Accident Sequence
A student pilot conducted several takeoffs and landings before departing the traffic pattern in a 1968-model Beech Musketeer. After leaving the pattern, witnesses observed the airplane flying at an altitude of approximately 20 feet above the trees. They reported that they did not hear the airplane's engine running. A witness stated that the airplane flew by her in a level attitude and, after clearing some power lines, began to descend. The airplane's left wing then impacted trees, and the airplane nosed down into the trees.
Post-Accident Examination
Continuity was established to all flight controls. Examination of the engine oil pressure and suction screens revealed the presence of metal particles, shavings, and flakes. The oil pressure relief valve plug, spring, and ball were removed. The ball had metal adhering to it, and the ball seat was contaminated with metal. According to a manufacturer representative, this contamination "may have prevented the ball from contacting the seat." A large amount of sludge was found inside the crankshaft. A teardown examination of the engine revealed evidence of a lack of lubrication.
Maintenance History
A review of the airplane's maintenance records indicated that the engine's last oil change was on July 2, 1999, at a total airplane and engine time of 1,665.0 hours. There was no record that the oil suction screen or oil pressure screens were cleaned during that oil change. The last documented cleaning of the oil screens was December 1, 1996. At the time of the accident, the airplane had accumulated a total time of 1,680.92 hours, and the engine had never undergone an overhaul.
Manufacturer Recommendations
The engine's operating manual states: "At each 100 hour inspection remove suction screen. Inspect for metal particles; clean and reinstall. Inspect and clean pressure screen every 25 hours."