The aircraft had concluded a photographic task and was climbing back to cruise altitude with full power selected. The pilot noted that the ‘engine load’ gauge was registering 74-79% instead of the expected 100%, and shortly afterwards he noticed that the engine oil pressure was dropping and that altitude and airspeed were also decreasing. He decided that a ditching on Lough Erne was preferable to any terrestrial forced-landing options, and a successful ditching was carried out.
Subsequent examination found a broken seal and a loose bolt attaching the oil pump to the oil gallery in the block. This had probably led to oil starvation of the turbocharger which then caused the turbocharger main bearing to degrade to an extent that precluded the turbocharger from attaining its demanded rotational speed.
Cessna F172M D-EESE 09-14.pdf (197.92 kb)