https://en.wikipedia.org/wiki/Thomas-Morse_MB-3
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. The MB-3A was the
mainstay fighter for the Air Service between 1922 and 1925.
In March 1918, the United States Army Air Service requested several American
aircraft manufacturers to design a new fighter, to be powered by a water-cooled
300 hp (220 kW) Wright-Hispano H, a license-built Hispano-Suiza 8, to replace
the French-built SPAD XIII. The Thomas-Morse Aircraft Corporation of Ithaca, New
York proposed the MB-3, designed by its British-born chief designer B. Douglas
Thomas, to meet this requirement, with an order for four prototypes being placed
in September 1918.
The MB-3 was a single seat two-bay biplane of similar layout to the SPAD XIII
that it was intended to replace. It was of wood and fabric construction with a
fixed conventional landing gear. Powerplant was the expected Wright-Hispano
water-cooled V-8 engine driving a two-bladed propeller and cooled by a radiator
mounted on the center-section of the upper wing. The pilot sat in an open
cockpit under a cut-out in the upper wing, with two 0.30 in Marlin machine-guns
mounted ahead of the pilot.
The first MB-3 made its maiden flight on 21 February 1919. Testing showed that
the fighter had good performance and handled well, but the cockpit was cramped
and gave a poor view for the pilot. The prototypes were plagued with fuel leaks
and suffered serious engine vibration, while maintenance was difficult, often
requiring holes to be cut in the fuselage structure to allow access. Despite
these problems, the Air Service was sufficiently impressed with the MB-3 to
place an order for 50 aircraft with Thomas-Morse in June 1920.
Role
Fighter
Manufacturer
Thomas-Morse Aircraft & Boeing
Designer
B. Douglas Thomas
First flight
21 February 1919
Introduction
March 1919
Retired
1925
Primary users
United States Army Air Service
United States Marine Corps
Number built
265
Unit cost
$7,240 USD
Variants
Thomas-Morse MB-6
Thomas-Morse MB-7
Two of the prototypes were entered in the 1920 Pulitzer Trophy race, with one
finishing in second place behind the Verville VCP-R, completing the 116 miles
(187 km) course in an average speed of 148 miles per hour (238 km/h). Completed
MB-3s started to roll out of Thomas-Morse's factory in April 1921, but
deliveries were delayed by an accident during testing when an MB-3 lost a
section of the upper wing during diving tests, this causing the type to be
grounded while the accident was investigated.
The 1st Pursuit Group began to receive MB-3s in January 1922, supplementing its
elderly SPADs and S.E.5as. In service, the new type was troublesome, being
unreliable (over a ten-day test period in May 1922, the number of servicable
MB-3s dropped from 20 out of 36 to just 3) and continuing to suffer the
vibration problems encountered by the prototypes, eventually traced to the rigid
engine mount.
The first delivery of the improved MB-3As took place on 29 July 1922, with the
last aircraft delivered on 27 December that year. The last 50 MB-3As were fitted
with larger tail surfaces. As well as allowing re-equipment of the four
squadrons of the 1st Pursuit Group, the MB-3As were issued to a number of
overseas squadrons, equipping two squadrons on Hawaii, one in the Philippines
and one in the Panama Canal Zone.
From 1926, the MB-3A started to be replaced by the Curtiss PW-8 and Boeing PW-9
fighters. A number of aircraft were refurbished and used as MB-3M advanced
trainers at Kelly Field, remaining in use until 1929.
was unpopular with the Marines, being withdrawn from use in July that year and
sold back to the Army for use as MB-3M trainers.
Specifications (MB-3A)
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)
Empty weight: 1,716 lb (778 kg)
Loaded weight: 2,539 lb (1,151 kg)
Performance
Maximum speed: 141 mph (123 knots, 228 km/h) at sea level
Cruise speed: 125 mph (109 knots, 201 km/h)
Endurance: 2?1/4 hr
Service ceiling: 19,500 ft (5,945 m)
Rate of climb: 1,235 ft/min (6.3 m/s)
Armament
Guns:
*
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