Engine Exhibited A Sudden Loss Of Power But Continued Running With Excessive Vibration

Location: Sherrills Ford, North Carolina Accident Number: ERA23LA262
Date & Time: May 31, 2023, 15:30 Local Registration: N2440S
Aircraft: Burton Searey Aircraft Damage: Substantial
Defining Event: Fuel starvation Injuries: 2 None
Flight Conducted Under: Part 91: General aviation - Personal

Analysis: The pilot of the amphibious, amateur-built airplane, who had purchased the airplane several months earlier and did not hold a rating for airplane single-engine sea, departed the lakefront grass runway and performed a sharp left turn to assume his enroute heading without retracting the airplane’s landing gear.

The pilot reported that, about halfway through the turn, the engine exhibited a sudden loss of power but continued running with excessive vibration. Remedial actions to restore power were unsuccessful. The pilot stated that he selected a forced landing site on the lake and moved the landing gear selector to the “up” position with “about 25 ft of altitude nearing 50 mph of airspeed.” Photographs taken by a witness showed that the airplane contacted the water with the landing gear extended. The pilot stated that the airplane pitched forward upon water contact and came to rest upright in the water with substantial damage to the fuselage and right wing strut.

Months before the accident, the pilot experienced a power loss event with the airplane that he and other owners of the same airplane make/model could not diagnose, ultimately agreeing that it was a case of the fuel tank unporting due to a low fuel state.

Immediately after the accident, the pilot started the engine several times, but it would “choke out” each time. Postaccident examination of the airplane revealed a gascolator occluded by rusty particles and containing water and trace amounts of fuel. The pilot reported that he was unaware of this gascolator in the fuel system, and that its occlusion could have led to both engine power loss events.

The owner declined to test run the engine after clearing the gascolator of contaminants, citing fears of further damage to the airplane since the engine was loose on its mounts. 

Probable Cause and Findings: The National Transportation Safety Board determines the probable cause(s) of this accident to be -- The pilot’s failure to configure the amphibious airplane’s landing gear before conducting a forced landing to a lake after a loss of engine power. Also causal was the occluded gascolator and the pilot’s lack of knowledge about the airplane’s fuel system, which resulted in his failure to locate and identify the condition of the gascolator following a previous loss of  engine power event. 

FMI: www.ntsb.gov