Report on air accident at Frøylandsvatnet in Bryne on 17 July 2017, involving Cessna U206E, LN-BEM

Aviation report 2020/24

The seaplane with the commander and two passengers onboard had just become airborne after a stop at Lake Frøylandsvatnet when engine power was lost. The commander performed an emergency landing at the south end of the lake. The aeroplane continued ashore and flipped over on its back. The three occupants escaped injury, while the aeroplane was significantly damaged. The investigation has revealed an oil leak lead to insufficient lubrication of a connecting rod bearing. This resulted in a bearing seizure and subsequently causing the connecting rod to break and penetrate the crankcase, before the engine stopped.

NSIA has found evidence indicating that a significant amount of engine oil vented out after LN-BEM departed from Sola seaplane harbour. The oil leakage is seen in connection with abnormal connecting rod bearing wear, possibly initiated by detonation in a cylinder on previous flight(s).

This report is in Norwegian only.

No safety recommendation is issued in connection with this investigation.

Published: 18.12.2020

Facts

Location Lake Frøylandsvatnet in Time municipality in Rogaland county / Norway
Occurrence date 17.06.2017
Aircraft Cessna 206 Stationair
Operator Private
Registration LN-BEM
Meteorological conditions VMC
County Rogaland
Type of occurrence Accident
Type of operation Private
Category of operation Light, aeroplane (< 5 700kg)
Aircraft category Single-engine, Seaplane (incl. amphibian), Piston engine
FIR/AOR ENSV (Stavanger ATCC)

Reports - same aircraft model

Reports - same category of operation