FAA Provides Update on 5G C-Band Implementation and Altimeter Retrofit Deadline
The Federal Aviation Administration (FAA) provided AAAE and other industry stakeholders a briefing on the latest with 5G C-Band implementation across the National Airspace System (NAS) and today's deadline for airlines to retrofit their airplanes' radio altimeters or be restricted from conducting low-visibility operations. We wanted to provide an update and an overview of what airports should know as the industry shifts into a significantly different operating environment on July 1.
We have developed a series of FAQs that are outlined below.
What is the current 5G C-Band operating environment? In December 2021, FAA found that radio altimeters could not work properly if they experience 5G C-Band signal interference and issued an airworthiness directive for all transport and commuter category airplanes. The directive prohibited airplanes equipped with these altimeters from conducting certain low-visibility operations at airports identified by FAA through Notice to Air Missions (NOTAMs). However, in January 2022, Verizon and AT&T agreed to voluntarily implement mitigation measures around airports, making it easier for manufacturers to demonstrate to FAA that their altimeters were not susceptible to potential interference and allowing operations to continue uninterrupted.
For the past approximately 18 months, the December 2021 airworthiness directive has created a system where FAA has been issuing (a) NOTAMs to identify the airports where certain low-visibility operations are prohibited absent express approval by FAA (because of the presence of potential 5G C-Band signal interference) and (b) case-by-case approvals for each airplane model, called AMOC approvals, which outline specific airports and runways that may be used by a specific airplane. After today, this system will not exist, as further described below.
Why are there changes coming on July 1? Since early 2022, Verizon, AT&T, and other telecommunication companies that have rights to the 5G C-Band have put significant pressure on FAA and the Biden Administration to require airlines to retrofit their airplanes with C-Band-resistant altimeters as soon as possible. Upgrading altimeter performance would allow the telecoms to remove some mitigation measures and provide better coverage to their customers. This has been the primary driver for change. However, FAA also recognizes that issuing thousands of NOTAMs and case-by-case approvals for each airplane is not a sustainable approach in the long term.
What changes will be made to the 5G C-Band operating environment on July 1? On July 1, the December 2021 airworthiness directive will be replaced by a new directive that was issued on May 26. Under the May 26 order, FAA will no longer allow airplanes with altimeters that have not been retrofitted-or meet specific performance standards-to conduct low-visibility operations after June 30. Setting standards for altimeters that are used in low-visibility operations ensures that the airplane will not be susceptible to 5G C-Band signal interference. In addition, it allows Verizon and AT&T to increase the power levels of their 5G C-Band antennas and remove some other mitigation measures that were implemented in January 2022.
What do you mean by 'low-visibility operations'? Unless the airplane is equipped with an altimeter meeting certain performance standards, FAA's May 26 directive prohibits the following types of operations after June 30: (1) ILS Instrument Approach Procedures (IAP) SA CAT I, SA CAT II, and CAT III; (2) automatic landing operations; (3) manual flight control guidance system operations to landing/head-up display (HUD) to touchdown operation; and (4) the use of enhanced flight vision system (EFVS) to touchdown under Part 91. These have been commonly referred to as 'low-visibility operations.'
What portion of the airlines' fleet is equipped with altimeters that allow them to conduct low-visibility operations with no restrictions? FAA has indicated that 85.6% of the domestic fleet (6,102 of 7,128 airplanes) and 66.7% of the international fleet (2,387 of 3,580) have been retrofitted or are equipped with suitable altimeters that meet the minimum performance standards. These numbers are increasing daily as airlines continue to retrofit their airplanes.
If an airplane has been retrofitted or is equipped with an altimeter that meets FAA's performance standards, are they limited to specific airports or runways where they may operate? No, after June 30, FAA's process of issuing case-by-case approvals, called AMOC approvals, for each airplane model will be eliminated. If the airplane is equipped with a suitable altimeter, that airplane can conduct low-visibility operations at any airport in the contiguous United States.
Will any changes be made to the 5G NOTAMs that have been issued over the past 18 months? Yes, FAA is overhauling the NOTAMs pertaining to 5G C-Band. As of this month, FAA had issued 2,866 Airport NOTAMs, 65 Airspace NOTAMs, and 921 IAP NOTAMs that included 5G C-Band related restrictions. FAA began removing these NOTAMs beginning on June 29 at 0202Z.
FAA published 20 Air Traffic Control Center (ARTCC) NOTAMs and 115 IAP NOTAMs, with an effective date of June 29 at 0201Z. Airports may see these new IAP NOTAMs that are specific to their facilities. These NOTAMs are advisory in nature and remind operators that certain operations are prohibited unless the airplane is equipped with an altimeter that meets FAA's performance standards. We have been informed by FAA that these new NOTAMs will remain in place for the near term but will eventually be removed.
What is the likeliness of operational disruptions as a result of the June 30 deadline? During our briefing, FAA would not comment on the possibility of disruptions due to the June 30 deadline, instead deferring to individual carriers. In a WSJ article, however, Secretary of Transportation Pete Buttigieg warned that there is a 'real risk of delays or cancellations' and 'represents one of the biggest-probably the biggest-foreseeable problem affecting performance this summer.' We encourage airports to discuss potential impacts with their airline partners and keep us apprised of any notable disruptions. Any information will be helpful as we continue to work with FAA and our industry partners on the issue.
What should airports expect on the 5G C-Band issue later in 2023 and beyond? Will this still be a problem? In the May 26 directive, FAA required any airplane conducting air carrier operations under Part 121 to be equipped with an altimeter that meets certain minimum performance standards by February 1, 2024. In other words, the airplane must be equipped with an appropriate altimeter or it cannot be used for any Part 121 operation after that date. The remainder of 2023 will be focused on ensuring that the entire domestic and international fleet is retrofitted.
Beyond 2023, all the telecommunication companies with rights in the 5G C-Band have agreed in writing to adhere to certain mitigation measures until January 1, 2028. According to FAA, the agreement allows FAA to protect SA CAT I, SA CAT II, CAT II, and CAT III approach operations without limitations. The agreement provides the aviation community with additional time to develop and implement more reliable radio altimeters that can withstand potential 5G C-Band interference after all mitigation measures are eventually removed.
