The aircraft with 78 people on board was travelling to Manchester
It has emerged that an oil bleed caused a serious incident on a Flybe flight from Knock Airport in July of last year.
The Air Accident Investigation Unit (AAIU) has established the plane was climbing through 17,000 feet when the crew were alerted by a strange smell and fumes after a smoke alarm went off in one of the toilets.
Smoke then became visible in both the cabin and flight deck, and the crew were forced to put on their oxygen masks.
The flight diverted to Dublin Airport and no on was injured.
The Bombardier aircraft, which had 74 passengers and four crew on board, was flying from Knock to Manchester.
Subsequent inspection by maintenance personnel found oil in the Handling Bleed-Off Valve (HBOV) - caused by a failure of carbon seals "due to distress and rupture" of a washer in the number one engine.
"Contamination of the secondary oil system due to the damaged seals caused fumes to enter the cabin and flight deck," the AAIU finds.
Read the full report here