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[Federal Register Volume 90, Number 6 (Friday, January 10, 2025)]
[Rules and Regulations]
[Pages 1850-1854]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2025-00371]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2024-0762; Project Identifier AD-2023-01194-T; 
Amendment 39-22911; AD 2024-25-09]
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 adopting a new airworthiness directive (AD) for 
certain The Boeing Company Model 757 airplanes. This AD was prompted by 
reports of several occurrences of a power transfer unit (PTU) control 
valve that failed to open when commanded. This AD requires installing 
new relays and changing certain wire bundles leading to the PTU control 
valve. The FAA is issuing this AD to address the unsafe condition on 
these products.

DATES: This AD is effective February 14, 2025.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of February 14, 
2025.

ADDRESSES: 
    AD Docket: You may examine the AD docket at regulations.gov under 
Docket No. FAA-2024-0762; 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.
    Material Incorporated by Reference:
     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.
     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-2024-0762.

FOR FURTHER INFORMATION CONTACT: Katherine Venegas, Aviation Safety 
Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 562-
627-5353; email: [email protected].

SUPPLEMENTARY INFORMATION:

Background

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 by adding an AD that would apply to certain The Boeing 
Company Model 757 airplanes. The NPRM published in the Federal Register 
on

[[Page 1851]]

March 25, 2024 (89 FR 20565). The NPRM was prompted by reports of 
several occurrences of a PTU control valve that failed to open when 
commanded. In the NPRM, the FAA proposed to require installing new 
relays and changing certain wire bundles leading to the PTU control 
valve. The FAA is issuing this AD to address failure of the PTU control 
valve, which in conjunction with a loss of the left engine or engine-
driven pump (EDP) during takeoff, may result in a failure of the 
landing gear to retract in a timely manner. This condition, if not 
addressed, could add drag, affect climb gradient, and prevent the 
airplane from clearing obstacles on takeoff. This condition can result 
in loss of continued safe flight and landing.

Discussion of Final Airworthiness Directive

Comments

    The FAA received a comment from the Air Line Pilots Association, 
International (ALPA), who supported the NPRM without change.
    The FAA received additional comments from Aviation Partners Boeing 
(APB), Boeing, Delta Air Lines (Delta), and United Parcel Service 
Airlines (UPS Airlines). United Airlines (United) supported the NPRM 
and also provided additional comments, as discussed below. The 
following presents the comments received on the NPRM and the FAA's 
response to each comment.

Effect of Winglets on Accomplishment of the Proposed Actions

    APB stated that the installation of winglets per Supplemental Type 
Certificate STC ST01518SE does not affect the accomplishment of the 
manufacturer's service instructions.
    The FAA agrees with the commenter that STC ST01518SE does not 
affect the accomplishment of the manufacturer's service instructions. 
Therefore, the installation of STC ST01518SE does not affect the 
ability to accomplish the actions required by this AD. The FAA has not 
changed this AD in this regard.

Request To Revise Unsafe Condition Statement

    Boeing requested two changes in the description of the unsafe 
condition. One change is in the description of the state of the landing 
gear retraction abilities from ``may result in a failure of the landing 
gear to retract'' to ``may result in a failure of the landing gear to 
retract in a timely manner.'' Boeing explained that the left hydraulic 
system's electric motor pump would still function, but has a smaller 
output capacity that results in being unable to retract the landing 
gear in the time required to clear obstacles. The other requested 
change is to clarify what conditions lead up to the slowed retraction 
of the landing gear. Boeing explained that loss of either the left 
engine or the EDP would lead to use of the electric motor pump and 
requested that the related phrase ``left engine and engine driven pump 
(EDP)'' be changed to ``left engine and/or engine driven pump (EDP).''
    The FAA agrees to revise the unsafe condition statement. The 
revisions provide a more accurate description of the unsafe condition 
and of what conditions lead up to a slow retraction of the landing 
gear. However, the FAA has revised ``left engine and engine driven pump 
(EDP)'' to ``left engine or engine-driven pump (EDP)'' instead of using 
``and/or.'' Although both failure conditions can occur, only one of the 
conditions is necessary to affect the landing gear retraction. The FAA 
has revised the Background section of this final rule and paragraph (e) 
of this AD accordingly.

