[Federal Register Volume 88, Number 118 (Wednesday, June 21, 2023)]
[Rules and Regulations]
[Pages 40065-40071]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-13156]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2023-0670; Project Identifier AD-2022-01427-T; 
Amendment 39-22463; AD 2023-12-05]
RIN 2120-AA64


Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: The FAA is superseding Airworthiness Directive (AD) 2022-03-
05, which applied to all The Boeing Company Model 747-8F and 747-8 
series airplanes and Model 777 airplanes. AD 2022-03-05 required

[[Page 40066]]

revising the limitations section of the existing airplane flight manual 
(AFM) to incorporate limitations prohibiting dispatching or releasing 
to airports, and approaches or landings on runways, when in the 
presence of interference from wireless broadband operations in the 3.7-
3.98 GHz frequency band (5G C-Band) as identified by Notices to Air 
Missions (NOTAMs). Since the FAA issued AD 2022-03-05, the FAA 
determined that additional limitations are needed due to the continued 
deployment of new 5G C-Band stations whose signals are expected to 
cover most of the contiguous United States at transmission frequencies 
between 3.7-3.98 GHz. This AD requires revising the limitations section 
of the existing AFM to incorporate limitations prohibiting dispatching 
or releasing to airports, and approaches or landings on runways, due to 
the presence of 5G C-Band interference. The FAA is issuing this AD to 
address the unsafe condition on these products.

DATES: This AD is effective June 21, 2023.

ADDRESSES: AD Docket: You may examine the AD docket at regulations.gov 
under Docket No. FAA-2023-0670; 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.

FOR FURTHER INFORMATION CONTACT: 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: [email protected].

SUPPLEMENTARY INFORMATION: 

Background

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 to supersede AD 2022-03-05, Amendment 39-21922 (87 FR 4150, 
January 27, 2022) (AD 2022-03-05). AD 2022-03-05 applied to all The 
Boeing Company (Boeing) Model 747-8F and 747-8 series airplanes and 
Model 777 airplanes equipped with a radio altimeter. The NPRM published 
in the Federal Register on May 3, 2023 (88 FR 27799). The NPRM was 
prompted by a determination that radio altimeters cannot be relied upon 
to perform their intended function if they experience interference from 
wireless broadband operations in the 5G C-Band, and a determination 
that this interference may affect other airplane systems using radio 
altimeter data, including the pitch control laws, including those that 
provide tail strike protection, regardless of the approach type or 
weather.
    In the NPRM, the FAA proposed to retain the AFM revisions required 
by AD 2022-03-05 until June 30, 2023. On or before June 30, 2023, the 
FAA proposed to require replacing those AFM revisions with limitations 
prohibiting dispatching or releasing to airports, and approaches or 
landings on runways, in the contiguous U.S. airspace for non-radio 
altimeter tolerant airplanes. For radio altimeter tolerant airplanes, 
the FAA proposed to allow the prohibited operations at 5G C-Band 
mitigated airports (5G CMAs) as identified in an FAA Domestic Notice. 
The FAA proposed this AD to address missing or erroneous radio 
altimeter data, which, in combination with multiple flight deck 
effects, could lead to loss of continued safe flight and landing.

Discussion of Final Airworthiness Directive

Comments

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

Support for NPRM

    Boeing and the Air Line Pilots Association, International (ALPA), 
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.

Request for Additional AMOC Relief

    Comment summary: All Nippon Airways (All Nippon) requested the FAA 
revise the proposed AD to allow AMOCs approved for AD 2023-10-02, 
Amendment 39-22438 (88 FR 34065, May 26, 2023) (AD 2023-10-02) as AMOCs 
for this AD.
    FAA response: The FAA does not agree. An airplane that is a radio 
altimeter tolerant airplane for purposes of AD 2023-10-02 will also be 
a radio altimeter tolerant airplane for purposes of this AD. However, 
because the hazards mitigated by AD 2023-10-02 are separate and 
distinct from the hazards mitigated by this AD, the FAA has determined 
that AMOCs approved for compliance with AD 2023-10-02 may not always be 
appropriate to address the unsafe condition specified in this AD. For 
this reason, operators with an approved AMOC for AD 2023-10-02 will 
need to request approval of it as an AMOC for compliance with this AD.

Request To Extend Compliance Time

    Comment summary: 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 commenter's concern 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.

Request for List of Compliant Radio Altimeters

    Comment summary: All Nippon requested the FAA clarify how to 
determine whether a radio altimeter (for example, LRA-900 P/N 822-0334-
004) corresponds to a radio altimeter tolerant airplane or non-radio 
altimeter tolerant airplane. An individual requested the FAA revise the 
AD to add the list of the part numbers for compliant radio altimeters 
(e.g., Collins LRA-900+ and THALES ERT-530R).
    FAA response: The FAA does not maintain a list of tolerant radio 
altimeters because the determination of a radio altimeter tolerant 
airplane must consider the installation details, which vary from 
airplane to airplane. The FAA has developed a policy statement that 
provides a means of compliance with this AD for all transport and 
commuter category airplanes and rotorcraft equipped with a radio 
altimeter. The FAA requested public comments on this proposed policy on 
May 8, 2023 (88 FR

[[Page 40067]]

29554). The proposed policy describes an acceptable framework and 
method for demonstrating that an airplane or rotorcraft is radio 
altimeter tolerant. The policy discusses compliance methods that should 
be applied to programs for type certificates, amended type 
certificates, STCs, and amended STCs. The proposed policy addresses how 
to assess 5G C-Band tolerance. Although most data submitted to 
demonstrate compliance in accordance with the FAA policy statement will 
be proposed by design approval holders, any person/entity can propose a 
method to demonstrate compliance.

