Northrop BT

BT

Northrop BT-1s over Miami in October 1939
Role	Dive bomber
Manufacturer	Northrop
First flight	19 August 1935
Primary user	United States Navy
Number built	55
Variants	SBD Dauntless

The Northrop BT was a two-seat, single-engine monoplane dive bomber built by the Northrop Corporation for the United States Navy. At the time, Northrop was a subsidiary of the Douglas Aircraft Company.

Design and development

The design of the initial version began in 1935. It was powered by a 700 hp (520 kW; 710 PS) Pratt and Whitney XR-1535-66 double row air-cooled radial engine and had hydraulically actuated perforated split flaps or "dive-brakes" and a landing gear that retracted backwards into fairing "trousers" beneath the wings.^[1] The perforated flaps were invented to eliminate tail buffeting during diving maneuvers.^[1]

The next iteration of the BT, the XBT-1, was equipped with a 750 hp (560 kW; 760 PS) R-1535. This aircraft was followed in 1936 by the BT-1, powered by an 825 hp (615 kW; 836 PS) R-1535-94 engine. One BT-1 was modified with a fixed tricycle landing gear and was the first such aircraft to land on an aircraft carrier.

BT-1 of VB-5 in 1938

The final variant, the XBT-2, was a BT-1 modified^[1] to incorporate landing gear which folded laterally into recessed wheel wells, leading edge slots, a redesigned canopy, and was powered by an 800 hp (600 kW; 810 PS) 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

BT-1 at El Segundo

VB-5 lineup of BT-1s

The U.S. Navy placed an order for 54 BT-1s in 1936 with the aircraft entering service during 1938. BT-1s served in USS Yorktown and Enterprise. 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."^[2] 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.
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 was modified as the DB-19 which was tested by the Imperial Japanese Navy as the DXD1 (Navy Experimental Type D Attack Plane)

Operators

United States

United States Navy

Specifications (BT-1)

BT-1 modified as a testbed for tricycle landing gear

Data from United States Navy Aircraft since 1911 ^[3]

General characteristics

Crew: two (pilot and gunner)
Length: 31 ft 8 in (9.65 m)
Wingspan: 41 ft 6 in (12.65 m)
Height: 9 ft 11 ft (3.02 m)
Wing area: 319 ft² (29.6 m²)
Empty weight: 4,606 lb (2,094 kg)
Max. takeoff weight: 7,197 lb (3,271 kg)
Powerplant: 1 × Pratt & Whitney R-1535-94 Twin Wasp Jr. double row radial air-cooled engine, 825 hp (615 kW)

Performance

Maximum speed: 193 knots (222 mph, 357 km/h) at 9,500 ft (2,900 m)
Cruise speed: 167 knots (192 mph, 309 km/h)
Range: 1,000 nmi (1,150 mi 1,852 km)
Service ceiling: 25,300 ft (7,710 m)
Rate of climb: 1,270 ft/min (6.5 m/s)

Armament

Guns:
- 1 × .50 in (12.7 mm) machine gun
- 1 × .30 in (7.62 mm) machine gun
Bombs: 1,000 lb (454 kg) bomb under fuselage

Notable mentions in media

Northrop BT-1s appeared in pre-war yellow wing paint schemes in the Technicolor film Dive Bomber (1941) starring Errol Flynn.

References

Notes

1 2 3 Rene J. Francillon (1990 ed), McDonnell Douglas Since 1920, Volume I. Annapolis, Maryland, Naval Institute Press
↑ "Northrop BT-1." historyofwar.org. Retrieved: 5 December 2009.
↑ Swanborough and Bowers 1976, p. 358.

