Definition
A two-seat biplane designed by the British de Havilland company during World War I, used as a light bomber and reconnaissance aircraft. After the war, the United States adopted the DH-4 for the first scheduled airmail service, where it became a workhorse of early American aviation.
Plain English
An early biplane, originally a British military aircraft, that the U.S. used to fly the first regular airmail routes after World War I.
Context Anchor
Seen in aviation history discussions about World War I aircraft, early airmail, and the growth of civil aviation in the United States.
Derivation
Named after Geoffrey de Havilland, the British aircraft designer who created it. 'DH' stands for de Havilland, and '4' indicates it was the fourth design in his series. Note: the FAA handbook spells the name 'de Haviland' (one 'l'), though the historically correct spelling is 'de Havilland.'
Why Pilots Care
The DH-4 is a touchstone in aviation history. Knowing it helps pilots understand how civil aviation in the U.S. grew out of military surplus aircraft and how airmail pilots laid the groundwork for today's airline system.
Intuition Check
Do not read “DH-4” as a modern FAA code or procedure. Here it is the model name of a specific historic airplane.
Example Sentence 1
Early airmail pilots flew the de Haviland DH-4 in open cockpits, often in poor weather and without modern navigation aids.
Example Sentence 2
Early pilots learned formation flying in the de Havilland DH-4 before moving to later designs.