[Federal Register Volume 84, Number 171 (Wednesday, September 4, 2019)]
[Proposed Rules]
[Pages 46496-46498]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-18980]
[[Page 46496]]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2019-0670; Product Identifier 2019-NM-104-AD]
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 737-200, -200C, -300, -400, and -
500 series airplanes. This proposed AD was prompted by an evaluation by
the design approval holder (DAH) indicating that the lower skin of the
fuselage skin lap splices along the lower fastener row of a certain
stringer lap splice on certain body station skin panels is subject to
widespread fatigue damage (WFD). This proposed AD would require
inspections of the lower skin of the fuselage skin lap splices along
the lower fastener row of a lap splice on certain body station skin
panels and applicable on-condition actions. 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 October 21,
2019.
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 http://www.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.
For service information identified in this NPRM, contact Boeing
Commercial Airplanes, Attention: Contractual & Data Services (C&DS),
2600 Westminster Blvd., MC 110-SK57, Seal Beach, CA 90740-5600; phone:
562-797-1717; internet: https://www.myboeingfleet.com. You may view
this referenced 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-2019-0670.
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-2019-
0670; 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, the regulatory evaluation, any comments received, and other
information. The street address for Docket Operations is listed above.
Comments will be available in the AD docket shortly after receipt.
FOR FURTHER INFORMATION CONTACT: James Guo, Aerospace Engineer,
Airframe Section, FAA, Los Angeles ACO Branch, 3960 Paramount
Boulevard, Lakewood, CA 90712-4137; phone: 562-627-5357; fax: 562-627-
5210; 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-2019-0670;
Product Identifier 2019-NM-104-AD'' at the beginning of your comments.
The FAA specifically invites comments on the overall regulatory,
economic, environmental, and energy aspects of this NPRM. The FAA will
consider all comments received by the closing date and may amend this
NPRM because of those comments.
The FAA will post all comments received, without change, to http://www.regulations.gov, including any personal information you provide.
The FAA will also post a report summarizing each substantive verbal
contacts received about this proposed AD.
Discussion
Fatigue damage can occur locally, in small areas or structural
design details, or globally, in widespread areas. Multiple-site damage
is widespread damage that occurs in a large structural element such as
a single rivet line of a lap splice joining two large skin panels.
Widespread damage can also occur in multiple elements such as adjacent
frames or stringers. Multiple-site damage and multiple-element damage
cracks are typically too small initially to be reliably detected with
normal inspection methods. Without intervention, these cracks will
grow, and eventually compromise the structural integrity of the
airplane. This condition is known as WFD. It is associated with general
degradation of large areas of structure with similar structural details
and stress levels. As an airplane ages, WFD will likely occur, and will
certainly occur if the airplane is operated long enough without any
intervention.
The FAA's WFD final rule (75 FR 69746, November 15, 2010) became
effective on January 14, 2011. The WFD rule requires certain actions to
prevent structural failure due to WFD throughout the operational life
of certain existing transport category airplanes and all of these
airplanes that will be certificated in the future. For existing and
future airplanes subject to the WFD rule, the rule requires that DAHs
establish a limit of validity (LOV) of the engineering data that
support the structural maintenance program. Operators affected by the
WFD rule may not fly an airplane beyond its LOV, unless an extended LOV
is approved.
The WFD rule (75 FR 69746, November 15, 2010) does not require
identifying and developing maintenance actions if the DAHs can show
that such actions are not necessary to prevent WFD before the airplane
reaches the LOV. Many LOVs, however, do depend on accomplishment of
future maintenance actions. As stated in the WFD rule, any maintenance
actions necessary to reach the LOV will be mandated by airworthiness
directives through separate rulemaking actions.
In the context of WFD, this action is necessary to enable DAHs to
propose LOVs that allow operators the longest operational lives for
their airplanes, and still ensure that WFD will not occur. This
approach allows for an implementation strategy that provides
flexibility to DAHs in determining the timing of service information
development (with FAA approval), while providing operators with
certainty regarding the LOV applicable to their airplanes.
The FAA has received a report indicating that an operator of a
Model 737-300 airplane discovered a crack in the skin at a chem-milled
step at body station (STA) 727B+10, just above stringer (S)-14R. The
airplane had accumulated 88,805 flight hours and 65,804 flight cycles
at the time the crack was found. Upon further inspection in the local
area using high frequency eddy current (HFEC) hole probe inspection,
multiple fastener hole cracks were
[[Page 46497]]
found in the S-14 lap splice lower row in the lower skin between STA
727A and STA 727E. The lower skin at S-14 is structure that may be
susceptible to WFD and may also have scratches that can propagate into
cracks. The scratch cracks may interact with fatigue cracking. This
condition, if not addressed, could result in rapid decompression or
loss of structural integrity of the airplane.
Related Service Information Under 1 CFR Part 51
The FAA reviewed Boeing Alert Requirements Bulletin 737-53A1382 RB,
dated May 6, 2019. The service information describes procedures for
detailed inspections for previous repairs, and repetitive dual
frequency eddy current (DFEC) inspections for cracks of the lower skin
of the fuselage skin lap splices along the lower fastener row of the S-
14 lap splice at specified locations on the STA 727 to STA 908 skin
panel in areas not inspected by other service bulletins, and applicable
on-condition actions. On-condition actions include open hole HFEC
inspections for cracks, and repair.
