Feeling The Heat?

The following information is derived from the FAA's Service Difficulty Reports and Aviation Maintenance Alerts.


Beechcraft A36 Bonanza

Dislodged Oil Pan Heat Pad

After removal of the left lower side engine compartment inspection panel, the left oil sump heater pad was found dislodged and wrapped around the throttle control arm and cable.

Part total time: unknown

Cessna 172N Skyhawk

Lubricated Heater Valve Hinge

During taxi, pilot reported smoke in the cockpit. Subsequent inspection found no defects with wiring or tubing, or the electrical and heating systems, and was ground-checked serviceable. Flight with maintenance personnel aboard noted odor of heated lubricant. This was the first flight since the heater valve hinge had been lubricated. Maintenance is requested to ensure ground runs are long enough to clear lubrication odors.

Part total time: Unknown

Cessna 402C Utiliner/Businessliner

Shorted Windshield Heating Grid

On climbout, the crew smelled electrical burning, declared an emergency and returned, landing uneventfully. Inspection revealed windshield heating grid was shorted and avionics static discharge suppressors were burnt. Removed and replaced heated windshield, avionics static discharge suppressors and, as a precautionary measure, windshield heat inverter.

Part total time: Unknown

Pilatus PC-12/45

Overheated Heater

Under-floor heater overheated, causing smoke in cabin. Heater got hot enough to start melting the heating elements. The thermal protection switch did not shut the heater off and the 70-amp circuit breaker did not trip.

Part total time: Unknown

Pilatus PC-12/45

Smoke And Fumes

Auxiliary cabin heat was turned on in cruise flight at FL240. Soon thereafter, smoke and fumes started developing in the cabin.

Part total time: 7966.0 hours

Pilatus PC-12/47E

Failed AOA Sensor Heating Element

During cruise, annunciator panel illuminated a caution message indicating angle-of-attack failure. Troubleshooting determined that the vane and tip heating elements were not functioning. Replaced unit.

Part total time: 133.0 hours

Piper PA-31-350 Navajo Chieftain

Breached Combustion Liner

Pilot reported smell of exhaust in cabin and CO detector started to change color when running cabin heater in climb. A pressure decay test revealed a breached combustion liner in the cabin heater (p/n CD140481), which was replaced with new. This is the second consecutive heater by this manufacturer that experienced a similar failure at less than 1000 hours since new.

Part total time: 866.0 hours


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