SEATTLE, Dec. 18, 1996 -- The U.S. Air Force and Boeing have successfully demonstrated that an AGM-86C Conventional Air Launched Cruise Missile (CALCM) guided only by Global Positioning System (GPS) navigation, can deliver precision strike accuracy.

During a Dec. 12 test flight, a modified CALCM launched from a B-52H flew for approximately four and one-half hours, and impacted the target area within the accuracy requirements necessary for a precision strike designation. The demonstration also included a steep-terminal-dive maneuver for delivering a penetrator warhead on target -- the first time such a maneuver has been performed by a CALCM.

CALCM -- a conventionally armed, unmanned and self-guided missile that can be used for precision strikes against fixed targets deep behind enemy lines -- are manufactured by converting surplus AGM-86B Air Launched Cruise Missiles (ALCMs) at the Boeing Defense & Space Group Oak Ridge, Tenn., facility. The original CALCM (Block 0), used most recently in strikes against Iraq, featured an early generation, single channel GPS receiver and a blast fragmentation warhead.

A new GPS receiver system featured in the test flight included several design changes to improve navigational accuracy. These changes included a sophisticated new navigational model, and algorithms to compensate for signal time delays caused by pressure and temperature changes in the Earth's atmospheric layers. Additional factors contributing to the highly accurate CALCM performance include an improved GPS receiver capability for tracking up to eight satellites simultaneously, and the use of Wide Area GPS Enhancement (WAGE) Phases I and II, which boost GPS satellite constellation performance. WAGE Phase I technology currently is integrated into the GPS constellation, while Phase II, which was made operational specifically for the test flight, is a prototype satellite enhancement system developed by the Air Force.

Carl Avila, Boeing Air Launched Missiles program manager, says the successful demonstration marks a significant step forward for the CALCM program.

"These results clearly show that future CALCM variants can deliver a conventional warhead from extremely long range stand-off positions, with the accuracy and terminal characteristics necessary to attack hard, reinforced or buried targets," Avila said. "These improvements provide a baseline for future CALCM models, but also can be easily incorporated into missiles currently in the field."

In July 1996, Boeing delivered to the Air Force a Block I CALCM with producibility enhancements that double the accuracy and warhead effectiveness of Block 0 CALCMs, for a conversion cost of approximately $150,000 per missile. The CALCM program is managed by the Oklahoma City Air Logistics Center at Tinker Air Force Base, Okla., and manufactured by Boeing Defense & Space Group at facilities in Oak Ridge, Tenn. CALCM subcontractors include Interstate Electronics Corp. (GPS receiver), Aerojet, (warhead), ELDEC (weapon interface electronics), Cherokee Nations Industries (cables), and E Systems (GPS antenna).