Request To Clarify Restrictions at Non-CMAs

    Comment summary: All Nippon and an individual requested the FAA 
clarify why the proposed AD would prohibit radio altimeter tolerant 
airplanes from landing at non-5G CMAs after July 2023. All Nippon 
stated that there are many non-5G CMAs that are unaffected by 5G C-Band 
interference and operations should not be restricted at such airports.
    FAA response: The FAA disagrees. Boeing has not submitted any 
substantiating data that demonstrates the hazards addressed by this AD 
are adequately mitigated for radio altimeter tolerant airplanes at non-
5G CMAs.

Conclusion

    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.

Interim Action

    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.

Effective Date

    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 may affect 
other airplane systems using radio altimeter data, including the pitch 
control laws, including those that provide tail strike protection, 
regardless of the approach type or weather, which, in combination with 
multiple flight deck effects, could lead to loss of continued safe 
flight and landing. 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.

Costs of Compliance

    The cost information below describes the costs to change the AFM. 
Although this AD largely maintains the AFM limitations currently 
required by AD 2022-03-05, 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 347 airplanes of U.S. 
registry. The FAA estimates the following costs to comply with this AD:

                                                 Estimated Costs
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                                                                                     Cost per      Cost on U.S.
                Action                         Labor cost           Parts cost        product        operators
----------------------------------------------------------------------------------------------------------------
AFM revision (retained action from AD   1 work-hour x $85 per                 $0             $85         $29,495
 2022-03-05).                            hour \1\ = $85.
New AFM revision (new required action)  1 work-hour x $85 per                  0              85      \2\ 29,495
                                         hour = $85.
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\1\ The labor rate of $85 per hour is the average wage rate for an aviation mechanic.
\2\ The estimated cost for this revision would not constitute a significant economic impact (even for small
  entities) because $85 is a minimal cost compared to the regular costs of maintaining and operating a Model 747-
  8F, 747-8, or 777 transport category airplane.

Authority for This Rulemaking

    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.

Regulatory Findings

    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.

[[Page 40068]]

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

The Amendment

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

PART 39--AIRWORTHINESS DIRECTIVES

0
1. The authority citation for part 39 continues to read as follows:

    Authority:  49 U.S.C. 106(g), 40113, 44701.


Sec.  39.13  [Amended]

0
2. The FAA amends Sec.  39.13 by:
0
a. Removing Airworthiness Directive (AD) 2022-03-05, Amendment 39-21922 
(87 FR 4150, January 27, 2022), and
0
b. Adding the following new AD:

2023-12-05 The Boeing Company: Amendment 39-22463; Docket No. FAA-
2023-0670; Project Identifier AD-2022-01427-T.

(a) Effective Date

    This airworthiness directive (AD) is effective June 21, 2023.

(b) Affected ADs

    This AD replaces AD 2022-03-05, Amendment 39-21922 (87 FR 4150, 
January 27, 2022) (AD 2022-03-05).

(c) Applicability

    This AD applies to all The Boeing Company airplanes identified 
in paragraphs (c)(1) and (2) of this AD, certificated in any 
category.
    (1) Model 747-8F and 747-8 series airplanes.
    (2) Model 777-200, -200LR, -300, -300ER, and 777F series 
airplanes.

(d) Subject

    Air Transport Association (ATA) of America Code 34, Navigation.

(e) Unsafe Condition

    This AD was prompted by a determination that radio altimeters 
cannot be relied upon to perform their intended function if they 
experience interference from wireless broadband operations in the 
3.7-3.98 GHz frequency band (5G C-Band), and a determination that 
this interference may affect other airplane systems using radio 
altimeter data, including the pitch control laws, including those 
that provide tail strike protection, regardless of the approach type 
or weather. The FAA is issuing this AD to address missing or 
erroneous radio altimeter data, which, in combination with multiple 
flight deck effects, could lead to loss of continued safe flight and 
landing.

(f) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.

