DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2020-1140; Project Identifier AD-2020-01009-T;
Amendment 39-21972; AD 2022-06-06]
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) 2017-14-
13, which applied to certain The Boeing Company Model 737-600, -700, -
700C, -800, -900, and -900ER series airplanes. AD 2017-14-13 required a
torque check of the screws in the cover assembly of the heel rest for
both the captain's and the first officer's rudder pedals, and
corrective action if necessary. This AD was prompted by a report of an
aborted takeoff because the rudder pedals were not operating correctly,
and subsequent reports of loose rudder pedal cover fasteners on
airplanes on which the actions required by AD 2017-14-13 were done and
on additional airplanes that were not included in the applicability of
AD 2017-14-13. This AD requires modifying the rudder pedal cover and
shroud assemblies, and applies to all The Boeing Company Model 737-600,
-700, -700C, -800, -900, and -900ER series airplanes and Model 737-8
and 737-9 airplanes. This AD also limits the installation of affected
parts under certain conditions. The FAA is issuing this AD to address
the unsafe condition on these products.

DATES: This AD is effective June 16, 2022.
The Director of the Federal Register approved the incorporation by
reference of certain publications listed in this AD as of June 16,
2022.

ADDRESSES: For service information identified in this final rule,
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; internet https://www.myboeingfleet.com.
You may view this service information 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
https://www.regulations.gov by searching for and locating Docket No.
FAA-2020-1140.

Examining the AD Docket

You may examine the AD docket at https://www.regulations.gov by
searching for and locating Docket No. FAA-2020-1140; 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: Douglas Tsuji, Aerospace Engineer,
Systems and Equipment Section, FAA, Seattle ACO Branch, 2200 South
216th St., Des Moines, WA 98198; phone: 206-231-3548; email:
douglas.tsuji@faa.gov.

SUPPLEMENTARY INFORMATION:

Background

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 to supersede AD 2017-14-13, Amendment 39-18957 (82 FR
33007, July 19, 2017) (``AD 2017-14-13''). AD 2017-14-13 applied to
certain The Boeing Company Model 737-600, -700, -700C, -800, -900, and
-900ER series airplanes. AD 2017-14-13 required a torque check of the
screws in the cover assembly of the heel rest for both the captain's
and the first officer's rudder pedals, and corrective action if
necessary.
The NPRM published in the Federal Register on January 21, 2021 (86
FR 6273). The NPRM was prompted by a report of an aborted takeoff
because the rudder pedals were not operating correctly and subsequent
reports of loose rudder pedal cover fasteners on airplanes on which the
actions required by AD 2017-14-13 had been done. These reports
demonstrated that the required torque checks were ineffective in
guaranteeing fastener retention and that additional airplanes that had
not been included in the applicability of AD 2017-14-13 are also
affected (i.e., all Model 737-8 and 737-9 airplanes; and Model 737-600,
-700, -700C, -800, -900, and -900ER series airplanes, having line
numbers 3556 and subsequent). In the NPRM, the FAA proposed to require
modifying the rudder pedal cover and shroud assemblies with a new
design that prevents the fasteners from backing out. The NPRM also
proposed to limit the installation of affected parts under certain
conditions, including modification of the cover or shroud assembly in
accordance with the requirements of paragraph (h) of this AD. The FAA
is issuing this AD to address cover assembly fasteners interfering with
the operation of a rudder pedal. A fastener can back out and restrict
rudder pedal motion and reduce differential braking control during
takeoff or landing, which could cause a high-speed runway excursion.

Discussion of Final Airworthiness Directive

Comments

The FAA received supportive comments from two commenters: Air Line
Pilots Association, International (ALPA) and United Airlines (UAL).
ALPA supported the NPRM without change. UAL supported the NPRM, but
requested clarification regarding the method for part marking, as
discussed later in this discussion.
The FAA also received comments from Boeing, Aviation Partners
Boeing, and Delta Air Lines (DAL). 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

Aviation Partners Boeing stated that the installation of winglets
per Supplemental Type Certificate STC ST00830SE does not affect
compliance with the proposed actions.
The FAA agrees with the commenter. The installation of STC
ST00830SE does not affect an operator's ability to accomplish the
actions required by this AD. The FAA has not changed this AD.

