What happened
During the takeoff roll and initial climb, the top engine cowling of the aircraft separated while at approximately 300 feet above the ground. The upper portion of the cowling struck the right side of the windshield and the right side of the horizontal stabilizer. Following the separation, the pilot returned to the airport and completed the landing without further incident. No injuries were reported.
The investigation
The investigation focused on the fragments of the engine cowling. The center portion of the top engine cowling was not recovered. While the right portion of the cowling separated in-flight, it was recovered; examination showed that the forward latch had broken and separated in half, and both the forward and aft latches were bent, twisted, and canted aft. The left portion of the cowling remained attached to its two latch points with no apparent damage to the latches.
Maintenance records indicated that this aircraft had a previous incident on October 22, 2003, involving a similar separation of the top engine cowling during climb out. Following that event, the cowling was replaced with a unit that had accumulated 11,800 flight hours. This replacement cowling had undergone several maintenance actions, including two repairs to the fiberglass structure on July 7, 2004, and September 14, 2004. The September repair specifically addressed a crack in the forward area of the top cowling.