83 FR 38250 - Airworthiness Directives; The Boeing Company Airplanes

DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration

Federal Register Volume 83, Issue 151 (August 6, 2018)

We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 757 airplanes. This AD was prompted by reports of bolt rotation in the engine drag fitting joint and fasteners heads; an inspection of the fastener holes revealed that cracks were found in the skin on two airplanes. This AD requires repetitive inspections for skin cracking and shim migration at the upper link drag fittings, diagonal brace cracking, and fastener looseness; and applicable on- condition actions. We are issuing this AD to address the unsafe condition on these products.

[Federal Register Volume 83, Number 151 (Monday, August 6, 2018)]
[Rules and Regulations]
[Pages 38250-38253]
From the Federal Register Online  [www.thefederalregister.org]
[FR Doc No: 2018-16499]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2018-0110; Product Identifier 2017-NM-125-AD; Amendment 
39-19345; AD 2018-16-05]
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 757 airplanes. This AD was prompted by reports 
of bolt rotation in the engine drag fitting joint and fasteners heads; 
an inspection of the fastener holes revealed that cracks were found in 
the skin on two airplanes. This AD requires repetitive inspections for 
skin cracking and shim migration at the upper link drag fittings, 
diagonal brace cracking, and fastener looseness; and applicable on-
condition actions. We are issuing this AD to address the unsafe 
condition on these products.

DATES: This AD is effective September 10, 2018.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of September 
10, 2018.

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-2018-
0110.

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-2018-
0110; 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 Docket Operations, 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: Chandra Ramdoss, Aerospace Engineer, 
Airframe Section, FAA, Los Angeles ACO Branch, 3960 Paramount 
Boulevard, Lakewood, CA 90712-4137; phone: 562-627-5239; fax: 562-627-
5210; email: [email protected].

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 757 airplanes. The NPRM published in the Federal Register on 
February 16, 2018 (83 FR 6984). The NPRM was prompted by reports of 
bolt rotation in the engine drag fitting joint and fasteners heads; an 
inspection of the fastener holes revealed that cracks were found in the 
skin on two airplanes. The NPRM proposed to require repetitive 
inspections for skin cracking and shim migration at the upper link drag 
fittings, diagonal brace cracking, and fastener looseness; and 
applicable on-condition actions.
    We are issuing this AD to address cracking in the wing upper skin 
and forward drag fittings, which could lead to a compromised upper link 
and reduced structural integrity of the engine strut.

Comments

    We 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. Micaela Murrugarra and 
United Airlines stated that they supported the NPRM.

Effect of Winglets on Accomplishment of the Proposed Actions

    Aviation Partners Boeing stated that accomplishing the supplemental 
type certificate (STC) ST01518SE does not affect the actions specified 
in the NPRM.
    We concur with the commenter. We have redesignated paragraph (c) of 
the proposed AD as paragraph (c)(1) of this AD and added paragraph 
(c)(2) to this AD to state that installation of STC ST01518SE does not 
affect the ability to accomplish the actions required by this AD. 
Therefore, for airplanes on which STC ST01518SE is installed, a 
``change in product'' alternative method of compliance (AMOC) approval 
request is not necessary to comply with the requirements of 14 CFR 
39.17.

Request To Include Additional Inspections

    American Airlines (AAL) and FedEx requested that we revise the 
proposed AD to include additional inspections. FedEx stated that 
releasing the proposed AD using Boeing Alert Requirements Bulletin 757-
57A0073 RB, dated July 14, 2017, would have potential safety and 
economic implications on the operator. FedEx stated that the safety 
concern in its entirety is not addressed in Boeing Alert Requirements 
Bulletin 757-57A0073 RB, dated July 14, 2017, and any additional 
mandated inspections issued later would require a duplication of effort 
to address the remaining fastener locations. FedEx requested that the 
proposed AD include additional inspections.
    AAL stated that due to the ongoing efforts at Boeing to conduct a 
safety analysis on cracking found in the upper

