What was found
(CAN) SHORTLY AFTER DEPARTURE, FLIGHT CREW ADVISED OF AVIONICS SMOKE FAULT. DISCUSSED WITH MOC, AND RETURNED TO DEPARTING STATION, LANDING AT 71,000 KG OVERWEIGHT BY 6500KG. NO EMERGENCY DECLARED. SKIN AIR OUTLET VALVE INOPERATIVE, SKIN AIR OUTLET VALVE REPLACED IAW AMM 21-26-53. OPS CHECK DONE IAW AMM 21-26-00-710-001.