What was found
WHEN WING AND STAB HEAT TURNED ON, THERE IS A BURNING ODOR IN CABIN AND COCKPIT. GROUND RUNS/CHECKS WERE UNABLE TO IDENTIFY PROBLEM. CHECK FLIGHT PERFORMED. NO FINDINGS. SECOND IDENTIFIED VERY LIGHT SMOKE FROM LT WING/STAB HEAT PIPE. PIPE HAD BEEN REWRAPPED WITH INSULATION AND A HEAT TAPE UTILIZED TO KEEP IN PLACE. TAPE ADHESIVE WAS GETTING HOT AND EMITTING SMOKE AND FUMES. REWRAPPED DUCT WITHOUT TAPE. SUBSEQUENT FLIGHT CHECKS REVEALED NO DISCREPANCY.