Requests To Revise AD To Address Missing Information in Service 
Information

    Boeing stated that additional engineering definition for wire 
routing is necessary for a group of airplanes identified in Boeing 
Alert Service Bulletin 757-29A0071, dated November 16, 2023, and Boeing 
Alert Requirements Bulletin 75-29A0071 RB, dated November 16, 2023, and 
that the service bulletin and requirements bulletin will be revised. 
Delta and United requested that paragraph (h) of the proposed AD be 
revised to add an exception to address the errors in the wire routing 
definition for the airplanes identified as Group 3 airplanes in Boeing 
Alert Requirement Bulletin 757-29A0071 RB, dated November 16, 2023 
(Group 3 airplanes). United also proposed that paragraph (g) of the 
proposed AD be revised to incorporate Revision 1 of Boeing Alert 
Requirement Bulletin 757-29A0071 RB, if it is created prior to the 
release of this AD. Both Delta and United noted that Boeing published 
Information Notice 757-29A0071 IN 01 to inform operators of issues with 
work instructions for the Group 3 airplanes and advised to stop work on 
those airplanes until new service information is published. United also 
reasoned that the requested revision would help United and other 
operators of Group 3 airplanes avoid applying for an AMOC when the 
final rule is issued.
    The FAA agrees with the need to provide additional definition for 
wire routing that affects Group 3 airplanes because those airplanes 
would be unable to comply with the instructions provided in Boeing 
Alert Requirement Bulletin 757-29A0071 RB, dated November 16, 2023. 
However, the FAA does not agree to revise the AD to reference Revision 
1 of Boeing Alert Requirement Bulletin 757-29A0071 RB, or to add an 
exception to address the errors in the instructions for Group 3 
airplanes. A later revision of Boeing Alert Requirement Bulletin 757-
29A0071 RB, dated November 16, 2023, has not been issued and the 
publication date is yet to be determined. To delay this action until 
the revised service information is published would be inappropriate 
since the FAA has determined that an unsafe condition exists and that 
the actions must be conducted on the other affected groups of airplanes 
to ensure continued safety. Operators may apply for approval to use 
later revisions as an alternative method of compliance with this AD 
under the provisions of paragraph (i) of this AD. The FAA has not 
changed this AD in this regard.

Request To Add an Exception To Allow Alternative Positions for 
Connectors

    Delta requested that paragraph (h) of the proposed AD be revised to 
add an exception that would allow the use of available connector 
positions on panels and disconnects other than the ones defined in 
Boeing Alert Requirement Bulletin 757-29A0071 RB, dated November 16, 
2023. Delta explained that the figures in Boeing Alert Requirement 
Bulletin 757-29A0071 RB, dated November 16, 2023, are specific in 
defining positions within the panels and disconnects where the 
connectors will be installed. Delta also stated that the specific 
location of the connector installation and disconnects in the panel are 
not necessary for the function of the system. Delta reasoned that 
allowing operators to install the connectors in alternative available 
positions would be acceptable for compliance with the proposed AD while 
also giving operators flexibility in addressing variations in each 
airplane's existing wiring.
    The FAA agrees that using only the defined positions within the 
panels and disconnect brackets for the new connectors to be installed 
is not necessary to address the unsafe condition, and that allowing 
alternatives would provide flexibility in complying with the 
requirements of this AD on airplanes that might have different wiring 
configurations. The action to perform the operational test verifies the 
functionality of the system and will

[[Page 1852]]

continue to be required. The FAA has added an exception to paragraph 
(h) of this AD to allow for installing connectors in alternative 
available positions on panels and disconnect brackets than those 
defined in Boeing Alert Requirement Bulletin 757-29A0071 RB, dated 
November 16, 2023.

Request To Allow Use of Other Kit Materials

    Delta requested a revision to paragraph (h) of the proposed AD to 
add an exception that would allow the use of operator-supplied 
materials that are the same as the Boeing-supplied materials in the 
parts kit specified in Boeing Alert Requirement Bulletin 757-29A0071 
RB, dated November 16, 2023. Delta explained that Boeing kits expire 
within 3 months because of a limitation on the placard (decal) adhesive 
and opined that operators should have the ability to supply the same 
decal if the Boeing-supplied decal expires before use. In addition, 
Delta also reasoned that operators should be able to supply their own 
materials if Boeing-supplied kits are not available in time to avoid 
delays in compliance with the proposed AD.
    The FAA does not agree to revise this AD regarding this request. 
The Boeing-supplied kits are specified in Boeing Alert Service Bulletin 
757-29A0071, dated November 16, 2023, which is not required by this AD. 
This AD requires Boeing Alert Requirements Bulletin 757-29A0071 RB, 
dated November 16, 2023, which identifies parts that are required for 
compliance. This AD does not require procuring the Boeing-supplied kits 
that are specified in Boeing Alert Service Bulletin 757-29A0071, dated 
November 16, 2023. No revision to this AD is necessary in this regard.

