DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2016-9189; Product Identifier 2016-NM-114-AD; Amendment
39-19578; AD 2019-03-26]
RIN 2120-AA64

Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: We are adopting a new airworthiness directive (AD) for certain
The Boeing Company Model 737-600, -700, -700C, -800, -900, and -900ER
series airplanes. This AD was prompted by reports of passenger service
units (PSUs) becoming detached from the supporting airplane structure
in several Model 737 series airplanes. This AD requires 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; measuring the distance between the hooks of the torsion
spring of the lanyard assembly; replacing discrepant lanyard
assemblies; and re-identifying serviceable lanyard assemblies. We are
issuing this AD to address the unsafe condition on these products.

DATES: This AD is effective April 8, 2019.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of April 8,
2019.

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, Transport Standards 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 on the internet at http://www.regulations.gov
by searching for and locating Docket No. FAA-2016-9189.

Examining the AD Docket

You may examine the AD docket on the internet at http://www.regulations.gov
by searching for and locating Docket No. FAA-2016-
9189; 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, the regulatory evaluation, any comments received, and
other information. The address for Docket Operations (phone: 800-647-
5527) 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: Scott Craig, Aerospace Engineer, Cabin
Safety and Environmental Systems Section, FAA, Seattle ACO Branch, 2200
South 216th St., Des Moines, WA 98198; phone and fax: 206-231-3566;
email: michael.s.craig@faa.gov.

SUPPLEMENTARY INFORMATION:

Discussion

We 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 737-600, -700, -700C, -800, -900, and -900ER series airplanes.
The NPRM published in the Federal Register on October 13, 2016 (81 FR
70647). The NPRM was prompted by reports of PSUs becoming detached from
the supporting airplane structure in several Model 737 series airplanes
during survivable accidents. The NPRM proposed to require modifying the
PSUs and life vest panels by removing the existing inboard lanyard and
installing two new lanyards on the outboard edge of the PSUs and life
vest panels.

We issued a supplemental NPRM (SNPRM) to amend 14 CFR part 39 by
adding an AD that would apply to certain The Boeing Company Model 737-
600, -700, -700C, -800, -900, and -900ER series airplanes. The SNPRM
published in the Federal Register on September 14, 2018 (83 FR 46666).
We issued the SNPRM to add airplanes to the applicability, add a
measurement of the distance between the hooks of the torsion spring of
the lanyard assembly, replace discrepant lanyard assemblies, and re-
identify serviceable lanyard assemblies.
We are 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
evacuation.

Comments

We gave the public the opportunity to participate in developing
this final rule. The following presents the comments received on the
SNPRM and the FAA's response to each comment.

Request To Include PSU-Mounted Liquid Crystal Display (LCD) Panels

JeJu Air requested that we consider adding actions similar to those
in the SNPRM for PSU-mounted LCD panels. JeJu Air noted that they
experienced an incident in which four PSU-mounted LCD panels dropped
during flight, resulting in minor injuries to several passengers. JeJu
Air stated that PSU-mounted LCD panels are not subject to routine
inspections through a manufacturer's maintenance planning document. The
commenter added that the PSU-mounted LCD panels are heavier than normal
PSUs and therefore could be riskier for passengers if they fall.
We acknowledge the commenter's concern. However, making the
requested change would require issuance of a second SNPRM with another
public comment period, delaying the issuance of a final rule. To delay
this action would be inappropriate, since we have determined that an
unsafe condition exists and that PSU modifications and lanyard
replacements must be made to ensure continued safety. We will consider
additional rulemaking to address PSU-mounted LCD panels. We have not
changed this AD in this regard.

Request To Revise the Applicability

Boeing requested that we revise the applicability of the proposed
AD (in the SNPRM) to The Boeing Company Model 737-600, -700, -700C, -
800, -900, and -900ER series airplanes ``as identified in Boeing
Service Bulletin 737-25-1707, Revision 1, dated May 18, 2018.'' Boeing
stated that including airplanes beyond those identified in Boeing
Service Bulletin 737-25-1707, Revision 1, dated May 18, 2018, would not
add to the safety of the operating fleet. Boeing added that airplanes
with potentially affected lanyard assemblies, whether included in
reworked airplanes, installed during production, or issued in kits, are
all categorized and addressed in Boeing Service Bulletin 737-25-1707,
Revision 1, dated May 18, 2018.
We disagree with the commenter's request. The PSUs and lanyard
assemblies are rotable parts that can be installed on airplanes that
previously did not have affected PSUs and lanyard assemblies installed.
Therefore, the applicability of this AD, ``all The Boeing Company Model
737-600, -700, -700C, -800, -900, and -900ER series airplanes,
certificated in any category, without a Boeing Sky Interior (BSI),''
ensures that no PSUs without the updated lanyard assemblies are
installed and the unsafe condition is addressed on all affected
airplanes. We have not changed this AD in this regard.

Request To Correct a Service Bulletin Effectivity Range

Boeing requested that we revise the ``Differences Between This
SNPRM and the Service Information'' section of the SNPRM to note that
the effectivity of Boeing Service Bulletin 737-25-1707, Revision 1,
dated May 18, 2018, is limited to ``line numbers 1 through 6099,''
rather than ``line numbers 1 through 6009.''
We acknowledge this typographical error. However, the ``Differences
Between This SNPRM and the Service Information'' section does not carry
over into this AD. Therefore, we have not changed this AD in this
regard.

