Incident Overview
After landing, as the pilot pulled into the ramp area, he observed an orange glow at his feet and notified airport personnel over the radio that a fire had started in the airplane. The pilot brought the aircraft to a stop, and airport crash fire rescue personnel extinguished the fire.
Examination Findings
An examination of the airplane revealed that the fire had burned a hole through the fuselage skin in the area of the Janitrol heater, just aft of the left wing root. The entire area forward of the Janitrol heater, including the wiring and plumbing of the heater, as well as the cockpit and cabin, was consumed by the fire.
Pilot Procedures and Handbook Information
The pilot reported that his normal procedure for using the Janitrol heater was to turn it off at the same time he extended the landing gear while on approach. The Pilot's Operating Handbook (POH), in the Description and Operations section, stated: "The three positions of the cabin heat control switch are 'HEAT,' 'FAN,' and 'OFF'...It is advisable to place the switch in the fan position for several minutes after the heater has been operating to allow the unit to cool down before it is turned off." The Normal Procedures section of the POH required that the switch be turned to the "FAN" position while completing the Before and After Landing checklists. The Shutdown checklist called for the switch to be switched to the "OFF" position.