NTSB Factual Report

On March 3, 2001, approximately 1730 Pacific standard time, an experimental-category Cassutt II airplane, N1431, owned and being operated by a private pilot, was substantially damaged in a loss of control and subsequent collision with terrain during a forced landing approach following a reported engine malfunction 2 miles west of Moses Lake, Washington. The pilot of the single-seat aircraft was not injured in the accident. Visual meteorological conditions were reported at Grant County International Airport, Moses Lake, Washington, at 1652, and no flight plan had been filed for the 14 CFR 91 personal flight from Othello, Washington, to Wenatchee, Washington.

The pilot reported that while en route, "the oil pressure dropped rapidly followed by decreasing engine RPM." The pilot stated that he decided to land on a frontage road for Interstate Highway 90 (I-90). During his approach, he "noticed a lot of dark smoke coming from the starboard side of [the] engine just as I was starting to turn final." He stated that at the same time, he noticed oncoming traffic on the road about 2 to 3 miles away. The pilot reported , "During base to final turn airspeed was allowed to decay causing excessive sink rate and not completing the turn on centerline for landing." He stated that "touchdown was made in soft sand with high vertical speed causing [the aircraft's] landing gear to fail and [the] nose of [the] aircraft to get in the dirt."

An FAA inspector who examined the aircraft after the accident reported that in his examination, he observed that a wrist pin plug in the airplane's Continental O-200-A engine had failed, producing metal that subsequently entered the engine oil system and restricted oil flow to the crankshaft. The FAA inspector reported that he also observed the connecting rod bearings to be severely distressed, but that the pilot had shut the engine down before complete failure of the rod bearings occurred. The FAA inspector reported that the pilot had bought the airplane a couple of months before the accident, and that the airplane had been stored for a long period of time (approximately 15 years) before the accident flight.

The accident airplane was built in 1968. The engine log did not contain any entries between September 6, 1983 (when the engine oil was changed and the screens were cleaned) and December 31, 2000, when the engine oil was changed and the screen was checked. There was no indication in the engine log that the engine preservation procedures for stored aircraft specified by the engine manufacturer (as per Teledyne Continental Motors Service Bulletin M84-10 R1, Service Bulletin M91-5, and Service Information Letter 99-1) had been followed during the September 1983 to December 2000 time frame. The airplane received a condition inspection on February 8, 2001 by an inspection authorization (IA) mechanic, and was signed off by the IA mechanic as being found to be in a condition for safe operation. The pilot's logbook indicated that the pilot first flew the accident aircraft on February 18, 2001, and accomplished five flights in the accident aircraft totaling 3.1 hours from his first flight in the aircraft to the accident. The pilot reported that the engine total time was 1,675 hours, with 184 hours since overhaul.

NTSB Probable Cause

Failure of a wrist pin plug in the engine, resulting in partial blockage of the engine lubrication system and partial failure of the engine connecting rod bearings; and the pilot's subsequent failure to maintain adequate airspeed during a forced landing approach, resulting in a stall.