What was found
PILOT REPORTED LOW AIRSPEED INDICATION. PITOT SYSTEM WAS PRESSURE CHECKED AND FOUND TO HAVE A LEAK. FOUND PITOT HEAT WIRING CHAFED/MELTED INTO PITOT PRESSURE TUBE APPROXIMATELY 3 INCHES ABOVE CONNECTOR. REPLACED TUBING AND SYSTEM PITOT HEAT WIRING SECURED AWAY FROM TUBING. NOTE: 2 DAYS LATER DURING AN ANNUAL INSPECTION OF ANOTHER 172, FOUND THE SAME PROBLEM, EXCEPT IT APPEARED THAT HEAT FROM THE WIRING HAD MELTED THE TUBING HALF-WAY THROUGH. THE SYSTEM STILL HELD GOOD PRESSURE.