A flight with 74 passengers and four crew was forced to make an emergency landing in Dublin when smoke appeared in the cabin and flight deck.
The Bombardier DHC commercial flight left Knock airport on the evening of July 31st last year bound for Manchester.
A report by the Air Accident Investigation Unit (AAIU) of the Department of Transport said the flight was climbing through 17,000ft when the crew were alerted by a strange odour and fumes on the flight deck followed by activation of a toilet smoke alarm.
Diverson
With smoke becoming visible in both the cabin and flight deck, the flight crew donned their oxygen masks.
The plane diverted to Dublin where it was inspected by the airport fire service.
Maintenance staff later found oil in an engine valve, caused by the failure of carbon seals due to the rupture of a washer part.
Contamination of the oil system due to the damaged seals had caused the fumes to enter the cabin and the flight deck.
Engine manufacturer of the Pratt and Whitney motor revealed there had been 19 incidents involving the same washer part since December 2014. In most cases, the problem required the unscheduled removal of an engine.
The investigation unit’s report indicated the washer had been redesigned for “infinite life” and, accordingly, the investigation did not require any safety recommendations.