Request To Remove a Requirement To Add an Identifying Mark

American Airlines (AAL) requested that we remove a requirement in
the proposed AD (in the SNPRM) to identify new lanyard assemblies as
serviceable by adding a permanent white mark. AAL noted that Figure 1,
step 3 of Boeing Service Bulletin 737-25-1707, Revision 1, dated May
18, 2018, which is Required for Compliance (RC), says to ``Identify the
lanyard assembly as serviceable with a permanent white mark, that can
be easily seen when the PSU is lowered.'' The commenter stated that new
lanyards received in certain kits are deemed serviceable, but not
identified with a white mark. AAL asked why the parts would be marked
at installation rather than inspection or fabrication, which seems to
place the burden on installers to determine the lanyard assembly is
serviceable.
We disagree with the commenter's request. Some previously delivered
lanyard assembly kits contained lanyards that were manufactured
incorrectly and might not properly secure the PSU in the event of an
accident. By inspecting and identifying the lanyard assembly during
installation, operators can ensure that the correct lanyard assembly is
installed on an airplane. On some airplanes, a correct lanyard assembly
may already be installed and only needs to be identified with a white
mark. Boeing Service Bulletin 737-25-1707, Revision 1, dated May 18,
2018, clearly identifies a serviceable lanyard assembly, and the white
mark is an important part of that definition. We have not changed this
AD in this regard.

Request To Provide More Details on PSU Removal and Installation

AAL requested that the Boeing 737NG Aircraft Maintenance Manual
(AMM) 25-23-61 provide more detailed instructions for removing and
installing the PSU. AAL noted that Boeing Service Bulletin 737-25-1707,
Revision 1, dated May 18, 2018, provides detailed instructions for
attaching the lanyard clip to the PSU rail, but the AMM does not
provide the same level of instructions. We infer that the commenter is
asking us to require Boeing to update the AMM to provide more details.
We acknowledge the commenter's request. The AMM is identified as an
affected publication in Boeing Service Bulletin 737-25-1707, Revision
1, dated May 18, 2018; however, this AD does not require compliance
with the AMM, and the AMM is not part of an RC step in the service
bulletin. The AMM is referred to as one source of information for
removing and installing the PSU, but as noted in paragraph (i)(4)(ii)
of this AD, operators may rely on their own accepted methods in
accordance with the operator's maintenance or inspection program for
those steps. In addition, Boeing Service Bulletin 737-25-1707, Revision
1, dated May 18, 2018, provides adequate details to address the unsafe
condition in this AD. Therefore, we have not changed this AD in this
regard.

Request To Revise the Costs of Compliance

AAL stated that Boeing Service Bulletin 737-25-1707, dated
September 24, 2015, provided a work-hours task total of 1.35 work-hours
per PSU. The commenter added that Boeing Service
Bulletin 737-25-1707, Revision 1, dated May 18, 2018, increased the
scope of work done on the PSU, but reduced the work-hours task total to
0.4 work-hours per PSU. We infer that the commenter is suggesting that
the work-hour estimates should be revised in the final rule.
We agree to clarify the Costs of Compliance section of this AD.
Boeing Service Bulletin 737-25-1707, Revision 1, dated May 18, 2018,
separates the work-hour estimates into multiple tables based on group
configurations and the type of work to be done. Adding all of the work-
hours from the applicable tables for a given configuration, the total
work-hours estimate is higher for certain configurations. Therefore,
the estimated costs in this AD represent the highest work-hours and
parts cost for all configurations. We have not changed this AD in this
regard.

Conclusion

We reviewed the relevant data, considered the comments received,
and determined that air safety and the public interest require adopting
this final rule as proposed, except for minor editorial changes. We
have determined that these minor changes:
Are consistent with the intent that was proposed in the
SNPRM for addressing the unsafe condition; and
Do not add any additional burden upon the public than was
already proposed in the SNPRM.

Related Service Information Under 1 CFR Part 51

We reviewed Boeing Service Bulletin 737-25-1707, Revision 1, dated
May 18, 2018. This service information describes 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, 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.
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 the ADDRESSES section.

Costs of Compliance

We estimate that this AD affects 2,015 airplanes of U.S. registry.
We estimate the following costs to comply with this AD:

Estimated Costs

According to the manufacturer, some or all of the costs of this AD
may be covered under warranty, thereby reducing the cost impact on
affected individuals. We do not control warranty coverage for affected
individuals. As a result, we have included all known costs in our cost
estimate.

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.
We are 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 is issued in accordance with authority delegated by the
Executive Director, Aircraft Certification Service, as authorized by
FAA Order 8000.51C. In accordance with that order, issuance of ADs is
normally a function of the Compliance and Airworthiness Division, but
during this transition period, the Executive Director has delegated the
authority to issue ADs applicable to transport category airplanes and
associated appliances to the Director of the System Oversight Division.

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) Is not a ``significant rule'' under DOT Regulatory Policies and
Procedures (44 FR 11034, February 26, 1979),
(3) Will not affect intrastate aviation in Alaska, and
(4) 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.

Adoption of 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 adding the following new airworthiness
directive (AD):