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COMPASS COPE B-Gull - YQM-94A Boeing

The objectives of the Compass Cope program were to design, develop, and test two high altitude sensor platform vehicles. The program consisted of the Boeing YQM-94A and the Teledyne Ryan YQM-98A. Both vehicles used conventional landing gear to permit runway takeoff and landing.

The Compass Cope was a large, high-altitude, long endurance unmanned aircraft. Its potential missions included (1) battle area surveillance, (2) communication, (3) targeting, and (4) signal intelligence. Work on the Compass Cope began in 1971 and 1972 after the Air Force received unsolicited proposals from the Boeing Company and Teledyne Ryan offering to demonstrate a high-altitude long-endurance aircraft. The Air Force awarded contracts to each company to demonstrate the technology necessary to build such an aircraft. During 1971 to 1975 each company designed, built, and tested prototypes of their aircraft.

UAVs have been under development by the Department of Defense since the late 1950s. During the period from 1950-1970 most of these systems were relatively small, less than 2,000 pounds, and were used for local area reconnaissance. During the Vietnam War the systems were modified for many different applications including armed reconnaissance, Signals Intelligence and Psychological Operations. These systems were still relatively inexpensive compared with manned aircraft of their day.

In the early 1970s DoD began developing and testing larger UAVs characterized by the Compass Cope series of systems. While still only a fraction of the cost of manned systems the cost of UAVs was beginning to increase as the size of the UAV increased and most importantly the size of the payload increased. The payload cost can often be of the same order as the cost of the airframe.

The HALE RPV (High-Altitude, Long Endurance, Remotely Piloted Vehicle) development has been undertaken by the Aeronautical Systems Division to satisfy that trend toward unmanned airborne relay aircraft for reasons of cost effectiveness, reduced crew vulnerability, increased station-keeping time, etc. Aircraft built under the HALE program were expected to fly at altitudes as high as 50,000 ft (15+ km) for up to 24 hours.

Although the RPV's were considered backup relay platforms, their inherent flexibility gave them advantages in their own right. Unlike conventional satellites, which require months of preparation and planning prior to being placed on station, RPV's generally can be on location within minutos or hours of the decision to launch. There are other advantages also: lower costs, less sophistication in design since the equipment does not have to be space-qualified, reduced vulnerability to jamming, and the ability to implement relay equipment changes quickly if battle requirements so dictate.

Two different classes of RPV have been evaluated for the HALE RPV role. One, the XQM-93A model, manufactured by E-Systems, Incorporated, was identified by the 478T Program Office as the aircraft to be used in the TRI-TAC Service Test Bed at Fort Huachuca, Arizona in 1977, when a system operational test and evaluation program would be carried out. The other class of RPV consists of the YQM-94A and YQM-98A models developed by Boeing and Teledyne Ryan under the Compass Cope program.

COMPASS COPE was an Air Force competition to develop a high-altitude, long-range, remotely piloted vehicle (RPV) designed for long-endurance photographic reconnaissance and electronic surveillance missions. Piloted from the ground, the RPV received guidance signals through a radio link. A television and other electronic equipment aboard Compass Cope sent in-flight data back to the ground-based pilot. Unlike most RPVs, which were ground- or air-launched and retrieved in mid-air, Compass Cope was designed to take off and land from conventional runways.

Perhaps the major disadvantage to a high-altitude RPV (Compass Cope) is its limited utility because of its long wing span (-90 ft, 27.4 m). The physical problems associated with handling an aircraft of that size, plus the need for a 2000-ft (610 m) take-off run, create obvious difficulties. The long wing span results from the need to fly in high altitude regions of sharply reduced dynamic pressure, q. Since q = 1/2pV2 , it is seen to be a function of atmospheric density, p, and, hence, of altitude. (It is also a function of the square of velocity, of course, but V is considered constant here. ) Through the relationship L = CLqS, which is the formula for aerodynamic lift, q is seen also to be a determinant of such lift. If the other factors (V and the coefficient of lift, CL) stay unchanged, the wing surface area, S, must increase, as p (and q) decrease, to maintain the same lift.

Boeing's Compass Cope vehicle command module consisted of standard cockpit instrumentation, data link equipment, a television screen, and a navigation display. Data link components included the APW-26 airborne transceiver, microwave command guidance system, wideband microwave data transmittal system for video, and a TPW-2A X-band radar van.

