Recent investigations by the US military regarding EGI maintenance actions revealed that the majority of EGIs returned to depot are fully functional. Fully operational EGIs are being misdiagnosed resulting in high No Fault Found (NFF) or Re-Test OK (RTOK) rates. Minimal troubleshooting equipment is available and current procedure is to return faulty EGIs back to the manufacturer for evaluation.

The CAST EMT3500-3 diagnostic tool identifies failures to ensure all EGIs returned to the Depot actually require repair. Its user-friendly interface minimizes key strokes while CDNU-like inputs and readouts significantly reduce the learning curve.

The system tests and validates basic GPS/INS navigation by performing stationary and dynamic testing of the receiver to:

• Validate GPS receiver operation under a simple jamming environment
• Determine the signal input quality of each channel
• Validate the operation of RAIM
• Isolate a bad/weak antenna or cabling issue
• Perform pass/fail testing on all inertial sensors
• Provide reports on GPS/IMU, BIT, OFP, Almanac and mini-bias status