As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) PILOT REPORTED THAT AIRSPEED INDICATOR WAS READING 20 KNOTS LOW. WHEN PITOT HEAD WAS REMOVED IT WAS FOUND THAT THE PLASTIC PITOT LINE WAS MELTED HALF WAY THRU BY THE WIRES TO THE PITOT HEAT ELEMENT. AS THESE WIRES GET WARM WITH THE PITOT HEAT ON, IT IS IMPORTANT TO ENSURE THE PITOT LINE IS NOT TOUCHING THESE WIRES.