What was found
CLT - FLT 1157 - CAPTAIN'S FLIGHT INSTRUMENTS, AIRSPEED, ALTIMETER FAILED AND GPWS WARNING CAME ON. FLIGHT RETURNED TO CLT WHERE AN OVERWEIGHT LANDING WAS MADE WITHOUT FURTHER INCIDENT. MAINTENANCE REPLACED NR 1 ADC. OPS CHECK OK. PERFORMED OVERWEIGHT LANDING INSPECTION, CHECKS OK. (Z)