[[Page 38251]]

link drag fitting layer on multiple airplanes, it encourages the FAA to 
work together with Boeing to include any new inspection requirements 
beyond those in Boeing Alert Requirements Bulletin 757-57A0073 RB, 
dated July 14, 2017, into the proposed AD. AAL commented that 
publication of the final rule without incorporating any new inspection 
requirements could drive additional unnecessary burden to operators by 
requiring multiple maintenance visits to conduct work that could have 
been consolidated.
    We disagree with the commenters' request. We do not consider that 
delaying this action until release of new service information is 
warranted since sufficient data and technology currently exist to 
justify the requirements in this AD within the required compliance 
time. We may consider further rulemaking in the future to require 
additional inspections based on revised service information, and if so, 
would determine an appropriate compliance time that would provide 
operators sufficient time to coordinate the inspection intervals. We 
have not changed this AD in this regard.

Request To Revise the Costs of Compliance

    AAL requested that we revise the costs of compliance in the NPRM. 
AAL stated that based on the inspections and repairs previously 
accomplished on 5 of its airplanes, it estimated 100 work-hours to 
complete the inspection requirements, 20 work-hours to complete a minor 
hole oversize repair, and 800 work-hours to accomplish a more complex 
hole repair or shim replacement. AAL also stated that the current 
fastener pricing procured from Boeing averages $445 per fastener.
    While we acknowledge AAL's varied work-hour estimates based on its 
repair experience for the requirements of this AD, we disagree with the 
commenter's request. The cost estimates and required man-hours are only 
approximate values and are not necessarily the same for different 
maintenance organizations and part suppliers. Because operators' 
schedules vary substantially, we cannot accommodate every operator's 
optimal scheduling in each AD. We have not changed this AD in this 
regard.

Request To Revise the Compliance Time

    AAL requested that we revise the grace period for the high 
frequency eddy current (HFEC) hole probe inspection from 3,000 flight 
cycles to 6,500 flight cycles after the effective date of this AD due 
to the extent of access that may be required to correct discrepancies. 
AAL stated that this proposed grace period would allow operators with a 
72-month heavy check interval, flying 3 flight cycles per day, to 
perform the required HFEC hole probe inspections at a visit with 
adequate span time and structures personnel to correct any possible 
findings. AAL also proposed adding interim inspections to justify this 
compliance-time extension.
    We disagree with the commenter's request. We have determined that 
the compliance time, as proposed, represents the maximum interval of 
time allowable for the affected airplanes to safely operate before the 
inspection and bolt replacement is done. Since maintenance schedules 
vary among operators, there would be no assurance that the airplane 
would be inspected and the bolt replaced during that maximum interval. 
In terms of adding interim inspections to justify the compliance-time 
extension, we have not received enough technical data to make this 
determination. However, under the provisions of paragraph (i) of this 
AD, we will consider requests for approval of interim inspections if 
sufficient data are submitted to substantiate that the change would 
provide an acceptable level of safety. We have not changed this AD in 
this regard.

