AD 2023-12-13

This AD is effective June 21, 2023.

AD Docket: You may examine the AD docket at regulations.gov under Docket No. FAA–2023–0921; or in person at Docket Operations between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this final rule, any comments received, and other information. The address for Docket Operations is U.S. Department of Transportation, Docket Operations, M–30, West Building Ground Floor, Room W12–140, 1200 New Jersey Avenue SE, Washington, DC 20590.

Brett Portwood, Continued Operational Safety Technical Advisor, COS Program Management Section, Operational Safety Branch, FAA, 3960 Paramount Boulevard, Lakewood, CA 90712–4137; phone: 817–222–5390; email: operationalsafety@faa.gov.

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to supersede AD 2022–05–04, Amendment 39–21955 (87 FR 10299, February 24, 2022) (AD 2022–05–04). AD 2022–05–04 applied to all The Boeing Company (Boeing) Model 737–100, –200, –200C, –300, –400, –500, –600, –700, –700C, –800, –900, and –900ER series airplanes, except for Model 737–200 and –200C series airplanes equipped with a certain flight control system. The NPRM published in the Federal Register on May 3, 2023 (88 FR 27725). The NPRM was prompted by a determination that radio altimeters cannot be relied upon to perform their intended function if they experience 5G C-Band interference, and a determination that, during approach, landings, and go-arounds, as a result of this interference, certain airplane systems may not properly function, resulting in increased flightcrew workload while on approach with the flight director, autothrottle, or autopilot engaged.

In the NPRM, the FAA proposed to retain the AFM revisions required by AD 2022–05–04 until June 30, 2023. On or before June 30, 2023, the FAA proposed to require replacing those AFM revisions with limitations requiring the same procedures for dispatch or release to airports, and approach, landing, and go-around on runways, at all airports for non-radio altimeter tolerant airplanes. For radio altimeter tolerant airplanes, the FAA proposed to allow the procedures at 5G CMAs as identified in an FAA Domestic Notice. The FAA proposed this AD to address 5G C-Band interference that could result in increased flightcrew workload and could lead to reduced ability of the flightcrew to maintain safe flight and landing of the airplane.

The FAA provided the public with an opportunity to comment on the proposed AD and received comments from seven commenters. The following presents the comments received on the NPRM and the FAA's response to each comment.

Boeing, the Air Line Pilots Association, International (ALPA), and an individual supported the NPRM without change.

The supportive comments from ALPA included additional viewpoints without a suggestion specific to the AD or a request the FAA can act on. These comments are outside the scope of this AD.

Comment summary: FlyPersia Airlines commented that the issue dates referenced for AD 2022–23–12 and AD 2022–05–04 in the background section of the proposed AD are incorrect. The commenter stated that where “The FAA issued AD 2022–23–12 (86 FR 69984, December 9, 2021)” is stated, the correct date should be December 7, 2021; in same section where the proposed AD specifies “AD 2022–05–04 (87 FR 10299, February 24, 2022),” the commenter stated the correct date should be February 16, 2022.

FAA response: The dates quoted by the commenter are within the parenthetical citations for referencing documents published in the Federal Register by volume, page, and publication date. These dates represent the dates each AD published in the Federal Register. The December 7, 2021, and February 24, 2022, dates the commenter referenced are the issuance dates specified in the signature block at the end of each AD ( i.e., the dates on which the ADs were issued by the FAA). No change to this AD is necessary because the citation dates are the correct publication dates.

Comment summary: Southwest Airlines and American Airlines expressed concern regarding the compliance time for the proposed actions and requested the FAA revise the AD to provide a minimum of 30 days from the effective date of the AD.

FAA response: The FAA understands the commenters' concerns and made every effort to publish this AD as soon as possible. After refraining from operating at their FCC-authorized levels for a year and a half, wireless companies are now able to operate at higher levels, yet still not at the levels authorized. Specifically, wireless companies expect to operate their networks in urban areas with minimal restrictions due to the completion of retrofits. Additionally, the FAA anticipates 19 additional telecommunication companies will begin transmitting in the C-Band after June 30, 2023. Although the FAA continues to work with the companies that intend to transmit in the 3.7–3.98–GHz band near 5G CMAs, the FAA has no agreement with those companies to provide the FAA with tower locations and other information necessary to support the current NOTAM/AMOC process. Therefore, the FAA will not be able to extend the June 30, 2023, date.

Comment summary: Aviation Partners Boeing stated that installing winglets under supplemental type certificate (STC) STC01219SE and STC ST00830SE on applicable Boeing models does not affect accomplishment of the actions specified in the proposed AD.

FAA response: The FAA agrees. The FAA has not changed this AD in this regard.

The FAA reviewed the relevant data, considered any comments received, and determined that air safety requires adopting this AD as proposed. Accordingly, the FAA is issuing this AD to address the unsafe condition on these products. This AD is adopted as proposed in the NPRM.

The FAA considers this AD to be an interim action. Once the Technical Standard Order (TSO) standard for radio altimeters is established, which will follow the existing international technical consensus on the establishment of the minimum operational performance standards (MOPS), the FAA anticipates that the MOPS will be incorporated into the TSO. Once a new radio altimeter TSO is developed, approved, and available, the FAA might consider additional rulemaking.

Section 553(d) of the Administrative Procedure Act (APA) (5 U.S.C. 551 et seq.) requires publication of a rule not less than 30 days before its effective date. However, section 553(d) authorizes agencies to make rules effective in less than 30 days when the agency finds “good cause.” Radio altimeters cannot be relied upon to perform their intended function if they experience interference from wireless broadband operations in the 5G C-Band. This interference can cause other airplane systems to not properly function, resulting in increased flightcrew workload while on approach with the flight director, autothrottle, or autopilot engaged. To address this unsafe condition, the actions required by this AD must be accomplished before the compliance date of June 30, 2023. The FAA based this date on the changes to the 5G C-Band environment beginning on July 1, 2023. These changes include increased wireless broadband deployment and transmissions closer to the parameters authorized by the FCC. The earlier operators learn of the requirements in this AD, the earlier they can take action to ensure compliance. An effective date less than 30 days would ensure the AD is codified earlier, thereby increasing awareness of its requirements. Therefore, the FAA finds that good cause exists pursuant to 5 U.S.C. 553(d) for making this amendment immediately effective.

The cost information below describes the costs to change the AFM. Although this AD largely maintains the AFM limitations currently required by AD 2022–05–04, the FAA acknowledges that this AD may also impose costs on some aircraft operators from having to change their conduct to comply with the amended AFM. However, the FAA lacks the data necessary to quantify the costs associated with aircraft operators changing their conduct.

The FAA estimates that this AD affects 2,328 airplanes of U.S. registry. The FAA estimates the following costs to comply with this AD:

Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. Subtitle VII: Aviation Programs, describes in more detail the scope of the Agency's authority.

The FAA is issuing this rulemaking under the authority described in Subtitle VII, Part A, Subpart III, Section 44701: General requirements. Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.

This AD will not have federalism implications under Executive Order 13132. This AD will not have a substantial direct effect on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government.

For the reasons discussed above, I certify that this AD:

(1) Is not a “significant regulatory action” under Executive Order 12866,

(2) Will not affect intrastate aviation in Alaska, and

(3) Will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act.

Accordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows:

1. The authority citation for part 39 continues to read as follows:

2. The FAA amends § 39.13 by:

a. Removing Airworthiness Directive (AD) 2022–05–04, Amendment 39–21955 (87 FR 10299, February 24, 2022), and

b. Adding the following new AD: