[Federal Register Volume 81, Number 131 (Friday, July 8, 2016)]
[Rules and Regulations]
[Pages 44503-44508]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2016-15904]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2015-6541; Directorate Identifier 2015-NM-135-AD; 
Amendment 39-18581; AD 2016-13-16]
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 all The 
Boeing Company Model 737-600, -700, -700C, -800, -900, and -900ER 
series airplanes. This AD was prompted by reports of a manufacturing 
oversight, in which a supplier omitted the required protective finish 
on certain bushings installed in the rear spar upper chord on 
horizontal stabilizers, which could lead to galvanic corrosion and 
consequent cracking of the rear spar upper chord. This AD requires an 
inspection or records check to determine if affected horizontal 
stabilizers are installed, related investigative actions, and for 
affected horizontal stabilizers, repetitive inspections for any crack 
of the horizontal stabilizer rear spar upper chord, and corrective 
action if necessary. We are issuing this AD to detect and correct 
cracking of the rear spar upper chord, which can result in the failure 
of the upper chord and consequent departure of the horizontal 
stabilizer from the airplane, which can lead to loss of control of the 
airplane.

DATES: This AD is effective August 12, 2016.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of August 12, 
2016.

ADDRESSES: For service information identified in this final rule, 
contact Boeing Commercial Airplanes, Attention: Data & Services 
Management, P.O. Box 3707, MC 2H-65, Seattle, WA 98124-2207; telephone 
206-544-5000, extension 1; fax 206-766-5680; Internet https://www.myboeingfleet.com. You may view this referenced service information 
at the FAA, Transport Airplane Directorate, 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-2015-
6541.

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-2015-
6541; 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

[[Page 44504]]

Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE., Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: Gaetano Settineri, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office 
(ACO), 1601 Lind Avenue SW., Renton, WA 98057-3356; phone: 425-917-
6577; 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 all The Boeing Company 
Model 737-600, -700, -700C, -800, -900, and -900ER series airplanes. 
The NPRM published in the Federal Register on November 30, 2015 (80 FR 
74726) (``the NPRM''). The NPRM was prompted by reports of a 
manufacturing oversight, in which a supplier omitted the required 
protective finish on certain bushings installed in the rear spar upper 
chord on horizontal stabilizers, which could lead to galvanic corrosion 
and consequent cracking of the rear spar upper chord. The NPRM proposed 
to require an inspection or records check to determine if affected 
horizontal stabilizers are installed, related investigative actions, 
and for affected horizontal stabilizers, repetitive inspections for any 
crack of the horizontal stabilizer rear spar upper chord, and 
corrective action if necessary. We are issuing this AD to detect and 
correct cracking of the rear spar upper chord, which can result in the 
failure of the upper chord and consequent departure of the horizontal 
stabilizer from the airplane, which can lead to loss of control of the 
airplane.

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

    Air Line Pilots Association International (ALPA) stated that it 
supports the NPRM. Boeing stated that is concurs with the NPRM.

Effect of Winglets on Accomplishment of the Proposed Actions

    Aviation Partners Boeing stated that installation of winglets per 
Supplemental Type Certificate (STC) ST00830SE (http://rgl.faa.gov/
Regulatory_and_Guidance_Library/rgstc.nsf/0/
184de9a71ec3fa5586257eae00707da6/$FILE/ST00830SE.pdf) does not affect 
the ability to accomplish the actions specified in the NPRM.
    We concur with the commenter. We have redesignated paragraph (c) of 
the proposed AD as paragraph (c)(1) and added new paragraph (c)(2) to 
this AD to state that installation of STC ST00830SE (http://
rgl.faa.gov/Regulatory_and_Guidance_Library/rgstc.nsf/0/
184de9a71ec3fa5586257eae00707da6/$FILE/ST00830SE.pdf) does not affect 
the ability to accomplish the actions required by this final rule. 
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 Revise the Proposed Applicability

