OSLO — How many plumbers does it take to fix an airplane toilet? The answer, so it seems, is more than 85.

On Jan. 27, Norwegian flight DY1156 experienced the definition of ‘irony’ when it was forced to return to Oslo due to a broken toilet, even though it was carrying close to 100 plumbers onboard.

A total of 85 tradesmen from Norway’s plumbing industry, including 65 from one company, Rørkjøp, were on the two-and-a-half hour flight to Munich. But despite their combined skill and experience, they were unable to fix the faulty loo.

“We would have liked to fix the restrooms, but unfortunately it had to be done from the outside and we did not take the opportunity to send a plumber [out] at 10,000 metres,” joked Rørkjøp CEO Frank Olsen, who spoke with Norwegian newspaper Dagbladet.

Upon its return to Oslo, the Boeing 737 aircraft “was repaired and continued with the flight later that day,” the airline spokesperson confirmed. “We would like to thank passengers for their patience and would like to apologize for the inconvenience.”