Cessna 210 Centurion / Turbo Centurion 210C; 210D
Flight Crew Instrument; Flight Crew Commercial; Flight Crew Multiengine
Flight Crew Last 90 Days 60; Flight Crew Total 1100; Flight Crew Type 550
Other / Unknown
Aircraft Equipment Problem Critical; Ground Event / Encounter Object; Ground Event / Encounter Ground Strike - Aircraft; Inflight Event / Encounter Fuel Issue
Aircraft Aircraft Damaged; Flight Crew Diverted; Flight Crew Landed in Emergency Condition
Human Factors; Aircraft
While on a 700 fpm descent for landing; leaving 5500 ft. (approximately) I started my before landing checklist. Mixture full rich; prop high...while I pushed the prop control in; the RPM's didn't change; there was no increase in RPMs but a drop; then I proceeded to add throttle hoping to gain some power back on the engine but it didn't affect it; the manifold gauge would increase but the power on the engine wasn't increasing; almost seemed like the engine was stuck on idle. Realizing there was something wrong with the engine I kept my descent but now trying to maintain about 90 kts. I was already cleared to land but I reported some engine trouble to the controller; at about 2500 ft. (approximately) I realized I wasn't going to be able to make it to the airport so I decided to turn towards the right just so I can align the aircraft on a highway; at that point I reported to the controller I wasn't going to the able to make it to the airport and that I was landing on the road. While getting close to the road my configuration was no flaps; power to idle; prop full in; mixture rich. Right before my flare onto the road; I cut off the mixture; and then decided to put the landing gear down. I decided to wait longer for the landing gear to come down because I wanted to improve my chances on trying to make it to the airport runway. The nose gear locked down but not the mains; the planes landed on its belly on the center of the road; but then the left wing hit a road sign breaking the fuel tank and sending the aircraft into a 180 turn and leaving the aircraft in a ditch in between both traffic lanes. After impact then I reported to the tower that I was ok and that I was shutting down all comms. I turned off the avionics; starter off; and master switch off; and then I evacuated the aircraft. For this trip I had 89 usable gallons (the aircraft was topped off); I departed on a direct flight burning 14 gallons per hour. While en route I had a constant tail wind at 10;500 ft. which gave me 165 kts indicated airspeed; and around 180-185 kts ground speed indicated by my portable GPS. After the landing I decided to check my flight time on my GPS and showed me 5 hours and 5 mins.
C210 pilot experiences a loss of engine power during descent for landing after a five hour flight. When it is determined that the airport cannot be reached a highway is chosen for landing. The gear is extended late and the main gear do not extend fully before landing on the road.