The subtle flight attendant behaviour that means your pilot is worried

who said that pilots will ask their crew to look for things for them if they think there's a problem.

In an article about air travel mysteries, they discussed when passengers should start to panic during flights.

They said: "If the head steward comes down the aisle glancing anxiously out the windows, that could be in response to a request from the cockpit to check on an engine."

However, even if the request reveals something as dramatic as an engine fire, things still aren't as severe as they might at first appear.

Stuff NZ continued: "Engine on fire? Spectacular, yes, especially at night, but not really a problem unless it’s the only engine turning, in which case it’s a big problem.

"Stay calm, statistically you’re much safer up here than behind the wheel of a car."

A faulty engine certainly wouldn't be cause for too much concern.

Planes are designed with such problems in mind, so passengers don't need to worry about it as much as they probably do.

Each different plane has its own ETOPS (Extended-range Twin-engine Operations Performance Standards) rating, which determines how far it can fly with only one engine.

Pilots will be well aware of the rating, so should there be a problem, they can locate a safe place within their ETOPS limits where they can radio for an emergency landing.

In 2003, a Boeing 777 proved just what planes are capable of during a test flight from Seattle to Taipei.

---

The Sun is giving away FREE foreign holidays - here's how to win one

---

According to , the plane flew for more than five hours with only one engine and arrived safely at its destination.

The aircraft was hoping to achieve one-engine flight times of only 220 minutes, but managed to exceed that by 80 minutes.

However, there are even rarer circumstances when planes have double engine failure.

While it is a massive statistical improbability, it's also not as life-threatening as it first may sound.

Planes are designed to glide rather than just fall straight out of the sky, giving pilots some time to develop a strategy.

Typically, if both engines failed at a plane's average cruising altitude of around 36,000ft, it would be able to travel for around 60 miles before coming into contact with the ground.

It could give the pilot as much as half an hour to find somewhere suitable to land, should they need it.

Meanwhile, this passenger's plane ran out of fuel as he was over the Atlantic Ocean.

And these passengers were horrified to hear a loud bang as a loose bolt ripped a hole in the side of their aircraft.