The FAA information page on the 5G vs radio altimeter issue.
Note especially the visual explanation of the answer to the question “if it’s safe in other countries, why would it be a problem here? (linked in the text with the word ‘France’)
It strikes me that this is significantly better done than most government communications (whether federal, state, or local) regarding Covid.
10 thoughts on “A Pretty Decent Example of Government Public Communications”
Sorry/not sorry, but there’s not a single regulatory agency in the US that deserves the benefit of the doubt right now.
Personally, I’d just as soon not be in an airplane doing an ILS Category II landing (ceilings below 100 feet, autopilot is controlling the airplane, radio altimeter is the source for altitude information) without some better indication that the RA data corresponds to reality than the claim of some telco that “it’s okay because that’s how they do it in France.”
I happened across it a couple of weeks ago when somebody at Instapundit posted about the Emirates airline President complaining about the 5G rollout.
It’s a good example of how to obfuscate the fact that you got rolled by another agency that’s actually going to make the government money and “regulates” businesses with a lot more political clout. Sure our safety zone is smaller, with higher power transmitters, and no change in antenna facing but we can make a pretty graphic to explain why that’s ok!
Christopher B…the graphic is pretty clearly intended to explain why that is *not* okay…that the French example is not directly relevant to the US because of those differences.
It seems that about 90% of the US commercial fleet (weighted by passenger capacity, or not?) has now been determined to have radio altimeters which are selective enough to prevent these problems.
For the others, I guess the airlines can redeploy them to routes that don’t have the 5G problem at their endpoints, while waiting for delivery of improved RAs. Maybe some will try to recover against that avionics manufacturers, but I expect the answer would be, “Well, you look like a sophisticated purchaser, and the selectivity data is right there on the data sheet we gave you.”
I wonder what type altimeter Kobe Bryant’s helicopter had ?
David, I simply disagree. In a dispute between people who want to write ad copy that they cover 99.9% of the US population with 5G versus the people moving hundreds of passengers every day in defiance of gravity, my sympathies lie with the later.
You can point to the airlines not wanting to spend to upgrade their equipment. Everybody else is motivated by money, too. The telcos don’t want to put up an more towers than they have to, and the government via the FCC decided long ago to sell bandwidth that could potentially interfere with the altimeters.
I operate historical railroad equipment as a hobby. Even though we’re a small volunteer operation we still have to follow the same FRA rules as the longer railroads (we’re just as wide). The first line in our annual safety review is always “every procedure in that operating manual is written in blood”. Nobody goes to work planning to have an accident, and everybody thinks they are operating with a sufficient margin for safety until accidents and fatalities prove they weren’t.
I get the primary purpose of the FAA site is to explain their decisions and why they think the system is safe, and that graphic is just there to explain why airlines didn’t complain about the French installation. It still fairly screams that the US system is designed to work if the altimeter was built in spec, install correctly, maintained correctly, and is operating correctly in an environment where the transmissions are at the Goldilocks power level and not doing anything wonky due to atmospherics or some malfunction in the antenna. If, If, If, If, If.
The FAA page is not clearly not communicating as well as I thought it was. I totally agree with you, Christopher, that safety is of first importance. The purpose of the graphic, IMO, is not to just explain that the system is safe, but also to explain why the restrictive action had to be taken in the first place.
The FAA has no control over what the telcos do (other than bureaucratic maneuvering vis the FCC, that may or may not work)…but they can issue Airworthiness Directives prohibiting operations under what they think are unsafe conditions…and that is what they did in this instance. There were a large number of airports where operations requiring RAs were banned under poor weather conditions. Individual aircraft types have been gradually released from the ban based on research about their installed RAs and how well they deal with adjacent-frequency interference from telco towers.
The graphic is there, I think, to explain why the assertion that “it works in Europe, so why don’t the bureaucrats just let it work here?”…which I’ve seen in a lot of places, I believe including the WSJ…is not a relevant to such operations would be wise/safe in the US, specifically because of those differences.
I think the upshot will be that the airlines (and certain charter operators and private aircraft owners) will indeed have to spend money to upgrade their equipment. They may try to use their economic leverage to to get the equipment makers to cover *part* of the cost (“We have a big purchase coming up for avionics for our next 50 airplanes…you do want to stay on our good side, don’t you?”)
One more point on this. The frequencies used by radio altimeters are in the range 4.2-4.4 GHz, and the cellular frequencies are 3.7-3.98 GHz. That’s a pretty wide frequency gap in between at least 200 MHz. I assume the RA designers weren’t worried much about interference because nothing else was using nearby frequencies *at the time those systems were designed*.
Here’s a good writeup on some of the technicalities.
I’m confused, my takeaway from the graphics is that the French regulation is *much* more strict than the American regulation….and? Then what am I supposed to think? I don’t trust American regulatory agencies *at all*, like zero percent, so what am I supposed to do with that graphic, and the FAA page? After two years of idiocy and incompetence and outright lies from every public health agency, and after the 737 Max fiasco, where the FAA apparently put zero effort into investigating anything, why should I believe that the US has hit on the right regulations, and Europe has not?
The apparent European regulations on cell tower location make sense *with the current installed fleet of radio altimeters*..keep them further away, reduce the power, angle the antenna patterns downward. Given that US cell towers do not follow this pattern, the only alternatives are:
–make them move
–ban ALL flights to relevant airports in weather cases where RA is required
–ban flights SELECTIVELY based on the selectivity of specific RAs installed (and excluding signals 200MHz away doesn’t sound like a huge technical challenge)
Alternative 3 is what is actually being done. Might have been better, from a total cost and chaos-minimization POV, to keep the cell towers further away in the first place, but given that that didn’t happen, A3 is probably the best solution at this time.
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