DH4 may refer to:
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Airco DH.4
The Aircraft Manufacturing Company Limited (Airco) was an early British aircraft manufacturer. Established during 1912, it grew rapidly during the First World War, referring to itself as the largest aircraft company in the world by 1918.
Ai ...
, British World War I two-seat biplane
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de Lackner HZ-1 Aerocycle, also known as the YHO-2 and DH-4 Heli-Vector (1950s)
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Bombardier Dash 8
The De Havilland Canada DHC-8, commonly known as the Dash 8, is a series of turboprop-powered regional airliners, introduced by de Havilland Canada (DHC) in 1984. DHC was later bought by Boeing in 1988, then by Bombardier in 1992; then by ...
Q400, turboprop passenger airliner (since 1996, called DH4 by various airlines)
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