Incident Overview
An aircraft experienced a power loss at an altitude of approximately 2,000 feet while flying over Fire Island Beach. The pilot executed a forced landing on the sandy beach. Upon touchdown, the landing gear sank into the soft sand, causing the aircraft to nose over.
Engine Examination
Post-incident examination of the engine revealed the presence of a foreign sealant material. This sealant originated from the gasket of the oil pressure screen housing and was found obstructing the main bearing oil supply holes. The number one connecting rod, along with its bearing and bolt, had failed. Metallic debris was discovered in the oil, the suction screen, and the oil pressure screen housing.
Maintenance History
The aircraft's engine had undergone both a 100-hour and an annual inspection just 1.7 hours prior to the failure. During these inspections, spectrometric oil analysis returned normal results, and the oil screen was cleaned. No abnormalities were noted.
Manufacturer Information
Textron Lycoming, the engine manufacturer, does not have a procedure that specifies the use of sealant on any gaskets during engine assembly. The presence of sealant in the oil system was inconsistent with standard assembly practices.
Findings
- Sealant from the oil pressure screen housing gasket was found in the main bearing oil supply holes.
- The number one connecting rod, bearing, and bolt failed.
- Metal particles were present in the oil, suction screen, and oil pressure screen housing.
- No contributing factors from the recent inspections were identified, as oil analysis was normal and the oil screen was clean at that time.