Doak VZ-4 | |
|---|---|
| 国家 | 美国 |
| 作用 | VTOL 研究转换飞机 |
| 首次飞行 | 1958年2月25日 |
| 建立 | 1 |
这 多克VZ-4 （或Doak型号16）是美国原型垂直起飞和降落（VTOL）飞机建于20世纪50年代，为美国陆军服务。只有一个原型被制造，美国陆军在1963年退出了积极的试验。
| Doak 16 VZ-4DA Walk Around | |
|---|---|
| Photographer | Vladimir Yakubov |
| Localisation | US Army Transportation Museum, Fort Eustis |
| Photos | 39 |
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General Characteristics and Role
The Doak 16, designated VZ-4DA by the U.S. Army, was an experimental Vertical Takeoff and Landing (VTOL) aircraft developed in the late 1950s. It was designed to explore the concept of a “convertiplane” that could take off and land vertically like a helicopter, but transition to forward flight like a conventional fixed-wing aircraft for faster cruise speeds. The Doak 16 used a unique propulsion system: a single engine drove two large, tilting ducted fans located at the wingtips. The entire fan assemblies could be rotated 90 degrees, a configuration known as a ducted fan tilt-wing. This technology was highly experimental, part of a push by the U.S. military to find practical VTOL solutions for observation and utility roles.
| Property | Typical Value (VZ-4DA) |
|---|---|
| 作用 | Experimental VTOL Research Aircraft |
| National Origin | United States (U.S. Army) |
| 制造商 | Doak Aircraft Company |
| First Flight | February 1958 (Conventional), February 1959 (Vertical) |
| 船员 | 2 (Pilot and Observer) |
| 长度 | 9.75 m (32 ft 0 in) |
| 翼展 | 4.88 m (16 ft 0 in) |
| 高度 | 3.05 m (10 ft 0 in) |
| Gross Weight | 1,450 kg (3,200 lb) |
Powerplant and Propulsion System
- Engine: 1 x Lycoming T53-L-1 turboshaft engine (later used in the Bell UH-1 Huey).
- Power Output: 825 shp (615 kW).
- Propulsion: Two tilting ducted fans (impellers), each connected to the engine via a transmission system to ensure synchronous rotation and thrust.
- Flight Control: In vertical mode, control was provided by vanes located in the ducted fan exhaust. In forward flight, conventional rudder, elevator, and ailerons were used.
- Maximum Speed (Cruise): Approximately 370 km/h (230 mph).
- Service Ceiling: 6,096 m (20,000 ft).
Program Outcome and Legacy
- Test Program: The VZ-4DA successfully demonstrated the transition from vertical to horizontal flight and back, validating the ducted fan tilt-wing concept.
- Performance: Although the tests were successful, the VZ-4DA suffered from complex mechanical systems required to articulate the fans and transfer power, and it had a limited payload capacity.
- Conclusion: The U.S. Army concluded the program in 1960. While the ducted fan concept showed promise, the Army ultimately shifted focus to lighter turboshaft helicopters (like the Bell UH-1) and other VTOL concepts that were considered more mechanically simple and scalable.
- Preservation: The single prototype built, tail number 56-6942, is preserved and on display at the U.S. Army Transportation Museum at Joint Base Langley-Eustis, Virginia.
意见 ： 2257
