[Federal Register Volume 84, Number 245 (Friday, December 20, 2019)]
[Rules and Regulations]
[Pages 70000-70003]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-27465]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2019-0406; Product Identifier 2019-NM-059-AD; Amendment
39-21006; AD 2019-24-17]
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 all
The Boeing Company Model MD-90-30 airplanes. This AD was prompted by
reports indicating that certain center wing stringers and skins are
potentially susceptible to cracking. This AD requires repetitive eddy
current, low frequency (ETLF) inspections of the left and right side
fastener holes for any crack; repetitive eddy current, high frequency
(ETHF) inspections of the lower skin for any crack; and repair if any
crack is found. The FAA is issuing this AD to address the unsafe
condition on these products.
DATES: This AD is effective January 24, 2020.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of January 24,
2020.
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 https://www.regulations.gov by searching for and locating Docket No. FAA-2019-
0406.
Examining the AD Docket
You may examine the AD docket on the internet at https://www.regulations.gov by searching for and locating Docket No. FAA-2019-
0406; 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 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: David Truong, Aerospace Engineer,
Airframe Section, FAA, Los Angeles ACO Branch, 3960 Paramount
Boulevard, Lakewood, CA 90712-4137; phone: 562-627-5224; fax: 562-627-
5210; email: [email protected].
SUPPLEMENTARY INFORMATION:
Discussion
The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 by adding an AD that would apply to all The Boeing Company
Model MD-90-30 airplanes. The NPRM published in the Federal Register on
June 21, 2019 (84 FR 29105). The NPRM was prompted by reports
indicating that based on Model MD-80 airplane service experience,
certain center wing stringers and skins are potentially susceptible to
fatigue-related cracking on Model MD-90 airplanes. The Model MD-80 and
Model MD-90 wings share the same basic design and experience similar
stresses, but no such cracking has been found on Model MD-90 airplanes.
Cracks on Model MD-80 airplanes were found in the center wing lower
stringers, at the inboard end where they are joined to the airplane
centerline by end fittings; in the lower stringer end fittings, at the
outboard end where they attach to stringers; and in the lower forward
and aft skins, underneath cracked stringers. If not addressed, this
cracking could result in the inability of the structure to sustain
limit loads, and adversely affect the structural integrity of the
airplane. The NPRM proposed to require repetitive ETLF inspections of
the left and right side fastener holes for any crack; repetitive ETHF
inspections of the lower skin for any crack; and repair if any crack is
found.
Comments
The FAA gave the public the opportunity to participate in
developing this final rule. The following presents the comments
received on the NPRM and the FAA's response to each comment.
Request for Clarification of Other Relevant Rulemaking Section
Boeing requested clarification regarding the number of cracking
occurrences reported in areas outside of those addressed by AD 2016-07-
28, Amendment 39-18473 (81 FR 21253, April 11, 2016) (``AD 2016-07-
28''), or Boeing Alert Service Bulletin MD80-
[[Page 70001]]
57A244, dated March 3, 2016. Boeing noted that in the NPRM, the Other
Relevant Rulemaking section stated that since AD 2016-07-28 was issued,
cracking was found at fastener holes common to stringers (S) S-11
through S-22, and around the external bracket angle at S-18 and S-19.
Boeing emphasized that there was only one case of cracking, at S-13.
In addition, Boeing requested that the Other Relevant Rulemaking
section in the NPRM be revised to explain that the new service
information that Boeing is developing for Model MD-80 airplanes is to
address potential cracking in new stringer locations and is not in
response to actual in-service reports of cracking.
The FAA agrees with the commenter's assessment of crack findings.
Of the cracks found since issuance of AD 2016-07-28, only one was found
at S-13--the only area not addressed by AD 2016-07-28. All remaining
crack findings were within the scope of the requirements of AD 2016-07-
28. As a result of these cracks, Boeing made the determination to
expand the inspection to stringers S-11 through S-22. This AD addresses
those stringers on Model MD-90-30 airplanes.
