If you’ve ever been flying commercially in the US, you know that at some point during the beginning of your takeoff, you’ll be asked to put your devices like your iPhone in “airplane mode.”
But what exactly does airplane mode do and do you really need to put your phone in it when flying?
In this article, I’ll explain exactly what airplane mode does and why it might be so important to keep your phone in airplane mode when flying.
I’ll also give you some scenarios where airplane mode can be useful outside of the airplane context.
What does airplane mode do?
Airplane mode disables wireless transmission features on your mobile devices such as: cellular data, Wi-Fi, and Bluetooth.
Airplane mode is primarily designed to reduce the interference from cellular radio waves that could potentially interfere with cellular transmission on the ground but some also believe it helps to reduce navigational and communication issues between pilots and air traffic control.
Let’s look at why airplane mode may or may not be needed.
Reducing radio waves on the ground
Believe it or not, it’s not the FAA but the Federal Communications Commission (FCC) that is the primary driving force behind airplane mode requirements.
They prohibit in-flight cell phone use to protect the integrity of ground-based cellular systems.
The worry is that a cell phone hurling through the sky could ping multiple cell phone towers at the same time.
Consider that the farther that some phones get from cell phone towers, the more “aggressive” they get with their signal requests.
So you could imagine that with potentially thousands of passengers in the sky shooting out their cell signals nonstop, this could create an unstable environment for cellular data.
When flying at high altitudes of 35,000 feet, it’s very debatable that a cell phone signal could reach cell phone towers on the ground.
It’s not that the cell signal could not extend that far out — a typical cellphone has enough power to reach a cell tower up to 45 miles away.
It’s more about the angles of the signals and how the towers receive and transmit those signals.
Take a look at the image below and that might give you an idea of the direction the signals typically go out. As you can see, it is more of a lateral transmission than vertical.
So when flying 35,000 feet above these towers, it makes sense that the signals would not be properly received.
However, when flying at much lower altitudes (some say around 2,000 to 8,000 feet), it sounds like much more of a possibility that phones in a plane could ping these towers.
Protect flight controls
It was once believed that cellular phone transmission could affect the flight controls like the navigation systems and therefore create a major flight safety risk.
That risk may have been more prevalent with older technology with unshielded wiring but it seems this risk on modern planes may be overblown.
According to the North Carolina Consumers Council (NCCC), there are no proven cases of cellular phone transmission interfering with a navigation system.
It’s said that the shielded wires in the cockpit now should prevent those radio waves from penetrating and causing issues.
But there are still a couple of concerns.
One, it’s worth noting that shielding can degrade over time.
Also, with phones always rapidly evolving, it can be hard to predict exactly how new devices could affect flight control systems.
So it seems that while modern planes are more equipped to deal with lots of electronics, there still may be some room for concern in some cases.
The biggest inconvenience these days might be cellular signals interfering with communications between the pilots and air traffic control.
The cell signals could cause distracting noise in the headsets of the pilots which could result in miscommunications.
And that could obviously be a major problem.
The noise in the pilots headset theory is challenged by a lot of people who state this type of interference is extremely rare or potentially even nonexistent with today’s tech.
The evidence is a bit mixed, but I think the conclusion here is that older aircraft and older cellular devices posed a much greater risk when it came to interference from cell signals.
That risk from cell signals is probably very low in modern times but due to all of the factors that would go into testing this and how quickly technology changes, it’s really hard to know for sure what that level of risk is at any given time.
Therefore, I would still err on the side of putting your phone in airplane mode just in case something unthinkable could happen.
What can you do in airplane mode?
When you put your phone into airplane mode, your phone may or may not disable three separate features.
The features that will be disabled include cellular transmission, Wi-Fi, and Bluetooth.
Airplane mode allows you to toggle Wi-Fi and Bluetooth back on if needed which allows you to still use Bluetooth headphones and connect to Wi-Fi on an airplane, for example.
I actually learned this the hard way years ago after unsuccessfully attempting to pair my Bluetooth headphones on a flight.
I went hours without any music or sound only to later find out that all I had to do was toggle my Bluetooth on to get it to work!
Wi-Fi is the exact same way.
Just toggle your Wi-Fi on and you can connect and even engage in text messaging and making Wi-Fi phone calls.
However, be aware that most airlines prohibit voice calls while flying, mostly because it can be super annoying to other passengers nearby.
A lot of smart phones like iPhones will remember the last configuration of your airplane mode to make things easier for you.
So if you enable Bluetooth while your phone is in airplane mode, it should be enabled the next time you put your phone in airplane mode.
What about GPS in airplane mode?
GPS functionality is a bit different from everything else mentioned.
Airplane mode disables the transmission from your device but GPS on your phone is not transmitting signals; it is receiving signals from satellites.
So, in theory, your phone could still register a GPS signal even when flying on a plane (some devices might disable GPS).
The problem is getting that signal through a high flying metal tube is not so easy.
In addition to that, the absurd speed at which planes fly can essentially confuse a lot of algorithms used by GPS software, making them struggle to pin point where you are.
This is why some people will prompt their phone to receive a GPS signal before boarding the plane — it will make it easier to track.
With your cellular data turned off, you also won’t have the benefit of assisted GPS which helps your phone receive a GPS signal in a timely manner (WiFi might be able to help).
So receiving a sufficient GPS signal on a plane is difficult and maybe even impossible.
However, if you are seated by the windows and you position your phone next to the plane window, a lot of times (with a bit of patience) you can still get a GPS signal.
