Narrative:

I was in flight from 8300 ft to zao at 6500 ft when I noticed that the noise in the cockpit got louder. I checked my engine RPM and the engine was over-revving to 3000 RPM. I pulled the power back to below 15 inches manifold pressure to get the engine back to 2500 RPM. I moved the propeller governor in and out to get the propeller to respond. This did not help my RPM problem. I was within 5 mi to gvl when the problem occurred and I began my descent into the airport. I made 2 passes around the field to observe aircraft traffic and loosing altitude. I called unicom for active runway, but no answer. Runway 29 was clear when I made my second pass. I turned downwind, base, and then final, lined up to land. This was the first time I saw the twin engine on the runway. He was all the way over to the right side of the runway. I added fuel to execute a go around and the engine over-revved to 3000 RPM again. I flew to the right and landed behind the aircraft. No aircraft or people were ever in danger from my action. There was no way for me to go around. The propeller was too flat and the engine would turn too many RPM. Once on the ground, I called the propeller shop and they sent mechanics out to repair the governor problem.

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Original NASA ASRS Text

Title: C210 PLT HAD THE PROP GO INTO FLAT PITCH RESULTING IN AN ENG OVERSPD. WHILE LNDG, HE HAD AN NMAC WITH A LIGHT TWIN.

Narrative: I WAS IN FLT FROM 8300 FT TO ZAO AT 6500 FT WHEN I NOTICED THAT THE NOISE IN THE COCKPIT GOT LOUDER. I CHKED MY ENG RPM AND THE ENG WAS OVER-REVVING TO 3000 RPM. I PULLED THE PWR BACK TO BELOW 15 INCHES MANIFOLD PRESSURE TO GET THE ENG BACK TO 2500 RPM. I MOVED THE PROP GOVERNOR IN AND OUT TO GET THE PROP TO RESPOND. THIS DID NOT HELP MY RPM PROB. I WAS WITHIN 5 MI TO GVL WHEN THE PROB OCCURRED AND I BEGAN MY DSCNT INTO THE ARPT. I MADE 2 PASSES AROUND THE FIELD TO OBSERVE ACFT TFC AND LOOSING ALT. I CALLED UNICOM FOR ACTIVE RWY, BUT NO ANSWER. RWY 29 WAS CLR WHEN I MADE MY SECOND PASS. I TURNED DOWNWIND, BASE, AND THEN FINAL, LINED UP TO LAND. THIS WAS THE FIRST TIME I SAW THE TWIN ENG ON THE RWY. HE WAS ALL THE WAY OVER TO THE R SIDE OF THE RWY. I ADDED FUEL TO EXECUTE A GAR AND THE ENG OVER-REVVED TO 3000 RPM AGAIN. I FLEW TO THE R AND LANDED BEHIND THE ACFT. NO ACFT OR PEOPLE WERE EVER IN DANGER FROM MY ACTION. THERE WAS NO WAY FOR ME TO GO AROUND. THE PROP WAS TOO FLAT AND THE ENG WOULD TURN TOO MANY RPM. ONCE ON THE GND, I CALLED THE PROP SHOP AND THEY SENT MECHS OUT TO REPAIR THE GOVERNOR PROB.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.