Martin 187 Baltimore

Light attack bomber introduced in 1941

Overview

Glenn L. Martin United States 1941–1944

The Martin 187 Baltimore was developed and manufactured by the Glenn L. Martin Company as a light attack bomber fitted with twin engines. It was designated as the A-30 in the United States. In May 1940, it was initially ordered by the French Air Force as a replacement to the Martin Maryland. The aircraft was introduced in 1941 and was retired in 1949.

Specifications

Units
Engine
2 × Wright GR-2600-A5B
Engine type
Piston
Power
2 × 1,700 hp · 1,268 kW
Avionics
—
Wing tips
No winglets
Seats
4
Crew
—
Cabin width
—
Cabin height
—
Cabin length
—
Exterior length
48 ft 7 in  ·  14.80 m
Tail height
17 ft 9 in  ·  5.40 m
Fuselage diameter
3 ft 7 in  ·  1.10 m
Wing span
61 ft 4 in  ·  18.70 m
Baggage volume
—
Gross weight
—
Empty weight
—
Max takeoff weight
24,000 lb  ·  10,900 kg
Max landing weight
—
Max payload
2,450 lb  ·  1,100 kg
Fuel capacity
490 gal · 1,900 L · 1,300 kg (AvGas)
Max cruise speed
295 kt  ·  339 mph  ·  546 km/h
Maximum speed
—
Cruise speed
—
Approach speed
102 kt  ·  117 mph  ·  189 km/h
Range
850 nm  ·  980 mi  ·  1,570 km
Fuel burn
—
Ceiling
24,000 ft  ·  7,300 m
Rate of climb
1,247 ft/min  ·  6 m/s
Takeoff distance
—
Landing distance
—
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Martin Baltimore

Operational Context

The Model 187 that was originally designated as A-23 featured a deeper fuselage and better engines. In May 1940, the Model 187 met the requirement of the Anglo-French Purchasing Commission for light to medium bomber aircraft. It was initially ordered by the French Air Force as a replacement for the Martin Maryland. A total of four hundred Model 187s were ordered. After the battle of France, the aircraft was given the designation Baltimore by the Royal Air Force when they subbed in the order. It was also designated as A-30 by the United States Army Air Force.

The Baltimore GR.V has a crew member of four: a pilot, navigator/bombardier, a radio operator, and a gunner. It has a length of 14.8 meters, a height of 4.32 meters, and a width of 1.1 meters. The wingspan is 18.7 meters and the wing area is 50 square meters. It has a wheelbase of 9.7 meters. The empty weight is 7,253 kg and the gross weight is 10,900 kg. The aircraft has a maximum takeoff weight of 10,900 kg, a maximum payload of 1,100 kg, and a fuel tank capacity of 490 US gallons.

The light bomber is powered by twin Wright GR-2600-A5B radial engines. It has fourteen cylinders arranged in two rows and produces a maximum thrust of 1,700 horsepower each. The aircraft has a maximum speed of 295 knots at 11,600 feet and a cruise speed of 195 knots. The travel range is 850 nautical miles and the service ceiling is 24,000 feet. The Martin Baltimore can climb at a rate of 1,247 feet per minute.

The Baltimore GR.V could be armed with four wing-mounted 7.62 mm M1919 Browning machine guns, two to four 7.7 mm machine guns in the dorsal turret, two 7.7 mm machine guns in ventral position, and provisions for up to four fixed rear-firing 7.7 mm machine guns. The aircraft could also carry 910 kg of internal bombs.