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Why you have to keep your mobile on ‘flight mode’ during a flight

15.7.2016 at 06:00
Would it really make a difference if you left your phone on?

“Please switch off all portable electronic devices, including any mobile phones, or set them to flight mode.”

You’ve repacked your miniature bottles into clear plastic bags, gone through security, found your departure gate, boarded your plane, and stowed your bags. You would like to get comfortable and resume scanning your social media feeds or reading that article.

But this announcement, heard at the beginning of thousands of flights across the globe every day, is yet another procedure that you must follow even if you’re not completely sure why. Would it really make any difference if you actually left your phone on?

Listen to your flight attendant

In 2014, the European Commission gave airlines permission to offer their passengers Internet access via 3G and 4G connections so they can send emails and surf the Web while in flight. The Commission’s move followed a decision by the European Aviation Safety Agency (EASA) that allowed the use of personal electronics such as tablets, smartphones and e-readers during all phases of a flight.

As airlines remain in charge of the services they choose to offer on board, according to the Commission, it would be advisable to play it safe and listen to the flight attendants: Just switch your phone to airplane mode.

Think of the pilots

“If the phone is kept on during the flight, it might disrupt navigation systems with various consequences,” says Arja Pulliainen, Special Adviser, Aerodromes and Security, at the Finnish Transport Safety Agency.

It is assumed that we must disable our mobiles as their signal interferes with navigation instruments. Pilots liken this electromagnetic interference to the sound of a CD skipping or the noise that can be heard when you answer a call on your mobile close to a speaker. As this din travels through headsets, it can potentially block radio frequency for one or two seconds and lead to confusion between the pilots and air traffic control.

The sound of (relative) silence

What exactly does airplane mode do? It disables a device’s wireless transmission functions such as cellular radio, Wi-Fi, and Bluetooth. (Certain airlines now offer in-flight Wi-Fi, and Pulliainen recommends checking your carrier’s rules while making your flight arrangements.) No interference means happy pilots in the cockpit.

On a practical note, airplane mode offers a quick way to prolong your device’s battery life provided you don’t need any of those wireless radios.

Of course, this restriction also carries social implications. A ban on mobile phone use during flights prevents unnecessary chatter. In a world that’s already too noisy, the airplane cabin is a refuge of relative silence. It would be such a relief if it were kept that way.