    Airlines for America (A4A) requested that we revise the 
applicability of the proposed AD to state ``This AD applies to all 
horizontal stabilizers with serial numbers identified in Boeing SB 737-
55A1097.'' A4A explained that the proposed AD is applicable to all 
Boeing Model 737-600, -700, -700C, -800, -900, and -900ER series 
airplanes; however, Boeing Alert Service Bulletin 737-55A1097, dated 
July 1, 2015, provides a list of affected horizontal stabilizers by 
serial number. A4A expressed that the physical plate inspections 
required by paragraph (g)(1)(ii) of the proposed AD are excessive and 
unneeded, as operators normally track serialized components without the 
need to physically inspect the airframe. A4A further reasoned that when 
paragraph (c) of the proposed AD is written against all Model 737 Next 
Generation airframes, the complexity of compliance reporting becomes 
more burdensome. The net result, stated A4A, is indefinite record 
keeping of AD compliance for airplanes that are not equipped with 
horizontal stabilizers affected by the manufacturing oversight.
    We do not agree to revise the applicability of this AD as requested 
by the commenter. Paragraph (g)(1) of this AD gives operators the 
option of performing either a records check or an inspection. If the 
operator's records are sufficient to determine the serial number of the 
horizontal stabilizers on the affected airplane, then a physical 
inspection is not required. Furthermore, the affected horizontal 
stabilizers are rotable parts, so it is possible that an affected 
horizontal stabilizer could be installed on numerous airplanes during 
its service life, even on a new production airplane once it enters 
service. As specified in paragraph 2.B.(2) of Chapter 6 of the AD 
Manual, FAA-IR-M-8040.1C (http://rgl.faa.gov/
Regulatory_and_Guidance_Library/rgOrders.nsf/0/
66ddd8e1d2e95db3862577270062aabd/$FILE/FAA-IR-M-8040_1C.pdf), when the 
unsafe condition results from the installation of the appliance or part 
on an aircraft, the AD action is issued against the aircraft, not the 
appliance or part. Therefore, we have determined that it is appropriate 
for this AD to apply to all airplanes of the specified model types. We 
have made no changes to the applicability of this AD.

Request To Allow Removal and Replacement of Affected Horizontal 
Stabilizers

    A4A requested that we revise paragraph (h)(2) of the proposed AD to 
allow removal of an affected horizontal stabilizer, and replacement 
with an unaffected or an affected horizontal stabilizer that is within 
the parameters of paragraph 1.E. ``Compliance,'' of Boeing Alert 
Service Bulletin 737-55A1097, dated July 1, 2015. A4A explained that 
paragraph (g)(2) of the proposed AD requires that the inspection 
specified in Boeing Alert Service Bulletin 737-55A1097, dated July 1, 
2015, be accomplished on any horizontal stabilizer found to be within 
the effectivity of Boeing Alert Service Bulletin 737-55A1097, dated 
July 1, 2015, and the compliance times found in paragraph 1.E., 
``Compliance.'' A4A expressed that if cracking is found, operators must 
repair in accordance with paragraph (h)(2) of the proposed AD; 
paragraph (h)(2) of the proposed AD requires repair in accordance with 
paragraph (j) of the proposed AD before further flight.
    We agree. We have determined that removing a damaged horizontal 
stabilizer and replacing it with a serviceable horizontal stabilizer, 
as provided in paragraph (i) of this AD, addresses the identified 
unsafe condition. We have revised paragraph (h)(2) of this AD 
accordingly.

Request for Review of Other Inspection Methods

    A4A requested that the FAA and Boeing review other non-destructive 
test (NDT) inspection options such as an ultrasound process to satisfy 
the proposed inspection requirements. A4A pointed out that paragraph 
(g)(2) of the proposed AD specifies a high frequency eddy current 
(HFEC) method for inspection of the rear spar upper chord. A4A 
explained that the FAA should be aware that other methods, specifically

