Narrative:

I departed under VFR conditions. I chose a weather avoidance route. Established in cruise at 11;500MSL. Seeing ambient conditions appear favorable for carburetor ice formation (visible moisture and OAT 6 deg celsius); I applied carburetor heat and saw a slight drop in propeller RPM as expected. Approximately one minute after applying carburetor heat the engine very suddenly stopped producing power. I immediately attempted numerous restarts by selecting different ignition combinations; fuel richness; and fuel sources to no avail. I then set best left/D at about 80KIAS giving a 500 FPM descent. I then looked for a viable landing airport and found ZZZ to be the closest to my position so I did an aggressive 170 deg turn to align the aircraft. Still in VFR conditions; I then began attempting restarts again only to find I had descended into IMC conditions and had no view of the ground below or of airspace ahead. Transitioning to instruments I realized I would not make it to the airport and decided to align myself with a collocated road leading to the airport. Without visual reference to said road I used my GPS graphical display to give me cues for approach alignment. Passing through 2000 MSL I contacted center and declared my emergency. The controller asked for a repeat and I did and then was asked to squawk 7700; which I did. I lost contact with ATC as my altitude decayed and no further transmissions or receptions were noted. Passing through 700 MSL I broke out of the clouds and immediately saw a road below me. I aligned for a flare to land; extended the landing gear; and noted one vehicle on the road ahead traveling in my direction. Additionally; I was forced to avoid high trees and power lines on both sides of the road and high-tension power lines crossing the road. I was able to fly beneath these and then over fly the vehicle touching down several hundred feet in front of it. Weaving between signage on opposite sides of the road; I was able to come to a stop and turn off the road onto a perpendicular access road without damage to myself; property; or the aircraft. I then shut down the engine which was still turning at very low RPM and secured the aircraft. Later in the day; the aircraft was moved for maintenance review. No apparent visual cues were noted to indicate the cause of the power loss. I decided to disassemble the aircraft and move it to my home airfield where further inspections could be done. The following day my a&P discovered a small portion of paper towel lodged in the carburetor intake with slight charring and significant fuel dye residue (100LL blue). Later discussion revealed a possible preflight error could have led to a paper towel having been left in the engine compartment after the preflight oil check the morning of the flight. This paper towel could have migrated into to the carburetor air intake via the application of carburetor heat air after having been moved by forced air from the updraft cooling configuration of the engine. The paper towel was removed; the engine air ducts re-attached and run with the engine producing nominal static power. The conditions experienced during the forced landing have not been able to be duplicated since the paper towel segment was removed. The aircraft will be reassembled; inspected; and tested for flight worthiness prior to the next flight. One item discussed with ATC after the fact was some of the verbiage used during my communications declaring the emergency. As a multi engine pilot I am used to saying 'I have lost an engine'. I used that phrase in my initial call to ATC and was told that the controller did not know if my aircraft was a single or multi engine aircraft. Additionally she was not familiar with my type and was not familiar with the airport I had chosen. I don't believe that changed the outcome in any way as I had situational awareness to get me to my desired objective. What was a bit frustrating was that I could hear her talking to other aircraft on other frequencies and wondered if that might have slowed down her ability to respond to the emergency. I made a recommendation to the ARTCC supervisor to query controllers during safety stand downs or refresher training on some of the smaller airports they might not be familiar with in their area of responsibility just to help them become more familiar with them.

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Original NASA ASRS Text

Title: The pilot of an experimental aircraft experienced engine power loss and executed a forced landing on a road with no damage or injuries. Engine problem was traced to a piece of paper towel that had been ingested by the carburetor.

Narrative: I departed under VFR conditions. I chose a weather avoidance route. Established in cruise at 11;500MSL. Seeing ambient conditions appear favorable for carburetor ice formation (visible moisture and OAT 6 deg Celsius); I applied carburetor heat and saw a slight drop in propeller RPM as expected. Approximately one minute after applying carburetor heat the engine very suddenly stopped producing power. I immediately attempted numerous restarts by selecting different ignition combinations; fuel richness; and fuel sources to no avail. I then set best L/D at about 80KIAS giving a 500 FPM descent. I then looked for a viable landing airport and found ZZZ to be the closest to my position so I did an aggressive 170 deg turn to align the aircraft. Still in VFR conditions; I then began attempting restarts again only to find I had descended into IMC conditions and had no view of the ground below or of airspace ahead. Transitioning to instruments I realized I would not make it to the airport and decided to align myself with a collocated road leading to the airport. Without visual reference to said road I used my GPS graphical display to give me cues for approach alignment. Passing through 2000 MSL I contacted Center and declared my emergency. The Controller asked for a repeat and I did and then was asked to squawk 7700; which I did. I lost contact with ATC as my altitude decayed and no further transmissions or receptions were noted. Passing through 700 MSL I broke out of the clouds and immediately saw a road below me. I aligned for a flare to land; extended the landing gear; and noted one vehicle on the road ahead traveling in my direction. Additionally; I was forced to avoid high trees and power lines on both sides of the road and high-tension power lines crossing the road. I was able to fly beneath these and then over fly the vehicle touching down several hundred feet in front of it. Weaving between signage on opposite sides of the road; I was able to come to a stop and turn off the road onto a perpendicular access road without damage to myself; property; or the aircraft. I then shut down the engine which was still turning at very low RPM and secured the aircraft. Later in the day; the aircraft was moved for maintenance review. No apparent visual cues were noted to indicate the cause of the power loss. I decided to disassemble the aircraft and move it to my home airfield where further inspections could be done. The following day my A&P discovered a small portion of paper towel lodged in the carburetor intake with slight charring and significant fuel dye residue (100LL blue). Later discussion revealed a possible preflight error could have led to a paper towel having been left in the engine compartment after the preflight oil check the morning of the flight. This paper towel could have migrated into to the carburetor air intake via the application of carburetor heat air after having been moved by forced air from the updraft cooling configuration of the engine. The paper towel was removed; the engine air ducts re-attached and run with the engine producing nominal static power. The conditions experienced during the forced landing have not been able to be duplicated since the paper towel segment was removed. The aircraft will be reassembled; inspected; and tested for flight worthiness prior to the next flight. One item discussed with ATC after the fact was some of the verbiage used during my communications declaring the emergency. As a multi engine pilot I am used to saying 'I have lost an engine'. I used that phrase in my initial call to ATC and was told that the controller did not know if my aircraft was a single or multi engine aircraft. Additionally she was not familiar with my type and was not familiar with the airport I had chosen. I don't believe that changed the outcome in any way as I had situational awareness to get me to my desired objective. What was a bit frustrating was that I could hear her talking to other aircraft on other frequencies and wondered if that might have slowed down her ability to respond to the emergency. I made a recommendation to the ARTCC Supervisor to query controllers during safety stand downs or refresher training on some of the smaller airports they might not be familiar with in their area of responsibility just to help them become more familiar with them.

Data retrieved from NASA's ASRS site as of April 2012 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.