82 FR 39344 - Airworthiness Directives; The Boeing Company Airplanes

DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration

Federal Register Volume 82, Issue 159 (August 18, 2017)

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 a report of a Krueger flap bullnose departing an airplane during taxi, which caused damage to the wing structure and thrust reverser. This AD requires a one-time detailed visual inspection for discrepancies in the Krueger flap bullnose attachment hardware, and related investigative and corrective actions, if necessary. We are issuing this AD to address the unsafe condition on these products.

[Federal Register Volume 82, Number 159 (Friday, August 18, 2017)]
[Rules and Regulations]
[Pages 39344-39347]
From the Federal Register Online  [www.thefederalregister.org]
[FR Doc No: 2017-16354]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2016-9112; Product Identifier 2016-NM-091-AD; Amendment 
39-18982; AD 2017-16-05]
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 737-600, -700, -700C, -800, -900, and -900ER 
series airplanes. This AD was prompted by a report of a Krueger flap 
bullnose departing an airplane during taxi, which caused damage to the 
wing structure and thrust reverser. This AD requires a one-time 
detailed visual inspection for discrepancies in the Krueger flap 
bullnose attachment hardware, and related investigative and corrective 
actions, if necessary. We are issuing this AD to address the unsafe 
condition on these products.

DATES: This AD is effective September 22, 2017.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of September 
22, 2017.

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 referenced service information 
at the FAA, Transport Standards Staff, 1601 Lind Avenue SW., Renton, 
WA. For information on the availability of this material at the FAA, 
call 425-227-1221. It is also available on the Internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2016-
9112.

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-
9112; or in person at the Docket Management Facility between 9 a.m. and 
5 p.m., Monday through Friday, except Federal holidays. The AD docket 
contains this AD, the regulatory evaluation, any comments received, and 
other information. The address for the Docket Office (phone: 800-647-
5527) is Docket Management Facility, 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: Alan Pohl, Aerospace Engineer, 
Airframe Section, FAA, Seattle Aircraft Certification Office (ACO) 
Branch, 1601 Lind Avenue SW., Renton, WA 98057-3356; phone: 425-917-
6450; fax: 425-917-6590; 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 737-600, -700, -700C, -800, -900, and -900ER series airplanes. 
The NPRM published in the Federal Register on September 29, 2016 (81 FR 
66874) (``the NPRM''). The NPRM was prompted by a report of a Krueger 
flap bullnose departing an airplane during taxi, which caused damage to 
the wing

[[Page 39345]]

structure and thrust reverser. The NPRM proposed to require a one-time 
detailed visual inspection for discrepancies in the Krueger flap 
bullnose attachment hardware, and related investigative and corrective 
actions, if necessary. We are issuing this AD to detect and correct 
missing Krueger flap bullnose hardware. Such missing hardware could 
result in the Krueger flap bullnose departing the airplane during 
flight, which could damage empennage structure and lead to the 
inability to maintain continued safe flight and landing.

Comments

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

Support for the NPRM

    Vincent Romano, a private citizen, and United Airlines (UAL), 
stated their support for the NPRM.

Effect of Winglets on Accomplishment of the Proposed Actions

    Aviation Partners Boeing stated that accomplishing the Supplemental 
Type Certificate (STC) ST00830SE does not affect the actions specified 
in the NPRM.
    We concur with the commenter. We have redesignated paragraph (c) of 
the NPRM as paragraph (c)(1) and added paragraph (c)(2) to this AD to 
state that installation of STC ST00830SE does not affect the ability to 
accomplish the actions required by this AD. Therefore, for airplanes on 
which STC ST00830SE 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 Reference the Latest Service Information

