|Directory of U.S. Military Rockets and Missiles|
|Copyright © 2002 Andreas Parsch|
When the USAF began the Compass Cope high-altitude RPV program in 1971, it was originally intended to have only one contractor, Boeing with its YQM-94A (q.v. for more info on the Compass Cope objectives). However, Teledyne Ryan proposed their Model 235 to the same specification, and because of their long experience in building unmanned drones and reconnaissance RPVs for the U.S. Air Force, they were awarded a contract for two YQM-98A prototypes in June 1972. Compass Cope was now a two-contractor competition, and Teledyne Ryan's entry was known as R-Tern, Compass Cope R or Cope-R.
The first flight of the YQM-98A occurred in August 1974. Being about a year behind the competing YQM-94A, the R-Tern's test program proceeded relatively smoothly. Powered by a Garrett ATF 3 (YF104-GA-100) turbofan engine, it could cruise at Mach 0.6 at 16700 m (55000 ft) for more than 24 hours. The longest flight actually had a duration of more than 28 hours. The flight test program ended in September 1975, and roughly around this time the designation of the RPV was changed to YGQM-98A.
|Photo: Bud Wolford (Teledyne Ryan)|
As the production Compass Cope vehicle, Teledyne Ryan proposed their Model 275. This featured a competely new engine installation with a General Electric TF34 turbofan, and had a redesigned tail unit. However, in August 1976 Boeing's YGQM-94A was announced winner of the Compass Cope competition, although the YGQM-98A had logged more hours and flights (90 hrs/17 flights vs. 17 hrs/4 flights) and demostrated much longer endurance (28 hrs vs. 17 hrs). Official reasons for selection of Boeing's design included the latter's lower cost. However, the point was moot in the end, because the whole Compass Cope program was cancelled in July 1977.
|Image: Matt Giacalone|
|Teledyne Ryan Model 275|
Note: Data given by several sources show slight variations. Figures given below may therefore be inaccurate!
Data for YQM-98A:
|Length||11.4 m (37 ft 4 in)|
|Wingspan||24.75 m (81 ft 2.5 in)|
|Height||2.4 m (8 ft)|
|Weight||6480 kg (14310 lb)|
|Ceiling||21300 m (70000 ft)|
|Range||> 15000 km (8100 nm)|
|Endurance||> 28 hours|
|Propulsion||Garrett YF104-GA-100 turbofan; 18.0 kN (4050 lb)|
 William Wagner, William P. Sloan: "Fireflies and other UAVs", Midland Publishing, 1992
 Kenneth Munson: "World Unmanned Aircraft", Jane's, 1988
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