cell phone on airplane

We’ve all heard the announcement to put your phone on airplane mode. Passenger phones must be put in airplane mode during flight. Have you ever wondered what would happen if you didn’t put your phone in airplane mode?

While most phones won’t affect the pilots’ instruments, some phones will interfere with some pilots’ and air traffic controllers’ communications if they aren’t put on airplane mode. This is because the emissions from your phone can at times be strong enough to produce an unpleasant noise due to parasitic demodulation.

However, technological advances have virtually eliminated avionics interference. Several of the incidents described in anecdotes date back several years (and multiple generations of technological development). 

In today’s aviation atmosphere, airplane mode is preferred solely to ensure that passengers pay attention to the safety briefing instead of talking or texting. 

Some airlines are only turning on cell repeaters and wi-fi routers once the plane has climbed higher than 10,000 feet. In the same way, passengers should pay attention to the flight attendants’ instructions once the plane descended below 10,000 feet, these devices are turned off when the plane dropped below 10,000 feet. 

Since they don’t significantly interfere with passengers’ ability to listen and follow the airline staff’s instructions, hard-cover books, electronic readers and tablets are allowed onboard during takeoff and landing.

Do I Really Need to Put My Phone in Airplane Mode?

You can also turn your phone off if you do not want to put it in flight mode. This has the added benefit of saving your battery till you land. If you plan on using your phone on the plane, though, putting it in airplane mode is a good idea. 

And on most flights, you will be able to access the internet over the aircraft’s onboard wifi. 

Flight mode automatically disables mobile networks. But you can still turn on the phone’s Wi-Fi directly.

If you leave your phone in airplane mode and don’t turn on the wifi you won’t have access to mobile apps that require data to function. You can still play games that do not require data, watch movies you have already downloaded, and listen to high-quality music. 

But if you simply turn on your phone’s wifi and access your flight’s internet you’ll be fine.

What Happens if You Don’t Put Your Phone on Airplane Mode?

Did you know that in the US it is a criminal offense for a passenger not to switch their phone to airplane mode? Yep. I don’t know if I’ve ever seen anybody charged for that particular offense though.

Did you know that not putting your phone on airplane mode has the potential to cause electromagnetic interference with the airplane’s navigation? It also has a tendency to drain your battery faster than normal as your phone will continue looking for a network to connect to for your entire flight.

On the flip side, these are some of the benefits of putting your phone on airplane mode while the airplane is in the air.

Saves battery life: When you put your phone in flight mode, it does not try to connect to any cellular network or wireless signal. This will save your battery, and this will result in your phone’s battery lasting for a long time. 

Increases charging speed: The moment you put your phone in flight mode, all the apps on your phone stop trying to download updates. They stop checking for the latest updates, which means most apps that need data are temporarily inactive. This will significantly increase the charging speed of your phone.

Fewer interruptions: When your phone is in flight mode, you have a break from the never-ending notifications, messages, and alerts on your phone. This helps you relax and sit comfortably without being interrupted by your phone. 

Reduces Exposure to EMF Radiation: When your phone is connected to a cellular network or another device via Bluetooth or WiFi, it generates EMF (electromagnetic field) radiation. However, the RF signals from your phone interfere with sensitive sensors and devices on the aircraft. Switching your phone to flight mode reduces the effects of EMF radiation. 

Minimizes roaming charges: Many passengers traveling by air suffer from high roaming charges for using mobile networks that are not part of their data plan. Switching your phone to airplane mode gives you the chance to avoid these charges. Especially if you are traveling internationally and you don’t want to pay the international fees.

If I’m on a short trip abroad, oftentimes I will just airplane my phone for my whole stay and turn on the Wi-Fi, so that when I’m near wifi I can connect and use my phone as normal and don’t have to worry about roaming or international surcharges.

Can Flight Attendants Tell if You Put Your Phone into Airplane Mode?

Flight attendants certainly don’t have superpowers that let them see what everyone is doing at all times on every flight. But they do have their ways of monitoring passenger activities during flight.

Thanks to advances in technology, closed-circuit television (CCTV) cameras are now installed on planes. So, you may be asked by a flight attendant to turn off your phone or put it in flight mode if you are using it when you shouldn’t be.

Other devices are also used on an airplane, but these devices are not there to invade the privacy of passengers. They are only installed to make sure everything is in order and to ensure passenger safety.

Also, use caution and make sure you check all your devices and put them in flight mode. Or better yet, turn them off before you board your flight to ensure your safety.

What happens if you don’t put your phone on airplane mode? 

It can interfere with an airplane’s communications and drain your phone’s battery since it will keep scanning and tower hopping while flying by different cell towers along your route

Did anyone ever crash a plane because they forgot to turn on airplane mode?

One time, I’ve personally witnessed a pilot forgetting to turn off his phone on short final and when that phone rings, it interferes with the flight instruments. Even though we were flying in visual flight rules, we immediately saw that the instruments were misreading, but that might not be the best thing to happen if we had been flying in very low visibility.

It is generally agreed that no. There is so little power transmitted by smartphones (less than half a watt). That is why aviation instruments are designed to resist the induction of unnecessary sound. 

Planes fly in and out of large airports where there are lots of high RF power levels and devices. 

It is well known that GSM technology can wreak havoc in audio equipment and headsets. Therefore, it would follow that harmonics of the central frequency of GSM technology could cause unexpected reactions from devices that have not been adequately hardened.

Perhaps, then, the .32 watts transmitted by modern cellular handsets are not responsible, but rather massive cell towers employing GSM technology which may be the actual cause of the interference. 

The physical length of the electrical wave is .75 GHz plus 8 GHz, the frequency at which smartphones operate. Small enough that it can be easily deflected off of anything, especially solid sheets made of many different materials.