What was found
CLT - FLT 1050 - AFTER T/O FROM CLT, AT APPROX 1,000 FT, THE ELEVATOR FEEL DIFFERENTIAL LIGHT ILLUMINATED AND THE NR 1 AUTOPILOT WOULD NOT ENGAGE, THE NR 1 ATC FAIL LIGHT ILLUMINATED, THE NR 2 EGT IND FAILED AND THE LEFT PACK WAS BLOWING SO HARD IT CREATED A SQUEAL THROUGHOUT THE AIR VENTS MAKING COMMUNICATION IMPOSSIBLE. FLT RETURND TO FIELD AT CLT AND LANDED W/O FURTHER INCIDENT. NO EMERGENCY WAS DECLARED. MX REMOVED AND REPLACED THE ELEVATOR FEEL COMPUTER. PERFORMED OPS CHECK OF SYSTEM PER MM 27-31-00. OP''S CHECK GOOD. REMOVED AND REPLACED THE NR 1 ATC TRANSPONDER (P/N 066-01127-1101) PER MM 34-53-02. OP''S CHECK GOOD. REMOVED AND REPLACED THE NR 2 EGT INDICATOR (P/N WL202-EED6). GROUND RAN A/C WIT