Martin MB-1

{{Infobox Aircraft Begin

|name= MB-1

|image= File:Martin MB-1 front right quarter SN AS 39059 P104 040315-F-9999G-013.jpg

|image_border= yes

|caption=Martin MB-1 GMB

}}{{Infobox Aircraft Type

|type=Large biplane bomber

|manufacturer=Glenn L. Martin Company

|first flight=17 August 1918

|introduced=1918

|designer=Donald Wills Douglas, Sr.{{cite book|title=The Pictorial History of American Aircraft|author=Yenne}}

|retired=

|status=

|primary user=United States Army Air Service

|more users=United States Navy
United States Marine Corps
United States Postal Service

|produced=

|number built=20Confusion over Air Service serial numbers has led to figures sometimes seen of 22 or more. However six were built on the first contract, and a later four built in 1919 before the end of the war cancelled all remaining ordered. Ten more were produced for the USN/USMC.

|variants with their own articles=

}}

The Martin MB-1 was an American large biplane bomber designed and built by the Glenn L. Martin Company for the United States Army Air Service in 1918. It was the first purpose-built bomber produced by the United States.

In 1921 Martin produced its KG.1 variant of the MB-1, with ten purchased by the Navy as torpedo bombers under the designation MBT. After two were purchased, the designation was changed to Martin MT.

Development

In response to a requirement from the Air Service for a bomber that was superior to the Handley Page O/400, Martin proposed the MB-1 and were rewarded with an initial production contract for six aircraft. The MB-1 was a conventional biplane design with twin fins and rudders mounted above the tailplane and a fixed tailwheel landing gear with four-wheel main gear. Powered by two 400 hp (298 kW) Liberty 12A engines, it had room for a crew of three in open cockpits.

Operational history

Initial delivery to the Air Service was in October 1918, with the aircraft designated GMB for Glenn Martin Bomber. The first four produced were configured as observation aircraft, and the next two as bombers. Four others were produced before the end of World War I cancelled all remaining war contracts. The last three aircraft each were configured experimentally, with separate designations: GMT (Glenn Martin Transcontinental), a long-range version with a 1,500 mi (2,400 km) range; GMC (Glen Martin Cannon) with a nose-mounted 37 mm (1.46 in) cannon; and GMP (Glenn Martin Passenger) as an enclosed ten-passenger transport. The GMP was later redesignated T-1. Six surviving aircraft were later modified and used by the United States Post Office Department as mail carriers. The design was the basis for the Martin MB-2, which had a greater load capability but was slower and less maneuverable.

Ten aircraft were used by the United States Navy from 1922 under the designations MBT and MT and were used as torpedo bombers, two by the Navy and eight by Marine Corps squadron VF-2M. On 5 October 1923, the Marine Corps entered an MT, serial number A-5720, in the National Air Races in St. Louis. The aircraft raced with the racing number 58, placing third on the {{convert|300|km|nmi mi|disp=flip}} course.{{cite journal|journal=Skyways|date=July 1995|page=31}}

They were used in the West Virginian Coal Wars, notably in the Battle of Blair Mountain, as bombers and aerial observers sent in by President Warren Harding. One aircraft was lost, crashing on the return flight, with the loss of three crewmen.

Variants

;MB-1

:Company and original military designation.

;GMB

:Glenn Martin Bomber - Air Service designation for the MB-1 aircraft.

;GMT

:Glenn Martin Transcontinental - designation for one aircraft with long range fuel tanks.

;GMC

:Glenn Martin Cannon - designation for one cannon equipped aircraft.

;GMP

:Glenn Martin Passenger - designation for one ten-seat passenger variant, later designated T-1

;MBT

:Martin Bomber-Torpedo - United States Navy/Marine Corps torpedo-bomber variant, two built.

;MT

:Martin Torpedo - United States Navy/Marine Corps version with an MB-1 fuselage and MB-2 wings, eight built, later designated the TM-1

;T-1

:GMP redesignated.

;TM-1

:MT redesignated.

Operators

Specifications

{{Aircraft specs

|ref=United States Military Aircraft since 1909 Swanborough and Bowers 1963, p. 327.

|prime units? = imp

|crew=three (pilot, bombardier, gunner)

|length m=13.67

|length ft=44

|length in=10

|span m=21.77

|span ft=71

|span in=5

|height m=4.45

|height ft=14

|height in=7

|wing area sqm=99.4

|wing area sqft=1,070

|empty weight kg=3,040

|empty weight lb=6,702

|gross weight kg=4,638

|gross weight lb=10,225

|eng1 number=2

|eng1 name=Liberty 12A liquid-cooled V-12

|eng1 kw=298

|eng1 hp=400

|max speed kmh=169

|max speed mph=105

|cruise speed kmh=148

|cruise speed mph=92

|range km=628

|range miles=390

|ceiling m=3,100

|ceiling ft=10,300

|climb rate ms=3.2

|climb rate ftmin=630

|armament = *Five .30-cal. machine guns

  • 1,040 lb of bombs

}}

{{aircontent

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References

Notes

{{Reflist}}

Bibliography

{{refbegin}}

  • Andrade, John. U.S. Military Aircraft Designations and Serials since 1909. Hinckley, UK: Midland Counties Publications, 1979. {{ISBN|0-904597-22-9}}.
  • The Illustrated Encyclopedia of Aircraft (Part Work 1982-1985). London: Orbis Publishing, 1985, p. 2419.
  • Swanborough, F.G and Peter M. Bowers. United States Military Aircraft since 1909. London: Putnam, 1963.
  • Taylor, Michael J. H. Jane's Encyclopedia of Aviation. London: Studio Editions, 1989. {{ISBN|0-517-10316-8}}.
  • {{cite magazine|url=https://www.flightglobal.com/pdfarchive/view/1921/1921%20-%200027.html|archive-url=https://web.archive.org/web/20150329011925/http://www.flightglobal.com/pdfarchive/view/1921/1921%20-%200027.html|url-status=dead|archive-date=March 29, 2015|title=The Glenn L. Martin Commercial Transport|magazine=Flight|volume=13|number=629|date=13 January 1921|pages=27–28}}

{{refend}}