Airliner diverts flight over full toilet tanks

When an airliner has to land, it has to land.

At least, that was the case with an Air Canada Rouge flight from Athens to Toronto that made an emergency diversion to Montreal recently for a surprising reason.

On-board sensors indicated that all of the Boeing 767’s toilets were full after much of the 10-hour flight, making them unusable for the final portion of the trip.

The flight carrying 240 passengers was delayed close to two hours as staff checked out the problem, which turned out to be a false alarm, a glitch with the lavatory system.

But the July 3 incident highlighted a little-known fact about modern passenger jets: the waste is not jettisoned from on high — threatening those on the ground with falling, frozen feces — but kept as extra baggage.

Still, having to divert a plane because the toilet tanks appeared to be full is highly unusual, said Peter Fitzgerald, a spokesman for Air Canada.

Outside aviation agreed. “It’s really quite rare; they usually have the capacity for the flight,” said John Pottinger, a British Columbia-based aviation-safety consultant.

“I have never heard of aircraft diverting because of unusable toilets, but I am sure that it has happened,” said David McNair of Ottawa’s McNair Flight Safety. “I don’t think that this is a safety problem, but more of a passenger-comfort decision, one that many people probably appreciated.”

Although in this case the alert turned out to be bogus, the system is designed to shut down the toilets if it thinks the tanks are full, said John Dejak, president of Aviotec International, an Mississauga, Ont.-based consulting firm.

The flight declared a “Pan pan” — indicating there is an urgent situation but no immediate danger — when the full-toilets indicator lit up, then landed at nearby Montreal, according to the Aviation Herald website.

Workers there carried out a “quick fix” on the mechanical problem that triggered the indicator, said Fitzgerald. It took another 18 hours of maintenance in Toronto later to fully repair it, he said.

Airliners have long had tanks on board to hold sewage and the International Civil Aviation Organization sets strict rules for how it’s handled on the ground, said Dejak.

“Any excrements from aircraft are treated very particularly,” he said. “It’s strictly controlled, because people are coming from other countries and so forth.”

That said, incidents persist of so-called “blue-ice” — sewage and antiseptic blue fluid that has frozen in the frigid high-altitude air — plummeting to earth, usually attributed to an accidental leak from one of the tanks.

Just last year, an Ottawaarea woman reported that a chunk of frozen waste tore a hole through the roof of her mother’s house.