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.
FAA's Determination
The FAA is proposing this AD because the agency evaluated all the
relevant information and determined the unsafe condition described
previously is likely to exist or develop in other products of the same
type design.
Proposed AD Requirements
This proposed AD would require accomplishment of the actions
identified in Boeing Alert Requirements Bulletin 737-53A1382 RB, dated
May 6, 2019, described previously, 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
service information at http://www.regulations.gov by searching for and
locating Docket No. FAA-2019-0670.
Costs of Compliance
The FAA estimates that this proposed AD affects 158 airplanes of
U.S. registry. The FAA estimates the following costs to comply with
this proposed AD:
Estimated Costs for Required Actions
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Cost on U.S.
Action Labor cost Parts cost Cost per product operators
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DFEC Inspections of S-14 Lap 18 work-hours x $85 $0 $1,530 per $241,740 per
Splices. per hour = $1,530 inspection. inspection.
per inspection.
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The FAA estimates the following costs to do any necessary on-
condition inspections that would be required. The FAA has no way of
determining the number of aircraft that might need these on-condition
actions:
Estimated Costs of On-Condition Actions
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Labor cost Parts cost Cost per product
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97 work-hours x $85 per hour = $0 $8,245
$8,245.
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The FAA has received no definitive data that would enable us to
provide cost estimates for the on-condition repairs specified in this
proposed AD.
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 proposed 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
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. 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 Proposed Amendment
Accordingly, under the authority delegated to me by the
Administrator, the FAA proposes to amend 14 CFR part 39 as follows:
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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 (AD):
The Boeing Company: Docket No. FAA-2019-0670; Product Identifier
2019-NM-104-AD.
(a) Comments Due Date
The FAA must receive comments by October 21, 2019.
(b) Affected ADs
None.
(c) Applicability
This AD applies to The Boeing Company Model 737-200, -200C, -
300, -400, and -500 series airplanes, certificated in any category,
as identified in Boeing Alert Requirements Bulletin 737-53A1382 RB,
dated May 6, 2019.
(d) Subject
Air Transport Association (ATA) of America Code 53, Fuselage.
(e) Unsafe Condition
This AD was prompted by an evaluation by the design approval
holder (DAH) indicating that the lower skin of the fuselage skin lap
splices along the lower fastener row of the stringer (S)-14 lap
splice on certain body station skin panels is subject to widespread
fatigue damage (WFD). The FAA is issuing this AD to address scratch
cracks and fatigue cracking which may interact and could result in
rapid decompression or loss of structural integrity of the airplane.
(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 737-53A1382 RB, dated May 6, 2019, do
all applicable actions identified in, and in accordance with, the
Accomplishment Instructions of Boeing Alert Requirements Bulletin
737-53A1382 RB, dated May 6, 2019.
Note 1 to paragraph (g): Guidance for accomplishing the actions
required by this AD can be found in Boeing Alert Service Bulletin
737-53A1382, dated May 6, 2019, which is referred to in Boeing Alert
Requirements Bulletin 737-53A1382 RB, dated May 6, 2019.
(h) Exceptions to Service Information Specifications
(1) For purposes of determining compliance with the requirements
of this AD: Where Boeing Alert Requirements Bulletin 737-53A1382 RB,
dated May 6, 2019 uses the phrase ``the original issue date of
Requirements Bulletin 737-53A1382 RB,'' this AD requires using ``the
effective date of this AD.''
(2) Where Boeing Alert Requirements Bulletin 737-53A1382 RB,
dated May 6, 2019, specifies contacting Boeing for repair
instructions or for alternative inspections: This AD requires doing
the repair, or doing the alternative inspections and applicable on-
condition actions using a method approved in accordance with the
procedures specified in paragraph (j) of this AD.
(i) Terminating Action
Certain skin panel replacements identified as terminating action
in Boeing Alert Requirements Bulletin 737-53A1382 RB, dated May 6,
2019, terminate the inspections in the corresponding locations
required by this AD.
(j) Alternative Methods of Compliance (AMOCs)
(1) The Manager, Los Angeles ACO 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 local Flight Standards
District 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 (k)(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 local flight standards district office/certificate holding
district 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, Los
Angeles ACO 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.
(k) Related Information
(1) For more information about this AD, contact James Guo,
Aerospace Engineer, Airframe Section, FAA, Los Angeles ACO Branch,
3960 Paramount Boulevard, Lakewood, CA 90712-4137; phone: 562-627-
5357; fax: 562-627-5210; email: [email protected].
(2) For service information 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; phone: 562-797-1717; internet: https://www.myboeingfleet.com.
You may view this referenced 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.
Issued in Des Moines, Washington, on August 23, 2019.
Suzanne Masterson,
Acting Director, System Oversight Division, Aircraft Certification
Service.
[FR Doc. 2019-18980 Filed 9-3-19; 8:45 am]
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