S92 was on its way back to Stavangar/Sola (ENZV) after a flight to the West Elara oil installation. During descent from 7 000 ft. towards 1 000 ft., at a height of approx. 4 500 ft. the crew received a caution that the oil pressure on the main gearbox had dropped below 45 psi. Shortly afterwards, the caution “INPUT / ACC # 1 HOT” came on. According to the emergency checklist, the crew pulled the left engine back to idle. When the oil pressure dropped further to below 35 psi, the oil cooler bypass was automatically switched on, as designed. During the further flight towards Sola, the oil temperature rose and the caution “INPUT / ACC # 2 HOT” came on. The highest recorded oil temperature before landing was 214 degrees C.
The crew declared mayday, and continued the descent to a height of 200 ft. They were preparing to land on the sea if the oil pressure were to disappear completely. The landing at Sola was undramatic and the helicopter was followed to standstill by the airport fire and rescue department.
The helicopter returned to revenue service on 13-Nov-20