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[Federal Register Volume 89, Number 248 (Friday, December 27, 2024)]
[Proposed Rules]
[Pages 105485-105487]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-30918]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2024-2713; Project Identifier AD-2024-00328-T]
RIN 2120-AA64

Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for certain The Boeing Company Model 777-200, -200LR, -300, -300ER, and 
777F series airplanes. This proposed AD was prompted by a report 
indicating that an airplane experienced a glideslope (G/S) beam anomaly 
during an instrument landing system (ILS) approach, which resulted in a 
higher-than-expected descent rate during the final segment of an ILS 
approach. The flightcrew might follow misleading flight director (F/D) 
guidance after disconnecting the autopilot, without reference to the 
other available information and flight deck indications. This proposed 
AD would require installing new autopilot flight director computer 
(AFDC) operational program software (OPS) and doing a software 
configuration check. The FAA is proposing this AD to address the unsafe 
condition on these products.

DATES: The FAA must receive comments on this proposed AD by February 
25, 2025.

ADDRESSES: You may send comments, using the procedures found in 14 CFR 
11.43 and 11.45, by any of the following methods:
     Federal eRulemaking Portal: Go to regulations.gov. Follow 
the instructions for submitting comments.
     Fax: 202-493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE, Washington, DC 20590.
     Hand Delivery: Deliver to Mail address above between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    AD Docket: You may examine the AD docket at regulations.gov under 
Docket No. FAA-2024-2713; 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 NPRM, any comments received, and other 
information. The street address for Docket Operations is listed above.
    Material Incorporated by Reference:
     For Boeing material identified in this proposed AD, 
contact Boeing Commercial Airplanes, Attention: Contractual & Data 
Services (C&DS), 2600 Westminster Blvd., MC 110-SK57, Seal Beach, CA 
90740-5600; telephone 562-797-1717; website myboeingfleet.com.
     You may view this material at the FAA, Airworthiness 
Products Section, Operational Safety Branch, 2200 South 216th St., Des 
Moines, WA. For information on the availability of this material at the 
FAA, call 206-231-3195. It is also available at regulations.gov under 
Docket No. FAA-2024-2713.

FOR FURTHER INFORMATION CONTACT: Michael Closson, Aviation Safety 
Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 206-
231-3973; email: [email protected].

SUPPLEMENTARY INFORMATION:

Comments Invited

    The FAA invites you to send any written relevant data, views, or 
arguments about this proposal. Send your comments to an address listed 
under the ADDRESSES section. Include ``Docket No. FAA-2024-2713; 
Project Identifier AD-2024-00328-T'' at the beginning of your comments. 
The most helpful comments reference a specific portion of the proposal, 
explain the reason for any recommended change, and include supporting 
data. The FAA will consider all comments received by the closing date 
and may amend this proposal because of those comments.
    Except for Confidential Business Information (CBI) as described in 
the following paragraph, and other information as described in 14 CFR 
11.35, the FAA will post all comments received, without change, to 
regulations.gov, including any personal

[[Page 105486]]

information you provide. The agency will also post a report summarizing 
each substantive verbal contact received about this NPRM.

Confidential Business Information

    CBI is commercial or financial information that is both customarily 
and actually treated as private by its owner. Under the Freedom of 
Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public 
disclosure. If your comments responsive to this NPRM contain commercial 
or financial information that is customarily treated as private, that 
you actually treat as private, and that is relevant or responsive to 
this NPRM, it is important that you clearly designate the submitted 
comments as CBI. Please mark each page of your submission containing 
CBI as ``PROPIN.'' The FAA will treat such marked submissions as 
confidential under the FOIA, and they will not be placed in the public 
docket of this NPRM. Submissions containing CBI should be sent to 
Michael Closson, Aviation Safety Engineer, FAA, 2200 South 216th St., 
Des Moines, WA 98198; phone: 206-231-3973; email: 
[email protected]. Any commentary that the FAA receives that is 
not specifically designated as CBI will be placed in the public docket 
for this rulemaking.

Background

    The FAA has received a report indicating that a Model 787-8 
airplane captured an anomalous G/S beam during an ILS approach, which 
resulted in a higher-than-expected descent rate during the final 
segment of an ILS approach due to persistent inertial coasting, which 
can result in misleading flight director guidance. When the autopilot 
was disconnected, the F/D continued to command a flight path away from 
the G/S without warning, which the flightcrew appeared to follow. Both 
GLIDESLOPE and TOO LOW TERRAIN alerts annunciated while the airplane 
continued to descend. Ultimately, the flightcrew was able to recover 
the airplane and conducted a Go-Around procedure. No injuries to 
passengers or crew, or damage to the airframe, was reported.
    It has been determined that Model 777 airplanes can experience the 
same anomaly. G/S beam anomalies that occur in a discrete G/S capture 
window can result in reversion to inertial paths in which the auto-
flight vertical guidance diverges from the G/S beam at higher-than-
expected descent rates. The flightcrew may follow the misleading F/D 
guidance after disconnecting the A/P, without reference to the other 
available information and flight deck indications. This condition, if 
not addressed, could result in a late touchdown, a runway excursion, or 
controlled flight into terrain.

Related Rulemaking

    The FAA may consider issuing additional rulemaking to address the 
identified unsafe condition on additional Boeing airplane models with 
the same G/S issue.

FAA's Determination

    The FAA is issuing this NPRM after determining that the unsafe 
condition described previously is likely to exist or develop on other 
products of the same type design.

