Swiss A220 engine shutdown traced to leak from unmodified oil cooler

Investigators have determined that a Swiss Airbus A220-100 engine shutdown during climb out of Paris was triggered by a faulty seal leading to a loss of oil pressure. The aircraft was en route to Zurich from Paris Charles de Gaulle and climbing through 22,000ft. Swiss investigation authority SUST says the crew had received several warning messages about low oil quantity and low oil pressure on the left-hand Pratt & Whitney PW1500G engine. The crew shut down the engine and proceeded to Zurich where the twinjet landed without further difficulty. SUST has traced the issue to a faulty O-ring seal on the engine’s fuel oil cooler. At the time of the incident, on 13 October 2018, a service bulletin was in circulation detailing replacement of a cooler component with one having a longer thread length and tighter torque. The bulletin had been published four months earlier but was classified as “less urgent”, says the inquiry, and had yet to be carried out on the A220 involved.<br/>