AD 2016-06-02
Recurring
final rule
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | The Boeing Company | 737-300 Series | Airworthiness Directives; The Boeing Company Airplanes |
| aircraft | The Boeing Company | 737-400 Series | Airworthiness Directives; The Boeing Company Airplanes |
| aircraft | The Boeing Company | 737-500 Series | Airworthiness Directives; The Boeing Company Airplanes |
Unsafe Condition
Cracking in the horizontal and vertical flanges of the rear spar upper chord of the horizontal stabilizer, which could lead to departure of the horizontal stabilizer from the airplane.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Inspect for cracking in the horizontal and vertical flanges of the rear spar upper chord of the horizontal stabilizer. Identify fasteners common to the rear spar upper chord upper gusset of the horizontal stabilizer center section. Perform related investigative and corrective actions if necessary. Repair cracked structure using an approved method or data meeting the certification basis of the airplane.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within the specified compliance times in terms of airplane flight cycles, as detailed in the referenced service information.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
The Boeing Company Model 737-300, -400, and -500 series airplanes.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
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.
Applicability Source Text
Show captured applicability text from the source AD
(c) Applicability
This AD applies to all The Boeing Company Model 737-300, -400,
and -500 series airplanes, certificated in any category.
Document Text
Show stored source text (verify against official source)
[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 [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2016-05515]
=======================================================================
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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.
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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:
<bullet> Federal eRulemaking Portal: Go to <a href="http://www.regulations.gov">http://www.regulations.gov</a>. Follow the instructions for submitting comments.
<bullet> Fax: 202-493-2251.
<bullet> 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.
<bullet> 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 <a href="https://www.myboeingfleet.com">https://www.myboeingfleet.com</a>. 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 <a href="http://www.regulations.gov">http://www.regulations.gov</a> by searching for and locating Docket No. FAA-2016-
4222.
Examining the AD Docket
You may examine the AD docket on the Internet at <a href="http://www.regulations.gov">http://www.regulations.gov</a> 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: <a href="/cdn-cgi/l/email-protection#5303322a3e323d7d003c3f27323d3a133532327d343c25"><span class="__cf_email__" data-cfemail="93c3f2eafef2fdbdc0fcffe7f2fdfad3f5f2f2bdf4fce5">[email protected]</span></a>.
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 <a href="http://www.regulations.gov">http://www.regulations.gov</a> 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:
<bullet> In accordance with a method that we approve; or
<bullet> 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 <a href="http://www.regulations.gov">http://www.regulations.gov</a>, 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 <a href="/cdn-cgi/l/email-protection#b0899df1fefd9dfcf1f1f3ff9df1fdfff39de2d5c1c5d5c3c4c3f0d6d1d19ed7dfc6"><span class="__cf_email__" data-cfemail="60594d212e2d4d2c2121232f4d212d2f234d3205111505131413200601014e070f16">[email protected]</span></a>.
(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: <a href="/cdn-cgi/l/email-protection#e4b4859d89858acab78b8890858a8da4828585ca838b92"><span class="__cf_email__" data-cfemail="b4e4d5cdd9d5da9ae7dbd8c0d5daddf4d2d5d59ad3dbc2">[email protected]</span></a>.
(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
<a href="https://www.myboeingfleet.com">https://www.myboeingfleet.com</a>.
(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: <a href="http://www.archives.gov/federal-register/cfr/ibr-locations.html">http://www.archives.gov/federal-register/cfr/ibr-locations.html</a>.
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
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Retrieved: Apr 6, 2026
Rights: U.S. Government Public Domain
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