Material Incorporated by Reference Under 1 CFR Part 51

    The FAA reviewed Boeing Alert Requirements Bulletin 777-22A0046 RB, 
dated October 25, 2022. This material specifies procedures for 
installing new AFDC OPS, doing a software configuration check, and 
making sure that the correct software part number is installed in the 
correct location. This material is reasonably available because the 
interested parties have access to it through their normal course of 
business or by the means identified in the ADDRESSES section.

Proposed AD Requirements in This NPRM

    This proposed AD would require accomplishing the actions specified 
in the material already described, except for any differences 
identified as exceptions in the regulatory text of this proposed AD. 
For information on the procedures and compliance times, see this 
material at regulations.gov under Docket No. FAA-2024-2713.

Costs of Compliance

    The FAA estimates that this AD, if adopted as proposed, would 
affect 266 airplanes of U.S. registry. The FAA estimates the following 
costs to comply with this proposed AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                     Cost per      Cost on U.S.
                 Action                          Labor cost           Parts cost      product        operators
----------------------------------------------------------------------------------------------------------------
Software installation and configuration  2 work-hours x $85 per              $13            $183         $48,678
 check.                                   hour = $170.
----------------------------------------------------------------------------------------------------------------

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

    The FAA determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD would 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 this proposed 
regulation:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Would not affect intrastate aviation in Alaska, and
    (3) Would not have a significant economic impact, positive or 
negative, on a substantial number of small entities under the criteria 
of the Regulatory Flexibility Act.

List of Subjects in 14 CFR Part 39

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

[[Page 105487]]

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 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 adding the following new airworthiness 
directive:

The Boeing Company: Docket No. FAA-2024-2713; Project Identifier AD-
2024-00328-T.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) by February 10, 2025.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to The Boeing Company Model 777-200, -200LR, -
300, -300ER, and 777F series airplanes, certificated in any 
category, as identified in Boeing Alert Requirements Bulletin 777-
22A0046 RB, dated October 25, 2022.

(d) Subject

    Air Transport Association (ATA) of America Code 22, Auto flight.

(e) Unsafe Condition

    This AD was prompted by a report indicating that an airplane 
experienced a glideslope (G/S) beam anomaly during an instrument 
landing system (ILS) approach, which resulted in a higher-than-
expected descent rate during the final segment of an ILS approach. 
The FAA is issuing this AD to address misleading flight director 
guidance that the flightcrew might follow after disconnecting the 
autopilot, without reference to the other available information and 
flight deck indications. The unsafe condition, if not addressed, 
could result in a late touchdown, a runway excursion, or controlled 
flight into terrain.

(f) Compliance

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

(g) Required Actions

    Except as specified in paragraph (h) of this AD: At the 
applicable times specified in paragraph 3., ``Compliance,'' of 
Boeing Alert Requirements Bulletin 777-22A0046 RB, dated October 25, 
2022, do all applicable actions identified in, and in accordance 
with, the Accomplishment Instructions of Boeing Alert Requirements 
Bulletin 777-22A0046 RB, dated October 25, 2022.

    Note 1 to paragraph (g):  Guidance for accomplishing the actions 
required by this AD can be found in Boeing Alert Service Bulletin 
777-22A0046, dated October 25, 2022, which is referred to in Boeing 
Alert Requirements Bulletin 777-22A0046 RB, dated October 25, 2022.

(h) Exception to Service Information Specifications

    Where the Compliance Time column of the table in the 
``Compliance'' paragraph of Boeing Alert Requirements Bulletin 777-
22A0046 RB, dated October 25, 2022, refers to ``the Original Issue 
date of Requirements Bulletin 777-22A0046 RB,'' this AD requires 
using the effective date of this AD.

(i) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, AIR-520, Continued 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 certification office, 
send it to the attention of the person identified in paragraph 
(j)(1) 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) An AMOC that provides an acceptable level of safety may be 
used for any repair, modification, or alteration required by this AD 
if it is approved by The Boeing Company Organization Designation 
Authorization (ODA) that has been authorized by the Manager, AIR-
520, Continued Operational Safety Branch, FAA, to make those 
findings. To be approved, the repair method, modification deviation, 
or alteration deviation must meet the certification basis of the 
airplane, and the approval must specifically refer to this AD.

(j) Related Information

    (1) For more information about this AD, contact Michael Closson, 
Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 
98198; phone: 206-231-3973; email: [email protected].
    (2) Material identified in this AD that is not incorporated by 
reference is available at the address specified in paragraph (k)(3) 
of this AD.

(k) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference of the material listed in this paragraph 
under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this material as applicable to do the actions 
required by this AD, unless the AD specifies otherwise.
    (i) Boeing Alert Requirements Bulletin 777-22A0046 RB, dated 
October 25, 2022.
    (ii) [Reserved]
    (3) For Boeing material identified in this AD, contact Boeing 
Commercial Airplanes, Attention: Contractual & Data Services (C&DS), 
2600 Westminster Blvd., MC 110-SK57, Seal Beach, CA 90740-5600; 
telephone 562-797-1717; website myboeingfleet.com.
    (4) You may view this material at the FAA, Airworthiness 
Products Section, Operational Safety Branch, 2200 South 216th St., 
Des Moines, WA. For information on the availability of this material 
at the FAA, call 206-231-3195.
    (5) You may view this material at the National Archives and 
Records Administration (NARA). For information on the availability 
of this material at NARA, visit www.archives.gov/federal-register/cfr/ibr-locations or email [email protected].

    Issued on December 19, 2024.
Suzanne Masterson,
Deputy Director, Integrated Certificate Management Division, Aircraft 
Certification Service.
[FR Doc. 2024-30918 Filed 12-26-24; 8:45 am]
BILLING CODE 4910-13-P
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