The Douglas B-18 Bolo was a military adaptation of the DC-2 commercial airliner to the long-range bombing role. Although totally obsolescent by the end of 1941, it was numerically the most important long-range bomber in service with the USAAC at the time of America's entry into World War 2.

In May of 1934, the Army announced a competition for a multi-engined bomber to replace the Martin B-10 the new bomber was to be capable of carrying a ton of bombs at more than 200 mph over a distance of 2000 miles. Competitors included the Martin 146, which was a streamlined and enlarged version of the B-10 twin-engined light bomber then already in Army service, plus the four-engined Boeing 299, which was eventually to emerge as the famed B-17 Flying Fortress.

The Douglas entry the DB-1 (Douglas Bomber 1) was designed around the wings of the DC-2 and was fitted with a deeper and fatter fuselage which contained a bomb bay within its center section. The DB-1 had larger tail surfaces than did the standard DC-2, plus a wing with a slightly larger span and area resulting from the fitting of rounded tips. 

Seeking to purchase combat aircraft the British Air Ministry approached the Douglas Co about the B-18 in late 1938. After review,  the RAF felt the Bolo was inadequate for their needs. In 1939,  the Royal Canadian Air Force (RCAF) purchased 20 B-18's, designated as the Digby Mk 1. The Digby was generally similar to the USAAC's B-18As, but had 0.303 cal machine guns as well as some other British and Canadian equipment. The first Digby entered RCAF service with No 10 (BR) Squadron, in late 1939. The Mk1s  were used to patrol the North Atlantic in search of German U-boats. The last Canadian Digby left service in 1946.

The major production version of the Douglas bomber was the B-18A. The B-18A differed from the B-18 in having the bomb-aimer's position moved upward and forward underneath an extended glazed housing, while the flexible forward-firing nose gun was moved further back and below and was mounted inside a globular ball turret. This led to the rather unusual geometry in which the bombardier sat above and ahead of the nose gunner. A transparent domed cap was added to round off the top of the dorsal turret, so that it no longer lay flush with the fuselage when retracted. The B-18A was powered by two 1000-hp Wright R-1820-53 radials driving fully-feathering propellers.

The first production B-18 was delivered US Army at Wright Field on February 23, 1937. The 17th Bombardment Group (Medium) based at March AAF received its first B-18 in early 1940 before moving to McChord AAF June 24, 1940, becoming the first aircraft assigned to the new base . The 12th Bombardment Group, also a McChord based unit, flew B-18's from the base until 1942.   

By the early 1940s, the deficiencies in the B-18/B-18A bomber were becoming readily apparent. In range, in speed, in bomb load, and particularly in defensive armor and armament, the design came up short, and was totally unsuited in the long-range bombing role for which had originally been intended. However, in spite of the known shortcomings in 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 Pearl Harbor. It was hoped that the B-18 could play a stopgap role until more suitable aircraft became available in quantity. The Bolos remaining in the continental USA and in the Caribbean were then deployed in a defensive role in anticipation of attacks on the US mainland. Fortunately, these attacks never materialized. 

In 1942, 122 B-18As were modified for the maritime reconnaissance bombing role to counter the U-boat menace. These modified aircraft were redesignated B-18B and featured a nose mounted radar set, replacing the bombardier's glassed area. The bombardier's station was moved below and behind the radome, where the forward turret had formerly been located. In addition, a  Magnetic Anomaly Detector (MAD) set was installed in a long tubular boom that extended behind and below the rudder. Some B-18Bs were also equipped with a set of bomb tracks underneath the wings which could fire bombs backwards in a prearranged pattern. B-18Bs are credited with two U-boat kills--U-654 on August 22, 1942 and U-512 on October 2, 1942. The antisubmarine role was relatively short lived, and the B-18s were superseded in this role in 1943 by the B-24 Liberator which had a substantially longer range and a much heavier payload. 

Two B-18A's were converted for use as transports and designated C-58, many others were used in this role without being redesignated.

Surviving USAAF B-18s ended their useful lives in training and transport roles within the continental USA, and saw no further combat action. Two B-18As were modified as unarmed cargo transports under the designation C-58. At the end of the war, those bombers that were left were sold as surplus on the commercial market. Some postwar B-18s of various models were operated as cargo or crop-spraying aircraft by commercial operators. 

• TYPE: Medium Bomber

• POWER: Two Wright R-1820-53 radials with 1000 hp. each

• SPEED: Maximum - 215 mph, Cruising - 167 mph. 

• RANGE : 1,150 miles (with 2496 lbs of bombs)

• SERVICE CEILING: 25,600 ft

• WEIGHTS: Empty: 16,321 lbs, Combat: 22,123, Maximum: 27,673 lbs

• MAXIMUM PAYLOAD: 4,400 lb. (1996 kg) of bombs carried internally

• DIMENSIONS: Span 89 ft 6 in, Length 57 ft 10 in, Height 15 ft 2 in.  

• CREW: Six;  two Pilots, one Navigator/Bombardier, and 3 gunners.

• PRODUCTION TOTALS: 134 (B-18), 217 (B-18A), 122 (B-18B -  B-18 & B-18A  conversions)

• UNIT COST : $80,000

• McCHORD BASED UNITS: 17th Bombardment Group, 89th Reconnaissance Squadron, 12th Bombardment Group,

The first aircraft assigned to McChord was also the first aircraft acquired by the McChord Air Museum, the Douglas B-18A Bolo. On May 28,1983 B-18 37-505 arrived to McChord from Tucson AZ in the belly of a Air Force C-5A. The one time fish hauler is currently undergoing an extensive restoration.     

OCTOBER 1940  

 JULY 1941  

(United States Army Air Corps)

JANUARY 1942  

(United States Army Air Corps)

FEBRUARY 1942

To Pendleton Army Air Field, OR   (Unit Unknown)

MARCH 1942

To Salt Lake Army Air Field, UT (Unit Unknown)

(United States Army Air Corps)

APRIL 1941  

To  368th Bombardment Squadron, Wendover Army Air Field, CA , wrecked 

(United States Army Air Corps)

OCTOBER 1942

To Ogden Air Depot, UT 

(United States Army Air Corps)

NOVEMBER 1942

To San Antonio Air Depot, Kelly Army Air Field, TX   (Unit Unknown) 

(United States Army Air Corps)

JANUARY 1943

To Langley Army Air Field, VA   (converted to B-18B) 

(United States Army Air Corps)

SEPTEMBER 1943

To Mobile Air Service Center, Brookley Army Air Field, AL

(United States Army Air Corps)

JULY 1943

To Morrison Army Air Field, FL ( for storage)

(United States Army Air Corps)

FEBRUARY 1945  

(United States Army Air Corps)

DATE UNKNOWN

Sold to Plains Aero Service, Dalbart TX

19 OCTOBER 1966  

08 FEBRUARY 1971

Sold to Larkin Aircraft Corp, Santa Cruz, CA ($4,000)

27 MARCH 1971

04 FEBRUARY 1971

Donation to Tucson Air Museum Foundation of Pima County   

28 MAY 1983

(United States Air Force Museum Program)