    All Nippon Airways (ANA), American Airlines (AAL), Boeing, 
Jet2.com, TUIfly GmbH (HAP), UAL, and Kennedy Juma, requested revising 
the NPRM to reference Boeing Alert Service Bulletin 737-57A1327, 
Revision 1, dated September 28, 2016. Some commenters pointed out that 
the original issue had some errors in the illustrations and needed 
certain clarifications. ANA and Boeing also requested that we provide 
credit for accomplishing the original issue of the service information.
    We agree that this final rule should reference the latest service 
information. Since we issued the NPRM, Boeing issued Boeing Alert 
Service Bulletin 737-57A1327, Revision 1, dated September 28, 2016. We 
have revised paragraphs (c)(1) (paragraph (c) of the proposed AD) and 
(g) of this AD to reference Boeing Alert Service Bulletin 737-57A1327, 
Revision 1, dated September 28, 2016, for accomplishment of the 
required actions. We have also revised this AD to provide credit for 
using Boeing Alert Service Bulletin 737-57A1327, dated May 20, 2016, to 
accomplish the required actions before the effective date of this AD.

Request To Correct the Latest Service Information

    AAL requested that Boeing Alert Service Bulletin 737-57A1327, 
Revision 1, dated September 28, 2016, be corrected to address errors in 
Figures 1, 2, 3, and 4. AAL stated that these errors affect the 
depiction of how the clevis assembly, clevis, and bullnose hinge lug 
are attached to each other, and suggested that revising the figures to 
correct the errors would clarify which parts must be subject to the 
detailed inspection.
    We acknowledge that Figures 1, 2, 3, and 4 of Boeing Alert Service 
Bulletin 737-57A1327, Revision 1, dated September 28, 2016, contain 
errors in the labeling of parts in the illustrations. However, the 
instructions in the tables in the figures correctly identify the parts 
and actions to be accomplished. Since the instructions are correct, the 
service bulletin adequately addresses the unsafe condition. We do not 
revise manufacturers' service information. However, Boeing might decide 
to revise Boeing Alert Service Bulletin 737-57A1327, Revision 1, dated 
September 28, 2016, to correct the errors. We have not changed the AD 
in this regard.

Request To Allow Alternate Replacement Procedure

    AAL and Southwest Airlines (SWA) requested that we revise the NPRM 
to provide an option to replace cracked or deformed bullnose hinge lugs 
or clevis assemblies with bullnose hinge lugs or clevis assemblies 
instead of replacement with a Krueger flap assembly, as specified in 
paragraph 3.B.2.a.(1)(a)1) of Boeing Alert Service Bulletin 737-
57A1327, Revision 1, dated September 28, 2016. AAL suggested that the 
replacement option could be done using certain sections of a component 
maintenance manual (CMM). SWA suggested the use of Boeing production 
installation drawings. Both AAL and SWA also stated that replacing only 
the affected bullnose hinge lugs or clevis assemblies would also reduce 
the cost of repair or replacement. SWA also stated that there is a 
limited inventory of Krueger flap assemblies and that limited 
inventory, combined with a 6-month compliance time could significantly 
impair operators.
    We understand that the suggested replacement option might reduce 
the burden on operators. However, we do not agree to revise this AD to 
include the suggested changes. The repairs provided by the suggested 
sections of the CMM address normal wear-and-tear, and these repairs may 
not be appropriate for addressing damage that might result from an 
improperly attached Krueger flap. Boeing informed us that there is no 
procedure in the CMM that would provide step-by-step instructions to 
remove only the bullnose other than by use of the drawing system. 
Engineering instructions would be needed to ensure that the remainder 
of the flap assembly is serviceable and not damaged in addition to the 
damaged bullnose hinge lugs or clevis assembly, and that level of 
instruction would be too much detail for an AD. However, once we issue 
this AD, any person may request approval of an AMOC under the 
provisions of paragraph (i) of this AD. We have not changed the 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 AD 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 correcting the unsafe condition; and
     Do not add any additional burden upon the public than was 
already proposed in the NPRM.

[[Page 39346]]

    We also determined that these changes will not increase the 
economic burden on any operator or increase the scope of this AD.

