What was found
PILOT REPORTED AN ADC FAILURE, LOSS OF AIRSPEED, ALTIMETER, VERTICAL SPEED, TAS AND OAT DISPLAYS DURING CRUISE. AIRCRAFT LANDED WITHOUT INCIDENT. MX TROUBLESHOOT AND INSPECTED ACFT AHRS 1 TAS ALERT IAW STC ICAW A0-01080-05, REV 1 AND REFERENCING FLIGHT-LINE MM A0-00601-05, REV A, PAGE 3-13. MX RESET GTP-59 AND GDC-74 CONNECTOR PLUGS AND PERFORMED GROUND OPS AND FUNCTIONAL CHECKS AND SELF-TESTS. ALL CHECKS WERE GOOD. ACFT RETURNED TO SERVICE - THREE FLIGHTS HAVE BEEN COMPLETED WITH NO FURTHER DEFECTS NOTED.