Doak VZ-4

Doak VZ-4
Role	VTOL research convertiplane
Manufacturer	Doak Aircraft Company
First flight	25 February 1958[1]
Status	preserved at Fort Eustis VA
Primary user	United States Army
Number built	1

The Doak VZ-4 (or Doak Model 16) was an American prototype VTOL aircraft built in the 1950s for service in the United States Army.

Development

The aircraft was originally powered by an 840 shp (630 kW) Lycoming YT53 turboprop engine. It was replaced with a 1,000 shp (750 kW) Lycoming T53-L-1 turbine.^[2] The turbine engine is mounted in the fuselage driving two wing-tip mounted tilting ducted fan propellers.

Only one aircraft was produced. Given serial number 56-6942, it is on display at the U.S. Army Transportation Museum located at Fort Eustis, Virginia.

Operators

USA

• NASA
• United States Army

Specifications

The Doak VZ-4 on display at Fort Eustis, Virginia, in April 2004

Data from The Illustrated Encyclopedia of Aircraft^[3]

General characteristics

• Crew: 2
• Length: 32 ft 0 in (9.75 m)
• Wingspan: 25 ft 6 in (7.77 m)
• Height: 10 ft 0 in (3.05 m)
• Wing area: 96 ft² (8.92 m²)
• Empty weight: 2,300 lb (1043 kg)
• Gross weight: 3,200 lb (1451 kg)
• Powerplant: 1 × Avco Lycoming YT-53 turboshaft, 840 hp (626 kW)

Performance

• Maximum speed: 230 mph (370 km/h)
• Range: 230 miles (370 km)
• Service ceiling: 6000 ft (1830 m)

Related lists

• List of military aircraft of the United States
  

References

Notes

1. ^ Swanborough and Bowers 1963, p. 583.
2. ^ Harding, Stephen. U.S. Army Aircraft Since 1947. Shrewsbury, UK: Airlife Publishing, Ltd., 1990. ISBN 1-85310-102-8.
3. ^ The Illustrated Encyclopedia of Aircraft 1985, p. 1454.

Bibliography

• The Illustrated Encyclopedia of Aircraft (Part Work 1982–1985). London: Orbis Publishing, 1985.
• Swanborough, F.G. and Peter M. Bowers. United States Military Aircraft since 1909. London: Putnam, 1963.