Related Service Information Under 1 CFR Part 51

    We reviewed Boeing Alert Service Bulletin 737-57A1327, Revision 1, 
dated September 28, 2016. The service information describes procedures 
for a one-time detailed visual inspection for discrepancies in the 
Krueger flap bullnose attachment hardware, and related investigative 
and corrective 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 1,495 airplanes of U.S. registry. 
We estimate the following costs to comply with this AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                       Cost per    Cost on U.S.
              Action                        Labor cost              Parts cost         product       operators
----------------------------------------------------------------------------------------------------------------
Inspection of the Krueger flap      3 work-hours x $85 per     None................         $255        $381,225
 bullnose hardware.                  hour = $255.
----------------------------------------------------------------------------------------------------------------

    We have received no definitive data that would enable us to provide 
cost estimates for the on-condition actions specified in this AD.
    According to the manufacturer, some 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 available 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 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):

2017-16-05 The Boeing Company: Amendment 39-18982; Docket No. FAA-
2016-9112; Product Identifier 2016-NM-091-AD.

(a) Effective Date

    This AD is effective September 22, 2017.

(b) Affected ADs

    None.

(c) Applicability

    (1) This AD applies to The Boeing Company Model 737-600, -700, -
700C, -800, -900, and -900ER series airplanes, certificated in any 
category, as identified in Boeing Alert Service Bulletin 737-
57A1327, Revision 1, dated September 28, 2016.
    (2) Installation of Supplemental Type Certificate (STC) 
ST00830SE (http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgstc.nsf/0/354588EE63741A068625807D006726F6?OpenDocument&Highlight=st00830se) 
does not affect the ability to accomplish the actions required by 
this AD. Therefore, for airplanes on which STC ST00830SE 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 a report of a Krueger flap bullnose 
departing an airplane during taxi, which caused damage to the wing 
structure and thrust reverser. We are issuing this AD to detect and 
correct missing Krueger flap bullnose hardware. Such missing 
hardware could result in the Krueger flap bullnose departing the 
airplane during flight, which could damage empennage structure and 
lead to the inability to maintain continued safe flight and landing.

(f) Compliance

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

(g) Inspection of the Krueger Flap Bullnose

    Within 6 months after the effective date of this AD, do a 
detailed inspection for discrepancies of the Krueger flap bullnose 
attachment hardware, and do all applicable related investigative and 
corrective actions,

[[Page 39347]]

in accordance with the Accomplishment Instructions of Boeing Alert 
Service Bulletin 737-57A1327, Revision 1, dated September 28, 2016. 
Do all applicable related investigative and corrective actions 
before further flight.

(h) Credit for Previous Actions

    This paragraph provides credit for the actions specified in 
paragraph (g) of this AD, if those actions were performed before the 
effective date of this AD using Boeing Alert Service Bulletin 737-
57A1327, dated May 20, 2016.

(i) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Seattle Aircraft Certification Office (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, Seattle ACO Branch, 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) For service information that contains steps that are labeled 
as Required for Compliance (RC), the provisions of paragraphs 
(i)(4)(i) and (i)(4)(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 sub-step is labeled ``RC Exempt,'' then 
the RC requirement is removed from that step or sub-step. 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 Alan Pohl, 
Aerospace Engineer, Airframe Section, FAA, Seattle ACO Branch, 1601 
Lind Avenue SW., Renton, WA 98057-3356; phone: 425-917-6450; fax: 
425-917-6590; 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 (k)(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.
    (i) Boeing Alert Service Bulletin 737-57A1327, Revision 1, dated 
September 28, 2016.
    (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 FAA, Transport 
Standards Branch, 1601 Lind Ave SW., Renton, WA. For information on 
the availability of this material at the FAA, call 425-227-1221.
    (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 Renton, Washington, on July 26, 2017.
Jeffrey E. Duven,
Director, System Oversight Division, Aircraft Certification Service.
[FR Doc. 2017-16354 Filed 8-17-17; 8:45 am]
 BILLING CODE 4910-13-P