|Roll||VTOL research convertiplane|
|Första flygningen||25 February 1958|
Den Doak VZ-4 (or Doak Model 16) was an American prototype Vertical Takeoff and Landing (VTOL) aircraft built in the 1950s for service in the United States Army. Only a single prototype was built, and the U.S. Army withdrew it from active trials in 1963.
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