This is the Guardian. If you've ever been on a flight that's hit a patch of turbulence, you'll know how it goes.

The seatbelt sign comes on, the shaking begins, and usually it's over within a few minutes with no damage done.

But for passengers on Tuesday's Boeing 777 flight from London to Singapore. The experience was far more traumatic.

Some of the 211 passengers on board were carried off on stretchers. Others were

triaged and treated on the tarmac of the airport.

A British man died and several others were injured when the plane encountered severe

turbulence a

study found that had been

something we'll have to get used to.

Last year a study found it had increased by 55%

between 1979 and 2020.

So why is this happening?

Is there anything we can do about it?

Or is severe turbulence here to stay?

I'm the Guardian Science Editor Ian Sample and this is Science Weekly.

Guy Grouton, you're an associate professor of aviation and environment at

Cranfield University. First of all I want to understand what turbulence is.

There are a couple of different types. Can you take me through them?

Turbulence is basically what happens when you get friction between air flow or wind

flowing in different directions. So if you can imagine wind going in

one direction at 50 miles an hour and going in another direction at 100 miles an hour

in between those two there's going to be

...