Why aren’t we allowed to use our phones on airplanes?


I’m not talking about playing games or watching stuff on flight mode, I’m talking about making calls and texting or using mobile data.

As a kid my parents told me that it interfered with the pilot and they couldn’t see but I realised that’s the same reason they don’t like the overhead light in the car.

In: Technology


Historically, aircraft instruments and systems that were vital for critical aircraft operations (especially takeoff and landing, but also navigation) were unshielded against cellular radiation from phones. The worse case I can think of is with ILS, instrument landing system, where the plane relies on radio communication with devices on the ground in order to make a safe approach to the runway. Especially when the pilot cannot make a visual approach. These could be interfered with, and there’s a risk that false readouts could lead to errors, given that phone technology is constantly changing like with 5G.

Phones have never caused a crash, but they have caused issues for pilots in the past. Nowadays, there are systems which actively block signals whilst in the air (IIRC, which is why you usually don’t have signal in flight even with a cell tower in line of sight), but some aircraft are able to route cell data through a system on the plane which can safely connect people to make calls and texts. There are even some carriers which offer WiFi services, however these can be extremely expensive as they rely on satellite communication.

Your phones use the same bandwidth used by flight crew to communicate with ground crew. Pilots have to regularly communicate their status to so called “earth stations”. As they are too high in the sky, they need lot of power to send the messages to the station. If your phone’s are on, they too communicate with base stations (of your network operator) which interferes with the signals sent by flight crew. To mitigate this, they might need more power, which still doesn’t guarantee successful message transmission. As we don’t want to interfere with more important messages being sent, it is usually advised to put the phones on flight mode.

I filmed an interview 8-9 years ago with the head of the FCC. He explained that it had more to do with messing up ground communications hopping from transmission tower to tower like that.

Historically early phones would sit on similar bandwidths to some of the airframe systems. Do you remember placing early phones near speakers and getting interference?

Now some of those systems could be critical to the navigation and control of the aircraft, coming into land suddenly get feedback throwing guidance off.

Although modern phones and modern aircraft will not interact with each other it is safer to have a blanket ban incase your on a plane that does react to some phones.