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Why do All Electronics Have to be Turned off for Takeoff and Landing?

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  • Originally Written By: A Kaminsky
  • Revised By: Phil Riddel
  • Edited By: Bronwyn Harris
  • Last Modified Date: 01 November 2016
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As the use of portable electronic devices (PEDs) has boomed, so have complaints about restrictions on their use, especially during airplane takeoff and landing. These regulations arose out of concern that radio emissions from PEDs might interfere with aircraft electronics systems. Takeoff and landing are critical times during a flight, and they require the crew’s full attention, constant communication with air traffic control and the correct functioning of all instruments. Opponents of these restrictions claim that the use of devices such as cell phones has not been shown definitively to have an effect on any operations of the aircraft. The Federal Aviation Administration (FAA) in the US and similar organizations in other countries have been taking the “better safe than sorry” approach.

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Regulations

As of 2013, FAA regulations state that cell phones are not to be used at any time during a flight, and most other PEDs, such as laptops, CD players and game machines, must be switched off during takeoff and landing. In most cases, the takeoff and landing periods are defined as while the airplane is below 10,000 ft (3,048 m). On average, an aircraft takes about 15-20 minutes to reach this altitude, so the restrictions only apply for two relatively short periods at the start and end of the flight. There are some devices that are exempt, including heart pacemakers, hearing aids and electric shavers, as these are known not to cause interference. The ban dates originally from 1988 and was intended not only to prevent radio interference, but also to avoid the possibility of injuries caused by PEDs flying around or passengers’ attention being distracted during safety demonstrations.

In August 2012, it was announced that the FAA was to reconsider its restrictions on the use of PEDs, although the ban on cell phone use would remain. A study group was set up to look into testing methods and determine which, if any, devices can be used safely. As of 2013, The FAA is awaiting the group’s recommendations.

Many modern airplanes have WiFi® systems that allow passengers to access the Internet via laptops and other devices. These systems are tested for compatibility with aircraft electronics and must be approved by the FAA. The making of calls using Voice-over-Internet-Protocol (VoIP) applications, however, is not permitted, in order not to cause irritation to other passengers.

Aircraft Electronic Systems

Airplanes contain a number of electronic systems to enable communication with the ground, assist with navigation and monitor the behavior of crucial components and equipment. These systems are collectively known as avionics. Many of them involve the transmission and receipt of radio signals and are therefore potentially susceptible to interference from devices that produce radio waves at similar frequencies. Radio frequency radiation can also induce electrical currents in wiring, so other avionics systems could be affected.

Avionics in modern airplanes are shielded from interference, but older planes that lack adequate screening may still be in service and, in any case, shielding cannot be comprehensive. The systems that use external antennae to receive signals are most at risk from interference as they are designed to pick up very weak signals and cannot be shielded. The aluminum frame of an aircraft can screen out radio waves, but there are gaps, such as the windows, through which interfering signals can pass and be picked up by antennae outside. The frame can also act as a resonant cavity, which amplifies signals from PEDs.

Portable Electronic Devices and Their Effects

All electrical equipment produces radio waves, whether this is intentional or not. Cell phones and devices connected to the Internet must do so to communicate with other devices. Perhaps less well known is the fact that CD and MP3 players, for example, also emit electromagnetic radiation at radio frequencies. PEDs have been shown to be capable of producing emissions through most of the radio spectrum used by aircraft systems. There is no proof that these can actually interfere with avionics, but there are a number of documented incidents, reported by pilots and other airline staff, that strongly suggest such interference.

There are a huge variety of portable electronic devices of various types and brands and checking the strength and frequencies of the emissions of each and every one is impractical. Although there is no conclusive evidence that PED emissions can interfere with systems in modern aircraft, there are too many unknowns for them to be considered safe for use at crucial times, such as takeoff and landing. While some devices, such as laptops, have built-in electronic shielding, this may deteriorate over time, get damaged or be removed and not replaced during an upgrade, so it cannot be guaranteed that they will not produce emissions. Since it is not feasible to check all individual PEDs for compatibility with aircraft systems, a ban on the use of all such devices below 10,000 ft (3048 m) is regarded as the most sensible option.

Cell phones transmit strong signals that can be received at great distances. This raises the possibility that they could interfere not only with aircraft systems, but also with ground-based communication at airports. This is the reason why their use is banned throughout a flight. Many modern cell phones have an “airplane” mode, which prevents calls being made, but allows some other functions to be used, such as playing games. Use of phones in this mode may be permitted, but it is left up to individual airlines.

