The Martin BM was a 1930s

American American(s) may refer to: * American, something of, from, or related to the United States of America, commonly known as the "United States" or "America" ** Americans, citizens and nationals of the United States of America ** American ancestry, pe ...

torpedo bomber built by the

Glenn L. Martin Company The Glenn L. Martin Company—also known as The Martin Company from 1957-1961—was an American aircraft and aerospace manufacturing company founded by aviation pioneer Glenn L. Martin, and operated between 1917-1961. The Martin Company produc ...

for the United States Navy.

Design and development

To meet the requirement for a special-purpose

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 througho ...

for the

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and

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, the US Navy's Bureau of Aeronautics designed a biplane with fixed tailwheel landing gear, designated Bureau Design 77. It had room for two crew in tandem. Two prototypes were ordered in June 1928, one from Martin (designated the XT5M-1) and one from the

Naval Aircraft Factory The Naval Aircraft Factory (NAF) was established by the United States Navy in 1918 in Philadelphia, Pennsylvania. It was created to help solve aircraft supply issues which faced the Navy Department upon the entry of the U.S. into World War I. ...

(designated the XT2N-1). The Martin XT5M-1 was powered by a

Pratt & Whitney R-1690-22 Hornet The Pratt & Whitney R-1690 Hornet was a widely used American aircraft engine. Developed by Pratt & Whitney, 2,944 were produced from 1926 through 1942. It first flew in 1927. It was a single-row, 9-cylinder air-cooled radial design. Displacemen ...

radial engine, and, following test during 1930, the Navy ordered 12 aircraft from Martin with the designation BM-1. The BM-1 had a more powerful R-1690-44 engine. A further order for four was followed by an order for 16 for the BM-2. Martin moved to a new factory in Baltimore, Maryland, where the XT5M-1 was built, and it was first flown on 17 May 1929. During testing, the aircraft suffered structural damage during a pullout from a dive and had to be returned to the factory. After a redesign and rebuilding of the wings, the XTM5-1 was handed over to the Navy in May 1930 for service trials. In April 1931, the Navy ordered 16 production aircraft to be designated the BM-1. Another 16 were ordered in October 1931 as the BM-2, a variant with minor improvements. The prototype was flown aboard the ''

Langley Langley may refer to: People * Langley (surname), a common English surname, including a list of notable people with the name * Dawn Langley Simmons (1922–2000), English author and biographer * Elizabeth Langley (born 1933), Canadian perfor ...

'' from November 1931 to prove its suitability as a carrier aircraft.

Operational history

The first production BM-1 ''A8879'' was delivered to the Navy at Anacostia for acceptance testing in September 1931. The Navy refused to accept the type after A8879 had a fatal crash during a test dive in September 1931. Martin modified the second production aircraft, used the same serial as the crashed aircraft and redelivered it to the Navy in January 1932. The second A8879 was accepted by the Navy on 27 February 1932 and it was followed by the delivery of 15 more, with the last being accepted in July 1931. In June 1932 the BM-1s were delivered to VT-1S squadron on board USS Lexington to replace the Martin T4Ms. In March 1933 the squadron was renamed VT-1B when it became part of the Battle Force, by October 1932 it had ten BM-1s and ten BM-2s in service. Between July 1934 and February 1935, the BM-1 and BM-2 was also operated by VB-3B, when it was formed for service aboard the ''Ranger''. Other carrier squadrons also operated the BMs for short periods before they moved on to other aircraft, including VB and VT5 (''Yorktown'') and VT6 (''Enterprise''). By the middle of 1938 only a small number of aircraft remained in service, most with VX-3D4 and VX-4D4 which were experimental squadrons based at Philadelphia. By the end of 1939, all BM-1s and BM-2s were out of service. An additional aircraft designated XBM-1 was built for trials and testing with the National Advisory Committee for Aeronautics.

Variants

;XT5M-1 :Prototype with R-1690-22 engine, one built. ;XT2N-1 :Prototype built by Naval Aircraft Factory ;BM-1 :Production aircraft, 17 built. ;BM-2 :Production aircraft with minor changes, 16 built. ;XBM-1 :Additional aircraft for trials and testing, transferred to NACA in 1940.

Operators

; * National Advisory Committee for Aeronautics *

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