ជិះយន្តហោះទៅ New York ឬ LA សប្តាហ៍ក្រោយ? ការចេញផ្សាយរបស់ FAA នៃ 1,500 5G NOTAMs មានន័យថាអ្នកអាចត្រូវបានពន្យារពេល

At 12 a.m. Thursday the Federal Aviation Administration began a massive drop of 1,500 notices to airmen (NOTAM) related to the commencement of 5G service next Wednesday. The NOTAMs range from simple advisories to prohibitions of precision instrument approaches at selected public-use airports that could result in delays, diversions and canceled flights.

The FAA’s guidance applies to airports within the 46 Partial Economic Areas in the U.S. that will see 5G service using the C-band. NOTAMs will likely still apply to a number of the 50 airports on the FAA’s list of airport locations with 5G buffer zones where 5G signals may be reduced in strength or not broadcast. The list includes most of the busiest commercial airports from coast to coast.

The NOTAMs are meant to address the risk of 5G interference with the radio altimeters that airplanes and helicopters rely on for low altitude flight, particularly in bad weather. I’ve recently detailed the technical and regulatory developments in previous articles here and here.

In a statement, the FAA said it is still “working to determine which radar altimeters will be reliable and accurate with 5G C-Band deployed in the United States.”

The Agency further explained that it “expects to provide updates soon about the estimated percentage of commercial aircraft equipped with altimeters that can operate reliably and accurately in the 5G C-Band environment. Aircraft with untested altimeters or that need retrofitting or replacement will be unable to perform low-visibility landings where 5G is deployed, as outlined in (NOTAMs) published at 0000 EST Thursday.”

The percentage of aircraft equipped with altimeters that the FAA determines អាចធ្វើបាន operate reliably and accurately in the 5G environment will be a key factor in the potential disruption to airline, private and business aircraft flights beginning next week.

The FAA has already sought to get ahead of likely pushback from the FCC and telecoms who have publicly criticized possible flight restrictions and the agreed to delay in 5G service by parsing their claims that operations in 5G environments in Europe have caused no disruptions.

In its “5G And Aviation Safety” webpage the FAA asserts that; “ Deployments of 5G technology in other countries often involve different conditions than those proposed for the U.S., including: Lower power level Antennas tilted downward to reduce potential interference to flights. Different placement of antennas relative to airfields. Frequencies with a different proximity to frequencies used by aviation equipment. The early stages of the 5G deployment in the U.S. will include mitigations that are partly similar to those used to help protect air travel in France. However, even these proposals have some significant differences.”

The Agency denotes these differences with its own graphic and the following points;

• Planned buffer zones for U.S. airports only protect the last 20 seconds of flight, compared to a greater range in the French environment.
• 5G power levels are lower in France. In the U.S., even the planned temporary nationwide lower power levels will be 2.5x higher than in France.
• In France, the government required that antenna must be tilted downward to limit harmful interference. Similar restrictions do not apply to the U.S. deployment.

The seriousness of the NOTAMs is evident in this specific notice for Los Angeles International Airport which emphasizes that takeoff and landing at LAX are “not authorized” except for aircraft using approved alternative methods of compliance (AMOCs).

The FAA has yet to approve an initial series of AMOCs but the National Business Aviation Association’s (NBAA) director for air traffic services and infrastructure, Heidi Williams, told aviation publication AINonline that airframers and avionics manufacturers are “aggressively working” on AMOC that could allow operators to supersede the notam directives.

This afternoon, the Airline Pilots Association International (ALPA) issued a forthright release that explained that ALPA experts are evaluating the just-released NOTAMs and reviewing the specific restrictions.

The ALPA says, “The NOTAMs prohibit aircraft from operating in poor weather conditions at more than 90 airports with passenger service, and even more airports with all-cargo service, across the nation—severely impacting operations across the entire aviation system.”

The FAA did not provide responses to questions this afternoon on how many more 5G NOTAMs it plans to issue prior to January 19, what NOTAMs it considers most restrictive or whether it anticipates significant air transport delays with these NOTAMs in effect.

The outlook for airline travel is thus uncertain, a delayed but long-anticipated reckoning of the clash between the FAA and aviation industry with the FCC and telecoms over 5G signals interference. The story will undoubtedly develop further in the next few days but if you’re flying to a major airport in bad weather next week, look out for delays.