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Discuss this Article

anon970208
Post 27

Most accidents occur either while takeoff or landing. If you are talking on the phone or listening to an Mp3 or a cd player, you aren't giving your full attention to the messages that are given by flight personnel. Missing vital information may be dangerous for you and other passengers.

anon345818
Post 26

It's a dumb rule and everybody knows it. It's outdated, unwarranted and it should be revoked.

anon339258
Post 25

This is just an example of bureaucratic inertia. No one really thinks that current electronic devices are going to cause a crash. However, because it is the current rule, someone must make the decision to change it. That person then is responsible if something happens. Consider the reverse: if we didn't have the current rule is there enough evidence to implement it?

anon329605
Post 24

If a person cannot discipline themselves to detach from an electronic device of any kind during a flight, then it's time to take their sorry, compulsive, sick carcass off the plane and find another mode of transportation. End of story.

anon320327
Post 23

Airlines say "keep your mobile devices switched off." Be a human. Think about the risk. Air travel is not similar to our roads. We don't know what will happen in the next minute. The cabin crew has to take care of you throughout the journey. Please don't panic during an emergency. Your mobile devices cannot save you. You can communicate with your loved one once you land.

anon317179
Post 22

Until such a time that the FAA and the airlines get out of the AM VHF/UHF scenario for communications and navigation, the restrictions will be maintained. Cell phones are digital and in the GHZ in frequency, whereas airplanes are broadcasting in old technology AM just above the FM broadcast band. the FAA is 30-40 years behind times and an agency that needs to get caught up to the 21st century. By the way, ERAM and NEXGEN are going to obsolete before they are even implemented.

anon308836
Post 21

It's just depressing that so many people complain about this rule, as if flying is something you're entitled to. Sure, you paid for the ticket, but by doing so you have agreed to their regulations and policies - so if you want to fly, suck it up. It's 20 minutes without your precious device. Who would've thought that is an outrageous request?

anon305822
Post 20

You know, once upon a time, hospitals demanded that all mobile phones be turned off when you entered the facility. Their rationale at the time: mobile technology could possibly interfere with the operation of life-saving devices. That's been over with for a long time now. I think, eventually, it will be a thing of the past on airlines, too.

anon304829
Post 19

Everyone of these long winded answers is either wrong or a waste of space. The answer is the airlines want your complete attention during the most critical parts of air travel in case anything goes wrong.

anon285909
Post 17

All airlines routinely turn a blind eye to the most commonly used electronic device - the modern wrist watch. It's battery powered, quartz controlled and ubiquitous. The next time you are challenged by a flight attendance to turn off your e-reader, just say that you will if he will. Demand he remove the battery from his watch before you turn off your electronic device. Then tell him to instruct the captain to do the same.

anon271683
Post 16

It is absolutely nothing to do with sending signals. It is all to do with evacuation safety. If an incident happens during takeoff or landing, all passengers must be able to hear what is being said, instead of sitting there with music playing and eyes closed. It is all down to reaction time and being able to evacuate within 90 seconds.

anon267986
Post 15

Here is one good reason that cell phones (not in flight mode) are really dangerous.

Read Aviation Herald and search for "shutting mobile phone". The Airbus (A321) nearly crashed....

If you are an Android user, try the Telphcon app on Google Play. That might save you one day.

anon255939
Post 14

To all of you who can't be without your precious devices for 10 - 15 minutes, please tell me:

1. How to determine conclusively which devices are totally safe?

2. How to monitor that only such devices are in use and all others are not.

3. Who is going to pay for the testing and the extra training and staff time it takes to properly monitor this?

I doubt if any of you are willing to pay a cent, either through higher fares or taxes to do this.

Suck it up and quit being such babies.

anon236670
Post 13

Here is the real proof there is no real threat:

If there was a real threat do you think the airline and government would rely on voluntary compliance by each passenger?

How do they know everyone has really turned their cell phone off? They don't. If cell phones were a real threat, they flight attendants would have some device to detect phones that were still turned on.

anon232229
Post 12

An excellent article. It points out that there is no evidence that there is any danger, but concludes that it's not unreasonable to sit silently for the few minutes that it might take to taxi and takeoff, under the most ideal circumstances imaginable, ignoring real-world delays. If it saves just one life, it's worth it! In fact, I think TSA should confiscate all electronic devices during the security check. After all, if one device can potentially cause a crash, imagine what an entire airplane full of terrorists could do with 300 iPods.

Also, the Department of Transportation needs to take this further. To wit:

Ban CD and DVD players in all cars. These devices contain lasers, and those lasers could

shine into the eye of a driver and cause an accident. It's not unreasonable to ask drivers to not listen to CDs, or kids not to watch DVDs in the back of the minivan, if it could save one life, is it?

Ban all mobile devices on Amtrak trains. Amtrak engineers routinely communicate with dispatchers, and if some electronic device could possibly interfere with those communications, the train could be involved in an accident.

Ban all electronic devices on our nation's mass transit systems, for the same reason.

Ban the use of mobile devices at airports, as those rogue signals could reach an airplane taxiing and cause the same catastrophic damage as someone on board using a Kindle.

Ban the use of electronic devices within a five-mile radius of all train tracks, highways and navigable waterways for the same reason.

