall the war incident that happened to their ex-president George Bush. His TBM-1C was downed by anti-aircraft guns at the Chichijima Island during his 58th battle flight in September of 1944. He baled out and was picked up by a US submarine.

Tarpon (the name given to TBF/TBM-1 in FAA) on attack.	The Avenger was famous for it high survivability. This plane was badly damaged by anti-aircraft guns and still managed to get back to the base.

Avenger could have shared its glory with the already mentioned “Chance Vought TBU-1 «Sea Wolf»”, the second winner of the 1939-40 contest. The prototype flew on December 22, 1941. It had similarly large bomb compartment, but was more heavily armed and armored than the Avenger. The more potent Pratt-Whitney R-2800-20 Double Wasp engine (2000 hp) allowed the aircraft to fly 60 km/h faster than its rival. Nevertheless, Vought works were busy with the Corsair fighter production, and the order for 1100 TBU-1 was placed at the Consolidated works, thus giving the model the “Consolidated TBY-2 «Sea Wolf»” mark. Minor construction shortcomings and slow work process resulted in fulfilling the order no sooner than in the late 1943. Moreover, the Consolidated works were busy with mass production of Liberator, a heavy bomber, and the famous amphibia plane Catalina, which made the situation more complicated. As a result, only 189 aircraftswere constructed from November of 1944 to August of 1945 when the order was annulled. Not one of them took part in the battles.

Bombers had been the major US Navy battle force till 1944. By December 1941 most models had become obsolete. The same happened with torpedo bombers. For instance, the bomber squadron stationed on the Hornet carrier till 1942 consisted of “Curtiss SBC-4 «Helldivers»”, the biplane adopted by Navy in 1939 with a maximum speed of 376 km/h and bomb loading of 453 kg. The XSBC-3 prototype first flew on June 14, 1934, as one of the nominees for the NAVAER contest. Other winners were Northrop monoplane XBT-1, Douglass XTBD-1 (the TBD-1 torpedo bomber prototype) and Vought XSB2U.

XSB2U, the two-seater metal lowplane with linen covering, retractable chassis and Pratt-Whitney R-1535-78 engine (700 hp) first flew on January 4, 1936. Serial “Chance Vought SB2U-1 «Vindicator»” was adopted by carriers in March of 1938. The first aircraft to take trial by fire was the V-156-F, delivered to France in a batch of 40 machines in the second half of 1940. As for the US forces, by summer of 1942 SB2U-3 was sill left on arms of the USS Ranger, the CV-4 light carrier and the Midway Island marine squadron. Seventeen of the B-17 Fortress aircraft, sixteen SBD-2 bombers, eleven Vindicators, and torpedo bombers took part in an unorganized attack against the Japanese Navy on June 4, 1942. Different groups approached the fleet one after another and were consequently destroyed by anti-aircraft guns and Zero fighters. None of the bombers made a direct hit. The losses were enormous. The next day the survived Vindicators made another useless attempt and suffered heavy losses again. These were the last battle flights for SB2U-3.

However, the fruitless attacks of the outdated aircrafts proved beneficial to the outcome of the battle. When 50 of the SBD-3 carrier-borne dive bombers from Enterprise and Yorktown appeared in the sky over the Japanese battle ships, most Zero fighters were on decks refueling after the battle with SB2U-1 and SBD-2, while the others were fighting Devastators at a low altitude. The attack of SBD-3 put three of the four Japanese battle carriers on fire (Akagi, Kaga and Sorou), which led to their destruction. Hirou, the fourth carrier, overlooked by the dive bombers, managed to send out two battle groups. They tracked Yorktown, and having lost over half of the aircraft succeeded with three bomb and two torpedo strokes. Later that evening, the Enterprise SBD-3 group located Hirou and made a series of fatal impacts. The Japanese Midway operation was confused. The Japanese fleet lost half of its carrier-borne battle aircraft. Dauntless SBD-3 dive bomber played the major role in this historical event.

SBD-2 above Enterprise 10 days before the Pearl Harbor tragedy (taken from [2], p. 12).	SBD-3 and TBD-1 preparing for take-off from the deck of Enterprise in May of 1942. (US Navy Historical center, http://www.history.navy.mil/)

The story of Dauntless started in 1934, when Northrop (Douglass division) created a draft project of XBT-1 monoplane. It was manufactured under the mark of Douglas SBD Dauntless and became one of the most successful US Navy battle aircraft. The total number of these machines received by Navy till August 1944 amounts to 5376 (338 of them were exported). The aircraft came in six basic modifications (from BT-1 and SBD-1 to SBD-6), with different specifications.

The first appearance of serial BT-1 on Enterprise and Yorktown in late 1936 was a failure, as the aircraft suffered fatal cross instability at a low speed and lacked engine draft. John Northrop didn’t give up. The purges of the XBT-2 prototype with a new engine and the propeller in the wind tunnel provided for the fully redesigned aerodynamics. Chassis were removed in the fuselage direction, the area of tail empennage was increased, forewings were added to achieve good efficiency of ailerons at low speeds. The aircraft flew, but this couldn’t save Northrop from being fired and the plane from being renamed into SBD-1 (Scout Bomber by Douglas). The aircraft wings had a revolutionary design: no longerons, cellular set – and were fitted with characteristic “openwork” back edge panels, that deviated downwards while landing, and both downwards and upwards while diving. Unfortunately, this construction didn’t provide for foldable wings, which led to early abandonment of the model. The SBD-1 was ordered in a small batch, as the aircraft didn’t comply with the Navy requirements to the crew protection and flight range.

SBD-5 designs from the NAVAER report on the measuring results of aircraft specifications (from June 1, 1944; top secret till 1980s).

The next SBD-2 model was equipped with fuel tanks of better capacity and auto pilot mechanism designed to facilitate long flights, but one of the 12,7-mm Browning machine guns had to be removed to compensate for the weight increase. It were these aircraft, on the flight from Lexington and Enterprise to Pearl Harbor bases on December 7, 1941 that became first US air losses and gained first air victories (they destroyed two out of the 27 Japanese planes near the Hawaiin Islands). On December 10 the Enterprise SBD-2, piloted by lieutenant Dixon sank the first enemy battle ship. Very soon pilots began joking that SBD meant “Slow But Deadly”.

It’s interesting that the SBD-3 batch which proved very successful in Midway battle had been initially manufactured for the Air Force of France in an attempt to oppose the German Junkers Ju-87 Stuka dive bombers. The whole batch (174 aircrafts), along with the 410 planes made for the US army, was requisitioned by the US Naval Forces. Battle lessons showed the necessity of additional armoring and protection, and brought back the second large-caliber machine gun. The single 7.62-mm machine gun was changed for a double one.