Request To Update the Service Information to the Latest Revision

Boeing requested that the FAA require Boeing Requirements Bulletin
737-27A1314 RB, Revision 2, dated July 6, 2021, because an individual
airplane was omitted from the effectivity of the previous revision of
the service bulletin (the NPRM proposed that operators do actions using
Boeing Alert Requirements Bulletin 737-27A1314 RB, Revision 1, dated
June 24, 2020).
The FAA agrees to require Boeing Requirements Bulletin 737-27A1314
RB, Revision 2, dated July 6, 2021, because the individual airplane
added to the effectivity of that service bulletin was already in the
applicability of the proposed rule and therefore no change to the
applicability of the final rule is necessary.
Furthermore, Boeing Requirements Bulletin 737-27A1314 RB, Revision
2, dated July 6, 2021, does not add new actions or revise the existing
actions specified in Boeing Alert Requirements Bulletin 737-27A1314 RB,
Revision 1, dated June 24, 2020, which the NPRM proposed as a method of
compliance for doing the actions required by this AD.
The FAA has revised this AD to specify that required actions be
done in accordance with Boeing Requirements Bulletin 737-27A1314 RB,
Revision 2, dated July 6, 2021, as applicable, and to give credit for
actions done in accordance with Boeing Alert Requirements Bulletin 737-
27A1314 RB, Revision 1, dated June 24, 2020.

Request To Change Applicability of the Proposed AD

Boeing requested that the applicability of the proposed AD be
revised to match the effectivity defined in Boeing Alert Requirements
Bulletin 737-27A1313 RB, Revision 1, dated June 24, 2020, or Boeing
Alert Requirements Bulletin 737-27A1314 RB, Revision 1, dated June 24,
2020. Boeing stated that the shroud and cover do not meet the
definition of ``rotable parts'' in the new configuration, because the
parts are no longer interchangeable following modification and must
also have the mating part (the part that attached to the aircraft
structure) modified to be installed. Boeing also stated a ``pre-
modified part'' cannot be installed on an airplane having the service
bulletin modifications. Based on this non-interchangeability, Boeing
does not consider these as rotable.
The FAA disagrees with changing the applicability, as specified in
paragraph (c) of this AD, because the FAA has determined there is a
rotability issue. It is true that an original shroud assembly cannot be
installed with an upper cover assembly modified as specified in the
requirements bulletins identified in this AD, and conversely a shroud
assembly modified as specified in the requirements bulletins cannot be
installed with an original upper cover assembly. However, it is still
physically possible to install an original shroud assembly and an
original upper cover assembly (the combination with the unsafe
condition) on an airplane not identified in the Boeing requirements
bulletins. Therefore, no changes have been made to this AD regarding
this request.

Request for Definition of ``Production Equivalent''

Boeing and DAL requested that the FAA revise paragraph (g) of the
proposed AD to further define what constitutes a ``production
equivalent.'' DAL asked if certain part numbers and subsequent part
numbers that are fully interchangeable can be installed. Boeing stated
that more guidance is needed for operators on how to verify that the
change is incorporated on production airplanes that have been
delivered. Boeing stated that for airplanes modified by Boeing,
operators do not have a corresponding maintenance record and that
delivery records may be used for verification of production equivalent.
The FAA agrees with the request. The NPRM did not provide a
definition of a ``production equivalent,'' which need not be further
modified. Paragraph (g) of this AD has been revised to include the
following information: ``A production equivalent can be determined by
its upper cover assembly part numbers (P/Ns 251A3122-15 (pilot) and
251A3122-16 (first officer), or later approved part numbers) and shroud
assembly part numbers (P/Ns 233A2319-5 or -6, or later approved part
numbers, used for both pilot and first officer).''

Request for Re-Identification of Modified Housing and Shrouds

DAL requested that the service information be revised. DAL stated
that modified housing and shrouds should be re-identified with a new
dash number instead of with the service bulletin number. DAL stated
that configuration control could be an issue if the pre- and post-
modification parts were to share a common part number. The commenter
asserted that in an aircraft on ground or ``AOG'' situation (such as
when a maintenance issue prevents the airplane from departing from an
airport until the issue is resolved), the operator could find out too
late that a part brought to the airplane is unmodified and is,
therefore, restricted for installation, which could lead to an
operational delay to allow for part modification prior to returning the
aircraft to service. DAL argued that a new, unique part number would
eliminate that risk.
The FAA disagrees with the requested change. The FAA acknowledges
that parts are typically identified by part numbers, and that continued
use of the same part number for both modified and unmodified parts
could make it difficult for operators to keep track of them. However,
the FAA disagrees with re-identifying modified parts with a new dash
number, because some operators have already modified their airplanes
using the existing service information and imposing this additional
requirement would necessitate work unrelated to addressing the unsafe
condition. Furthermore, waiting for revised service information that
incorporates the identification of new dash numbers would delay the
issuance of this AD. After this AD is issued, operators could
coordinate with the manufacturer to create a unique new part number for
parts modified in accordance with the service information, and the
manufacturer could propose installation of the new part number as an
alternative method of compliance (AMOC) to this AD. This AD has not
been changed with regard to this request.

