Narrative:

Plan was to fly from ZZZ to [destination] for fuel.weather clear - light winds from east/north east.preflight i.a.w. Checklist: 4.5 qts oil; 4.0 gal fuel in left wing tank; 4.5 gal fuel in right wing tank.start; taxi to runway xx and run-up normal.takeoff on runway xx into left quartering headwind. Flew runway heading to left cross wind to left downwind while continuing to climb out of pattern altitude. Approximately mid field downwind turned left to southwest over top of ZZZ on course to [destination]. Continued cruise/climb at 70 mph to 2500 MSL on course. At 2500 MSL reduced power to 2150 rpm; engine instruments checked normal and trimmed for cruse.shortly after level off; engine began running rough;losing power with oil pressure dropping to zero. Immediately made a climbing 180 left turn to north back towards ZZZ. Engine continued to lose power. Trimmed to maintain 60 mph and secured engine by turning mags; master; generator and fuel all to off.recognized that there was not enough altitude to make it back to ZZZ and began looking for best alternate landing area. Having seen the large plant to the east with long wide straight access road; no apparent power lines; little traffic and aligned into the wind; turned in that direction. Continuing to monitor traffic on the road; positioned aircraft for a left base for landing to the northeast. On rolling out for final saw a car traveling in same direction at similar speed so side slipped aircraft to lose altitude; speed and create separation to land behind the car. Landing in center of road and roll out normal. Once stopped exited the aircraft and pulled aircraft tail perpendicular to road into grass on the side of breakdown lane so aircraft wing would not obstruct traffic on road and waited for authorities. Aircraft wings were removed; and the aircraft transported by trailer to ZZZ.preliminary examination of the aircraft looks like the oil temperature probe that screws into the back of the oil screen cap became loose allowing the oil to be pumped out the loose fitting. There is still a lot of oil all over the engine compartment so will need to verify but this looks like the source of the leak. The oil screen cap was properly safety wired to the engine block but the temperature probe is not designed to be safety wired on to the oil screen cap. Perhaps it should be.

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Original NASA ASRS Text

Title: Aeronca Champion pilot reported oil system failure which resulted in an engine shutdown and a forced landing.

Narrative: Plan was to fly from ZZZ to [destination] for fuel.Weather clear - light winds from east/north east.Preflight i.a.w. checklist: 4.5 qts oil; 4.0 gal fuel in left wing tank; 4.5 gal fuel in right wing tank.Start; taxi to runway XX and run-up normal.Takeoff on runway XX into left quartering headwind. Flew runway heading to left cross wind to left downwind while continuing to climb out of pattern altitude. Approximately mid field downwind turned left to southwest over top of ZZZ on course to [destination]. Continued cruise/climb at 70 mph to 2500 MSL on course. At 2500 MSL reduced power to 2150 rpm; engine instruments checked normal and trimmed for cruse.Shortly after level off; engine began running rough;losing power with oil pressure dropping to zero. Immediately made a climbing 180 left turn to north back towards ZZZ. Engine continued to lose power. Trimmed to maintain 60 mph and secured engine by turning mags; master; generator and fuel all to off.Recognized that there was not enough altitude to make it back to ZZZ and began looking for best alternate landing area. Having seen the large plant to the east with long wide straight access road; no apparent power lines; little traffic and aligned into the wind; turned in that direction. Continuing to monitor traffic on the road; positioned aircraft for a left base for landing to the northeast. On rolling out for final saw a car traveling in same direction at similar speed so side slipped aircraft to lose altitude; speed and create separation to land behind the car. Landing in center of road and roll out normal. Once stopped exited the aircraft and pulled aircraft tail perpendicular to road into grass on the side of breakdown lane so aircraft wing would not obstruct traffic on road and waited for authorities. Aircraft wings were removed; and the aircraft transported by trailer to ZZZ.Preliminary examination of the aircraft looks like the oil temperature probe that screws into the back of the oil screen cap became loose allowing the oil to be pumped out the loose fitting. There is still a lot of oil all over the engine compartment so will need to verify but this looks like the source of the leak. The oil screen cap was properly safety wired to the engine block but the temperature probe is not designed to be safety wired on to the oil screen cap. Perhaps it should be.

Data retrieved from NASA's ASRS site 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.