[[Page 44505]]

ultrasound inspection, may be better NDT diagnostic techniques, and 
that an ultrasound inspection, compared to the proposed HFEC process, 
may detect early crack development from the fitting holes versus 
cracking that has propagated up to and near the surface of the rear 
spar upper chord.
    We partially agree. We agree with the commenter that other 
inspection methods may be better NDT diagnostic techniques and note 
that alternative methods of compliance (AMOCs) have been granted to ADs 
when updated service information containing improved procedures to 
address an unsafe condition becomes available.
    We disagree to include other inspection options in this final rule, 
because the inspection technique required in this AD adequately 
addresses the unsafe condition and is accompanied by service 
information, which includes detectable crack lengths and inspection 
intervals. If additional service information that provides alternative 
NDT inspection methods becomes available, under the provisions of 
paragraph (j) of this AD, we will consider requests for approval of an 
AMOC if sufficient data are submitted to substantiate that the 
inspection method would provide an acceptable level of safety. We have 
made no changes to this AD in this regard.

Requests for Clarification of Parts Installation Requirements

    A4A requested that we reword paragraphs (g) and (i) of the proposed 
AD to allow operators to maintain or install any affected horizontal 
stabilizer on any airplane, provided that the horizontal stabilizer is, 
or will be, inspected as specified in paragraph 1.E., ``Compliance,'' 
of Boeing Alert Service Bulletin 737-55A1097, dated July 1, 2015. A4A 
explained that paragraphs (i)(1) and (i)(2) of the proposed AD preclude 
installation of an affected horizontal stabilizer without accomplishing 
the required inspection. A4A explained further that other maintenance 
activity could cause a horizontal stabilizer to be removed and 
reinstalled prior to reaching the compliance times specified in Boeing 
Alert Service Bulletin 737-55A1097, dated July 1, 2015. With the 
potential interpretation of paragraph (g)(2) of the proposed AD being 
to inspect immediately, the initial inspection would be significantly 
accelerated, and the inspection schedule would be altered for the 
remaining life of the component.
    All Nippon Airways (ANA) requested that we clarify the parts 
installation restrictions specified in paragraph (i) of the proposed AD 
to reduce the burden for operators. ANA explained that parts 
installation is restricted based on its serial number, and that 
paragraph (i)(2)(i) of the proposed AD requires initial inspection 
specified in paragraph (g)(2) of the proposed AD before further flight. 
ANA expressed that this requirement is applicable if the flight cycles 
and/or the date of issuance the original certificate of airworthiness, 
or the original export certificate of airworthiness for the horizontal 
stabilizer are unknown or have already exceeded the proposed compliance 
time specified in paragraph (g)(2) of the proposed AD. ANA reasoned 
that, if the flight cycles and the date of issuance of the original 
certificate of airworthiness or the original export certificate of 
airworthiness of the horizontal stabilizer are known, and the flight 
cycles and years on the horizontal stabilizer are less than the 
compliance times specified in paragraph 1.E., ``Compliance,'' of Boeing 
Alert Service Bulletin 737-55A1097, dated July 1, 2015, operators may 
conduct the inspection specified in paragraph (g)(2) of this AD at the 
time specified in paragraph (g)(2) of this AD.
    We agree to clarify. An affected horizontal stabilizer that has not 
reached the inspection threshold or the next repeat interval is still 
in compliance with this AD at the time it is installed on the airplane. 
We have revised paragraph (i)(2)(i) of this AD to read ``Initial and 
repetitive HFEC inspections specified in paragraph (g)(2) of this AD 
are completed within the compliance times specified in paragraph (g)(2) 
of this AD.'' We also agree to clarify that the 10-year compliance time 
specified in paragraph 1.E. ``Compliance,'' of Boeing Alert Service 
Bulletin 737-55A1097, dated July 1, 2015, is measured using the 
airplane the affected horizontal stabilizer was delivered on.

