Love it or hate it, flying is necessary if we want to get to a faraway destination. For those of us who love to read e-books or listen to music on our phone to pass the time, however, taking a flight in China can be a boring experience.
This is because Chinese airlines didn’t allow smartphones to be powered on during flights, even in flight mode. However, since Oct 1, airlines are now allowed to lift the ban if they wish.
The reason behind the ban is something called electromagnetic interference. This is when electrical signals mess with other electronic equipment, causing them to react in unusual ways.
And according to a study by plane manufacturer Boeing in 2014 published by CNN, electromagnetic interference can sometimes cause flight equipment to react, too.
During the study, Kenny Kirchoff, a Boeing engineer, measured the radio signals sent out by a laptop’s Wi-Fi radio.
“You can see that some of the signals from the laptop actually jump over the limit,”Kirchoff told CNN at the time.
“So that means there’s a potential that this piece of equipment could interfere with [plane instruments].”
This issue is worse with mobile phones, which constantly send and receive strong signals while they search for a connection to the network. Even in flight mode, many phones still do this.
Despite this, there were just 29 cases of electromagnetic interference caused by mobile phones reported worldwide between 2003 and 2009, according to CNN.
Besides, the instruments in modern planes are protected from electromagnetic interference by metal “shields”.
You’ve probably already seen this technology if you’ve ever seen the inside of a TV cable.
Covering the main wire in the center are often two or three layers of metal that protect the TV signal from outside interference caused by other devices.
Similarly, the metal box design of microwave ovens keeps the interference they create from escaping.
Many Chinese airlines are now expected to allow passengers to use their smartphones freely, meaning that we can finally catch up on our favorite books and songs while at 30,000 feet in the air.