back to article 5G C-band rollout at US airports slowed over radio altimeter safety fears

America's aviation watchdog has said the rollout of 5G C-band coverage near US airports won't fully start until next year, delaying some travelers' access to better cellular broadband at crowded terminals. Acting FAA Administrator Billy Nolen said in a statement this month that its discussions with wireless carriers "have …

  1. Inventor of the Marmite Laser Silver badge

    "the FAA said it has a job to do: maintain the US' reputation as having the safest aviation "in the world.""

    And there was me thinking Boeing (experts in lithospheric braking) was Americn.

    1. Xalran

      reputation ? it's already gone to hell.

      I think that after the 737Max debacle and the fact that they were the last country in the world to ground them the FAA reputation when it comes to safety ( or lack of thereoff ) has no need to be maintained.

      They need to rebuild it from the bottom of abyss that scandal dumped them.

  2. HildyJ Silver badge
    Facepalm

    I hate when AT&T is right

    Another thing to blame on the beancounters. If the airlines had purchased compliant gear in the first place, there would have been NO problem; then or now.

    But the beancounters reasoned that the rest of the band was unused (at the time) and adding filters to their altimeters cost money. Cha-ching!

    It's too bad the FAA can't require airline accountants to fly on non-compliant planes.

    1. Paul Hovnanian Silver badge

      Re: I hate when AT&T is right

      "filters and replacement units for the mainline commercial fleet should be available on a schedule that would permit the work to be largely completed by July 2023"

      What exactly do they mean by "should be"? Designed? Tested? Manufacturing capacity allocated and parts supplies secured? Resources available to retrofit the aircraft fleet? Or is this more of a hopeful "should"?

      Maybe the FCC shouldn't have sold a slice of the guard band to the telecoms. And now they "should" pay them back for bandwidth they they may never be permitted to use. Garmin has expressed concern about the possibility of 5G interference with their state of the art, newly designed equipment (never mind all the old stuff in use for decades). And their radio altimeters are used in helicopters for things like search and rescue or life flights to hospitals. Not something that can be confined to cell sites near airports.

    2. Anonymous Coward
      Anonymous Coward

      Re: I hate when AT&T is right

      The equipment was compliant when it was fitted in the 1980s. The aircraft in question are mostly 737 varients and 5G wasn't a thing back then. Aircraft radio altimeters have to deal with a lot of distortion and frequency shift from the various things the signals bounce off of on the ground, so they deliberately have fairly wide band filters. Radar is not nearly as simple as "you transmit on frequency X, so you filter for exactly frequency X on the response".

      1. Xalran

        Re: I hate when AT&T is right

        yes but the affected 737 radio altimeters are known to use sucky components... it's not the wide band filter itself that's the issue... it's the fact that the components used are beyond accepted tolerances.

        put in simple term : when a 1% tolerance 100K Ohm resistor should have been used a 20% one has been put....

        So for 100000 :

        - 1% is 99900 ohm to 101000.

        - 20% is 98000 ohm to 120000

        the difference should be obvious.

  3. Matthew Brasier

    frankly unlikely to have an effect on airline safety

    Unfortunately "frankly unlikely" is not good a good enough margin of error for filling an aluminum tube full of people, hurling it through the air, then trying to land it precisely on a 40ft wide strip of tarmac in dense fog with a 40kt crosswind.

  4. Xalran

    The Fun is

    Japan has a C-Band 5G that goes to 4.1Ghz and there's been no issue there.

    ( they just made sure the main lobe from the antenna was not pointing down a landing strip )

    Europe has the same C-Band... and there's been no issue there.

    ( nothing was done here... because of the EU power limitation in mobile phone antenna emissions already in place since 2/3G )

    So the FAA twisted panty from my point of view is just a knee jerk reaction after the 737Max Debacle ( and they probably have a few other skeletons in the closets waiting to explode ) and the fact that US Airlines fly old planes bought on the cheap.

    1. Anonymous Coward
      Anonymous Coward

      Re: The Fun is

      This is not correct - the FAA proposed the same solution that is used elsewhere - don't position C-band base stations near airports (note that airports don't necessarily have 1 approach route, so its about a radius from the airport). The FCC rejected that because they want to provide C-band coverage in airports and town centres near airports, and because the FCC was lazy about planning 5G rollout on the assumption that they could just C-band all the things.

      1. Xalran

        Re: The Fun is

        Except that it's incorrect C-Band is used in airports all around the world.

        True, they did some adaptation ( 500m distance between the strip and the antenna along with cell orientation in Japan for example, cell orientation and limited use of power in transmission in Europe. )

        The FAA just went knee jerk because it blew up in USA after the rest of the world had already implemented other measures that didn't raise any concern from the Air Regulators there and they **had to be seen doing something** after the 737Max Debacle.

        As for approach routes... you don't land sidewise on a landing strip, so it's from either long end, even with an airport that has several set of strips most of the time they are parrallel, and if they are not there's 4 to 6 approach vectors, hell even 8 at worst where adaptation could be used.... And I'm not even talking of the range... C-Band propagation is poor, if dots are used indoor the signal won't even be available on the planes. So with a good planned coverage, the signal will be inexistant beyond the ramp.

POST COMMENT House rules

Not a member of The Register? Create a new account here.

  • Enter your comment

  • Add an icon

Anonymous cowards cannot choose their icon

Other stories you might like

Biting the hand that feeds IT © 1998–2022