What was found
ON DEPARTURE THE LEFT ADC FAILED GIVING ERRONEOUS AIRSPEED AND ALTITUDE INDICATIONS ALONG WITH MULTIPLE FLAGS. WE WERE IN CRITICAL PHASE OF FLIGHT SO IMMEDIATELY CHECKED THE RIGHT PFD AND STANDBY TO DETERMINE THEY WERE WORKING PROPERLY. SWITCHED THE LEFT ADC TO ALT. WE SWITCHED THE ADC BACK TO CHECK AND IT GAVE THE SAME ERRONEOUS READINGS. AMM: 34-12-01-4 AMM: 34-12-00-5 REMOVED AND REPLACED LEFT ADC. LEFT ADC OPERATIONAL TEST CHECKS GOOD. ALL WORK ACCOMPLISHED PER ABOVE REFERENCES. AMM: 34-11-00-5 PERFORMED LOW RANGE PITOT-STATIC TEST PER ABOVE REF TEST O.K.