The etiquette of reclining seats on flights

A US flight had to be diverted after one passenger prevented another from reclining her seat, according to reports. When is it acceptable to lean back at 30,000ft, asks Jon Kelly.

You can see the nervous glances on any flight when the seatbelt light is pinged off, as each passenger anxiously wonders: "Do I have a recliner in front of me? Are my precious seven inches of legroom safe?"

Incursions into personal space are a familiar source of aggravation at high altitudes. So it's not surprising that, according to reports, a United Airlines flight from Newark to Denver was diverted when a passenger prevented the woman in front of him from leaning back using a $21.95 (£13) lock called a Knee Defender. The plastic clips go on the metal arms of the tray table, physically preventing the seat in front from being reclined. The clips come with a card that can be given to affected passengers to explain the motivation of the user.

After the passenger allegedly refused requests from cabin crew to remove the Knee Defender, the un-laid back fellow traveller in front allegedly hurled a glass of water at him.

The man's methods may be extreme, but some travellers - unable to work on their laptops, eat, or simply enjoy the meagre proportions of economy class to the full as a result of leaners-back - will sympathise. For some time now, a backlash against reclining has been under way.

Earlier this year, a frequent business traveller's call for a "revolt" against reclining seats went viral. A survey by Skyscanner in 2013 suggested nine out of 10 travellers wanted to see them banned. Another poll for CabinCrew.com indicated that more than 60% of international cabin crew had observed an argument between passengers as a result of them.

It's not just the manufacturers of the Knee Defender that have sought to capitalise. In May Monarch Airlines announced plans to scrap reclining seats, following the example set by Ryanair.

But recliners can offer reasonable excuses. They may be very tall or affected by other physical impairments. On a red-eye, different rules apply - everyone wants to maximise their chances of catching an hour or two of sleep.

So what to do? The advice offered by Debrett's is to "ease your chair gently into a reclining position, which will avoid a sudden invasion of the limited legroom of the passenger behind".

Etiquette expert Jean Broke-Smith takes a firmer line. On overnight flights there is a tacit understanding that everyone will lean back when the lights go off, she says. On long-haul journeys it is acceptable. Otherwise, she says, "I think it's very rude." She adds: "At the very least, you should turn around and say, 'Excuse me' first."

Asking passengers to talk politely to each other? Fasten your seatbelts now, please.

Send us your views on reclining using the form on the right.

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