FLIGHTMARE After Sichuan Airlines co-pilot is nearly sucked out of the cockpit

This week pilot Liu Chuanjian was partially sucked through a broken cockpit window on a Sichuan Airlines flight in China.Wuhan to Osaka flight

And last month passenger Jennifer Riordan was killed when she was half sucked out of a broken Southwest Airlines window on flight 1380.

But we do know that outside a plane at cruising altitude, air pressure is two-and-a-half times lower than within the plane cabin.

This means that if there is a broken window or a hole, a blast of air can suck out seats, passengers and whatever else is on board the plane.

The Guardian spoke to aviation expert David Haward.

He said: "This is not a frequent danger. A lot of research work was done in the 40s and 50s to make sure it wasn’t a danger – double-skinned windows and precautions like that.”

David also pointed out that passengers aren’t “sucked out” of planes.

He said: "The fuselage is pressurised, so they are pushed out."But reassuringly, he says not to worry about these things happening when it comes to air travel.

For example, the recent Southwest incident wasn’t to do with a fault with the window – the window broke when an engine blew and damaged it.

Of course nobody wants to be on a plane with a broken engine either, but accidents like this are very rare and they shouldn’t affect where you choose to sit on a plane.

David explains that there is no recorded instance of a plane window breaking on its own and that is usually down to poor maintenance if it does happen.The air pressure inside the plane is much higher than outside the plane, because the air is very thin at an altitude of 35,000 feet.

This means that humans can’t breathe well enough to get sufficient oxygen and develop hypoxia – a condition where the body gradually shuts down and can eventually die.

As a result of this, aircraft cabins are typically pressured to around the same level as is typically found at sea level.
Why is air pressure a problem if a hole appears in the plane?

The stark difference in air pressure inside and outside the plane becomes a problem if a hole appears in the aircraft.

If a large enough hole appears, the aircraft is at serious risk of explosive decompression.

The air inside the cabin would be pushed to the outside incredibly quickly - as fast as 0.5 seconds.