Directory of U.S. Military Rockets and Missiles|
Appendix 4: Undesignated Vehicles
|Copyright © 2004 Andreas Parsch|
In 1955, Northrop's Radioplane division began the development of the RP-77 aerial target drone. The RP-77 was a propeller-driven aircraft with a general layout roughly similar to Radioplane's ubiquitous OQ-19 family. Two prototypes each of the RP-77 and RP-77A were built, the -77 with a four-cylinder McCulloch and the -77A with a six-cylinder Lycoming piston engine. The RP-77B and RP-77C with turbo-supercharged McCulloch and Lycoming engines, respectively, were never built. In May 1957, Radioplane made an unsolicited proposal to the U.S. Army for the RP-77D turboprop-powered version, and in June that year, the Army awarded a contract for 20 RP-77Ds for evaluation. The RP-77D first flew in March 1958.
The RP-77D was powered by a Boeing Model 502-10F turboprop, and was zero-length launched with the help of four Loki rocket motors. The drone was radio-controlled from the ground, and could be tracked by radar for non-line-of-sight operations. At the end of the flight, it was recovered by a multi-stage parachute system. The RP-77D could be fitted with the usual aerial target equipment like radar and IR augmentation devices and scoring equipment. However, options for reconnaissance, meteorological and air-sampling payloads were also envisioned. It was even planned to build an RP-77D variant, which could act as the carrier aircraft for the smaller RP-76 rocket-powered target.
Until December 1958, the Army conducted a total of 39 test flights of the RP-77D to evaluate the system and establish the aircraft's performance envelope. However, the test results did apparently not warrant a production run for the RP-77D. The planned RP-86 reconnaissance variant was also not built. During 1959, Radioplane implemented some improvements to the RP-77D (including a larger wing), which increased its performance, but this effort didn't raise any additional interest from the military.
Note: Data given by several sources show slight variations. Figures given below may therefore be inaccurate!
Data for RP-77D (initial configuration):
|Length||4.53 m (14 ft 10.4 in)|
|Wingspan||4.66 m (15 ft 3.6 in)|
|Height||1.58 m (5 ft 2.4 in)|
|Weight||476 kg (1050 lb)|
|Speed||630 km/h (390 mph)|
|Ceiling||14200 m (46500 ft)|
|Propulsion||Boeing 502-10F turboprop; 211 kW (285 shp)|
 Richard A. Botzum: "50 Years of Target Drone Aircraft", Northrop, 1985
 Frederick I. Ordway III, Ronald C. Wakeford: "International Missile and Spacecraft Guide", McGraw-Hill, 1960
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