Really, is it unreasonable to suffer these minor inconveniences if it could save just one life?

anon203914
Post 11

it is rubbish. paternalism at its best. Really, if you cannot design an aircraft to not be taken down by a 12 year old with a CD player, better leave it parked at the gate.

anon155869
Post 9

I can understand turning off devices that transmit some kind of signal, but what's wrong with an electronic device that doesn't send out any wireless signals such as a simple mp3 player? Leave me alone flight attendant!

anon146877
Post 8

What about the thousands of electronic devices that are being operated by the people within the airport? I'm guessing there is less risk due to the distance between the tower and passengers in the terminal. But again, there is some risk.

So how big is the risk with passengers' electronics affecting communications? Is it greater than the chance of the brakes or tires failing upon landing? And even if it did happen, what then are the chances that an actual catastrophic accident would occur? I think you have an extremely low probability of all examples above.

So this begs the question, is it worth the extremely small risk? I'm going to conservatively say that an average day has at least

1000 passengers that are business men/women and could conduct business in the 25 minutes of silence time. And then let's say they average 25 dollars an hour. You can see where I'm going with this. Every day we lose a significant amount of production time to electronic silence. And then throw in trying to quantify the entertainment or "baby crying avoidance" value of other passengers' devices.

I think the heavy cost outweighs the miniscule risk.

anon112008
Post 6

Amen to the elephant comment - further - to me the most comical aspect of this is that when it commercially serves the interests of the airlines "safety" rules can be modified or overlooked.

The risk of threatening interference from my 2.4Ghz wifi signal is heightened by my inability to pay the airline for its' use. When it is possible for this signal to be monetized it rapidly becomes "safe enough" when cruising.

Does anyone actually believe that if there were even the slightest evidence of interference while cruising or otherwise that use of such resources would be allowed?

How long until we can pay ten more dollars to avoid having our e-reading or mp3 reverie interrupted?

anon75734
Post 5

@anon75582: Check out the Subcommittee on Aviation Hearing on Personal Electronic Devices for a discussion on the subject --CD players are mentioned. The point of the article is that, while the chances of something happening like that are pretty slim, it is possible, so the FAA and the airlines take the safe route and say turn these devices off.

anon75582
Post 4

There is a significant difference between radio emitters (cell phones, radio transceivers, wifi antennae on laptops and handhelds) and relatively passive devices such as digital watches, simple mp3 players (not the wireless networking enabled ipods or zune etc), wireless-less handhelds and wireless-less ereaders.

The magnetic field generated by a device that does not have a radio transceiver is so low and so short range that no, they cannot interfere with anything in a modern airplane.

The claim that CD players could cause problems in pre-1984 jets needs some proof (a link to the study that found this, for instance. It's just an unsubstantiated bogus claim otherwise). Even in old 737s, no normal consumer electronic device without transmitter will generate an electromagnetic field powerful enough to cause even a minute current in a wire held only a few inches away from it.

anon64074
Post 3

My friend works for Jetstar in Australia (a discount airline owned in part by Qantas). He is the captain or co-pilot for them. He keeps his mobile phone on and in his pocket the entire time while flying.

It is well known that electronic devices pose no threat, however (as always) are cautious "just in case". Secondly, in the case of all electronic devices (legally manufactured or imported), they are tested to operate adequately with EMC emissions and are tested not to put out any unusual EMC emissions. This is the FCC/CE or Ctick certification.

In australia, there is A-tick which is for wireless devices/telecommunication devices. Items are designed not to interfere. If they could, they wouldn't pass

the expensive testing process. Lastly, back in the analog days of mobile phones it was possible to make a phone call (hopping towers at considerable speed), however it was impossible to track the caller for billing purposes.

Now, this sounds like total rubbish to me, but, if true, then it could also be a reason why mobile phones were banned. That info came from a Jet star trainer that trained air hostesses. Could be utter garbage, however the first two things I said were true.

anon56025
Post 2

Incorrect, anon47943 - the article does mention that "Signals from some electronic devices, such as portable CD players have been known to cause interference in the communications or navigation systems of older, pre-1984 jets". There is evidence, even if it's 25 years old.

Your examples are exaggerated, and in the case of elephants, absurd. Remember that most crashes occur on takeoff and landing, and keeping electronic devices off (not just in silent mode) not only ensures that radio waves are kept to a minimum, but means that in the event of an emergency, passengers would be able to actually hear the crew, something that would be rather difficult with earbuds or headphones.

While I agree that interference from electronic devices is

unlikely to ever occur, remember that airlines are commercial businesses, and can be sued. They are protecting their own assets - this way, if a crash occurs and it is determine that someone's device is at fault, the airline can say "Hey, we told them to turn it off."

Not the most noble of rules, but a necessary one for running a business.

anon47943
Post 1

After admitting that there is no evidence that these devices present a risk, the article concludes that "It is not unreasonable" to make us turn them off because it's only for a few minutes. By this logic, I could say that people should refrain from speaking during that same period, or from thinking about elephants. After all, it's not impossible that these things could cause harm, and it's only for a few minutes.

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