Chinese authorities have released a Finnair jet from quarantine after impounding it for a day in response to reports that a mouse had crept onboard.
A business-class traveller on Tuesday's eight-hour flight from Helsinki to Shanghai claimed to have spotted the rodent, and informed a member of the cabin crew. In line with aviation regulations, the Finnair crew then informed the Chinese authorities.
International rules say that a report of a possible rodent onboard must be made even if only one person thinks they see it.
On landing, the Shanghai authorities impounded the Airbus 340-300 series plane for 24 hours – a decision which Finnair said they were “surprised” by, as it goes beyond the requirements of international regulations.
The quarantine meant Finnair was forced to cancel the outbound and return flight the following day.
Finnair said that on inspection, no explanation for the mouse sighting was found, but refused to comment on whether the report may have been a hoax.
Pekka Henttu, head of aviation for Finland’s transport authority Trafi, told Yle that rodents on board aircraft are rare, but not unheard of.
However, he said the Chinese authorities’ response in this case was exceptional. “It could have been for safety reasons, or hygiene, but we don’t know on what basis they decided to quarantine the aircraft,” he said.
Henttu also recalls that seven years ago a rat was spotted onboard a Finnair plane by a business-class passenger while the jet was on the tarmac at Delhi airport. On closer inspection the animal turned out to be a mouse, Henttu says.
Rodents can pose a risk to aircraft, with one reported case in Germany where a rodent was deemed responsible for a light aircraft accident after it became lodged in the fuel feed to the engine.
In the case of the Delhi mouse, Finnair crews were unable to trap the rodent for some time, despite searches between flights, Henttu says. After a week the unhappy creature made a “fatal mistake” and ended up dead.