DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2021-0504; Project Identifier AD-2020-01380-T;
Amendment 39-21876; AD 2021-26-17]
Airworthiness Directives; The Boeing Company Airplanes
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
SUMMARY: The FAA is superseding Airworthiness Directive (AD) 2019-03-
26, which applied to certain The Boeing Company Model 737-600, -700, -
700C, -800, -900, and -900ER series airplanes. AD 2019-03-26 required
modifying the passenger service units (PSUs) and life vest panels by
replacing the existing inboard lanyard and installing two new lanyards
on the outboard edge of the PSUs and life vest panels; measuring the
distance between the hooks of the torsion spring of the lanyard
assembly; replacing discrepant lanyard assemblies; and re-identifying
serviceable lanyard assemblies. This AD was prompted by a determination
that certain airplanes are listed in the wrong configuration and
certain PSUs have not been correctly re-identified. This AD retains the
requirements of AD 2019-03-26, and, for certain airplanes, requires an
inspection to determine if the re-identified PSU part number is
correct, and further re-identification if necessary. The FAA is issuing
this AD to address the unsafe condition on these products.
DATES: This AD is effective February 15, 2022.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of February 15,
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.
Examining the AD Docket
You may examine the AD docket at https://www.regulations.gov by
searching for and locating Docket No. FAA-2021-0504; 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: Tony Koung, Aerospace Engineer,
Safety and Environmental Systems Section, FAA, Seattle ACO Branch, 2200
South 216th St., Des Moines, WA 98198; phone and fax: 206-231-3985;
The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 to supersede AD 2019-03-26, Amendment 39-19578 (84 FR 7266,
March 4, 2019) (AD 2019-03-26). AD 2019-03-26 applied to certain The
Boeing Company Model 737-600, -700, -700C, -800, -900, and -900ER
series airplanes. The NPRM published in the Federal Register on June
30, 2021 (86 FR 34653). The NPRM was prompted by a determination that
certain airplanes are listed in the wrong configuration and certain
PSUs have not been correctly re-identified. In the NPRM, the FAA
proposed to continue to require the requirements of AD 2019-03-26, and,
for certain airplanes, would require an inspection to determine if the
re-identified PSU part number is correct, and further re-identification
if necessary. The FAA is issuing this AD to address PSUs and life vest
panels detaching from the supporting airplane structure, which could
lead to passenger injuries and impede passenger and crew egress during
Discussion of Final Airworthiness Directive
The FAA received comments from two commenters, including The Boeing
Company and an individual, who supported the NPRM without change.
The FAA received additional comments from two other commenters,
including All Nippon Airways (ANA) and Aviation Partners Boeing (APB).
The following presents the comments received on the NPRM and the FAA's
response to each comment.
Request To Allow Credit for Earlier Revision of Service Information
ANA requested that the proposed AD be revised to add a note to
allow use of Boeing Service Bulletin 737-25-1707, Revision 1, dated May
18, 2018. ANA stated that it has some airplanes that are identified as
``Group 1'' airplanes in Boeing Special Attention Service Bulletin 737-
25-1707, Revision 2, dated July 27, 2020, and on which Revision 1 of
the service bulletin was accomplished. ANA added that the changes
described in Revision 2 of the service bulletin do not affect the work
instructions for airplanes identified as ``Group 1'' and believed that
Revision 1 could also be used to comply with the proposed requirements.
The FAA disagrees with the request to revise this AD to allow use
of Boeing Service Bulletin 737-25-1707, Revision 1, dated May 18, 2018,
as it is not necessary. Group 1 is divided into three configurations,
depending on whether or not earlier revisions of Boeing Special
Attention Service Bulletin 737-25-1707, Revision 2, dated July 27,
2020, have been done. Group 1 airplanes on which Boeing Service
Bulletin 737-25-1707, Revision 1, dated May 18, 2018, has been done are
defined as Group 1, Configuration 3 airplanes. The
Accomplishment Instructions of Boeing Special Attention Service
Bulletin 737-25-1707, Revision 2, dated July 27, 2020, specify for
Group 1, Configuration 3 airplanes, that no further action is required,
and therefore this AD does not require further action. The FAA has not
revised this AD in this regard.
Effects of Winglets on Accomplishment of the Proposed Actions
APB stated that the installation of winglets per Supplemental Type
Certificate (STC) ST00830SE does not affect the accomplishment of the
manufacturer's service instructions.
The FAA agrees with the commenter that STC ST00830SE does not
affect the accomplishment of the manufacturer's service instructions.
Therefore, the installation of STC ST00830SE does not affect the
ability to accomplish the actions required by this AD. 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. Except for minor editorial changes, this AD is adopted as
proposed in the NPRM. None of the changes will increase the economic
burden on any operator.
Related Service Information Under 1 CFR Part 51
The FAA reviewed Boeing Special Attention Service Bulletin 737-25-
1707, Revision 2, dated July 27, 2020. This service information
specifies procedures for modifying the PSUs and life vest panels by:
Replacing the existing inboard lanyard and installing two new lanyards
on the outboard edge of the PSUs and life vest panels (secondary
retention features); measuring the distance between the hooks of the
torsion spring of the lanyard assembly; replacing any discrepant
lanyard assemblies; and re-identifying serviceable lanyard assemblies.
For some airplanes, the service information specifies procedures for
inspecting PSUs for correct re-identification part numbers and, if
necessary, re-identifying the PSU. 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
Costs of Compliance
The FAA estimates that this AD will affect 2,045 airplanes of U.S.
registry. The FAA estimates the following costs to comply with this AD:
||Cost per product
||Cost on U.S. operators
|Measurement and modification
(retained actions from AD 2019-03-26)
||Up to 70 work-hour x
$85 per hour = $5,950
||Up to $13,000
||Up to $18,950
||Up to $38,752,750
|Inspection of re-identified parts
(per PSU) (new actions)
||1 work-hour x $85 per
hour = $85
The FAA estimates the following costs
to do any necessary
replacements or re-identifications that will be required based on the
results of the inspection. The FAA has no way of determining the number
of aircraft that might need these replacements or re-identifications:
|Replacement or re-identification
(per PSU or life vest panel)
||Up to 2 work-hour x
$85 per hour = $170
Up to $196
Up to $366
The FAA has included all known costs
in its cost estimate.
According to the manufacturer, however, some of the costs of this AD
may be covered under warranty, thereby reducing the cost impact on
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.
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
(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
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 (AD) 2019-03-26, Amendment 39-19578
(84 FR 7266, March 4, 2019); and
b. Adding the following new AD: