What was found
OWNER ADVISED TECHNICIAN THAT NEITHER OF THE TWO AIRSPEED INDICATORS WERE READING. WHEN TECHNICIAN OPENED INSPECTION PANELS NEAR THE PITOT PROBE, THE PLASTIC TUBING WAS FOUND TO BE MELTED THROUGH BY WHAT APPEARED TO BE A WIRE. TECHNICIAN FOUND THAT THE WIRES COMING FROM THE HEATER TO BE TWISTED SOLID CORE WIRES INSULATED WITH CLEAR SILICONE. AFTER TURNING ON PITOT HEAT, TECHNICIAN NOTED THAT THESE WIRES, ATTACHED DIRECTLY TO THE HEATER, BECAME UNCOMFORTABLY HOT. IT IS LIKELY THAT THESE WIRES ARE CONDUCTING HEAT FROM THE HEATER AND BECOMING HOT ENOUGH TO MELT THROUGH PLASTIC TUBING. TECHNICIAN RECOMMENDS ENSURING THAT PITOT HEAT WIRING IS ROUTED AWAY FROM PLASTIC TUBING OR REPLACING THE FIRST 4-6" FROM THE PROBE WITH METAL TUBING.