Request for Specific Repair Instructions and Terminating Action

    A4A requested that repair instructions be provided either in a 
revision to the service information, or via the structural repair 
manual (SRM). A4A also requested that the proposed AD be revised to 
include a preventive, terminating action including the option to remove 
and replace the subject bushings in the upper chord fitting during a 
heavy check schedule. A4A expressed that the NPRM and Boeing Alert 
Service Bulletin 737-55A1097, dated July 1, 2015, provide neither 
specific repair methods nor a means to terminate the inspections. A4A 
reasoned that the NPRM requires corrective action for any crack that is 
discovered, and that such action is to be performed in accordance with 
paragraph (j) of the proposed AD, which is the AMOC section. A4A said 
that, although no known inspections have revealed cracking, we (the 
FAA) must believe that findings will occur, and that operators would 
benefit by having guidance from Boeing without the need for an AMOC 
request. Similarly, A4A expressed, without a repair plan, there should 
also be a means of terminating the inspections entirely. A4A pointed to 
a recent experience concerning seat track cracking that exposed the 
difficulties of embarking upon a required inspection plan without a 
defined recovery path. A4A referred to AD 2013-23-04, Amendment 39-
17659 (78 FR 68693, November 15, 2013) (``AD 2013-23-04''), and stated 
that AD also directed operators to the AMOC process.
    We do not agree. An AD is issued to address an identified unsafe 
condition, as required by 14 CFR part 39. The determination of the 
unsafe condition, mitigating action, and compliance times in this AD 
has all been coordinated with Boeing. This AD is being issued to 
address the lack of corrosion protection on a critical structural 
element. As a result, dissimilar metal corrosion may cause cracking of 
the horizontal stabilizer rear spar upper chord. With no service 
history of cracking yet reported, it is expected that any cracking will 
be limited and not result in a significant disruption to affected 
operators. The inspections required by this AD provide an acceptable 
level of safety for the affected airplanes. We have reviewed with 
Boeing the implementation issues associated with AD 2013-23-04 and 
expect that Boeing will provide us with approvable data for repair and 
terminating actions in a timely manner to address any cracking found.
    For these reasons, we do not consider that delaying this action 
until after the possible release of revised service information is 
warranted, since sufficient technology and service information 
currently exist to accomplish the required actions within the 
compliance time. However, under the provisions of paragraph (j) of this 
AD, we will consider requests for approval of AMOCs for revised service 
information, repairs, or terminating actions if sufficient data are 
submitted to substantiate they would provide an acceptable level of 
safety. For these reasons, we have made no changes to this AD in this 
regard.

[[Page 44506]]

Request To Clarify Specific Parts of the Service Information

    ANA stated that paragraph (g)(1)(i) of the proposed AD should refer 
to Part 1, and paragraph (g)(1)(ii) of the proposed AD should refer to 
Part 2 of the Accomplishment Instructions of Boeing Alert Service 
Bulletin 737-55A1097, dated July 1, 2015. ANA did not provide a reason 
for this request.
    From these statements, we infer that ANA is requesting that we 
revise paragraphs (g)(1)(i) and (g)(1)(ii) of the proposed AD. We agree 
that the changes requested by ANA provide additional clarity. We have 
added ``Part 1 of'' to paragraph (g)(1)(i) and ``Part 2 of'' to 
paragraph (g)(1)(ii) of this AD.

Request for Assurance of Parts Availability

    A4A also requested that, prior to release of the AD, we assure that 
Boeing has sections of the rear spar available for the horizontal 
stabilizer including a typical splice repair plan for each affected 
737-NG fleet. A4A also requested that Boeing also provide or have 
available, horizontal stabilizers that are service ready prior to the 
release of the AD.
    We do not agree. We do not consider that delaying this action until 
Boeing has assured that replacement parts will be available is 
warranted. This AD is issued to address an identified unsafe condition, 
as required by 14 CFR part 39. The determination of the unsafe 
condition, mitigating action, and compliance times in this AD has all 
been coordinated with Boeing. This AD is being issued to address the 
lack of corrosion protection on a critical structural element. As a 
result, dissimilar metal corrosion may cause cracking of the horizontal 
stabilizer rear spar upper chord. With no service history of cracking 
yet reported, it is expected that any cracking will be limited and not 
be a significant disruption to affected operators. We understand that 
Boeing will make horizontal stabilizer parts and assemblies available 
as necessary for operators to address possible on-condition actions. 
However, since it is unknown how many repairs or replacements may be 
necessary and what parts would be necessary for each repair, we cannot 
estimate the type and number of parts needed. If parts availability 
becomes an issue, under the provisions of paragraph (j) of this AD, we 
may approve requests for adjustments to the compliance time for doing a 
repair or replacement if data are submitted to substantiate that such 
an adjustment would provide an acceptable level of safety. We have made 
no changes to 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 AD with the changes described previously and minor editorial 
changes. We have determined that these minor changes:
     [Agr]re 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.
    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 737-55A1097, dated July 
1, 2015. The service information describes procedures for an inspection 
or records check to determine if affected horizontal stabilizers are 
installed, related investigative actions, HFEC inspections for any 
crack of the horizontal stabilizer rear spar upper chord, and 
corrective action if necessary. 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 1,397 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 or records check...........  1 work-hour x $85 per                 $0             $85        $118,745
                                         hour = $85.
----------------------------------------------------------------------------------------------------------------

