The B-18 was designed in response to the same U.S. Army Air Corp (USAAC) request for
a "multi-engine" bomber that Boeing responded to in 1935 with the
B-17. Because the Army was not ready to fund
four-engine bomber development, the USAAC decided to purchase the less expensive
Douglas B-18.
The Bolo was developed as a modification of the popular
DC-2. Bolos in service during World War II were used in an anti-submarine
patrol capacity; the B-18B having the bombardier's compartment replaced
with a search radar with a large radome.
The
Canadians named the B-18 the Digby, after a British airfield.
