
[Federal Register Volume 81, Number 49 (Monday, March 14, 2016)]
[Rules and Regulations]
[Pages 13271-13274]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2016-05515]


=======================================================================
-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2016-4222; Directorate Identifier 2016-NM-017-AD; 
Amendment 39-18433; AD 2016-06-02]
RIN 2120-AA64


Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule; request for comments.

-----------------------------------------------------------------------

SUMMARY: We are adopting a new airworthiness directive (AD) for all The 
Boeing Company Model 737-300, -400, and -500 series airplanes. This AD 
requires repetitive inspections for cracking in the horizontal and 
vertical flanges of the rear spar upper chord of the horizontal 
stabilizer, and related investigative and corrective actions if 
necessary. This AD was prompted by a report of cracking in the center 
section of the horizontal stabilizer. We are issuing this AD to detect 
and correct cracking of the rear spar center section of the horizontal 
stabilizer that could lead to departure of the horizontal stabilizer 
from the airplane.

DATES: This AD is effective March 29, 2016.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of March 29, 
2016.
    We must receive comments on this AD by April 28, 2016.

ADDRESSES: You may send comments, using the procedures found in 14 CFR 
11.43 and 11.45, by any of the following methods:
     Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
     Fax: 202-493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE., Washington, DC 20590.
     Hand Delivery: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE., Washington, DC 20590, between 9 a.m. and 5 p.m., 
Monday through Friday, except Federal holidays.
    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-2016-
4222.

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-
4222; 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 street address for the Docket Office (phone: 
800-647-5527) is in the ADDRESSES section. Comments will be available 
in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Payman Soltani, Aerospace Engineer, 
Airframe Branch, ANM-120L, FAA, Los Angeles Aircraft Certification 
Office (ACO), 3960 Paramount Boulevard, Lakewood, CA 90712-4137; phone: 
562-627-5313; fax: 562-627-5210; email: Payman.Soltani@faa.gov.

SUPPLEMENTARY INFORMATION: 

Discussion

    We have received a report of cracking in the center section of the 
horizontal stabilizer. A review of empennage loading of the Model 737-
300, -400, and -500 series airplanes identified several loading 
discrepancies that included landing rollout (LRO) buffet condition 
within the ground-air-ground (GAG) operational loads. These loading 
discrepancies impact the operating stress level on the rear spar upper 
chord of the horizontal stabilizer center section, which can lead to 
cracking. We have determined that the inspection threshold for 
detecting the cracking needs to be lower than the existing required 
compliance threshold of 66,000 total flight cycles. This horizontal 
stabilizer center section cracking, if not corrected, could result in 
departure of the horizontal stabilizer from the airplane.

Related Rulemaking

    On April 8, 2008, we issued AD 2008-09-13, Amendment 39-15494 (73 
FR 24164, May 2, 2008), for all Boeing Model 737-300, -400, and -500 
series

[[Page 13272]]

airplanes. AD 2008-09-13 requires revising the FAA-approved maintenance 
or inspection program to include inspections that will give no less 
than the required damage tolerance rating for each structural 
significant item (SSI), doing repetitive inspections to detect cracks 
of all SSIs, and repairing cracked structure.

Related Service Information Under 1 CFR Part 51

    We reviewed Boeing Alert Service Bulletin 737-55A1100, dated 
January 26, 2016. This service information describes procedures for 
inspections for cracking in the horizontal and vertical flanges of the 
rear spar upper chord of the horizontal stabilizer, an inspection to 
identify the fasteners common to the rear spar upper chord upper gusset 
of the horizontal stabilizer center section, and related investigative 
and corrective actions 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.

FAA's Determination

    We are issuing this AD because we evaluated all the relevant 
information and determined the unsafe condition described previously is 
likely to exist or develop in other products of the same type design.

AD Requirements

    This AD requires accomplishing the actions specified in the service 
information described previously, except as discussed under 
``Differences Between this AD and the Service Information.'' For 
information on the procedures and compliance times, see this service 
information at http://www.regulations.gov by searching for and locating 
Docket No. FAA-2016-4222.
    The phrase ``related investigative actions'' is used in this AD. 
Related investigative actions are follow-on actions that (1) are 
related to the primary action, and (2) further investigate the nature 
of any condition found. Related investigative actions in an AD could 
include, for example, inspections.
    The phrase ``corrective actions'' is used in this AD. Corrective 
actions are actions that correct or address any condition found. 
Corrective actions in an AD could include, for example, repairs.

