A Finnair flight had to return to its origin airport when the cabin appeared to fill with smoke. There were no injuries, but what happened?
The incident happened on the fifth of January, involving Finnair flight AY-141. This would take its passengers and crew from Helsinki Vantaa Airport (EFHK) in Finland, to Bangkok Suvarnabhumi (VTBS) in Thailand. On this occasion, the flight was already just over an hour late, as it got ready for departure.
The pilots lined up their A350 with runway 15 in Helsinki, making an uneventful takeoff. But very early in their climb, they got reports of smoke or steam filling up the cabin of the Finnair aircraft. Eventually, the situation intensified, causing smoke detectors to go off at different parts of the Airbus.
All airlines take smoke events seriously, and Finnair is no exception. The flight crew stopped their climb at 4,000 feet. Despite having enough fuel on board for a 10-hour flight, the crew elected not to burn or dump fuel. Instead, they quickly circled back for a landing to Helsinki, on runway 22L. So the flight lasted only 11-12 minutes.
Finnair A350 Smoke Event – Aftermath
So, what happened? Many of the flight’s passengers first thought this was steam, not smoke. This was because the cabin crew had previously advised that they may see steam coming off the air conditioning system. However, the Finnair passengers were soon able to smell the smoke, as it intensified.
According to Finland’s AIBF, the problem had to do with de-icing liquid. Before taking off, the flight spent about 13 minutes on the de-icing pad. The exact sequence of events is not clear. But it appears that some de-icing glycol ended up getting ingested by the APU (auxiliary power unit). Such events are not unheard of, but they still shouldn’t happen. The AIBF is not investigating this smoke event any further, but Finnair is.
The aircraft in this smoke incident is a Finnair Airbus A350-941 (Rolls Royce Trent engines), with tail number OH-LWH. It is just under five years old. After their short but eventful flight, the passengers of this flight got to spend the night at an airline-provided hotel. The same aircraft departed for Bangkok the next day, almost exactly 24 hours after the incident flight.