Aeroplane toilets: how concerned should we be about the chance of airborne sewage?

Name: Aeroplane toilets.

Location: At the back, sometimes in the middle – and at the front if you are rich enough.

Aeroplanes … remind me again? People used to travel on them, sometimes for holidays.

Oh yes, I had almost forgotten about them over the past 18 months. Why are they – or their toilets – in the news? Because in Windsor, a man, his garden and his garden umbrellas were covered in sewage, thanks to the contents of a plane toilet falling from the sky.

The poor man! Well, yes, that’s what a local councillor, Karen Davies, told the Royal Borough of Windsor and Maidenhead’s aviation forum after her constituent got in touch about the incident in July.

Exactly the time of year you want to be enjoying your garden and garden umbrellas. Quite.

Surely planes wait until they have landed to empty their … ahem … goods? Usually, yes. The vacuum toilet used on planes, patented by James Kemper in 1975, sucks the waste into a holding tank where it is stored until the plane lands on the ground. Blue liquid, called Skykem, disinfects the bowl and helps kill odours.

When you say planes “usually” wait until they have landed to empty the tank … Well, there is such a thing as “blue ice” – frozen sewage that has leaked from an airborne plane. Airlines aren’t allowed to drop sewage from the sky – pilots have no dump button – but there have been incidents. Fictional ones, too. In an episode of the HBO drama Six Feet Under, a woman is killed by a big chunk of it.

And what if the plane isn’t high enough for it to be cold enough for the sewage to freeze? Well, that’s possibly what happened in Windsor. One councillor at the meeting, John Bowden, called it a “one-in-a-billion chance”, according to the Telegraph. Another, Geoff Paxton, who has 40 years’ experience working at airports, said vacuum toilets have all but eliminated the risk, but that possibly “something came out of the vent at low altitude”.

Did the man at least claim on insurance? “Not for the sake of a couple of garden umbrellas, in terms of bumping up his premium,” said Davies. “So he’s just had to take it on the chin.”

Literally. Well, maybe, if he was looking up at the plane at the time.

Do say … well, sing: “Blue Ice, baby’s got blue ice.”

Don’t say: “Is it a bird, is it a … oh, it’s a turd.”