Differences Between the AD and the Service Information

    Boeing Alert Service Bulletin 737-55A1100, dated January 26, 2016, 
specifies to contact the manufacturer for instructions on how to repair 
certain conditions, but this AD would require repairing those 
conditions in one of the following ways:
     In accordance with a method that we approve; or
     Using data that meet the certification basis of the 
airplane, and that have been approved by the Boeing Commercial 
Airplanes Organization Designation Authorization (ODA) whom we have 
authorized to make those findings.
    Boeing Alert Service Bulletin 737-55A1100, dated January 26, 2016, 
specifies compliance using ``horizontal stabilizer center section 
flight cycles'' or ``center section flight cycles;'' this AD requires 
compliance for those conditions or compliance times in terms of 
airplane flight cycles.

FAA's Justification and Determination of the Effective Date

    An unsafe condition exists that requires the immediate adoption of 
this AD. The FAA has found that the risk to the flying public justifies 
waiving notice and comment prior to adoption of this rule because 
cracking of the rear spar center section of the horizontal stabilizer 
could lead to departure of the horizontal stabilizer from the airplane. 
Therefore, we find that notice and opportunity for prior public comment 
are impracticable and that good cause exists for making this amendment 
effective in less than 30 days.

Comments Invited

    This AD is a final rule that involves requirements affecting flight 
safety and was not preceded by notice and an opportunity for public 
comment. However, we invite you to send any written data, views, or 
arguments about this AD. Send your comments to an address listed under 
the ADDRESSES section. Include the docket number FAA-2016-4222 and 
Directorate Identifier 2016-NM-017-AD at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of this AD. We will 
consider all comments received by the closing date and may amend this 
AD because of those comments.
    We will post all comments we receive, without change, to http://www.regulations.gov, including any personal information you provide. We 
will also post a report summarizing each substantive verbal contact we 
receive about this AD.

Costs of Compliance

    We estimate that this AD affects 400 airplanes of U.S. registry.
    We estimate the following costs to comply with this AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                  Cost on U.S.
             Action                     Labor cost           Parts cost     Cost per product       operators
----------------------------------------------------------------------------------------------------------------
Inspections....................  Up to 15 work-hours x                $0   Up to $1,275 per    Up to $510,000
                                  $85 per hour = $1,275                     inspection cycle.   per inspection
                                  per inspection cycle.                                         cycle.
----------------------------------------------------------------------------------------------------------------

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

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                     Cost per
                  Action                                Labor cost                 Parts cost        product
----------------------------------------------------------------------------------------------------------------
Repair....................................  8 work-hours x $85 per hour = $680           (\1\)             $680
----------------------------------------------------------------------------------------------------------------
\1\ We have received no definitive data that would enable us to provide parts cost estimates for the actions
  specified in this AD.


[[Page 13273]]

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.

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):

2016-06-02 The Boeing Company: Amendment 39-18433; Docket No. FAA-
2016-4222; Directorate Identifier 2016-NM-017-AD.

(a) Effective Date

    This AD is effective March 29, 2016.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to all The Boeing Company Model 737-300, -400, 
and -500 series airplanes, certificated in any category.

(d) Subject

    Air Transport Association (ATA) of America Code 55, Stabilizers.

(e) Unsafe Condition

    This AD was prompted by a report of cracking in the center 
section of the horizontal stabilizer. We are issuing this AD to 
detect and correct cracking of the rear spar center section of the 
horizontal stabilizer that could lead to departure of the horizontal 
stabilizer from the airplane.

(f) Compliance

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

(g) Actions for the Rear Spar Upper Chord Horizontal Flange of the 
Horizontal Stabilizer Center Section

    At the applicable times specified in table 1 of paragraph 1.E., 
``Compliance,'' of Boeing Alert Service Bulletin 737-55A1100, dated 
January 26, 2016, except as required by paragraphs (j)(1), (j)(2), 
and (j)(3) of this AD: Do the actions required by paragraph (g)(1) 
or (g)(2) of this AD; and do all applicable related investigative 
and corrective actions; in accordance with the Accomplishment 
Instructions of Boeing Alert Service Bulletin 737-55A1100, dated 
January 26, 2016, except as required by paragraph (j)(4) of this AD. 
Do all applicable related investigative and corrective actions at 
the applicable times specified in tables 5, 6, 7, and 8 of paragraph 
1.E., ``Compliance,'' of Boeing Alert Service Bulletin 737-55A1100, 
dated January 26, 2016. For airplanes on which ``Option 1'' of 
``CONDITION 15: SURFACE HFEC INSPECTION OF THE CHORD AROUND THE 
GUSSETS--NO CRACK FOUND'' is done as specified in the Accomplishment 
Instructions of Boeing Alert Service Bulletin 737-55A1100, dated 
January 26, 2016, repeat the inspection specified in paragraph 
(g)(2) of this AD thereafter at the applicable times specified in 
table 8 of paragraph 1.E., ``Compliance,'' of Boeing Alert Service 
Bulletin 737-55A1100, dated January 26, 2016.
    (1) Do an inspection to identify the fasteners common to the 
rear spar upper chord upper gusset of the horizontal stabilizer 
center section.
    (2) Do a surface high frequency eddy current (HFEC) inspection 
of the rear spar upper chord around the two inboard gusset plates 
common to the thrust and auxiliary beams for any crack.

