SEA95LA087

After several touch-and-go landings, the private pilot made a full stop landing, taxied back, and took off again. No problems were reported during the takeoff. The pilot entered the traffic pattern and attempted another landing. The pilot stated that she immediately lost directional control of the airplane after the nose landing gear settled onto the runway. The airplane veered off the left side of the runway, skidded into the dirt, nosed over, and was substantially damaged. Examination of the nose landing gear assembly revealed that the center scissor bolt was missing and the nose gear was cocked to one side. The bolt was found on the runway about 800 feet from the wreckage. Examination of the bolt revealed that no cotter key had been installed to secure the nut.

On May 1, 1995, about 1035 hours Pacific daylight time, N2548Y, a Cessna 172, registered to Methow Valley Flyers, Inc., Twisp, Washington, nosed over during landing at the Twisp Airport and was substantially damaged. The private pilot, the sole occupant, received minor injuries. Visual meteorological conditions prevailed and no flight plan had been filed. The personal flight was conducted under 14 CFR 91.

The pilot stated that she performed several touch-and-go landings at another airport without any reported problems. She then flew to Twisp Municipal Airport to practice more landings. She entered the traffic pattern and landed uneventfully on runway 28. She then back taxied the airplane for another takeoff.

According to the pilot:

The takeoff roll seemed normal. I flew the pattern, touched down just beyond the displaced threshold as I'd planned, lowered the nose gear, and couldn't control the direction of the plane.... It veered onto the left and skidded into the dirt. The nose wheel stopped. The rest of the plane kept going and flipped over.

According to an FAA certified airframe and powerplant mechanic who was visiting the area at the time of the accident, the nose gear was cocked 90 degrees to one side. Further examination revealed that the nose landing gear assembly center scissor bolt was missing. The bolt secures the connection of the two scissor castings of the nose gear assembly.

The bolt was later found about 1,000 feet from the threshold of the departure end of the runway, and 800 feet prior to the final resting site of the wreckage. According to the mechanic, the bolt did not exhibit any mechanical abnormalities. Closer inspection of the bolt revealed that the cotter key was missing, and the cotter key hole was filled with grease, oil residue, and dirt. The mechanic further stated that no cotter key appeared to have been installed on the bolt.