I’ll be the butthead and say it. So you have 200 Cell phones. 50 don’t give a damn. So, you are going to have interference. No matter what. Tell me why in the world Boeing, Airbus, etc., or the FAA, don’t mandate shielding à la mil spec. I understand your post, but it makes no sense. The issue exists, it will definitely not go away, but we muddle through?
The issue is caused by a lack of communication management by regulators and manufacturers. But even then, with the best policies and rules, we have nature. RFI (radio frequency interference) can arise from a multitude of sources. External sources include terrestrial communication towers, 5G base stations, improperly shielded electronic equipment, UAV activity and atmospheric phenomena such as solar flares or sporadic E-layer activity. Internally, onboard electronic devices, including malfunctioning avionics or improperly used passenger devices, can also contribute to interference. Natural sources, such as ionospheric activity or solar flares, can further degrade or distort signals in the VHF and UHF bands. All these things are present at all times so I find it difficult to ascribe cell phone usage as a major (or even minor) cause for static on the headphones. If passenger phones were the issue, then at all times the static would occur. But as our author tells us, the issue comes and goes. I’m betting the number of cell users onboard doesn’t vary much, so the cause(s) must be numerous and fleeting (the exception being broken equipment like a headset that has a loose wire). This was my nit to pick concerning the article - I don’t believe cell phones onboard cause the mentioned static. I think it is an old pilots tale because nobody has been able to reliably reproduce the issue. This paper speaks of the many problems in just identifying the source issues much less the corrective measures. https://www.mdpi.com/2079-9292/14/12/2483
Because you can’t just say “hey everybody, let’s switch all our ground equipment, and all the radios in all the airplanes around the world, to use different frequencies that won’t be affected by cell phones. Oh, and we have to do all of it - ALL of it - at once. And we need to make sure that whatever equipment we switch to has been vetted for safety and reliability.” It would be better to try to wean cell phones off troublesome frequencies, but by their nature they will likely never be interference free, and it would take many years. The closest we have to an easy solution is “everybody use airplane mode”.
No Sam, that’s silly. But what we could have done, starting in the late 1990’s when this was first identified as an issue by pilots, manufacturers, FAA and FCC was to begin hardening the electronics in aviation and requiring cell phones to manage “spectrum leakage” and poor communication hygiene. Paragraph (b)(5) of 14 CFR 91.21 permits airlines to determine if devices can be used in flight. So, it would seem that the individual airlines have decided that interference is acceptable (or they make more money). My point is that this has been a known issue for over 20 years and technological fixes have been known and available and in 2025 this is an issue that could have been resolved.
Hardening isn’t a magic bullet. I would lay the blame at the feet of the FCC and all the lobbyists who have been recarving spectrum allocation, aggressively playing down interference issues, packing things ever closer together, ignoring the fact that the technological barriers to building a radio with near-zero frequency spillover are formidable. Everybody’s been getting bit by this, not just aviators; there are satellites in geostationary orbit right now that have had some transponders disabled because they’re no longer permitted to use spectrum they were built for. Any fix could realistically only be done with spectrum isolation and reallocation, and political/monetary considerations make that not very realistic either. The airlines can’t do a whole lot by themselves.
I always switch my phone OFF prior to boarding a flight & only switch it back on again when I’m safely in the arrivals terminal at my destination airport, just to play it safe. If anyone tries calling, texting or emailing me during my flight, it can wait until I land before I’ll respond to it.
…I saw the team on the tv show Mythbusters tackle the myth about cell phone usage on a plane & if it would affect the plane’s performance & you pretty much covered every point they raised & found out when they experimented with it.
Excellent explanation. Thank you. I would presume it hurts your battery life to have your phone constantly searching for signal while in flight so practically it just makes sense. Now why is my detachable keyboard on my iPad such a safety threat on take off and landing?! 😀
Thank you!
Thanks for the explanation. It sure would be helpful if more travelers understood the reason.
