Piper PA-28-180 N180LR accident near Greenville, North Carolina

Probable cause

Inadequate maintenance by the operator and maintenance personnel, which resulted in a loss of engine power due to oil starvation.

NTSB analysis

The pilot made a forced landing in a swamp after the engine lost complete power. The landing resulted in substantial damage to the airplane and serious injuries to both occupants. Postaccident examination of the engine found large amounts of metallic flakes and debris in the oil filter and oil sump screen. When the engine was disassembled, wear was noted on the camshaft lobes and associated lifters, and the No. 2 aft piston pin plug. The No. 2 forward piston plug was missing and metal shavings consistent with the plug were found in the oil suction sump screen. Metallurgical examination of engine components revealed damage consistent with the engine operating at high operating temperatures due to a lack of lubrication and hard contact damage after the No. 3 connecting rod released during operation. No preexisting material failures were identified. Therefore, the wear noted in the engine most likely became excessive, and over time produced metal shavings and debris that collected in the oil screen, which led to oil starvation. The bearings and connecting rods overheated, which resulted in the release of the No. 3 connecting rod from its crankshaft journal during engine operation.

A review of the engine maintenance records revealed the oil had been changed and the filter replaced but had not been checked for about 8 months before the accident. Per a Mandatory Service Bulletin released by the engine manufacturer, titled “Oil Servicing, Metallic Solids Identification After Oil Servicing, and Associated Corrective Action,” the oil filter and oil sump suction screen were to be checked after each oil change. This check was to see if the engine was being contaminated with metallic particles due to excessive wear and to help prevent a future engine failure. In addition, the engine manufacturer recommended the engine be overhauled every 12 years or 2,000 hours to “mitigate engine deterioration that occurs with age, including corrosion of metallic components…” Engine maintenance records indicated the engine was last overhauled about 21 years before the accident, and had accrued 2,118.5 hours of operation at the time of the accident. As such, the engine was 9 years past its recommended overhaul interval and 118 hours over the recommended time in service. Had the airplane operator overhauled the engine as recommended by the engine manufacturer, and if maintenance personnel checked the oil filter/and oil sump suction screen in the months leading up to the accident, it is likely they would have observed metallic debris being produced by the engine due to excessive wear. Both actions would likely have prevented the engine failure due to oil starvation.

Text from the NTSB. Open the NTSB docket for ERA23LA218 for the full record.