    We estimate the following costs to do any necessary inspections 
that would be required based on the results of the inspection or 
records check. We have no way of determining the number of aircraft 
that might need these inspections:

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                     Cost per
                  Action                                 Labor cost                 Parts cost        product
----------------------------------------------------------------------------------------------------------------
Inspections...............................  4 work-hours x $85 per hour = $340..              $0            $340
----------------------------------------------------------------------------------------------------------------

    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 costs in our cost 
estimate.
    We have received no definitive data that would enable us to provide 
cost estimates for the on-condition repairs 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

[[Page 44507]]

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.

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):

2016-13-16 The Boeing Company: Amendment 39-18581; Docket No. FAA-
2015-6541; Directorate Identifier 2015-NM-135-AD.

(a) Effective Date

    This AD is effective August 12, 2016.

(b) Affected ADs

    None.

(c) Applicability

    (1) This AD applies to all The Boeing Company Model 737-600, -
700, -700C, -800, -900, and 900ER series airplanes, certificated in 
any category.
    (2) Installation of Supplemental Type Certificate (STC) 
ST00830SE (http://rgl.faa.gov/Regulatory_and_Guidance_Library/
rgstc.nsf/0/184de9a71ec3fa5586257eae00707da6/$FILE/ST00830SE.pdf) 
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 55, Stabilizers.

(e) Unsafe Condition

    This AD was prompted by reports of a manufacturing oversight, in 
which a supplier omitted the required protective finish on certain 
bushings installed in the rear spar upper chord on horizontal 
stabilizers, which could lead to galvanic corrosion and consequent 
cracking of the rear spar upper chord. We are issuing this AD to 
detect and correct cracking of the rear spar upper chord, which can 
result in the failure of the upper chord and consequent departure of 
the horizontal stabilizer from the airplane, which can lead to loss 
of control of the airplane.

(f) Compliance

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

(g) Serial Number Check or Inspection To Determine if Certain 
Horizontal Stabilizers Are Installed, Related Investigative Actions, 
Repetitive Inspections for Cracks, and Corrective Action

    (1) Except as specified in paragraph (h)(1) of this AD, within 
the compliance time identified in paragraph 1.E., ``Compliance,'' of 
Boeing Alert Service Bulletin 737-55A1097, dated July 1, 2015, do 
the actions specified in paragraph (g)(1)(i) or (g)(1)(ii) of this 
AD.
    (i) Do a records check to determine if an affected horizontal 
stabilizer is installed and if any horizontal stabilizer has been 
exchanged, and do all applicable related investigative actions, in 
accordance with Part 1 of the Accomplishment Instructions of Boeing 
Alert Service Bulletin 737-55A1097, dated July 1, 2015. Affected 
horizontal stabilizers are identified in the Accomplishment 
Instructions of Boeing Alert Service Bulletin 737-55A1097, dated 
July 1, 2015.
    (ii) Do an inspection of the horizontal stabilizer 
identification plate to determine if any affected horizontal 
stabilizer is installed, in accordance with Part 2 of the 
Accomplishment Instructions of Boeing Alert Service Bulletin 737-
55A1097, dated July 1, 2015. Affected horizontal stabilizers are 
identified in the Accomplishment Instructions of Boeing Alert 
Service Bulletin 737-55A1097, dated July 1, 2015.
    (2) If, during any action required by paragraph (g)(1)(i) or 
(g)(1)(ii) of this AD, any affected horizontal stabilizer is found: 
Except as specified in paragraph (h)(1) of this AD, within the 
compliance time identified in paragraph 1.E., ``Compliance,'' of 
Boeing Alert Service Bulletin 737-55A1097, dated July 1, 2015, do a 
high frequency eddy current (HFEC) inspection for any crack of the 
horizontal stabilizer rear spar upper chord and do all applicable 
corrective actions, in accordance with the Accomplishment 
Instructions of Boeing Alert Service Bulletin 737-55A1097, dated 
July 1, 2015, except as required by paragraph (h)(2) of this AD. 
Repeat the inspection thereafter at intervals identified in 
paragraph 1.E., ``Compliance,'' of Boeing Alert Service Bulletin 
737-55A1097, dated July 1, 2015.

