The Northrop BT was an American two-seat, single-

engine An engine or motor is a machine designed to convert one or more forms of energy into mechanical energy. Available energy sources include potential energy (e.g. energy of the Earth's gravitational field as exploited in hydroelectric power ...

monoplane A monoplane is a fixed-wing aircraft configuration with a single mainplane, in contrast to a biplane or other types of multiplanes, which have multiple planes. A monoplane has inherently the highest efficiency and lowest drag of any wing con ...

dive bomber A dive bomber is a bomber aircraft that dives directly at its targets in order to provide greater accuracy for the bomb it drops. Diving towards the target simplifies the bomb's trajectory and allows the pilot to keep visual contact through ...

built by the

Northrop Corporation Northrop Corporation was an American aircraft manufacturer from its formation in 1939 until its 1994 merger with Grumman to form Northrop Grumman. The company is known for its development of the flying wing design, most successfully the B-2 Sp ...

for the

United States Navy The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage ...

. At the time, Northrop was a subsidiary of the

Douglas Aircraft Company The Douglas Aircraft Company was an American aerospace manufacturer based in Southern California. It was founded in 1921 by Donald Wills Douglas Sr. and later merged with McDonnell Aircraft in 1967 to form McDonnell Douglas; it then operated a ...

. While unsuccessful in its own right, the BT was subsequently redesigned into the

Douglas SBD Dauntless The Douglas SBD Dauntless is a World War II American naval scout plane and dive bomber that was manufactured by Douglas Aircraft from 1940 through 1944. The SBD ("Scout Bomber Douglas") was the United States Navy's main carrier-based scout/di ...

, which would form the backbone of the Navy's dive bomber force.

Design and development

The design of the initial version began in 1935. It was powered by a Pratt and Whitney XR-1535-66 double row air-cooled

radial engine The radial engine is a reciprocating type internal combustion engine configuration in which the cylinders "radiate" outward from a central crankcase like the spokes of a wheel. It resembles a stylized star when viewed from the front, and is ...

and had hydraulically actuated perforated split

flap Flap may refer to: Arts, entertainment, and media * ''Flap'' (film), a 1970 American film * Flap, a boss character in the arcade game ''Gaiapolis'' * Flap, a minor character in the film '' Little Nemo: Adventures in Slumberland'' Biology and he ...

s (

dive brake Dive brakes or dive flaps are deployed to slow down an aircraft when in a dive. They often consist of a metal flap that is lowered against the air flow, thus creating drag and reducing dive speed.Crane, Dale: ''Dictionary of Aeronautical Terms, ...

s), and main

landing gear Landing gear is the undercarriage of an aircraft or spacecraft that is used for takeoff or landing. For aircraft it is generally needed for both. It was also formerly called ''alighting gear'' by some manufacturers, such as the Glenn L. Mart ...

that retracted backwards into fairing "trousers" beneath the wings.Rene J. Francillon (1990 ed), ''McDonnell Douglas Since 1920, Volume I''. Annapolis, Maryland, Naval Institute Press The perforated flaps were invented to eliminate tail buffeting during diving maneuvers. The next iteration of the BT, the XBT-1, was equipped with a R-1535. This aircraft was followed in

1936 Events January–February * January 20 – George V of the United Kingdom and the British Dominions and Emperor of India, dies at his Sandringham Estate. The Prince of Wales succeeds to the throne of the United Kingdom as King E ...

by the BT-1, powered by an R-1535-94 engine. One BT-1 was modified with a fixed

tricycle landing gear Tricycle gear is a type of aircraft undercarriage, or ''landing gear'', arranged in a tricycle fashion. The tricycle arrangement has a single nose wheel in the front, and two or more main wheels slightly aft of the center of gravity. Tricycle ...

and was the first such aircraft to land on an

aircraft carrier An aircraft carrier is a warship that serves as a seagoing airbase, equipped with a full-length flight deck and facilities for carrying, arming, deploying, and recovering aircraft. Typically, it is the capital ship of a fleet, as it allows a ...

