COMPASS COPE R-Tern - YQM-98A Ryan
The YQM-98A R-Tern (Model 235) Compass Cope-R was a Teledyne-Ryan high-altitude, long-range research vehicle designed for long endurance reconnaissance. It took off and landed on conventional runways. Only two were built. One set a world endurance record in 1974 of 28 hours and 11 minutes for unmanned, unrefueled flight.
In 1970, the Air Force joined with the National Security Agency for Project Compass Cope. The NSA wanted a HALE-UAV with electronic signals intelligence capability. Sharing the project made it more affordable for the Air Force. The program gave out two contracts, one to Boeing and one to Ryan. The YQM-98A (Compass Cope-R, for Ryan) first flew in August 1974. It surpassed the endurance records set by the Compass Dwell program with one flight lasting over 28 hours, without refueling. That record remained for 26 years until another Ryan UAV, the RQ-4 Global Hawk, flew for over 30 hours without landing or refueling. Although the tests demonstrated the potential for HALE-UAVs, many people still believed all the needs for intelligence gathering could still be accomplished by more reliable, manned flights. The program was cancelled soon after setting the endurance record.
Compass Cope, which involves a high altitude, long endurance RPV with ground launch and recovery capability. The Ryan YQM-98 R-Tern was a reconnaissance drone developed by Ryan Aeronautical. The USAF had three UAS programs of interest during the 1970s, all designed to address the challenges identified within the European battlefield.
Compass Cope was the next step in the high altitude, long endurance combat support UAS. It sought to overcome the performance limitations of Compass Dwell through more expensive technological advances, thus driving up the development costs. The flight-profile model consists of an outbound and a return segment, each of which is about one hour long, and the cruise segment of 22 hours. There are also takeoff and recovery segments.
Additionally, European airspace regulations hampered operations as they prevented unmanned systems from flying in civilian airspace. Because of these constraints, the USAF ultimately turned to a modified U-2 to meet its immediate operational needs. While the U-2 lacked the endurance of Compass Dwell and Compass Cope, it was more cost effective to operate, and could fly higher and carry a bigger payload.
The peculiar operational requirements of the Compass Cope RPV imposed stringent reliability requirements on the vehicle flight control system. These operational requirements include a mission duration of over 24 hours, the capability of fully automatic flight from takeoff through recovery phases, and the capability of operating within civil airspace and into civil airfields. The Compass Cope development program requires a cost effective FCS configuration definition capable of satisfying the appropriate reliability requirements. The Air Force Flight Dynamics Laboratory responded to this need.
If the Compass Cope could be shown to be as safe as manned military aircraft when flying within civil airspace and into civil airfields, Cope would most likely, obtain operational approval of the aviation community, since these aircraft have already been accepted. Values for the suggested Cope loss probabilities can be derived from military aircraft loss statistics. Various redundancy configurations for the Cope FCS can then be evaluated against these suggested values. It is difficult to fina a military aircraft similar to Cope in either performance, physical characteristics or mission requirements. However, an argument can be made for using fighter aircraft over other military types as a reference.
A prime prototype contractor for this project specifying a four man operations team composed of two pilots and two radar technicians. Tactical Air Command, on the other hand, specified a six man team composed of three engineers and three radar technicians. Flight tests and simulations were conducted by Air Force Flight Dynamics Laboratory (AFFDL) to determine the suitability of automatic take-off and landing for the Compass Cope RPV. Automatic take-off and landinp systens are being designed to achieve a better accident risk figure than a human pilot or ground controller (the design goal for future airline systems is an overall risk which is less than 1 in 10- 7). As automatic systems become more and more reliable, pilot skills for future RPV operators would be de-emphasized.
The communication data links between the RPV and the ccntrol facility would be line-of-sight; therefore, it nay be necessary to use some type of relay or additional remote facilities downstream if extended range is desired (due to the curvature of the earth, the line-of-sight of a ground facility to an airborne RPV at 50,000 feet is only about 200 nautical miles). For the Compass Cope operation, an additional vehicle would sometimes be used solely as a communication relay. Because of this possible relay requirement, the data links may be subject to failure or interruption between any of three points: the RPV, the ground facilIIity, or the relay.
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