Request To Allow Part Marking by Hand Lettering

DAL requested a change in paragraph (i) of the proposed AD to
specify either rubber stamp or hand lettering, because hand lettering
is an acceptable alternate method of part marking for the affected
part. DAL also stated that the manufacturer agrees hand lettering is an
acceptable alternative to the rubber stamp method. In addition, UAL
requested that the FAA clarify the part marking in the required for
compliance (RC) step of the service information that refers to the
standard overhaul practices manual (SOPM). UAL stated that the SOPM
includes a note referring to alternate marking methods (i.e., hand
lettering instead of rubber stamp).
The FAA disagrees with the request to modify paragraph (i) of this
AD because the service information does not specify the method by which
the part marking must be applied. This AD requires that part marking
must be done. However, the method of part marking is not mandated, as
the service information refers to the SOPM. The use of the ``refer to''
indicates the SOPM is guidance on how to do the part marking. The SOPM
specifies using a rubber stamp and allows for hand lettering as an
alternative action so operators may use either method or may use an
accepted alternative. This AD has not been changed regarding this
request.

Request To Change To Allow Installation of New Housing

DAL requested a change to correct certain discrepancies in Boeing
Alert Service Bulletin 737-27A1314, Revision 1, dated June 24, 2020. In
the non-RC sections ``Work Package 1, Part 2: Installation, Test and
Close Access'' and ``Work Package 2, Part 2: Installation, Test and
Close Access,'' DAL asked for a change in wording of the proposed AD to
indicate that a ``new or changed'' upper cover assembly could be
installed. The commenter explained that the work instructions allow
either Option 1 (modify then reinstall existing housing) or Option 2
(install new housing).
The FAA disagrees with the request. While the non-RC work
instructions in Boeing Alert Service Bulletin 737-27A1314, Revision 1,
dated June 24, 2020, accurately describe the allowable installations,
changing the AD would not be warranted because the indicated sections
are not within Boeing Alert Requirements Bulletin 737-27A1314 RB,
Revision 2, dated July 6, 2021 (or within Revision 1, dated June 24,
2020). ``Work Package 1, Part 2: Installation, Test and Close Access''
and ``Work Package 2, Part 2: Installation, Test and Close Access,'' of
Boeing Alert Service Bulletin 737-27A1314, Revision 2, dated July 6,
2021, are for reference only. The manufacturer may choose to update
this section of the service information in a future revision, but this
section does not affect compliance with this AD. Operators can use
either option as specified in Boeing Alert Requirements Bulletin 737-
27A1314 RB, Revision 2, dated July 6, 2021. This AD has not been
changed regarding this request.

Clarification of Parts Installation Prohibition

Paragraphs (k)(1) and (2) of the proposed AD specified the parts
installation prohibition for airplanes with an original airworthiness
certificate or original export certificate of airworthiness issued
after the effective date of this AD and prior to the effective date of
this AD. However, airplanes with an original airworthiness certificate
or original export certificate of airworthiness issued on the effective
date of this AD were not identified in either paragraph. The FAA has
revised paragraph (k)(1) of this AD to include the parts installation
prohibition for airplanes with an original airworthiness certificate or
original export certificate of airworthiness issued on or after the
effective date of this AD.

Conclusion

The FAA reviewed the relevant data, considered the comments
received, and determined that air safety requires adopting the
requirements of this AD.

Related Service Information Under 1 CFR Part 51

The FAA reviewed Boeing Alert Requirements Bulletin 737-27A1313 RB,
Revision 1, dated June 24, 2020; and Boeing Alert Requirements Bulletin
737-27A1314 RB, Revision 2, dated July 6, 2021. The service information
describes procedures for modifying the captain's and first officer's
rudder pedal cover and shroud assemblies. This service information is
reasonably available because the interested parties have access to it
through their normal course of business or by the means identified in
ADDRESSES.

Costs of Compliance

The FAA estimates that this AD affects 2,048 airplanes of U.S.
registry. The FAA estimates the following costs to comply with this AD:

Estimated Costs for Required Actions

The FAA has included all costs in its cost estimate. According to
the manufacturer, however, some or all of the costs of this AD may be
covered under warranty, thereby reducing the cost impact on affected
operators.

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.

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

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]

2. The FAA amends Sec. 39.13 by:

a. Removing Airworthiness Directive 2017-14-13, Amendment 39-18957 (82
FR 33007, July 19, 2017); and

b. Adding the following new AD: