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AM Mauler
An AM-1 of the U.S. Naval Test Center
Role Attack aircraft
National origin United States
Manufacturer Glenn L. Martin Company
First flight 26 August 1944
Introduction March 1948
Retired 1953
Primary user United States Navy
Number built 151

The Martin AM Mauler (originally BTM) was a shipboard attack aircraft of the United States Navy. Designed during World War II, the Mauler encountered production delays and did not enter service until March 1948. A total of 151 aircraft were built, remaining in front line service only until 1950, when the Navy standardized on the smaller and simpler Douglas AD Skyraider. Maulers remained in reserve squadrons until 1953. In service the Mauler earned the nickname "Able Mable" because of its remarkable load carrying ability, once lifting a 14,179 lb useful load, including 10,689 lbs of ordnance, perhaps the heaviest load ever carried by a single-engine piston-powered aircraft.[1]

Design and development

In the 1930s and early 1940s the Navy differentiated between two types of carrier-borne bomber: the torpedo bomber and the dive bomber. In 1943 this distinction was abandoned and the US Navy invited proposals for a new multi-purpose bomber. In 1944 four new designs were offered: the Curtiss XBTC-1/2, Douglas XBT2D-1, Kaiser-Fleetwings XBTK-1 and the Martin XBTM-1. Martin was tasked to provide a back-up to the Curtiss design which had been selected as a replacement to their SB2C Helldiver.[2] Due to the US Navy's concern that the Curtiss design was overly complex and that the company's production record was particularly suspect in the Helldiver development phase, Martin was instructed to create an "unexperimental" design that would be a reliable platform for the Pratt & Whitney R-4360 Wasp Major that powered both aircraft.[3] Two prototypes were ordered from Martin on 31 May 1944.[4]

A Naval Air Reserve AM-1Q.

The first XBTM-1 flew on 26 August 1944, piloted by O.E. "Pat" Tibbs, Martin's Chief Test Pilot.[5] The second prototype soon joined the fight test unit, followed by 16 pre-production BTM Maulers. In 1946 the aircraft designation was changed to AM-1.[5]

The AM-1Q was developed for electronic countermeasures (ECM) duties. The fuselage fuel tank was removed to make room for the ECM operator and his equipment. Twelve aircraft were built on the main production line.[6]

Operational history

VA-174 AM-1 taking off from the USS Kearsarge in 1949

Delivery of Maulers began in July 1947, but problems with the tail hooks damaging the rear fuselage delayed service entry another year and the Mauler did not enter service until March 1948, when Maulers began operating with VA-17A in the Atlantic Fleet.[4] Maulers gained a reputation as remarkable load lifters; on one occasion a Martin test pilot flew one hauling three 2,200 lb (1,000 kg) torpedoes, twelve 250 lb (110 kg) bombs, guns, and a full load of ammunition — a total of 10,689 pounds (4,848 kg) of ordnance, and a 14,179 pounds (6,431 kg) useful load, a record at the time for a single-engine aircraft. Gross weight for that flight was 29,332 pounds (13,305 kg). Bomb loads in carrier service were smaller, and the aircraft gained a mostly-deserved reputation for being hard to land on carrier decks, leading to the nickname of "Awful Monsters". Pilots more favorably impressed by the bombload interpreted AM as "Able Mable".[7]

With the prospect of flying the AD-1 Skyraider and AM-1 in carrier operations, the US Navy assigned the Maulers to Atlantic Fleet squadrons. Although the Skyraider was a third smaller and carried a third less bombload, it proved more reliable in service and easier to fly and land, and Navy pilots preferred it. In 1950 the decision was made to use the Mauler only from shore-based units and later that year all but Naval Reserve units abandoned the type. The aircraft operated with reserve squadrons until 1953.[8]

Two AM-1s during armament tests


Two prototypes built.[8]
A total of 132 production aircraft, another 651 aircraft were cancelled.[9]
A radar contermeasures variant, 17 aircraft built[9]
Proposed carrier onboard delivery variant of the AM, named Mercury; not built.[10]


United States
  • United States Navy
    • VA-44, VA-45, VA-84, VA-85, VA-174, VC-4.[11]
    • Reserve attack squadrons at NAS Grosse Ile, NAS St. Louis, NAS Glenview, NAS Dallas, NAS Columbus, NAS Atlanta [12]


AM-1 at the National Museum of Naval Aviation.

Out of 151 Maulers built, only four are known to exist:

On display
In storage or under restoration
  • 22260 - in storage at the Glen L. Martin Maryland Aviation Museum in Maryland. This aircraft formerly belonged to the Commemorative Air Force (formerly the Confederate Air Force), and was kept in flying condition until the 1980s.[15]
  • 122403 - in storage at the Planes of Fame in Chino, California.[16]

Specifications (AM-1 Mauler)

Line drawings for an AM-1.

Data from American Combat Aircraft, Third Edition[17]

General characteristics

  • Crew: 1 (2 in AM-1Q)
  • Length: 41 ft 2 in (12.55 m)
  • Wingspan: 50 ft 0 in (15.24 m)
  • Height: 16 ft 10 in (5.13 m)
  • Wing area: 496 ft² (46.1 m²)
  • Empty weight: 15,257 lb (6,935 kg)
  • Loaded weight: 22,323 lb (10,146.8 kg)
  • Max. takeoff weight: 25,737 lb (11,698.6)
  • Powerplant: 1 × Pratt & Whitney R-4360-4 Wasp Major radial engine, 2,975 hp (2,219 kW)


  • Maximum speed: 367 mph (323 knots, 618.57 km/h)
  • Cruise speed: 188 mph (165 knots, 302.6 km/h)
  • Range: 1,437 mi (1,260 nmi, 2,334 km)
  • Service ceiling: 27,000 ft (8,320 m)
  • Rate of climb: 2,780 ft/min (14.1 m/s)


  • Guns: 4 × 20 mm M2 cannons @ 200 r.p.g.
  • Bombs: 4,500 lb (2,045 kg) normal load

See also


  1. Wagner 1982, p. 368; another contender is the TB2D Skypirate.
  2. Andrews and Boyne 1974, p. 8.
  3. Andrews and Boyne 1974, p. 9.
  4. 4.0 4.1 Swanborough and Bowers 1990, p. 358.
  5. 5.0 5.1 Andrews and Boyne 1974, p. 12.
  6. Kowalski 1995, p. 60.
  7. O'Rourke, G.G., CAPT USN. "Of Hosenoses, Stoofs, and Lefthanded Spads". United States Naval Institute Proceedings, July 1968.
  8. 8.0 8.1 Swanborough and Bowers 1990, p. 359.
  9. 9.0 9.1 Andrade 1979, p. 182
  10. Breihan 1995, p. 143
  11. Kowalski 1995, pp. 47–60.
  12. Kowalski 1995, pp. 61–71.
  13. "Martin AM-1 Mauler/Bu. 22275" Tillamook Air Museum. Retrieved: 19 July 2009.
  14. "Martin AM-1 Mauler/Bu. 122397" National Museum of Naval Aviation Retrieved: 28 March 2012.
  15. "Martin AM-1 Mauler/Bu. 22260" Glen L. Martin Maryland Aviation Museum. Retrieved: 19 July 2009.
  16. "Martin AM-1 Mauler/Bu. 122403" 2008. Retrieved: 28 March 2012.
  17. Wagner 1982, p. 368.
  • Andrade, John. U.S.Military Aircraft Designations and Serials since 1909, Midland Counties Publications, 1979, ISBN 0-904597-22-9
  • Andrews, Hal and Walter Boyne. The Fable of Able Mable: Flying Fifteen Tons of Midnight Blue Beastie." Airpower, Vol. 4, Issue 4, July 1974.
  • Breihan, John R. Martin Aircraft, 1909-1960. Santa Ana, CA: Narkiewicz/Thompson, 1995. ISBN 978-0913322031
  • Green, William and Gerald Pollinger. The Aircraft of the World. London: Macdonald, 1955.
  • Kowalski, Bob. Martin AM-1/1-Q Mauler. Simi Valley, CA: Ginter Books, 1995. ISBN 0-942612-24-8.
  • Swanborough, Gordon and Peter M. Bowers. United States Navy Aircraft since 1911. London: Putnam Aeronautical Books, Third edition 1990. ISBN 0-85177-838-0.
  • Wagner, Ray (1982). American Combat Planes, Third Edition. USA: Doubleday & Company. ISBN 0-385-13120-8. 
  • Wilson, Stewart. Combat Aircraft Since 1945. Fyshwick, Australia: Aerospace Publications Pty Ltd., 2000. ISBN 1-875671-50-1.

External links

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