Bibliography

Bowers, Peter M. United States Navy Aircraft since 1911. Annapolis, MD: Naval Institute Press, 1990, ISBN 0-87021-792-5.
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. ISBN 0-89747-195-4.
Gunston, Bill. The Illustrated History of McDonnell Douglas Aircraft: From Cloudster to Boeing. London: Osprey Publishing, 1999. ISBN 1-85532-924-7.
Kinzey, Bert. SBD Dauntless in Detail & Scale, D&S Vol.48. Carrollton, TX: Squadron/Signal Publications, Inc., 1996. ISBN 1-888974-01-X.
Listemann, Phil. Northrop BT-1 (Allied Wings No.3). France: www.raf-in-combat.com, 2008. ISBN 2-9526381-7-9.
Swanborough, Gordon and Peter M. Bowers. United States Navy Aircraft since 1911. London: Putnam, Second edition, 1976. ISBN 0-370-10054-9.

External links

Wikimedia Commons has media related to Northrop BT.

Douglas military aircraft

Fighters	XP-48 P-70 F-6 F-10 XFD F3D F4D F5D XF6D

Ground attack	XA-2 A-20 A-24 A-26 A-33 A-1 A-3 A-4/A-4AR/A-4SU DT T2D XT3D TBD SBD BD XBTD XTB2D AD XA2D A3D A4D

Bombers	YB-7 YB-11 B-18 XB-19 XB-22 B-23 B-26 XB-31 XB-42 XB-43 B-66 DB-1 DB-2 DB-7 DB-8 DB-19 DB-73 Boston I/II/III/IV/V Digby I Havoc I/II DXD1

Observation	O-2 OD O2D O-31 O-35 O-38 O-43 YO-44 O-46 O-53 YOA-5

Patrol	PD P2D P3D

Reconnaissance	F-3

Transports	C-1 C-21 C-32 C-33 YC-34 C-38 C-39 C-41 C-41A C-42 C-47 C-48 C-49 C-50 C-51 C-52 C-53 C-54 C-58 UC-67 C-68 C-74 C-84 C-110 XC-112/YC-112 XC-114 YC-116 C-117 C-118 C-124 YC-129 C-133 C-9 C-24 RD R2D R3D R4D (R4D-2 & R4D-4) R5D JD R6D CC-129 Dakota I/III/IV Dakota II LXD1 PD.808 Skymaster I

Gliders	XCG-17

Training aircraft	BT-1 BT-2 XT-30

Experimental	DWC D-558-1 D-558-2 X-3

Northrop aircraft

Manufacturer
designations

'Greek' series	Alpha Beta Gamma Delta

'N' series	Note: Northrop company designations include a wide variety of technologies. Only aircraft, aero engines, and missiles are linked here. N-1 N-2 N-3 N-4 N-5 N-6 N-7 N-8 N-9 N-10 N-12 N-14 N-15 N-16 N-18 N-19 N-20 N-21 N-23 N-24 N-25 N-26 N-29 N-31 N-32 N-34 N-35 N-36 N-37 N-38 N-39 N-40 N-41 N-46 N-47 N-48 N-49 N-50 N-51 N-52 N-54 N-55 N-59 N-60 N-63 N-65 N-67 N-68 N-69 N-71 N-72 N-73 N-74 N-77 N-81 N-82 N-94 N-96 N-102 N-103 N-105 N-110 N-111 N-112 N-117 N-124 N-132 N-133 N-134 N-135 N-138 N-141 N-144 N-149 N-150 N-151 N-155 N-156 N-205 N-267 N-285 N-300

'P' series	P530 P600 P610

By role

Attack	YA-13 XA-16 A-17 Nomad YA-9

Bombers	YB-35 YB-49 B-62 BT B2T B-2

Drones	Q-4

Fighters	3A XP-56 P-61 XP-79 F-89 XFT F2T F-5/CF-5/CF-116 YF-17 F-18L F-20 YF-23

Reconnaissance	F-15 RF-61 RF-5

Trainers	T-38

Transports	Alpha Beta Gamma Delta C-19 C-100 YC-125 RT

Experimental	N-1M N-9M JB-1 MX-324 MX-334 M2-F2 M2-F3 HL-10 Tacit Blue X-4 X-21

Names