If you look at your maps on your phone, you might see a little dot located on a “map” that looks more like a sea of blankness. And that is because data is required to populate your map.
But, if you were to have a map downloaded off-line and your phone received a GPS signal through the window, you should be able to see your position on a map, albeit with questionable accuracy.
Airlines with in-flight entertainment (seatback TVs or streaming) often have maps for you to see where you are so relying on your phone for a map view is not always necessary.
What happens if you don’t put your phone in airplane mode?
If you choose to defy the orders of putting your device in airplane mode, here are some of the outcomes that you might face.
Get a slap on the wrist or kicked off the plane…
If a flight attendant notices your phone is not in airplane mode, because you are yapping on the phone or because they just happened to glance over and see your screen (should be very rare), they’ll probably just request for you to put your phone in airplane mode.
This could amount to a polite request but it could also come off as an admonishment.
Basically, it could just be an embarrassing scene and other passengers may not appreciate that you may have put their safety “at risk” by being selfish.
In a worst-case scenario it might even land you on an airline’s no-fly list!
So it’s a good idea to avoid these situations when possible by just keeping your phone in airplane mode.
You could cause disruptions for the pilots
If it is true about pilots hearing static noise from cell signals in their headsets (which I do believe is the case), you could be interfering with the communications going to and from the person trying to navigate you safely from Point A to Point B.
Is that really something that you want to risk by keeping airplane mode off?
Could you cause a plane to crash?
It seems unlikely that you would directly interfere with plane navigation systems simply by keeping airplane mode off.
After all, if there was a real threat to airline safety from cell phone signals, it would be such a high national security concern that phones would not even be allowed to be turned on in planes.
The risk from a terrorist attack would just be way too high.
But as just discussed, cell phone signals can probably interfere with the pilots ability to communicate and hear instructions from air traffic control.
In a perfect storm scenario, it would not be impossible for something horrible to happen.
So while not putting your phone on airplane mode will not directly cause a plane to crash, it could contribute to a dangerous scenario under the worst of circumstances.
Get hit with a fine?
Although there are some reports that passengers could face a fine for not putting a phone in airplane mode, I struggled to find confirmed cases of passengers getting fined for not putting their phone in airplane mode.
It seems that if fines were being issued on a regular basis, that would not be the case.
But while you may not have to worry about getting a fine, you might still be out of pocket if you choose to leave airplane mode off.
How exactly is that the case?
If you don’t turn on airplane mode it’s possible that your device could connect to the in-flight roaming network and you could be billed several hundred dollars for usage!
Cell phone battery goes dead quicker
Not putting your phone in airplane mode means that it could keep working to connect with cell phone towers.
That could drain your battery very quickly.
When should you use airplane mode?
Obviously, when you are requested by flight attendants to put your phone in airplane mode you should comply.
But there are a handful of scenarios where airplane mode could come in handy.
Coming back in the country
Something that hardly anybody knows about or thinks about is the need for putting their phone in airplane mode when they are coming back in the country through customs.
The point of doing this is to prevent a customs agent from snooping through everything on your phone.
In case you were not aware, a customs agent can seize your phone and search all of its contents without needing a warrant or even suspicion.
The limitation is that they cannot access anything that is stored on the cloud. So if you were to exit out of your apps and put your phone into airplane mode, that would be the extent of anything a customs agent could inspect.
You’re unsure about roaming charges
Some phones can be a little bit confusing when it comes to roaming settings.
People don’t always know exactly what setting needs to be turned on or off and because of that they run the risk of getting hit with huge roaming charges.
Some people also just forget to disable roaming.
By putting your phone in airplane mode you can be guaranteed that you will not be subject to any unexpected roaming fees.
A lot of times whenever I have trouble getting reception I utilize airplane mode to to get me service.
This will help “reset” your phone to seek out cell phone towers and speed up the process for getting you service.
In my experience, this has been really handy when arriving in a new country. When my phone struggles to get service I simply put it in airplane mode and then take it back out and it often resolves the issue.
If you ever are running low on your battery one of the best ways to preserve it is to put your phone in airplane mode. You’d be surprised how quickly your battery can be drained when it’s attempting to get a signal.
Put your phone on airplane mode, dim your screen, and you just extended your battery life so that you can hopefully make it to your next charging session.
This can be extremely helpful when traveling or when out and about in remote places such as when you’re hiking.
When you need a break
When you just need a break from communication, it’s easy to just put your phone in airplane mode so that you won’t be bothered with phone calls, text messages, and emails.
This is also a refreshing thing to do when traveling.
Nothing is worse than getting hit with a work email when trying to enjoy the sights of a museum or an amazing dinner at sunset.
Airplane mode can be your solution for staying present in the moment.
Airplane mode is designed to disable transmission from your mobile devices.
While many people doubt or seriously question the necessity for it, it seems that in certain instances cell phones from planes can interfere with cellular data on the ground and also with the ability of pilots to clearly communicate and potentially even navigate.
Future innovation may resolve some of the issues and more studies might give us answers to the questions that remain about the disruption of cell phone use on a plane, but for now given what we know, I think it makes sense to keep our phones on airplane mode until we have more clarity on the potential effect of these devices.
Daniel Gillaspia is the Founder of UponArriving.com and creator of the credit card app, WalletFlo. He is a former attorney turned full-time credit card rewards/travel expert and has earned and redeemed millions of miles to travel the globe. Since 2014, his content has been featured in major publications such as National Geographic, Smithsonian Magazine, Forbes, CNBC, US News, and Business Insider. Find his full bio here.