(g) Definitions

    (1) For purposes of this AD, a ``5G C-Band mitigated airport'' 
(5G CMA) is an airport at which the telecommunications companies 
have agreed to voluntarily limit their 5G deployment at the request 
of the FAA, as identified by an FAA Domestic Notice.
    (2) For purposes of this AD, a ``radio altimeter tolerant 
airplane'' is one for which the radio altimeter, as installed, 
demonstrates the tolerances specified in paragraphs (g)(2)(i) and 
(ii) of this AD, using a method approved by the FAA.
    (i) Tolerance to radio altimeter interference, for the 
fundamental emissions (3.7-3.98 GHz), at or above the power spectral 
density (PSD) curve threshold specified in figure 1 to paragraph 
(g)(2)(i) of this AD.
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Figure 1 to paragraph (g)(2)(i)--Fundamental Effective Isotropic PSD 
at Outside Interface of Aircraft Antenna
[GRAPHIC] [TIFF OMITTED] TR21JN23.087

    (ii) Tolerance to radio altimeter interference, for the spurious 
emissions (3.7-3.98 GHz), at or above the PSD curve threshold 
specified in figure 2 to paragraph (g)(2)(ii) of this AD.


[[Page 40069]]


    Figure 2 to paragraph (g)(2)(ii)--Spurious Effective Isotropic 
PSD at Outside Interface of Aircraft Antenna
[GRAPHIC] [TIFF OMITTED] TR21JN23.088

    (3) For purposes of this AD, a ``non-radio altimeter tolerant 
airplane'' is one for which the radio altimeter, as installed, does 
not demonstrate the tolerances specified in paragraphs (g)(2)(i) and 
(ii) of this AD.

(h) Retained Airplane Flight Manual (AFM) Revision

    This paragraph restates the requirements of paragraph (g) of AD 
2022-03-05. Within 2 days after January 27, 2022 (the effective date 
of AD 2022-03-05): Revise the Limitations Section of the existing 
AFM to include the information specified in figure 3 to paragraph 
(h) of this AD. This may be done by inserting a copy of figure 3 to 
paragraph (h) of this AD into the existing AFM.


[[Page 40070]]


    Figure 3 to paragraph (h)--AFM Limitations Revisions
    [GRAPHIC] [TIFF OMITTED] TR21JN23.089
    
(i) New Requirement: AFM Revision for Non-Radio Altimeter Tolerant 
Airplanes

    For non-radio altimeter tolerant airplanes, do the actions 
specified in paragraphs (i)(1) and (2) of this AD.
    (1) On or before June 30, 2023, revise the Limitations Section 
of the existing AFM to include the information specified in figure 4 
to paragraph (i) of this AD. This may be done by inserting a copy of 
figure 4 to paragraph (i) of this AD into the existing AFM. 
Incorporating the AFM revision required by this paragraph terminates 
the AFM revision required by paragraph (h) of this AD.
    (2) Before further flight after incorporating the limitations 
specified in figure 4 to paragraph (i) of this AD, remove the AFM 
revision required by paragraph (h) of this AD.

Figure 4 to paragraph (i)--AFM Revision for Non-Radio Altimeter 
Tolerant Airplanes
[GRAPHIC] [TIFF OMITTED] TR21JN23.090

(j) New Requirement: AFM Revision for Radio Altimeter Tolerant 
Airplanes

    For radio altimeter tolerant airplanes, do the actions specified 
in paragraphs (j)(1) and (2) of this AD.
    (1) On or before June 30, 2023, revise the Limitations Section 
of the existing AFM to include the information specified in figure 5 
to paragraph (j) of this AD. This may be done by inserting a copy of 
figure 5 to paragraph (j) of this AD into the existing AFM. 
Incorporating the AFM revision required by this paragraph terminates 
the AFM revision required by paragraph (h) of this AD.
    (2) Before further flight after incorporating the limitations 
specified in figure 5 to paragraph (j) of this AD, remove the AFM 
revision required by paragraph (h) of this AD.

Figure 5 to paragraph (j)--AFM Revision for Radio Altimeter Tolerant 
Airplanes
[GRAPHIC] [TIFF OMITTED] TR21JN23.091

(k) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Operational Safety Branch, FAA, has the 
authority to approve AMOCs for this AD, if requested using the 
procedures found in 14 CFR 39.19. In accordance with 14 CFR 39.19, 
send your request to your principal inspector or responsible Flight 
Standards Office, as appropriate. If sending information directly to 
the manager of the Operational Safety Branch, send it to the 
attention of the person identified in paragraph (l) of this AD. 
Information may be emailed to: [email protected].
    (2) Before using any approved AMOC, notify your appropriate 
principal inspector, or lacking a principal inspector, the manager 
of the responsible Flight Standards Office.
    (3) AMOCs approved for AD 2021-23-12, Amendment 39-21810 (86 FR 
69984, December 9, 2021), providing relief for specific radio 
altimeter installations are approved as AMOCs for the requirements 
specified in paragraph (h) of this AD until June 30, 2023.

(l) Related Information

    For more information about this AD, contact Brett Portwood, 
Continued Operational Safety Technical Advisor, COS Program 
Management Section, Operational Safety Branch, FAA, 3960 Paramount

[[Page 40071]]

Boulevard, Lakewood, CA 90712-4137; phone: 817-222-5390; email: 
[email protected].

(m) Material Incorporated by Reference

    None.

    Issued on June 9, 2023.
Michael Linegang,
Acting Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2023-13156 Filed 6-16-23; 11:15 am]
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