Why do we have to put phones on airplane mode on a flight – and what happens if you don’t?

Most of us have a routine when we board a plane – we find our seat, put our bags in the overhead locker, and then proceed to switch our mobile phones to airplane mode.

Whether you’re flying out of the UK, across America, or through Asia, it’s something you’re required to do on every flight.

There are many rules and requirements we are accustomed to follow without hesitation, such as not smoking, opening the window blinds and putting our trays up during takeoff and landing.

Switching our phones to airplane mode is a habit we’ve become accustomed to each time we fly, but why do we need to do this? Although turning your phone off also does the job, many of us have the option turn turn airplane mode on, which allows us to use our device while turning off all mobile data, bluetooth and cellular.

In some modern aircrafts they now offer WI-FI on board for people to connect to whilst still being in airplane mode.

This gives us the ability to still check those vital emails, scroll through Instagram or speak to relatives whilst up above the clouds.

Announcements are made on flights to ensure people follow this protocol and turn their phones or tablets onto aeroplane mode before the flight takes off, but no reason at the time is given.

Why do we need to turn our phones on airplane mode?

On many aircrafts the use of devices that transmit signals is not permitted.

As your phone needs a connection and would be out of range of the telephone towers whilst in the sky, it would constantly be searching for a connection.

As a result of this, because the phone can’t find a connection it would send an intensive, strong electrical signal.

This electrical signal could potentially interfere with the planes navigation equipment and landing guidance system, as well as the cockpit equipment. This is increasingly important now 5G is so commonplace.

It can even cause an annoying sound in the pilot’s headphones because of this signal.

This noise can also be disruptive to other crew members when trying to communicate with each other through the inflight speaker system.

By switching the phones to airplane mode means any signal transmissions by the device are blocked.

What happens if you don’t put your phone on airplane mode?
According to a pilot, it’s never been proven that a mobile phone signal has “interfered with the navigation performance of an aircraft.” They added to Business Insider: “But just because it’s never happened doesn’t mean it will never happen.”

Still, pilots have noted that mobile phones can cause notable audible interferences with radios, comparing it to the sound of a music track skipping.

This sort of interference could potentially block one or two seconds of transmission, which could cause confusion between pilots and air traffic control.

It is possible that not all phone signals would interfere with the plane’s systems, but it is a crucial protocol to ensure a safe flight.