C208 PLT HAS FUMES IN THE ACFT; NOTIFIES ATC AND DIVERTS TO NEAREST ARPT.

Narrative

A STRONG ODOR DEVELOPED IN THE ACFT. THE SOURCE AND NATURE OF THE ODOR COULD NOT BE DETERMINED. NO SMOKE WAS OBSERVED. WHEN THE ODOR CONTINUED TO INTENSIFY; I CONTACTED ATC; ADVISED THEM OF THE SITUATION; AND ASKED FOR VECTORS TO THE NEAREST ARPT. I HAD DONNED THE OXYGEN MASK; AS PER COMPANY POLICY AS REGARD TO SUSPICIOUS ODORS; BUT DID NOT DECLARE AN EMER BECAUSE IN MY MIND THIS WAS PRECAUTIONARY. I HAD NO REDUNDANT INFO WHICH WOULD INDICATE FIRE OF ELECTRICAL OR ENG NATURE. THE SOURCE SEEMED TO ORIGINATE IN THE COCKPIT BUT INFUSED THE WHOLE ACFT SO QUICKLY I COULD NOT PINPOINT THE LOCATION; SO HAZMAT SPILL DID NOT SEEM LIKELY EITHER. I HAD SOMETHING HAPPENING THAT I KNEW WAS NOT RIGHT AND I THOUGHT IT BEST TO ANALYZE ON THE GND AND NOT OVER THE WATER; AWAY FROM HELP. SO I DEVIATED TO THE NEAREST ARPT. I HAD NO PAPER APCH PLATES SO ATC PROVIDED ARPT AND RWY INFO. I HAVE GPS WITH THIS INFO BUT THEY WERE ABLE TO PROVIDE THE INFO MUCH QUICKER THAN I COULD DIAL IT IN. THEY PROVIDED EXCELLENT SVC. I LANDED. IT TURNED OUT TO BE A FAILED AVIONICS FAN WHICH WAS MELTING (PLASTIC WAS BUBBLING) AND HOT AVIONICS.