Cessna 210 Centurion / Turbo Centurion 210C; 210D
Flight Crew Instrument
Flight Crew Last 90 Days 30; Flight Crew Total 890; Flight Crew Type 130
Aircraft Equipment Problem Less Severe; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
General Maintenance Action
Aircraft
While taxiing out to active runway; I noticed a voltage fluctuation. I contacted ground control and stated that I was having a charging system problem and needed to return to my hangar. Ground gave me new taxi instructions and I complied. While circling back smoke begin to enter the cockpit from the glove box area (to the right of copilot's yoke). I called ground again and advised that I believed I might have an electrical fire. Requested direct to the fire station on the field and this was immediately granted. Ground controller said she would phone fire station. I cut all electrical power at this point and taxied to the fire station where I killed the engine with the mixture; then shut off mags. I evacuated 3 passengers; then grabbed the extinguisher.  Fireman were around the plane by this time. I retrieved a toolbox from the baggage compartment and uncowled the engine with the firemen holding an extinguisher at the ready. There was no smoke or evidence of fire in the engine compartment and no longer any smoke in the cockpit. I climbed back into the cockpit and investigated the glovebox area. At this time the cigar lighter power resistor was found to be very hot. Aircraft was towed to maintenance. Upon investigation; it was found that one of the connections to the power resistor was quite loose. This apparently increased the resistance and i2R heat production at that point. The resistor is bolted to the aluminum bottom of the glove box. The heat melted a pen in the glovebox and badly charred a wooden pencil. This was apparently the source of the smoke. The power resistor was replaced and the circuit now checks out OK.
P210N pilot reported seeing smoke in the cockpit during taxi; so he headed for the fire station. Smoke was traced to an overheating power resistor.