Turboprop engine mechanic Staff Sgt. Carla West performs an inspection of a newly installed tailpipe assembly on an EC-130H Compass Call aircraft at the 41st Electronic Combat Squadron, Davis-Monthan Air Force Base, Ariz., on Dec. 19, 1999. Compass Call is the designation for a modified version of a C-130 Hercules aircraft configured to perform tactical command, control and communications countermeasures. Specifically, the modified aircraft uses noise jamming to prevent communication or degrade the transfer of information essential to command and control of weapon systems and other resources. It primarily supports tactical air operations but also can provide jamming support to ground force operations. West is from Albuquerque, N. M.