WPR13LA161

The pilot reported that, after about 30 minutes in cruise flight, the engine began to run roughly, followed by a loss of power. The pilot attempted to restart the engine twice but was unsuccessful. He then initiated an emergency landing on a dirt road. During the landing roll, the left wing struck an irrigation pipe, which resulted in the airplane departing the road and coming to rest in a field. A postaccident engine examination revealed that the engine was modified with an Ellison throttle body under an experimental, amateur-built airworthiness certificate. Attempts to run the engine with the Ellison throttle body installed were unsuccessful. Once the throttle body was removed, the engine successfully started. An examination and teardown of the throttle body did not reveal any anomalies that would have caused the throttle body to malfunction.

On March 25, 2013, about 1300 mountain standard time, an experimental Owens Velocity 173 airplane, N33SV, experienced a loss of engine power during cruise flight and the pilot made a forced landing on a dirt road near Maricopa, Arizona. The pilot/owner operated the airplane under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. The pilot and two passengers were not injured; the airplane sustained substantial damage to the wings and fuselage. Visual meteorological conditions prevailed for the local area flight that departed the Pegasus Airpark, Queen Creek, Arizona, about 1230. No flight plan had been filed.The pilot reported that the airplane was airborne for about 30 minutes when the engine began to run rough followed by a loss power. He attempted twice to restart the engine, but was unsuccessful. The pilot identified a dirt road as a landing spot and performed an emergency landing. During the landing rollout the airplane struck an irrigation pipe, departed the road, and came to rest in an open field. Postaccident examination revealed that the fuel tanks contained 20 gallons of fuel; additionally, the engine controls and fuel selector continuity were established. The ignition system, primary fuel system, and drive train were examined and found to be functioning normally. After several unsuccessful attempts were made to start the engine with the modified Ellison throttle body attached, the throttle body was then removed and the engine started successfully. An examination of the throttle body revealed no anomalies that would have precluded normal operation.