A Ryanair flight from Romania passed all phases of a good thriller movie onboard. Eventually, the Boeing 737-800 did reach London, UK, where it landed in a third attempt. 

Mayday-Mayday declared Ryanair pilots just minutes after taking off from Bucharest Henri Coandă International Airport (OTP) in Romania, on January 21, 2020. The flight FR1006 was due to fly to London (UK), but the flight plan quickly changed when during the climb the aircraft’s cabin filled with thick smoke. To make matters worse, it was not clear where the smoke was coming from. 

Soon after the pilots stopped the climb, the thick fog began clearing out, prompting the crew to cancel the Mayday. After burning off fuel, the aircraft successfully landed back in Otopeni. It is suspected that the mysterious fog onboard the Boeing 737-800 could have been caused by de-icing fluid entering the air conditioning system due to improper de-icing prior to takeoff.

The aircraft in question, Boeing 737-800 registration number EI-EVH, was already the second employed for the task to carry the passengers to London. The previous airliner, also a Boeing 737, reportedly had to be replaced prior to take-off due to a mechanical issue. 

Ryanair operates an all-Boeing 737 fleet of 354 aircraft. While the 20 Boeing 737 MAXs remain grounded, the Irish low cost carrier currently relies on 737-800s (average age of 9.3 years) for operations. The EI-EVH was delivered to the airline eight years ago, in February 2012.