On March 5, 2005, approximately 1700 Pacific standard time, a Simpkins RV-6A single-engine airplane, N664DS, sustained substantial damage following a loss of control and nose over during the landing roll at the Flying M Airport (OR05), Yamhill, Oregon. The airplane was registered to and operated by a private individual. The certificated private pilot received serious injuries and his sole passenger sustained fatal injuries. Visual meteorological conditions prevailed for the personal flight, which was operated in accordance with 14 CFR Part 91, and a flight plan was not filed. The flight to OR05 departed the Country Squire Airport, Sandy, Oregon, at 1630. In a telephone interview with the NTSB investigator-in-charge (IIC), and according to the Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1/2), the pilot reported that after arriving at OR05 he overflew the airstrip to check the windsock; winds were variable at 2 miles per hour. The pilot stated that he elected to land on Runway 25, which he characterized as "a soft field one-way runway located at the foot of the coastal mountains surrounded by trees and hills." The pilot stated that he entered the pattern on an extended left downwind, and that on final approach, "Everything looked normal. Wind and weather conditions were good." The pilot reported that after touching down on the main [landing gear], "...I felt the plane drift to the left. I applied pressure to the right rudder to keep the airplane on the center of the runway, but the rudder wasn't effective at all." The pilot stated that the airplane then went down an embankment and flipped over, coming to rest inverted with the nose of the airplane pointing back toward the east. When asked by the IIC if he attempted to add some right brake to correct, the pilot replied, "...no. Everything happened so fast [I] just didn't have time after trying to correct with right rudder." The pilot reported that the landing surface was soft, and its condition was rough and wet. The pilot related to the IIC that during the summer of 2004 he noticed the left brake dragging while taxiing for takeoff, which the aircraft owner subsequently repaired. The pilot stated that he had flown the airplane several times prior to the accident, including the previous week, and didn't notice any problems with the brakes. The pilot reported no anomalies with the airframe or engine which would have prevented normal operations. A postaccident examination of the brakes and brake system by a certificated airframe and powerplant mechanic revealed no anomalies which would have prevented normal operation. An FAA inspector who traveled to the accident site reported damage to the aircraft included the propeller spinner being crushed and broken, one propeller blade was bent rearward approximately 45 degrees, and the top of the rudder and vertical stabilizer were damaged. Additionally, the cockpit canopy overhead roll bar had collapsed, the left wing tip was damaged, and the nose landing gear was damaged. The inspector also reported that after the airplane was turned upright and while being moved from the accident location, both wheels turned freely and neither brake exhibited any signs of dragging. The airplane was released to the owner's representative on March 16, 2005.