(h) Repetitive Inspections of the Vertical Flange of the Rear Spar 
Upper Chord on the Horizontal Stabilizer Center Section

    At the applicable times specified in table 2 of paragraph 1.E., 
``Compliance,'' of Boeing Alert Service Bulletin 737-55A1100, dated 
January 26, 2016, except as required by paragraphs (j)(1) and (j)(2) 
of this AD: Do a surface HFEC inspection of the vertical flange of 
the rear spar upper chord; and do all applicable corrective actions; 
in accordance with the Accomplishment Instructions of Boeing Alert 
Service Bulletin 737-55A1100, dated January 26, 2016, except as 
required by paragraph (j)(4) of this AD. Do all applicable 
corrective actions before further flight. Repeat the inspection of 
the vertical flange of the rear spar upper chord thereafter at the 
time specified in table 2 of paragraph 1.E., ``Compliance,'' of 
Boeing Alert Service Bulletin 737-55A1100, dated January 26, 2016.

(i) Repetitive Inspections of the Vertical Flange Stiffener Fasteners 
of the Rear Spar Upper Chord on the Horizontal Stabilizer Center 
Section

    At the applicable times specified in table 3 of paragraph 1.E., 
``Compliance,'' of Boeing Alert Service Bulletin 737-55A1100, dated 
January 26, 2016, except as required by paragraphs (j)(1) and (j)(2) 
of this AD: Do the actions required by paragraph (i)(1) or (i)(2) of 
this AD; and do all applicable related investigative and corrective 
actions; in accordance with the Accomplishment Instructions of 
Boeing Alert Service Bulletin 737-55A1100, dated January 26, 2016, 
except as required by paragraph (j)(4) of this AD. Do all applicable 
related investigative and corrective actions at the applicable times 
specified in tables 3 and 4 of paragraph 1.E., ``Compliance,'' of 
Boeing Alert Service Bulletin 737-55A1100, dated January 26, 2016. 
Repeat the inspection specified in paragraph (i)(2) of this AD 
thereafter at the applicable times specified in tables 3 and 4 of 
paragraph 1.E., ``Compliance,'' of Boeing Alert Service Bulletin 
737-55A1100, dated January 26, 2016.
    (1) Do an open hole HFEC inspection of the vertical flange at 
the stiffeners of the rear spar upper chord on the horizontal 
stabilizer center section for any crack.
    (2) Do a surface HFEC inspection of the vertical flange around 
the stiffeners of the rear spar upper chord on the horizontal 
stabilizer center section for any crack.

(j) Exceptions to Service Information

    (1) Where paragraph 1.E., ``Compliance,'' of Boeing Alert 
Service Bulletin 737-55A1100, dated January 26, 2016, 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) Where paragraph 1.E., ``Compliance,'' of Boeing Alert 
Service Bulletin 737-55A1100, dated January 26, 2016, refers to 
condition or compliance time in ``horizontal stabilizer center 
section flight cycles'' or ``center section flight cycles,'' this AD 
requires

[[Page 13274]]

compliance for those conditions or compliance time in terms of 
airplane flight cycles.
    (3) The Condition column of table 1 in paragraph 1.E., 
``Compliance,'' of Boeing Alert Service Bulletin 737-55A1100, dated 
January 26, 2016, refers to ``horizontal stabilizer center section 
flight cycles.'' This AD, however, applies to the airplanes with the 
specified airplane total flight cycles as of the effective date of 
this AD.
    (4) Where Boeing Alert Service Bulletin 737-55A1100, dated 
January 26, 2016; specifies to contact Boeing for appropriate 
action: Before further flight, repair using a method approved in 
accordance with the procedures specified in paragraph (k) of this 
AD.

(k) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Los Angeles 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 (l) of this AD. 
Information may be emailed to 9-ANM-LAACO-AMOC-Requests@faa.gov.
    (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, 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 required by paragraph (j)(4) of this AD: For 
service information that contains steps that are labeled as Required 
for Compliance (RC), the provisions of paragraphs (k)(4)(i) and 
(k)(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.

(l) Related Information

    For more information about this AD, contact Payman Soltani, 
Aerospace Engineer, Airframe Branch, ANM-120L, FAA, Los Angeles ACO, 
3960 Paramount Boulevard, Lakewood, CA 90712-4137; phone: 562-627-
5313; fax: 562-627-5210; email: Payman.Soltani@faa.gov.

(m) 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 737-55A1100, dated January 26, 
2016.
    (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, Transport 
Airplane Directorate, 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 March 3, 2016.
Michael Kaszycki,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2016-05515 Filed 3-11-16; 8:45 am]
BILLING CODE 4910-13-P