Request To Replace the Inspection Type From the Proposed Action

    The Boeing Company and FedEx requested that we revise the proposed 
AD to remove the requirement of the dye-penetrant inspection of the 
bolts and to include a requirement to perform a detailed inspection of 
the bolts. Boeing stated that the dye-penetrant inspection of the bolts 
to look for cracking in the fillet between head and shank is 
problematic due to the coating on the bolt, creating an unacceptably 
high chance for false indication. Boeing commented that it has 
determined that replacing the dye-penetrant inspection with a detailed 
inspection is as an acceptable means to detect cracking in the fillet 
between head and shank. Boeing commented that it should be noted that 
the bolt head cracking is not the unsafe condition specified in Boeing 
Alert Requirements Bulletin 757-57A0073 RB, dated July 14, 2017. Boeing 
also commented that the bolt head cracking correlates with clamp loss, 
which can be a predecessor to early fatigue cracking of the wing skin; 
the condition duly mitigated by Boeing Alert Requirements Bulletin 757-
57A0073 RB, dated July 14, 2017.
    FedEx stated that the bolt dye-penetrant inspection is not an 
effective method due to the coating on the bolts. FedEx stated that 
Boeing indicates that it plans to revise the service information to 
provide an alternative detailed inspection that will be more effective. 
FedEx requests that the proposed AD include the revised inspection to 
allow operators a way to determine if the existing bolts are in a 
serviceable condition.
    We agree with the commenters' request. We have added paragraph 
(h)(3) to this AD accordingly to allow a detailed inspection for cracks 
in the fillet between head and shank on the removed fasteners in lieu 
of the dye-penetrant inspection. Either inspection will provide an 
adequate level of safety.

Request To Increase Shim Migration Limits

    AAL requested that we increase the shim migration limits. AAL 
stated that according to Boeing Alert Requirements Bulletin 757-57A0073 
RB, dated July 14, 2017, any shim migration of the horizontal shims 
greater than 0.200 inch and any shim migration where the migrated shim 
is greater than 0.020 inch thick are considered ``Major'' shim 
migration, which, according to paragraph (h) of the proposed AD, would 
require an approval for an alternative method of compliance for the 
corrective action.
    AAL commented that the shim migration limits noted above are far 
more conservative than the two-shim migration allowable limits 
currently contained in Boeing Model 757 Structural Repair Manual (SRM) 
54-50-90 for shim locations in the pylon. AAL stated that both SRM 
allowable limits have no restriction on shim thickness and allow 
migration of at least 25 percent of the total shim area.
    AAL recommended applying these same general principles from these 
SRM sections to the shims specified in the Boeing Alert Requirements 
Bulletin 757-57A0073 RB, dated July 14, 2017, and increasing the limits 
for minor shim migration to include full shim thickness, and migration 
up to 0.5 inch. AAL stated that the inspections contained in Boeing 
Alert Requirements Bulletin 757-57A0073 RB, dated July 14, 2017, and 
proposed in the proposed AD, are already adding additional surveillance 
of the upper link drag fitting to the upper wing skin joint, which 
would mitigate any risk associated with the increase in shim migration 
limits.
    We disagree with the commenter's request. Shim inspection 
procedures do not currently exist for the wing skin joint described in 
Boeing Alert Requirements Bulletin 757-57A0073 RB, dated July 14, 2017. 
However, under

[[Page 38252]]

the provisions of paragraph (i) of this AD, we will consider requests 
for approval of an AMOC if sufficient data are submitted to 
substantiate that the change would provide an acceptable level of 
safety. 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 with the changes described previously and minor 
editorial changes. We have 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.
    We also determined that these changes will not increase the 
economic burden on any operator or increase the scope of this final 
rule.

Related Service Information Under 1 CFR Part 51

    We reviewed Boeing Alert Requirements Bulletin 757-57A0073 RB, 
dated July 14, 2017. This service information describes procedures for 
repetitive detailed inspections for skin cracking and shim migration at 
the upper link drag fittings, repetitive general visual inspections for 
diagonal brace cracking and fastener looseness, and applicable on-
condition actions. 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 606 airplanes of U.S. registry. We 
estimate the following costs to comply with this AD:

                                      Estimated Costs for Required Actions
----------------------------------------------------------------------------------------------------------------
                                                                                               Cost on  U.S.
           Action                  Labor cost         Parts cost      Cost per  product          operators
----------------------------------------------------------------------------------------------------------------
Inspections................  83 work-hours x $85                $0  $7,055 per inspection  $4,275,330 per
                              per hour = $7,055                      cycle.                 inspection cycle.
                              per inspection cycle.
----------------------------------------------------------------------------------------------------------------

    We have received no definitive data that would enable us 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.
    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

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):

2018-16-05 The Boeing Company: Amendment 39-19345; Docket No. FAA-
2018-0110; Product Identifier 2017-NM-125-AD.

(a) Effective Date

    This AD is effective September 10, 2018.

(b) Affected ADs

    None.

(c) Applicability

    (1) This AD applies to The Boeing Company Model 757-200, -200PF, 
-200CB, and -300 series airplanes, certificated in any category, as 
identified in Boeing Alert Requirements Bulletin 757-57A0073 RB, 
dated July 14, 2017.
    (2) Installation of Supplemental Type Certificate (STC) 
ST01518SE does not affect the ability to accomplish the actions 
required by this AD. Therefore, for airplanes on which STC ST01518SE 
is installed, a ``change in product'' alternative method of 
compliance (AMOC) approval request is not necessary to comply with 
the requirements of 14 CFR 39.17.

(d) Subject

    Air Transport Association (ATA) of America Code 57, Wings.

(e) Unsafe Condition

    This AD was prompted by bolt rotation in the engine drag fitting 
joint and fasteners

[[Page 38253]]

heads; an inspection of the fastener holes revealed that cracks were 
found in the skin on two airplanes. We are issuing this AD to detect 
and correct cracking in the wing upper skin and forward drag 
fittings, which could lead to a compromised upper link and reduced 
structural integrity of the engine strut.

(f) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.

(g) Required Actions

    Except as required by paragraph (h) of this AD: At the 
applicable times specified in the ``Compliance'' paragraph of Boeing 
Alert Requirements Bulletin 757-57A0073 RB, dated July 14, 2017, do 
all applicable actions identified in, and in accordance with, the 
Accomplishment Instructions of Boeing Alert Requirements Bulletin 
757-57A0073 RB, dated July 14, 2017.

    Note 1 to paragraph (g) of this AD: Guidance for accomplishing 
the actions required by this AD can be found in Boeing Alert Service 
Bulletin 757-57A0073, dated July 14, 2017, which is referred to in 
Boeing Alert Requirements Bulletin 757-57A0073 RB, dated July 14, 
2017.

(h) Exceptions to Service Information Specifications

    (1) For purposes of determining compliance with the requirements 
of this AD: Where Boeing Alert Requirements Bulletin 757-57A0073 RB, 
dated July 14, 2017, uses the phrase ``the original issue date of 
the requirements bulletin,'' this AD requires using ``the effective 
date of this AD.''
    (2) Where Boeing Alert Requirements Bulletin 757-57A0073 RB, 
dated July 14, 2017, specifies contacting Boeing, this AD requires 
repair using a method approved in accordance with the procedures 
specified in paragraph (i) of this AD.
    (3) Where Boeing Alert Requirements Bulletin 757-57A0073 RB, 
dated July 14, 2017, specifies a dye-penetrant inspection for cracks 
in the fillet between head and shank on the removed fasteners,'' 
this AD allows a detailed inspection for cracks in the fillet 
between head and shank on the removed fasteners, as an optional 
method of compliance with the dye-penetrant inspection.

(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 Commercial Airplanes 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.

(j) Related Information

    (1) For more information about this AD, contact Chandra Ramdoss, 
Aerospace Engineer, Airframe Section, FAA, Los Angeles ACO Branch, 
3960 Paramount Boulevard, Lakewood, CA 90712-4137; phone: 562-627-
5239; 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; telephone 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.

(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.
    (i) Boeing Alert Requirements Bulletin 757-57A0073 RB, dated 
July 14, 2017.
    (ii) Reserved.
    (3) For Boeing 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, call 202-741-6030, or go to: http://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued in Des Moines, Washington, on July 24, 2018.
James Cashdollar,
Acting Director, System Oversight Division, Aircraft Certification 
Service.
[FR Doc. 2018-16499 Filed 8-3-18; 8:45 am]
 BILLING CODE 4910-13-P