The FAA acknowledges that the service information for the Model MD-
80 airplanes, Boeing Service Bulletin MD80-57A244, dated March 3, 2016,
which is mandated by AD 2016-07-28, has been revised. Boeing Service
Bulletin MD80-57A244, Revision 1, dated October 1, 2019, updates the
inspection method and expands the inspection area. The FAA may consider
further rulemaking in the future to mandate these changes for Model MD-
80 airplanes.
Because the Other Relevant Rulemaking section in SUPPLEMENTARY
INFORMATION is not retained in final rules, the FAA has not revised
this final rule in regard to these issues.
Request To Revise Cost Information
Delta Air Lines (DAL) requested clarification regarding the number
of airplanes on the U.S. registry that would be affected by the NPRM.
DAL stated that the Costs of Compliance paragraph indicated that an
estimated 43 airplanes would be affected. However, DAL is the only U.S.
operator of the affected airplanes, and DAL reports that there are 65
airplanes in their operations specification.
The FAA agrees with the commenter and has revised the Costs of
Compliance paragraph in this final rule accordingly.
Request for Legible Service Information
DAL requested that better quality copies of certain sheets of
Boeing Drawing SN09570007 be provided to operators. The commenter
stated that the poor quality of these sheets renders them useless in
terms of doing inspections and is concerned about showing compliance
with the requirements specified in the proposed AD.
The FAA acknowledges the commenter's concern regarding the
legibility of certain sheets of Boeing Drawing SN09570007. Since Boeing
Alert Service Bulletin MD90-57A031, dated March 19, 2019, does not
include Boeing Drawing SN09570007 in the ``Required for Compliance
(RC)'' section, the drawing is not required to comply with this AD. The
drawing is referenced in Paragraph 1.J.2., Planning Information,
References, Data Supplied with the Service Bulletin, in Boeing Alert
Service Bulletin MD90-57A031, dated March 19, 2019. Operators notified
Boeing about the illegible drawing sheets, and in response, Boeing
issued Boeing Multi Operator Message MOM-MOM-19-0549-01B, dated October
4, 2019, which provides clearer images of Boeing Drawing SN09570007.
The FAA recognizes that Boeing Drawing SN09570007 may provide helpful
information to operators. Therefore, the FAA has added Note 1 to
paragraph (g) of this AD to notify operators that if they have
illegible pages of Boeing Drawing SN09570007, additional guidance can
be found in Boeing Multi Operator Message MOM-MOM-19-0549-01B, dated
October 4, 2019.
Conclusion
The FAA reviewed the relevant data, considered the comments
received, and determined that air safety and the public interest
require adopting this final rule with the changes described previously
and minor editorial changes. The FAA determined that these minor
changes:
Are consistent with the intent that was proposed in the
NPRM for addressing the unsafe condition; and
Do not add any additional burden upon the public than was
already proposed in the NPRM.
The FAA also determined that these changes will not increase the
economic burden on any operator (other than the estimated number of
affected airplanes as explained under the ``Request to Revise Cost
Information'' section of this final rule) or increase the scope of this
final rule.
Related Service Information Under 1 CFR Part 51
The FAA reviewed Boeing Alert Service Bulletin MD90-57A031, dated
March 19, 2019. This service information describes procedures for
repetitive ETLF inspections of the left and right side fastener holes
for any crack, repetitive ETHF inspections of the lower skin for any
crack, and repair if any crack is found. 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
The FAA estimates that this AD affects 65 airplanes of U.S.
registry. The FAA estimates the following costs to comply with this AD:
Estimated Costs
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Cost on U.S.
Action Labor cost Parts cost Cost per product operators
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Inspection.............. 30 work-hours x $85 per $0 $2,550 per $165,750 per
hour = $2,550 per inspection cycle. inspection cycle.
inspection cycle.
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The FAA has received no definitive data that would enable the
agency to provide cost estimates for the on-condition actions specified
in this 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
[[Page 70002]]
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) 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.
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
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):
2019-24-17 The Boeing Company: Amendment 39-21006; Docket No. FAA-
2019-0406; Product Identifier 2019-NM-059-AD.
(a) Effective Date
This AD is effective January 24, 2020.
