Douglas B-18 Bolo

https://en.wikipedia.org/wiki/Douglas_B-18_Bolo

The Douglas B-18 Bolo is an American medium bomber which served with the United
States Army Air Corps and the Royal Canadian Air Force (as the Digby) during the
late 1930s and early 1940s. The Bolo was built by the Douglas Aircraft Company,
based on its DC-2, and was developed to replace the Martin B-10.

By 1940, it was considered to be underpowered, to have inadequate defensive
armament and to carry too small a bomb load. Many were destroyed during the
attacks on Pearl Harbor and the Philippines in December 1941.

In 1942, the B-18 survivors were relegated to antisubmarine, transport duty, and
training. A B-18 was one of the first American aircraft to sink a German U-boat,
U-654 on 22 August 1942 in the Caribbean.

In 1934, the United States Army Air Corps put out a request for a bomber with
double the bomb load and range of the Martin B-10, which was just entering
service as the Army's standard bomber. In the evaluation at Wright Field the
following year, Douglas showed its DB-1. It competed with the Boeing Model 299
(later developed into the Boeing B-17 Flying Fortress) and Martin Model 146.

While the Boeing design was clearly superior, the crash of the B-17 prototype
(caused by taking off with the controls still locked) removed it from
consideration. During the depths of the Great Depression, the lower price of the
DB-1 ($58,500 vs. $99,620 for the Model 299) also counted in its favor. The
Douglas design was ordered into immediate production in January 1936 as the
B-18.

The DB-1 design was essentially that of the DC-2, with several modifications.
The wingspan was 4.5 ft (1.4 m) greater. The fuselage was deeper, to better
accommodate bombs and the six-member crew; the wings were fixed in the middle of
the cross-section rather than to the bottom due to the deeper fuselage. Added
armament included nose, dorsal, and ventral gun turrets


Role
Medium bomber

Manufacturer
Douglas Aircraft Company

First flight
April 1935

Introduction
1936

Retired
1946 Brazilian Air Force

Status
Retired

Primary users
United States Army Air Corps
United States Army Air Forces
Royal Canadian Air Force
Brazilian Air Force

Produced
1936–ca. 1939

Number built
350

Unit cost

US$58,500 (1935)


Developed from
Douglas DC-2

Developed into
Douglas B-23 Dragon

Deliveries of B-18s to Army units began in the first half of 1937, with the
first examples being test and evaluation aircraft being turned over to the
Materiel Division at Wright Field, Ohio, the Technical Training Command at
Chanute Field, Illinois, the Aberdeen Proving Ground, Maryland, and Lowry Field,
Colorado. Deliveries to operational groups began in late 1937, the first being
the 7th Bombardment Group at Hamilton Field, California.

Production B-18s, with full military equipment fitted, had a maximum speed of
217 mph, cruising speed of 167 mph, and combat range of 850 miles. By 1940, most
USAAC bomber squadrons were equipped with B-18s or B-18As.

However, the deficiencies in the B-18/B-18A bomber were becoming readily
apparent to almost everyone. In range, in speed, in bomb load, and particularly
in defensive armor and armament, the design came up short, and the Air Corps
conceded that the aircraft was obsolete and totally unsuited in the long-range
bombing role for which it had originally been acquired. To send crews out in
such a plane against a well-armed, determined foe would have been nothing short
of suicidal.

However, in spite of the known shortcomings of the B-18/B-18A, the Douglas
aircraft was the most numerous American bomber type deployed outside the
continental United States at the time of the attack on Pearl Harbor. It was
hoped that the B-18 could play a stopgap role until more suitable aircraft such
as the Boeing B-17 Flying Fortress and Consolidated B-24 Liberator became
available in quantity.

Specifications (B-18A)

General characteristics
Crew: 6
Length: 57 ft 10 in (17.63 m)
Wingspan: 89 ft 6 in (27.28 m)
Height: 15 ft 2 in (4.62 m)
Wing area: 959 ft² (89.1 m²)
Empty weight: 16,320 lb (7,403 kg)
Loaded weight: 24,000 lb (10,866 kg)
Max. takeoff weight: 27,673 lb (12,552 kg)
Powerplant: 2 × Wright R-1820-53 radial engines, 1,000 hp (746 kW) each

Performance
Maximum speed: 216 mph (188 knots, 348 km/h) at 10,000 ft (3,050 m)
Cruise speed: 167 mph (145 knots, 269 km/h)
Range: 900 mi (787 nmi, 1,450 km)
Ferry range: 2,100 mi (1,826 nmi, 3,380 km)
Service ceiling: 23,900 ft (7,285 m)
Climb to 10,000 ft (3,050 m): 9.9 min

Armament

Guns: 3 × .30 in (7.62 mm) machine guns
Bombs: 4,400 lb (2,000 kg)




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