On November 12, 2005, about 1000 Pacific standard time, a Vans RV-4, N14GK, lost partial engine power and struck wires during an attempted emergency landing near Apple Valley, California. The private pilot was operating the airplane under the provisions of 14 CFR Part 91. The pilot, the sole occupant, sustained no injuries; the airplane received substantial damage. The local flight departed Hesperia airport about 0935, en route to the North Las Vegas, Nevada, airport. Visual meteorological conditions prevailed, and no flight plan had been filed. In a written statement to the National Transportation Safety Board, the pilot stated that he struck power wires during an attempt to land the aircraft after a partial loss of engine power. About 12 to 15 minutes after departure, the airplane experienced a partial loss of power and the pilot decided to make an emergency landing on a dirt road. Throughout the descent the engine would momentarily regain then lose power repeatedly. On short final approach the engine regained power and the pilot applied full throttle. The aircraft struck the power lines while attempting to climb out. The pilot was able to recover but noticed a 2-foot section of his left wing had been torn off. The pilot was able to maneuver and land at the nearby Apple Valley airport about 1000. The pilot reported that he has not been able to resolve the reason for the engine power loss. The pilot did not report any mechanical malfunction of the engine.