I’ll be the butthead and say it. So you have 200 Cell phones. 50 don’t give a damn. So, you are going to have interference. No matter what. Tell me why in the world Boeing, Airbus, etc., or the FAA, don’t mandate shielding à la mil spec. I understand your post, but it makes no sense. The issue exists, it will definitely not go away, but we muddle through?
The issue is caused by a lack of communication management by regulators and manufacturers. But even then, with the best policies and rules, we have nature. RFI (radio frequency interference) can arise from a multitude of sources. External sources include terrestrial communication towers, 5G base stations, improperly shielded electronic equipment, UAV activity and atmospheric phenomena such as solar flares or sporadic E-layer activity. Internally, onboard electronic devices, including malfunctioning avionics or improperly used passenger devices, can also contribute to interference. Natural sources, such as ionospheric activity or solar flares, can further degrade or distort signals in the VHF and UHF bands. All these things are present at all times so I find it difficult to ascribe cell phone usage as a major (or even minor) cause for static on the headphones. If passenger phones were the issue, then at all times the static would occur. But as our author tells us, the issue comes and goes. I’m betting the number of cell users onboard doesn’t vary much, so the cause(s) must be numerous and fleeting (the exception being broken equipment like a headset that has a loose wire). This was my nit to pick concerning the article - I don’t believe cell phones onboard cause the mentioned static. I think it is an old pilots tale because nobody has been able to reliably reproduce the issue. This paper speaks of the many problems in just identifying the source issues much less the corrective measures. https://www.mdpi.com/2079-9292/14/12/2483
Because you can’t just say “hey everybody, let’s switch all our ground equipment, and all the radios in all the airplanes around the world, to use different frequencies that won’t be affected by cell phones. Oh, and we have to do all of it - ALL of it - at once. And we need to make sure that whatever equipment we switch to has been vetted for safety and reliability.” It would be better to try to wean cell phones off troublesome frequencies, but by their nature they will likely never be interference free, and it would take many years. The closest we have to an easy solution is “everybody use airplane mode”.
No Sam, that’s silly. But what we could have done, starting in the late 1990’s when this was first identified as an issue by pilots, manufacturers, FAA and FCC was to begin hardening the electronics in aviation and requiring cell phones to manage “spectrum leakage” and poor communication hygiene. Paragraph (b)(5) of 14 CFR 91.21 permits airlines to determine if devices can be used in flight. So, it would seem that the individual airlines have decided that interference is acceptable (or they make more money). My point is that this has been a known issue for over 20 years and technological fixes have been known and available and in 2025 this is an issue that could have been resolved.
Hardening isn’t a magic bullet. I would lay the blame at the feet of the FCC and all the lobbyists who have been recarving spectrum allocation, aggressively playing down interference issues, packing things ever closer together, ignoring the fact that the technological barriers to building a radio with near-zero frequency spillover are formidable. Everybody’s been getting bit by this, not just aviators; there are satellites in geostationary orbit right now that have had some transponders disabled because they’re no longer permitted to use spectrum they were built for. Any fix could realistically only be done with spectrum isolation and reallocation, and political/monetary considerations make that not very realistic either. The airlines can’t do a whole lot by themselves.
I always switch my phone OFF prior to boarding a flight & only switch it back on again when I’m safely in the arrivals terminal at my destination airport, just to play it safe. If anyone tries calling, texting or emailing me during my flight, it can wait until I land before I’ll respond to it.
…I saw the team on the tv show Mythbusters tackle the myth about cell phone usage on a plane & if it would affect the plane’s performance & you pretty much covered every point they raised & found out when they experimented with it.
Thank you for that candid view on what keeping your phone on means, airplane mode on it is! ☺️
Excellent explanation. Thank you. I would presume it hurts your battery life to have your phone constantly searching for signal while in flight so practically it just makes sense. Now why is my detachable keyboard on my iPad such a safety threat on take off and landing?! 😀