What happens if you don't turn off your smartphone on an airplane?

In this season, there are more opportunities to use airplanes, such as going on a trip during summer vacation or returning to Obon. When you get on the plane, you hear an announcement to turn off your mobile phone, but what if you don't turn it off? Is there something going wrong with the airplane, or maybe it can cause a crash? In this issue of YouTube's science video channel "SciShow," we will discuss the effects of powering smartphones and mobile phones on airplanes and their surroundings.


Why turn off your smartphone on an airplane


Every time you get on an airplane, you hear announcements like turning off your phone or setting it to airplane mode.

If you're not sitting in your seat or sleeping, you'll hear the announcement. You may ignore the announcement and send an email, thinking that the flight attendants will not be barred.

So what are the risks? Does an airplane crash because of a playful conversation with a friend by email?

At least in theory.

The problem with electronic devices such as mobile phones and tablets is electromagnetic interference. It may interfere with airplane communicators and navigation systems.

One type of electromagnetic interference is called "front door interference." Radio waves leak through gaps in windows and metal frames and are received by antennas mounted outside the aircraft. These antennas are used to communicate with control towers and communicate with GPS satellites, which may prevent the exchange of important information.

The other is "backdoor interference". The radio waves travel through the cables inside the airplane, interfering with the electrical signals and adding noise.

However, since 1980, aircraft electrical systems have withstood lightning strikes and other electromagnetic interference. So you will be protected from even the slightest interference from your phone or tablet.

Also, the fact that each and every person has tried not to use electronic devices such as mobile phones and tablets during flight has not led to any major problems. Some pilots say that if passengers use electronics, the aircraft's instruments will go out of order, but this is unlikely.

Researchers are constantly trying to remedy such problems, so there is no trouble. The potential for some interference, if any, is rare and will not be a serious problem that could endanger the aircraft.

But there are other reasons why using a cell phone or turning off airplane mode while flying is prohibited.

In 1991, when mobile phones were still as big as bricks, the FCC (Federal Communications Commission) speculated that in-flight mobile phones could interfere with terrestrial mobile phone signals. When a mobile phone approaches the towers from the air, the system becomes confused.

In addition, because airplanes move quickly, they switch from one tower to another and occupy valuable bandwidth.

But that doesn't happen, and in recent years airplanes themselves have been shielded. Cell phone communications won't crash the plane or disrupt the phone line.

But be sure to follow the rules unless your mobile phone is a special airplane available.