The Boeing Compass Cope vehicle had an automatic guidance system that permitted total or partial pre-programmed missions, permitted maximum evasive maneuvers, provided safe control and recovery in the event of loss of carrier, and reduced the operator's workload by assuming the tasks of guidance, event timing, and progress monitoring. If the operator wished to "fly" the vehicle, he could specify altitude, airspeed, Mach number, heading, or program a waypoint. The vehicle was designed for single control, but almost always during demonstration, Boeing used extra personnel for assistance.

The Boeing Aerospace Co. built the B-Gull YQM-94A in 1972 for a fly-off competition with the Teledyne-Ryan YQM-96A designed to meet the same specifications. The first prototype YQM-94A made its initial flight on June 1973, but was destroyed in a crash on August 4, 1973. The vehicle on display at the USAF Museum is the second prototype. It flew for the first time on Nov. 2, 1974. Later tests included a successful endurance flight of 17 hours 24 minutes at altitudes of more than 55,000 feet.

Following the tests, the Air Force decided to enter full-scale development with the Compass Cope. After a competitive phase between Teledyne Ryan and Boeing, the Air Force selected Boeing as the contractor. In August 1976 the Air Force awarded them a $77.2 million cost plus incentive fee development contract to desion, build, and test three aircrafL, including the necessary supporting equipment, by late 1980. The Air Force said that the contract is a two phase contract covering subsystem development as well as development of the full production system; Boeing is currently limited to subsystem design and test effort.

The total development program, including Air Force and contractor costs, was estimated at $160 million. The Boeing development contract also gives the Air Force the option to buy 20 production aircraft and 2 ground command systems. The estimated unit flyaway cost of these 20 aircraft is $4.5 million with a total production program cost of about $202 million. Production is planned to start in early 1981 provided development was successfully completed and funds were available. Although only 20 aircraft were initially planned for production, an Air Force official said they may purchase up to 108 of these aircraft.

Review of the Compass Cope program by the Defense Systems Acquisition Review Council was necessary because the need for and iost effectiveness of the system have not been fully establishzed. The Tactical Air Command, which was expected to be the primary user, questioned the need for the Compass Cope as late as April 1976. In a message to the Air Force vice chief of Staff, the Vice Commander of the Tactical Air Command said.

  1. There was no operational need for the Compass Cope System because there was no firm vehicle requirement.
  2. Alternative aircraft, such as the U-2, T-39, and RF-4 should be considered for the Precision Location Strike System and Side Looking Airborne Radar.
  3. Development and procurement funds planned for the Compass Cope program are needed for more critical programs.

The Vice Chief of Staff agreed that piloted aircraft could do many of the missions which may be assigned to the Compass Cope but said the Compass Cope development program should be continued until the Air Force had fully investigr -d the program and its cost effectiveness.

The Air Force completed a cost-effectiveness study for the Compass Cope as a carrier for the Precision Emitter Location Strike System [PELSS], which was one of the potential missions. They compared it with 10 existing manned aircraft and concluded from their study that no one system dominated the others on the basis of cost, effectiveness, and survivability.

The Air Force later concluded from the study that Compass Cope and U-2 were the most effective carriers of the Precision Emitter Location Strike System and contracted for a cost comparison of the two aircraft. That study showed that the Compass Cope could operate at a lower life cycle cost as a carrier of the Precision Emitter Location Strike System. The Air Force studied the cost of other potential Compass Cope missions but the studies have not been completed as of 1977.

Another issue is whether the Compass Cope may be restricted during some routine operations. The Air Force expected to operate the aircraft in the United States, Germany, Belgium, The Netherlands, United Kingdom, and Italy. In the United States, the Federal Aviation Administration permits RPV operations in positive control airspace (all airspace above 18,000 feet), and in restricted and warning areas. When RPVs are flying outside these areas, they must comply with the "see and avoid' concept or be accompanied by a chase plane which can communicate with the control source.

Air Force officials said the restrictions should not severely affect U.S. operations because of the limited number of Compass Cope aircraft and operating bases. They are also considering onboard sensors, such as a television camera or a collision avoidance system, which could ease existing restrictions. Air Force officials said that the British, Italian, and Dutch governments think Compass Cope can be integrated into their air traffic control systems without major problems.

After the USAF decided not to buy production versions of the Compass Cope vehicle, the remaining YQM-94A was retired to the USAF Museum in September 1979.

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Page last modified: 14-01-2018 18:56:15 ZULU