The final variant, the XBT-2, was a BT-1 modified to incorporate landing gear which folded laterally into recessed wheel wells,

leading edge slot A leading-edge slot is a fixed aerodynamic feature of the wing of some aircraft to reduce the stall speed and promote good low-speed handling qualities. A leading-edge slot is a spanwise gap in each wing, allowing air to flow from below the wing ...

s, a redesigned

canopy Canopy may refer to: Plants * Canopy (biology), aboveground portion of plant community or crop (including forests) * Canopy (grape), aboveground portion of grapes Religion and ceremonies * Baldachin or canopy of state, typically placed over an ...

, and was powered by an Wright XR-1820-32 radial. The XBT-2 first flew on 25 April 1938, and after successful testing the Navy placed an order for 144 aircraft. In 1939 the aircraft designation was changed to the Douglas SBD-1 with the last 87 on order completed as SBD-2s. By this point, Northrop had become the El Segundo division of Douglas aircraft, hence the change.

Operational history

The U.S. Navy placed an order for 54 BT-1s in 1936 with the aircraft entering service during 1938. BT-1s served on and . The type was not a success in service due to poor handling characteristics, especially at low speeds, "a fatal flaw in a carrier based aircraft.""Northrop BT-1."
''historyofwar.org''. Retrieved: 5 December 2009. It was also prone to unexpected rolls and a number of aircraft were lost in crashes.

Variants

;XBT-1 :Prototype, one built. ;BT-1 :Production variant, 54 built. ;BT-1S: A BT-1 (c/n346, BuNo 0643) was fitted with a fixed tri-cycle undercarriage. This aircraft was damaged in a crash on 6 February 1939, returned to Douglas and repaired to BT-1 standard. Northrop XBT-1 and XBT-2 comparison

;XBT-2 :One BT-1 modified with fully retractable landing gear and other modifications. ;BT-2 :Production variant of the XBT-2, 144 on order completed as SBD-1 and SBD-2. ;Douglas DB-19 :One BT-1 (c/n346, BuNo 0643), the former BT-1S, was modified as the DB-19 which was tested by the

Imperial Japanese Navy The Imperial Japanese Navy (IJN; Kyūjitai: Shinjitai: ' 'Navy of the Greater Japanese Empire', or ''Nippon Kaigun'', 'Japanese Navy') was the navy of the Empire of Japan from 1868 to 1945, when it was dissolved following Japan's surrender ...

as the Douglas DXD1 (long designation - Douglas Navy Experimental Type D Attack Aircraft)

Operators

; *

Specifications (BT-1)

Notable mentions in media

Northrop BT-1s appeared in pre-war yellow wing paint schemes in the Technicolor film ''

Dive Bomber A dive bomber is a bomber aircraft that dives directly at its targets in order to provide greater accuracy for the bomb it drops. Diving towards the target simplifies the bomb's trajectory and allows the pilot to keep visual contact through ...

'' (1941) starring

Errol Flynn Errol Leslie Thomson Flynn (20 June 1909 – 14 October 1959) was an Australian-American actor who achieved worldwide fame during the Classical Hollywood cinema, Golden Age of Hollywood. He was known for his romantic swashbuckler roles, freque ...

References

;Notes ;Bibliography * Bowers, Peter M. ''United States Navy Aircraft since 1911''. Annapolis, MD: Naval Institute Press, 1990, . * Brazelton, David. ''The Douglas SBD Dauntless, Aircraft in Profile 196''. Leatherhead, Surrey, UK: Profile Publications Ltd., 1967. No ISBN. * Drendel, Lou. ''U.S. Navy Carrier Bombers of World War II''. Carrollton, TX: Squadron/Signal Publications, Inc., 1987. . * Gunston, Bill. ''The Illustrated History of McDonnell Douglas Aircraft: From Cloudster to Boeing''. London: Osprey Publishing, 1999. . * Kinzey, Bert. ''SBD Dauntless in Detail & Scale, D&S Vol.48''. Carrollton, TX: Squadron/Signal Publications, Inc., 1996. . * Listemann, Phil. ''Northrop BT-1'' (Allied Wings No.3). France: www.raf-in-combat.com, 2008. . * Swanborough, Gordon and Peter M. Bowers. ''United States Navy Aircraft since 1911''. London: Putnam, Second edition, 1976. .

External links

VectorSite: The Douglas SBD Dauntless & Curtiss SB2C Helldiver

{{Authority control B01T Northrop BT1 Single-engined tractor aircraft Low-wing aircraft Carrier-based aircraft Aircraft first flown in 1935 World War II dive bombers of the United States