Doak VZ-4

  Base model:VZ-4
  Designation System:U.S. Air Force
  Designation Period:1956-1962
  Basic role:VTOL Research

Not Yet Available

Known serial numbers

Examples of this type may be found at
United States Army Transportation MuseumFort EustisVirginia

VZ-4 on display

United States Army Transportation Museum


Recent comments by our visitors
 John Ulyate
 Yorba Linda, CA
Dave Henry:
Contact me at exdoak@aol.com
07/14/2011 @ 08:24 [ref: 40850]
 Dave Henry
 , CA
I am designing a small tilt duct VTOL aircraft and could use help from any of the original designers or current enthusiasts who could send me any useful design information on the Doak VZ-4. Helpful information includes the inlet vane system, duct tilt design, ancillary hover stability augmentation, detailed flight characteristics, duct fan design, etc. Thank you!
06/19/2011 @ 17:43 [ref: 39666]
 don scimonelli
 washington, DC
I have some information. one of the reasons I built south capitol street heliport was for the doak and we await its arrival. two more items are needed to completes the vz4 mission, first attachment of the personal injury emergency triage apparatus second and most important today’s advancements in aviation technology,

02/14/2009 @ 07:55 [ref: 23720]
 Ronald W. Sparks, PE
 Wilmington, NC
How would I aquire the Plans, Specifications and Test reports on this Aircraft (Doak Vz-4)?

04/22/2004 @ 21:09 [ref: 7267]
 Mark G Brislawn
 Orange, CA
Doak Aircraft Company obtained a contract to build the VZ4DA
(the Doak 16) in the summer of 1956. The engineering staff
peaked at around a dozen engineers in '57 or '58.

I worked at Doak from Dec 1956 thru Oct 1960. My early work
included component design such as the pitch and yaw vanes in
the exhaust gas (for hover control), layout of the pilot's
instrument panel, molds to make the fiberglass propellers &
inlet guide vanes, and then design of the flight test instru-
mentation system. During flight test at Edwards AFB I was
responsible for gathering the flight test data. After a
Summary Report was written, primarily by Ray Ulyate, work
shifted to newer versions of the twin-duct aircraft. A re-
cession in aerospace in '59 or '60 however, especially in
subcontracts to small firms, eliminated over 90% of the
company employees causing Mr Doak to close the company down
in Nov or Dec of 1960.

Douglas Aircraft Co. thought highly of the ducted propeller
concept, saw a flight test demonstration, and as a result
bought up the engineering files and patent rights to the
aircraft. Four of us moved on to the El Segundo Division of
Douglas Aicraft where we helped in writing an unsolicited
proposal to the U.S.Army to improve the VZ4DA but by this
time the army had apparently decided to concentrate on

06/23/2001 @ 18:01 [ref: 2513]
 John R.(Ray) Ulyate
 Placentia, CA
I worked on the design of the Doak VZ-4DA (Doak Model 16)
(1957-1958) and supervised flight tests of the aircraft at
Edwards (1958-1960). First conversion from horizontal flight
to vertical flight (and vice-versa) was accomplished on May
5th, 1959. Following completion of our 50 hour flight test
program the aircraft was delivered to NASA (Langley,VA) for
further testing. The airplane is currently located at the
U.S.Army Transportation Museum, Ft.Eustis, VA
05/23/2000 @ 14:26 [ref: 229]


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