title: DH4
text: # DH4
  
  DH4 may refer to:
  
  * Airco DH.4, British World War I two-seat biplane
  * de Lackner HZ-1 Aerocycle, also known as the YHO-2 and DH-4 Heli-Vector (1950s)
  * Bombardier Dash 8 Q400, turboprop passenger airliner (since 1996, called DH4 by various airlines)
  