(b) Affected ADs
None.
(c) Applicability
This AD applies to all The Boeing Company Model MD-90-30
airplanes, certificated in any category.
(d) Subject
Air Transport Association (ATA) of America Code 57, Wings.
(e) Unsafe Condition
This AD was prompted by reports indicating that certain center
wing stringers and skins are potentially susceptible to cracking.
The FAA is issuing this AD to address cracking of the center wing
stringers and skins, which could result in the inability of the
structure to sustain limit loads, and adversely affect the
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 in paragraph (h) of this AD: At the
applicable times specified in paragraph 1.E., ``Compliance,'' of
Boeing Alert Service Bulletin MD90-57A031, dated March 19, 2019, do
all applicable actions identified as ``RC'' (required for
compliance) in, and in accordance with, the Accomplishment
Instructions of Boeing Alert Service Bulletin MD90-57A031, dated
March 19, 2019.
Note 1 to paragraph (g) of this AD: Boeing Alert Service
Bulletin MD90-57A031, dated March 19, 2019, refers to Boeing Drawing
SN09570007, as data supplied with this service bulletin. If the
pages of Boeing Drawing SN09570007 are illegible, guidance can be
found in Boeing Multi Operator Message MOM-MOM-19-0549-01B, dated
October 4, 2019.
(h) Exceptions to Service Information Specifications
(1) For purposes of determining compliance with the requirements
of this AD: Where Boeing Alert Service Bulletin MD90-57A031, dated
March 19, 2019, uses the phrase ``the original issue date of this
service bulletin,'' this AD requires using ``the effective date of
this AD.''
(2) Where Boeing Alert Service Bulletin MD90-57A031, dated March
19, 2019, specifies contacting Boeing for repair instructions and
doing the repair: This AD requires doing the repair using a method
approved in accordance with the procedures specified in paragraph
(i) of this AD.
(i) 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 (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 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.
(4) Except as specified by paragraph (h) of this AD: For service
information that contains steps that are labeled as Required for
Compliance (RC), the provisions of paragraphs (i)(4)(i) and (ii) of
this AD apply.
(i) The steps labeled as RC, including substeps under an RC step
and any figures identified in an RC step, must be done to comply
with the AD. If a step or substep is labeled ``RC Exempt,'' then the
RC requirement is removed from that step or substep. An AMOC is
required for any deviations to RC steps, including substeps and
identified figures.
(ii) Steps not labeled as RC may be deviated from using accepted
methods in accordance with the operator's maintenance or inspection
program without obtaining approval of an AMOC, provided the RC
steps, including substeps and identified figures, can still be done
as specified, and the airplane can be put back in an airworthy
condition.
(j) Related Information
(1) For more information about this AD, contact David Truong,
Aerospace Engineer, Airframe Section, FAA, Los Angeles ACO Branch,
3960 Paramount Boulevard, Lakewood, CA 90712-4137; phone: 562-627-
5224; fax: 562-627-5210; email: [email protected].
(2) Service information identified in this AD that is not
incorporated by reference is available at the addresses specified in
paragraphs (k)(3) and (4) of this AD.
(k) Material Incorporated by Reference
(1) The Director of the Federal Register approved the
incorporation by reference (IBR) of the service information listed
in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
(2) You must use this service information as applicable to do
the actions required by this AD, unless the AD specifies otherwise.
[[Page 70003]]
(i) Boeing Alert Service Bulletin MD90-57A031, dated March 19,
2019.
(ii) [Reserved]
(3) 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; telephone 562-797-1717; internet https://www.myboeingfleet.com.
(4) 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.
(5) You may view this service information that is incorporated
by reference at the National Archives and Records Administration
(NARA). For information on the availability of this material at
NARA, email [email protected], or go to: https://www.archives.gov/federal-register/cfr/ibr-locations.html.
Issued in Des Moines, Washington, on December 4, 2019.
Michael Kaszycki,
Acting Director, System Oversight Division, Aircraft Certification
Service.
[FR Doc. 2019-27465 Filed 12-19-19; 8:45 am]
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