Thomas-Morse MB-3

From Wikipedia, the free encyclopedia

MB-3
MB-3 of 94th Pursuit Squadron, 1st Pursuit Group, Selfridge Field, Michigan
Type	Fighter
Manufacturer	Thomas-Morse & Boeing
Designed by	B. Douglas Thomas[1]
Maiden flight	21 February 1919[1]
Introduced	March 1919
Retired	1925
Primary users	United States Army Air Service United States Marine Corps
Number built	260[2]
Unit cost	$7,240 USD

The Thomas-Morse MB-3 was an open-cockpit biplane fighter primarily manufactured by the Boeing Company for the U.S. Army Air Service in 1922.

Contents 1 Development 2 Variants 3 Specifications (MB-3A) 4 References

[edit] Development

Ordered by the U.S. Army on the basis of a promised 150 mph (241 km/h) top speed and a 1,500 ft.min (7.62 m/s) initial climb, the MB-3 designed by B. Douglas Thomas was a single-seat unstaggered single-bay biplane of wooden construction and fabric covering^[1].

Developed in 1919 by the Thomas-Morse Aircraft Corporation of Ithaca, New York, the MB-3 fighter was based on the French Spad-7, with rights on the design held by the Air Service. Thomas-Morse produced fifty MB-3's for the Air Service and ten for the U.S. Marine Corps but were underbid by Boeing for contracts to deliver 200 additional planes, which Boeing designated the MB-3A. Boeing's mass production methods allowed it to profit while still charging a lower price (in the case of the MB-3A, $7,240 per copy)^[3], but was the beginning of the decline of Thomas-Morse. Boeing credits this contract with rescuing the company from financial difficulties following the cancellation of orders after World War I, and with being the impetus for its rise as a premier manufacturer of military aircraft^[4].

Army pilot Frank B. Tyndall pulled the wings off an MB-3A flown from a short runway near the Boeing factory and parachuted to safety after a spectacular low-level bail-out. Boeing made minor structural refinements and created completely new tail surfaces for the last 50 aircraft delivered^[5].

The MB-3A was delivered to the Air Service beginning in 1922 and was its primary pursuit aircraft. By 1925 the MB-3A was considered obsolete, and with the re-organization of the Air Service into the U.S. Army Air Corps in 1926, it was replaced by the Curtiss PW-8 and Boeing PW-9 fighters.

[edit] Variants

• MB-3 - 54 built by Thomas-Morse
• MB-3A - 200 built by Boeing with a revised cooling system
• MB-3M - MB-3As religated to advanced training duties
• MB-6 - 3 built by Thomas-Morse, one became the R-2 racer, 19 inch wing-span, 400 hp (300 kW)Wright H3 engine^[2].
• MB-7 - 1 built by Thomas-Morse, to the Marine Corps, 24 inch wing-span^[2]
• R-5 - two racers ordered for the 1922 Pulitzer race, all-metal TM-22 parasol monoplanes developed from a combined primary trainer and pursuit model that B. Douglas Thomas was trying to sell to the Army^[5].
• MB-9 - pursuit version with a wrap-around corrugated metal fuselage and a Curtiss D-12 engine, one built^[5]
• MB-10 - two-seat trainer modification of the MB-9, the same airframe with a new section spliced into the fuselage and a Le Rhône rotary engine fitted further forward to correct for balance^[5]

[edit] Specifications (MB-3A)

Data from "United States Military Aircraft Since 1909" by F. G. Swanborough & Peter M. Bowers (Putnam New York, ISBN 085177816X) 1964, 596 pp.

General characteristics

• Crew: One
• Length: 20 ft 0 in (6.10 m)
• Wingspan: 26 ft 0 in (7.92 m)
• Height: 8 ft 7 in (2.59 m)
• Wing area: 229 ft² (21.28 m²)
• Empty weight: 1,716 lb (778 kg)
• Loaded weight: 2,539 lb (1,151 kg)
• Powerplant: 1× Wright H Vee, 300 hp (217 kW)

Performance

• Maximum speed: 141 mph (228 km/h)
• Cruise speed: 125 mph (201 km/h)
• Range: 280 mi (455 km)
• Service ceiling 19,500 ft (5,943.6 m)
• Rate of climb: 1,235 ft/mn (374 m/mn)

Armament

• 2 × fixed forward firing 0.30 inch (7.62 mm) machine guns or
• 1 × 0.30 inch (7.62 mm) and 1 × 0.50 inch (12.7 mm) machine guns or
• 2 × fixed forward firing 0.50 inch (12.7 mm) machine guns

[edit] References