Passengers clogged the toilets so badly on an eight-hour New York bound flight crew were forced to turn the plane around.
The journey from Vienna to New York was called off two hours in, after cabin crew found five of the eight toilets were unusable and couldn't flush properly, an Austrian Airlines spokesperson said.
There were around 300 people on board the flight who had to be rebooked on other flights.
According to the airline, this is the first time blocked toilets have disrupted one of their flights.
Usually flights are diverted to the nearest airport when the toilets are jammed.
The Austrian Airlines plane is now back in operation.
Planes don't have a sparkling reputation when it comes to hygiene, and it turns out there are all sorts of areas passengers ought to avoid for a pleasant trip.
For instance, falling asleep against the window is said to be a big no-no, since it's likely several heads and grubby fingers have rested there before you. But it is impossible to avoid some germ hotspots - like the toilet - when you're travelling on a long flight.
Thankfully, a former flight attendant has shared when it is best to make your toilet trips if possible, plus when you'll want to avoid the loos, and the reasoning makes a lot of sense.
Chatting to bathroom specialists, Sanctuary Bathrooms, a former flight attendant who previously worked for a major airline, said: "The worst time to use the aeroplane loo is right before take-off and at the very end of a flight, especially if it's long-haul."
As you can work out, it is during these times the bog will see the most use and so is most likely to get dirty.
For the same reason, the bathroom can quickly turn unpleasant after a bout of turbulence, when passengers are required to remain in their seats.
As soon as the light changes on the seatbelt sign, you can expect a rush to the loos.
Hopefully, nobody is feeling sick, but even without this factor, there's bound to be an influx.
Instead, it could be worth trying to use the loo before the food is served.
The former cabin crew member explained: "Plane food is not nutritious. It can be oily and high in salt and fat; things that don't tend to be great for gut health or bowel movements.
"If a meal isn't sitting right with a passenger and they need to use the loo because of it, you don't want to be in there straight after."
In 2018 a Norwegian Air flight with 85 plumbers on board had to turn back to Oslo after it's toilets became clogged. The plumbers said they'd need to get to the plane's exterior to fix it.
