Radioplane RP-77
| RP-77D | |
|---|---|
 | |
| Type | Target drone |
| Place of origin |  United States |
| Service history | |
| In service | 1955-1958 |
| Used by | United States Army |
| Production history | |
| Manufacturer | Radioplane |
| No. built | 24 |
| Specifications | |
| Mass | 1,050 pounds (480 kg) |
| Length | 14.9 feet (4.53 m) |
| Wingspan | 15.3 feet (4.66 m) |
| Engine | Boeing 502 turboprop 285 shaft horsepower (213 kW) |
| Flight ceiling | 47,000 feet (14,000 m) |
| Maximum speed | 425 miles per hour (684 km/h) |
Guidance system | Radio |
The Radioplane RP-77 was a small target drone missile, constructed largely of plastic materials, produced by the Radioplane division of the Northrop Corporation. Although the RP-77D was successfully tested by the United States Army, the decision was made not to procure the aircraft.
Design and development
The development of the RP-77 began in 1955.[1] Similar in outline to Radioplane's earlier OQ-19, four prototypes of the RP-77 were constructed, two each of the RP-77, powered by a four-cylinder McCulloch piston engine, and of the RP-77A, powered by a six-cylinder Lycoming engine.[1] Results of flight-testing were insufficient to interest the U.S. Army, however in 1957 a proposal for an improved RP-77D, powered by a Boeing 502 turboprop, resulted in a contract for the construction of 20 aircraft.[1]
Making extensive use of glass-polyester plastic construction,[2][3] the RP-77D was launched using a rocket-assisted take-off system consisting of four Loki rockets, was fitted with a radio control apparatus, and, with the assistance of radar tracking, could be operated at a considerable distance from its launching point.[1] In addition to equipment typically carried by target drones, the RP-77D could be equipped with reconnaissance or meteorological sensors, or with air sampling equipment.[1] The RP-77D utilised the RPTA tracking system, developed by Radioplane, using audio frequency tones for control.[4] Recovery at the end of the flight was by parachute.[5]
An improved version of the RP-77D was projected, with provision for launching RP-76 target missiles.[1]
Operational history
Evaluation of the RP-77D by the Army took place throughout 1958, nearly 40 test flights being conducted.[1] Although the test results were generally satisfactory, it was determined that the performance of the aircraft was an insufficient improvement over existing types in service to have the aircraft ordered into production, and the project was cancelled, along with the improved RP-86, a dedicated reconnaissance variant.[1]
Following the termination of the Army's evaluation, Radioplane, as a private venture, conducted an improvement program for the RP-77D, fitting the aircraft with a larger wing, along with other modifications that improved the performance of the drone. However these improvements were insufficient to produce a renewed interest from the Army.[1]
Variants
- RP-77B
- Proposed version of RP-77 with turbo-supercharged engine, none built.[1]
- RP-77C
- Proposed version of RP-77A with turbo-supercharged engine, none built.[1]
- RP-77D
- Production prototype with Boeing 502 turboprop; twenty built for evaluation.[1]
- RP-86
- Proposed reconnaissance version of RP-77D; none built.[1]
See also
Aircraft of comparable role, configuration, and era
References
- Notes
- Bibliography
- Duffin, Daniel J. (1958). Laminated Plastics. Reinhold Plastics Applications Series. New York: Reinhold Publishing Corporation. ASIN B0000CK84G.
- International Aeronautic Federation, 1961. Interavia. Jane's Information Group.
- Merrill, Arthur M, 1956. Plastics Technology, Volume 2.
- Parsch, Andreas (2004). "RP-77D". Directory of U.S. Military Rockets and Missiles, Appendix 4: Undesignated Vehicles. designation-systems.net. Retrieved 2010-11-25.
- Royal Aeronautical Society, 1959. The Aeronautical Journal, Volume 63.