Back to Squawk list
  • 51

FAA To Take Regulatory Action Over 5G Altimeter Interference

The FAA plans to issue a Special Airworthiness Information Bulletin and an Airworthiness Directive in coming days concerning the rollout of 5G cellular phone service in 46 major metropolitan areas of the U.S. on Dec. 5, according to Reuters. ( More...

Sort type: [Top] [Newest]

Tim Dyck 12
When any industry decides to implement new technology it should be that industries responsibility to ensure it is safe to use that technology without interfering with others. The telecome industry should be responsible for keeping their equipment from interfering with others not the other way around.
w2bsa 13
It’s pretty simple really. Cheaply designed and constructed equipment will cause or receive interference. Well designed and constructed equipment will not receive nor cause interference. It’s the job of the FAA to insure that the equipment used aboard airplanes is well designed and constructed. It’s the job of the FCC to insure that each user of spectrum can function without interference. Although, the numbers don’t show it, there’s a large amount of spectrum between those two services. We’re talking billions of cycles per second here. Also, mobile telephone systems are designed to work toward the ground rather than up into the air where the telephone signals are basically useless.
Tim Dyck 6
There are a lot of aircraft with equipment that was more then adequate at the time of manufacturing. But now your expecting the owners of these aircraft to invest in newer and much more expensive equipment because some multi billion dollar telecoms isn’t willing to make their equipment safe for the aircraft industry. It should be up to the telecom companies installing their new equipment to ensure it doesn’t interfere with existing equipment in other industries.
Joe Keifer 5
I used to think that too but then the telephone calls from United Flight 93 on 9/11 changed my mind about how and where mobile phones work.
Colin Seftel 8
It is indisputable that calls were made from United 93 on 9/11 and this was documented by the FBI.

GTE Airfone systems were common then. Of the 37 phone calls placed from flight 93, 35 were placed on the Airfone system. This was traceable not only to the particular aircraft, but to a specific phone in a specific row on that aircraft. In 2001,
the dominant (but declining) cell phone system was the analog AMPS system at 850 MHz with up to 3 watts transmission power on the mobile side. The AMPS system had far greater range than today’s digital systems. The range on the ground was up to 25 miles. At altitude, this range is enhanced.

Digital cell systems can detect if your cell phone seems to be in an aircraft and will restrict your use of the cell phone in order to avoid cascading interference with cell phones on the ground. In 2001, this block did not exist for the AMPS system.

For those reasons phone calls were possible from Flight 93 but would not be possible today.
lynx318 4
This isn't about phones on planes, rather 5G phone towers interfering with altimeters of planes landing or taking off.
Rebel Helms -6
Well you should reevaluate that opinion my friend. Phones wouldn’t work that high in 2001 just a little idea of where I’m going with this comment. It wasn’t possible. The truth is, the technology to transmit cell phone signals from an airplane didn’t exist til 2003, when Qualcomm developed their patented 3G technology. The first CDMA test call was made in 2004 aboard an American Airlines MD-80 aircraft flying over Dallas. It was made by Qualcomm’s CEO to demonstrate the new 3G technology, with special permissions granted by the FAA.
Kairho Carroll 5
Back in those days, Airfones were on board many planes, often in convenient seat back locations. Reports based on FBI information show 35 calls were placed from Airfones on that flight.

Cell phone technology was not yet available nor needed.
Joe Keifer 4
Roger that. I was basing my opinion on that movie "Flight 93" that portrayed some of the calls being originated on cellular/mobile phones. It wouldn't be the first time that Hollywood got the facts wrong.
Craig Good 3
Maybe you think it wasn't possible but that doesn't change the fact that it happened.
Joe Keifer 3
I'm good with my opinion and thanks for yours!
N Walsh 0
Dead on with that comment. That whole story never held water.
D Rotten -7
Yes; you are CORRECT! There were NO 'phone calls' from airplanes that day.

[This comment has been downvoted. Show anyway.]

James Driskell 14
There was a lot of noise about frequency saturation before this came about but no one at the FAA or FCC was listening. Radar altimeters are important, 5G isn't.
ADXbear 5
How hell did this conflict get missed? Or tested with 5g phones.. sounds like many cities will have to drop 5g..
sparkie624 9
Very Easily, the FAA Was sleeping and the FCC Wasn't and didn't care! they wanted the Money for the Spectrum. Greed!
Colin Seftel 5
I disagree, the difference between the top of the 5G C-band and the bottom of the radalt band is 220MHz. The FCC's spectrum allocation is perfectly justifiable from an engineering perspective. No airworthy radalt could be affected, but the FAA are being ultra-cautious, as they should be.
Kairho Carroll 5
Please read the PPP linked by Forrest Phillips above: According to that, even a 10x larger guard band could still be detrimental.
mbrews 1
Thanks for the link, Kairho. Slide 15 shows the basic risk to Radar Altimeter being overwhelmed by high power 5G.

" ...Radar altimeters are inherently wideband systems, and currently have no requirements for front-end rejection—may be more susceptible to blocking than other types of receivers..."
bentwing60 2
James is spot on, "LightSquared" comes to mind, and replied to on another thread. It Was a big deal with a lot of big money invested and lost. And sparkie hits another homer!
dmedders -1
Government agencies not doing their jobs…SHOCKING.
Forrest Phillips 4
So this article talks about "potential" risks, etc. That made me wonder what studies had actually been done. A quick search yielded this interesting document:
Jeff Jones 3
Agreed the FAA should take action.
JSilva35 1
In HAM radio transmissions, the FCC requires the person transmitting the signal to make the correction to the interference, NOT THE PERSON RECEIVING THE SIGNAL. This is total B.S.
DGR Rathborne 1
question : other than the USA and Canada , are there any other countries have the same concern ? And if so what are they doing about it ? These are very serious concerns . But i don't have enough knowledge , to offer a comment . Can any one assist me ? Thank you ........DGR
Chris B -1
Why didn’t the FAA object to the FCC’s proposal to do this ?

Total FAA failure to recognize and see the big picture.

[This comment has been downvoted. Show anyway.]

Bandrunner 4
Back in your box, you.
Larry Iglehart 2
10/4 Bandrunner.Rebel is a pod.


Don't have an account? Register now (free) for customized features, flight alerts, and more!
This website uses cookies. By using and further navigating this website, you accept this.
Did you know that FlightAware flight tracking is supported by advertising?
You can help us keep FlightAware free by allowing ads from We work hard to keep our advertising relevant and unobtrusive to create a great experience. It's quick and easy to whitelist ads on FlightAware or please consider our premium accounts.