01.18.22

Failing At Analysis

Posted in Aeronautical, AT&T, Operators, Regulatory, Services, Spectrum, Verizon at 10:45 pm by timfarrar

What on earth has gone wrong in the C-band rollout that has led to hundreds if not thousands of planes now being grounded? That’s the question that so far the news reports seem to have failed to get a grip on, given the complex technology and difficulty in interpreting what is going on behind the scenes between the FAA, FCC and wireless companies.

On January 4 a deal was announced between the FAA and the wireless companies to delay the rollout by two weeks in exchange for DoT and FAA agreeing that they “will not seek or demand any further delays of C-Band deployment, in whole or in part”. The FAA also committed that it would “work to issue AMOCs as filed by aviation stakeholders to allow for operation of aircraft to the extent permissible.”

The FAA is issuing two forms of notices to deal with the possibility of interference from 5G. The first of these is the NOTAM (Notice To Air Missions) for a specific airport, which sets out constraints on aircraft operations, such as restrictions on use of particular flight paths during bad weather. The second is the AMOC (Alternative Means Of Compliance) which allows certain altimeters (and therefore the specific aircraft types which carry them) to be exempt from these flight path restrictions if the FAA’s analysis has shown that the altimeter type is “high performing” (i.e. resilient to the possibility of interference).

What appears to have happened in the last two weeks is that the FAA has failed to issue as many AMOCs as had been expected and therefore a very large number of aircraft remain subject to the NOTAM restrictions. As of Tuesday, the FAA had only approved two types of altimeter, which account for “about 45% of the US commercial aircraft fleet” and “include Boeing’s 737, 747, 757, 767, MD-10 and MD-11 and the Airbus A310, A319, A320, A321, A330 and A350.” This leaves more than half of the US fleet subject to restrictions, including most regional and wide body jets, notably Boeing’s 777, 787 and 747 aircraft.

Over the weekend we heard stories, based on FAA briefings, about new constraints on 787 operations because “during the two-week delay in deploying new 5G service, safety experts determined that 5G interference with the aircraft’s radio altimeter could prevent engine and braking systems from transitioning to landing mode, which could prevent an aircraft from stopping on the runway.”

But the FAA appears to have failed to complete its analysis of the 777 and 747 during this period, and in what seems to have been an attempt to force the FAA to address the issue, Boeing released an advisory to airlines on Monday evening covering the 777 and 747-8 which “recommends operators do not operate 777 aircraft on approach and landing to U.S. runways” unless there is an alternative means of compliance. This language presumably means that Boeing believes that these altimeters should be approved through the AMOC process, but the FAA has failed to act. As a result, international airlines are now cancelling flights to the US on Wednesday or rearranging them to use other aircraft including the 787 and A380.

One obvious question (even ignoring the delays in taking action before January 3) is why the FAA has been so slow to make the expected progress over the last two weeks. Is it sheer incompetence? Or did the FAA think it was going to be able to extract a better deal from the wireless carriers, with a new and permanently lower signal level, as some aviation experts think could happen? Certainly the FAA now appears to have abandoned its commitment not to demand “further delays of C-Band deployment” and instead secured an indefinite delay to deployments near additional airports, instead of the maximum of 50 airports agreed to on January 3 (which is essentially a return to the demands from DoT on December 31). And the FAA maintained its hostility to C-Band operations even after signing an agreement not to try and delay them.

No wonder, even FCC Chair Rosenworcel, after keeping quiet during the January 3 negotiations, expressed frustration noting that “the FAA has a process in place to assess altimeter performance in the 5G environment and resolve any remaining concerns. It is essential that the FAA now complete this process with both care and speed.” Conversely, the DoT, who on January 4 celebrated the “the amazing [FAA] team for long hours over the holiday to minimize flight disruptions” are now conspicuously silent about the lack of progress over this most recent holiday weekend, with no commitment from the Secretary of Transportation to move quickly.

So how does this end? Will the FAA issue the AMOC approvals for the 777 and 747-8 on Wednesday before tens of thousands of Americans are stranded overseas, as the airline CEOs predicted on Monday? That seems to be what US airlines are betting on, at least for now. And what about regional jets, which account for most of the remaining aircraft, and whose representatives are complaining they have been left out of the agreement? In that case, disruption may be sporadic, since there is no grounding order and cancellations will be dependent on the weather, so things may not come to a head until the next major winter storm.

None of this looks good for the Administration and it certainly isn’t “great work by all involved” as the White House Chief of Staff suggested. However, it looks like the FAA will have to bear the lion’s share of the blame for what seems highly likely to be substantial disruption in air travel over the next few days and possibly much longer when it comes to regional jets.

UPDATE (Thu Jan 20): After the debacle on Tuesday, with the cancellation of 777 and 747-8 flights by multiple international airlines, it seems the FAA was embarrassed (or forced) into accelerating the issuance of AMOC approvals for additional altimeters, approving the 777 on Wednesday morning, and the number of altimeters approved and percentage of the US fleet covered has now grown very quickly:
Tuesday Jan 18: 2 altimeters and 45% of the US fleet
Wednesday Jan 19: 5 altimeters and 62% of the US fleet
Thursday Jan 20: 13 altimeters and 78% of the US fleet.

The result has been that most disruption has been avoided, although regional jets remain a concern, with some problems resulting from low visibility. However, the rapid pace of approvals, and the expectation from airlines that there won’t be “any material disruption going forward”, further discredits the FAA’s fearmongering over the weekend, not least because an AMOC has now been issued covering all 787 jets, which were supposedly the cause of greatest alarm. Suggestions that airlines would need to “swap out the altimeters” in a process lasting years and costing billions of dollars, also appear to be well wide of the mark.

At this point the consensus seems to be that this has been a crisis created by the FAA’s foot dragging, and the more AMOC approvals that are issued, the more obvious that becomes. So the biggest remaining question is whether and when the Secretary of Transportation will ask for the resignation of the FAA Administrator, who after all is a holdover from the last administration, and therefore will make a convenient scapegoat for this whole episode? However, it also shouldn’t go unnoticed that the reaction of the President (echoed by members of Congress) was to push “as hard as I can to have the 5G folks hold up” rather than calling out the incompetence and delaying tactics of the FAA.

UPDATE (Fri Jan 21): It seems like I was far too confident last night that the 5G problem is on its way to being solved, despite airline executives declaring that the doomsday scenario is over because “The technical experts that are working on it tell us it’s really not that complicated once they all are able to share information and work on it…So they seem encouraged that we’ll be able to address this in a way that allows for full deployment of 5G, including near airports.”

As described by the Regional Airline Association, the tests are conducted by manufacturers and then those plans are “submitted…to the FAA” who issue the AMOC. The airlines appear confident that those manufacturer tests show there will be no problems even after full deployment of 5G.

But the FAA’s statements appear to confirm that they are only issuing AMOCs approving altimeters to operate while the current 5G deployment restrictions remain in place: “The new safety buffer announced Tuesday around airports in the 5G deployment further expanded the number of airports available to planes with previously cleared altimeters to perform low-visibility landings.”

So it is perhaps no wonder Boeing is refusing to comment because they don’t want to get into a public shouting match with the FAA, despite the behind the scenes confrontation over the 777 at the beginning of this week outlined above. But you can be sure that many aviation interests are demanding that the restrictions continue permanently and the FAA is preparing for another showdown on July 5th, when the current six month period of restrictions is set to expire.

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