Request To Extend Compliance Time Due to Parts Availability

    UPS Airlines requested a revision to paragraph (h) of the proposed 
AD to add an exception to a compliance time identified in Boeing Alert 
Requirement Bulletin 757-29A0071 RB, dated November 16, 2023. This 
requested exception would extend the calendar time limit from the 
proposed 30 months after the effective date of the AD to 36 months 
after the effective date of the AD. UPS Airlines explained that the 
availability of the Boeing-supplied parts kit could affect the ability 
to comply with the proposed compliance times. UPS Airlines stated that 
there are only 15 of the Boeing-supplied kits in stock as of the date 
of the NPRM, with an anticipated lead time of 175 to 352 days if all 15 
kits are purchased and the inventory depleted. UPS Airlines added that 
they have 429 airplanes in a configuration group that would require the 
same part kit.
    The FAA does not agree to revise the AD regarding this issue. As 
explained in the previous comment, the Boeing-supplied kits are not 
part of the requirements of Boeing Alert Requirement Bulletin 757-
29A0071 RB, dated November 16, 2023, and are specified in Boeing Alert 
Service Bulletin 757-29A0071, dated November 16, 2023, thus operators 
may procure the parts from their supplies without an AMOC or revision 
to this AD. In developing an appropriate compliance time for this 
action, the FAA considered the recommendations of the manufacturer, the 
urgency associated with the subject unsafe condition, the availability 
of required parts, and the practical aspect of accomplishing the 
required modification within a period of time that corresponds to the 
normal scheduled maintenance for most affected operators. In 
consideration of these items, the FAA has determined that the 
compliance time of 30 months or 2,760 flight hours after the effective 
date of this AD, whichever occurs first, will ensure an acceptable 
level of safety. However, under the provisions of paragraph (i) of this 
AD, the FAA will consider requests for approval of an extension of the 
compliance time if sufficient data are submitted to substantiate that 
new compliance times would provide an acceptable level of safety.

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. Except for minor editorial changes, and 
any other changes described previously, this AD is adopted as proposed 
in the NPRM. None of the changes will increase the economic burden on 
any operator.

Material Incorporated by Reference Under 1 CFR Part 51

    The FAA reviewed Boeing Alert Requirements Bulletin 757-29A0071 RB, 
dated November 16, 2023. This material specifies procedures for 
changing the wire bundle from circuit breaker C4054 to the P33 panel, 
installing new relays in the P33 panel, and changing wire bundles to 
the PTU control valve. 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.

Costs of Compliance

    The FAA estimates that this AD affects 467 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
----------------------------------------------------------------------------------------------------------------
Installations, changes, and tests..  45 work-hours x $85 per              $3,260          $7,085      $3,308,695
                                      hour = $3,825.
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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.

[[Page 1853]]

    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.

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 adding the following new airworthiness 
directive:

2024-25-09 The Boeing Company: Amendment 39-22911; Docket No. FAA-
2024-0762; Project Identifier AD-2023-01194-T.

(a) Effective Date

    This airworthiness directive (AD) is effective February 14, 
2025.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to The Boeing Company Model 757-200, -200PF, -
200CB, and -300 series airplanes, certificated in any category, and 
identified in Boeing Alert Requirements Bulletin 757-29A0071 RB, 
dated November 16, 2023.

(d) Subject

    Air Transport Association (ATA) of America Code 29, Hydraulic 
power.

(e) Unsafe Condition

    This AD was prompted by reports of several occurrences of a 
power transfer unit (PTU) control valve that failed to open when 
commanded. The FAA is issuing this AD to address failure of the PTU 
control valve, which, in conjunction with a loss of the left engine 
or engine-driven pump (EDP) during takeoff, may result in a failure 
of the landing gear to retract in a timely manner. This condition, 
if not addressed, could add additional drag, affect climb gradient, 
and prevent the ability to clear obstacles on takeoff. This 
condition can result in loss of continued safe flight and landing.

(f) Compliance

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

(g) Required Actions

    Except as specified by paragraph (h) of this AD: At the 
applicable times specified in the ``Compliance'' paragraph of Boeing 
Alert Requirements Bulletin 757-29A0071 RB, dated November 16, 2023, 
do all applicable actions identified in, and in accordance with, the 
Accomplishment Instructions of Boeing Alert Requirements Bulletin 
757-29A0071 RB, dated November 16, 2023.

    Note 1 to paragraph (g):  Guidance for accomplishing the actions 
required by this AD can be found in Boeing Alert Service Bulletin 
757-29A0071, dated November 16, 2023, which is referred to in Boeing 
Alert Requirements Bulletin 757-29A0071 RB, dated November 16, 2023.

(h) Exceptions to Service Information Specifications

    (1) Where the Compliance Time column of the tables in the 
``Compliance'' paragraph of Boeing Alert Requirements Bulletin 757-
29A0071 RB, dated November 16, 2023, uses the phrase ``the Original 
Issue date of Requirements Bulletin 757-29A0071 RB,'' this AD 
requires using the effective date of this AD.
    (2) Where the figures in the Accomplishment Instructions of 
Boeing Alert Requirements Bulletin 757-29A0071 RB, dated November 
16, 2023, specify certain positions on the P33 panel and disconnect 
bracket AD0880 or AD0881 for installing the connectors, this AD 
allows any open position on the P33 panel or disconnect bracket 
AD0880 or AD0881 for installing the connectors.

(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 Katherine 
Venegas, Aviation Safety Engineer, FAA, 2200 South 216th St., Des 
Moines, WA 98198; phone: 562-627-5353; 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) 
this AD.

(k) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference (IBR) 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 757-29A0071 RB, dated 
November 16, 2023.
    (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].

[[Page 1854]]

    Issued on January 6, 2025.
Suzanne Masterson,
Deputy Director, Integrated Certificate Management Division, Aircraft 
Certification Service.
[FR Doc. 2025-00371 Filed 1-8-25; 8:45 am]
BILLING CODE 4910-13-P
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