On June 29, 1999, approximately 2000 mountain daylight time, an experimental Withington Kitfox 1200, N818HW, impacted apple trees during an attempted takeoff from an alfalfa field about 8 miles west of Caldwell, Idaho. The private pilot received minor injuries, but the aircraft, which was owned and operated by the pilot, sustained substantial damage. The 14 CFR Part 91 local personal pleasure flight was being operated in visual meteorological conditions. No flight plan had been filed, and there was no report of an ELT transmission. According to the FAA inspector who talked with the pilot after the accident, he accidentally tried to depart from an open field with the flaps deployed further than they should have been for takeoff. The pilot felt that with the flaps in the incorrect position, the aircraft's normal takeoff roll was extended and its expected rate of climb was decreased. After becoming airborne, it became evident to the pilot that the aircraft might not clear a power line in its path. The pilot therefore flew under the power line, but failed to clear apple trees that were just beyond the wires. The pilot, who failed to return an NTSB Form 6120.1/2, reported that there was no indication of engine or flight control malfunction.