(h) Exceptions to the Service Information Specifications

    (1) Where Boeing Alert Service Bulletin 737-55A1097, dated July 
1, 2015, specifies a compliance time ``after the original issue date 
of this service bulletin,'' this AD requires compliance within the 
specified compliance time after the effective date of this AD.
    (2) If any cracking is found during any inspection required by 
this AD, and Boeing Alert Service Bulletin 737-55A1097, dated July 
1, 2015, specifies to contact Boeing for appropriate action: Before 
further flight, repair using a method approved in accordance with 
the procedures specified in paragraph (j) of this AD, or replace 
with a serviceable horizontal stabilizer as specified in paragraph 
(i) of this AD.

(i) Parts Installation Restrictions

    As of the effective date of this AD, no person may install a 
horizontal stabilizer on any airplane, except as specified in 
paragraphs (i)(1) and (i)(2) of this AD.
    (1) A horizontal stabilizer may be installed if the part is 
inspected in accordance with ``Part 2: Horizontal Stabilizer 
Identification Plate Inspection'' of the Accomplishments 
Instructions of Boeing Alert Service Bulletin 737-55A1097, dated 
July 1, 2015, and no affected serial number is found.
    (2) A horizontal stabilizer may be installed if the part is 
inspected in accordance with ``Part 2: Horizontal Stabilizer 
Identification Plate Inspection'' of the Accomplishments 
Instructions of Boeing Alert Service Bulletin 737-55A1097, dated 
July 1, 2015, and an affected serial number is found, provided that 
the actions specified in paragraphs (i)(2)(i) and (i)(2)(ii) of this 
AD are done, as applicable.
    (i) Initial and repetitive HFEC inspections specified in 
paragraph (g)(2) of this AD are completed within the compliance 
times specified in paragraph (g)(2) of this AD.
    (ii) All applicable corrective actions are done before further 
flight as required by paragraph (h)(2) of this AD.

(j) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Seattle Aircraft Certification Office (ACO), 
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 ACO, send it to the 
attention of the person identified in paragraph (k) of this AD. 
Information may be

[[Page 44508]]

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 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, to make 
those findings. For a repair method to be approved, the repair 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 
(j)(4)(i) and (j)(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. 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.

(k) Related Information

    For more information about this AD, contact Gaetano Settineri, 
Aerospace Engineer, Airframe Branch, ANM 120S, FAA, Seattle Aircraft 
Certification Office (ACO), 1601 Lind Avenue SW., Renton, WA 98057-
3356; phone: 425-917-6577; fax: 425-917-6590; email: 
[email protected].

(l) 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 737-55A1097, dated July 1, 
2015.
    (ii) Reserved.
    (3) For Boeing service information identified in this AD, 
contact Boeing Commercial Airplanes, Attention: Data & Services 
Management, P.O. Box 3707, MC 2H-65, Seattle, WA 98124-2207; 
telephone 206-544-5000, extension 1; fax 206-766-5680; Internet 
https://www.myboeingfleet.com.
    (4) You may view this service information at the FAA, 1601 Lind 
Avenue 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 June 23, 2016.
Dorr M. Anderson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2016-15904 Filed 7-7-16; 8:45 am]
 BILLING CODE 4910-13-P