The United States government shutdown caused by the lawmakers’ impasse on the federal budget has caused flight delays due to the shortage of air traffic controllers (ATC) manning airport towers.

But there were other unusual causes of flight delays for European airlines.

An Air Corsica flight from Paris Orly airport to the French city of Ajaccio could not land on 15 September but was forced to fly around in circles above the Mediterranean Sea “for 18 minutes,” Agence France-Presse (AFP) reports.

France’s civil aviation authority said the ATC on duty had fallen asleep at his post. The flight landed safely after the controller woke up, according to AFP.

After the sleeping ATC of France, Finnair’s blunder grounded eight of the airline’s planes on 13 October, stranding at least 11,000 passengers.

In an apology to the impacted flyers, Pekka Korhonen, Finnair’s senior vice president for technical operations, said the planes had to be grounded for passenger safety after their cabins had been cleaned, according to paddleyourownkanoo.com.

The website quoted Korhonen explaining in the letter that cleaners had washed the planes’ seat covers with water, removing their fire-retardant coating. The cleaning method was not recommended by the seat cover supplier, but it was approved by the seat manufacturer, confusing the cleaners, he said.

A total of 1,700 seats in eight Airbus A321 single-aisle aircraft were affected and Finnair was replacing all the covers by sourcing them from different suppliers. Six of the grounded planes are to return to service this week after all their seat covers are replaced, paddleyourownkanoo.com reports.