Incident Overview
At an altitude of 9,000 feet and approximately 20 minutes into the flight, the pilot of N554AC reported a loss of right engine power. Chicago Air Route Traffic Control Center (ARTCC) advised that the nearest airport was Kalamazoo, located 28 miles west. The aircraft began to descend. At 0330:53, Chicago ARTCC reported that N554AC was approximately 6 miles from Kalamazoo Airport. The pilot stated, "my right engine cowling is gone...I don't know if I'm going to make it."
Witness Observations and Crash Site
Witnesses observed the aircraft flying at "tree top level" before it impacted in a heavily wooded area near Interstate 94, approximately 5 miles from the airport. The pilot, the sole occupant, was killed.
Investigation Findings
Examination revealed that the right engine case had been improperly repaired with welds. The number 2 cylinder separated from the case due to fatigue cracking in the through bolts and studs. The force of the cylinder separation caused the top section of the engine cowling to detach.
Official Probable Cause
The official probable cause includes:
- Loss of engine power due to mechanical failure/malfunction during cruise.
- Improper maintenance (major repair) by other maintenance personnel.
- Fatigue of the engine assembly.
- Separation of the cylinder.
- Separation of the cowling.
- Forced landing due to unsuitable terrain and bright night light conditions.
- In-flight collision with trees.