AD 2012-21-18

Recurring final rule

Airworthiness Directives; The Boeing Company Airplanes

AD Number
2012-21-18
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Docket No. FAA-2012-0728
FR Citation
77 FR 65803
Technical illustration of a riveted aircraft structural panel and frame
Problem area Airframe structure

Applicability

TypeManufacturerModelDetails
aircraft The Boeing Company MD-90-30 Airworthiness Directives; The Boeing Company Airplanes

Unsafe Condition

Fatigue cracks found in Stringer 11 at the outboard flap, inboard drive hinge at Station Xrs=164.000, which could result in the wing structure not supporting the limit load condition, leading to loss of the structural integrity of the wing.

AI-generated summary from the source AD text. Verify against the official source before acting.

Required Actions

Conduct repetitive inspections for cracks in Stringer 11 using in-tank eddy current high frequency (ETHF) inspections. Perform a splice repair if cracks are found, followed by post-repair inspections at specified intervals. Repair any cracks found during post-repair inspections.

AI-generated summary from the source AD text. Verify against the official source before acting.

Compliance Time

Within 9,470 flight cycles after the effective date of this AD or before the accumulation of 14,000 total flight cycles, whichever occurs later.

AI-generated summary from the source AD text. Verify against the official source before acting.

Affected Aircraft

The Boeing Company Model MD-90-30 airplanes, certificated in any category, as identified in Boeing Alert Service Bulletin MD90-57A030, dated February 14, 2012.

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 certain The Boeing Company Model MD-90-30 airplanes. This AD was prompted by reports of fatigue cracks found in Stringer 11 at the outboard flap, inboard drive hinge at Station Xrs=164.000. This AD requires repetitive inspections for cracks in Stringer 11, and a splice repair if necessary; and repetitive post-repair inspections, and repair if necessary. We are issuing this AD to detect and correct such cracking, which could result in the wing structure not supporting the limit load condition, which could lead to loss of the structural integrity of the wing.

Applicability Source Text

Show captured applicability text from the source AD
(c) Applicability

    This AD applies to The Boeing Company Model MD-90-30 airplanes, 
certificated in any category, as identified in Boeing Alert Service 
Bulletin MD90-57A030, dated February 14, 2012.

Document Text

Show stored source text (verify against official source)
[Federal Register Volume 77, Number 211 (Wednesday, October 31, 2012)]
[Rules and Regulations]
[Pages 65803-65805]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2012-26187]


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

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2012-0728; Directorate Identifier 2012-NM-050-AD; 
Amendment 39-17234; AD 2012-21-18]
RIN 2120-AA64


Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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

SUMMARY: We are adopting a new airworthiness directive (AD) for certain 
The Boeing Company Model MD-90-30 airplanes. This AD was prompted by 
reports of fatigue cracks found in Stringer 11 at the outboard flap, 
inboard drive hinge at Station Xrs=164.000. This AD requires repetitive 
inspections for cracks in Stringer 11, and a splice repair if 
necessary; and repetitive post-repair inspections, and repair if 
necessary. We are issuing this AD to detect and correct such cracking, 
which could result in the wing structure not supporting the limit load 
condition, which could lead to loss of the structural integrity of the 
wing.

DATES: This AD is effective December 5, 2012.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in the AD as of December 5, 
2012.

ADDRESSES: For service information identified in this AD, contact 
Boeing Commercial Airplanes, Attention: Data & Services Management, 
3855 Lakewood Boulevard, MC D800-0019, Long Beach, CA 90846-0001; 
telephone 206-544-5000, extension 2; fax 206-766-5683; Internet <a href="https://www.myboeingfleet.com">https://www.myboeingfleet.com</a>. You may review copies of the referenced service 
information at the FAA, Transport Airplane Directorate, 1601 Lind 
Avenue SW., Renton, Washington. For information on the availability of 
this material at the FAA, call 425-227-1221.

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>; 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 Document 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: Roger Durbin, Airframe Branch, ANM-
120L, FAA, Los Angeles Aircraft Certification Office (ACO), 3960 
Paramount Boulevard, Lakewood, California 90712-4137; phone: (562) 627-
5233; fax: (562) 627-5210; email: <a href="/cdn-cgi/l/email-protection#8dffe2eae8ffa3e9f8ffefe4e3cdebececa3eae2fb"><span class="__cf_email__" data-cfemail="03716c6466712d677671616a6d436562622d646c75">[email&#160;protected]</span></a>.

SUPPLEMENTARY INFORMATION:

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 to include an AD that would apply to the specified products. 
That NPRM published in the Federal Register on August 1, 2012 (77 FR 
45515). That NPRM proposed to require repetitive inspections for cracks 
in Stringer 11, and a splice repair if necessary; and repetitive post-
repair inspections, and repair if necessary.

Comments

    We gave the public the opportunity to participate in developing 
this AD. We have considered the comment received. Boeing supports the 
NPRM (77 FR 45515, August 1, 2012).

Conclusion

    We reviewed the relevant data, considered the comment received, and 
determined that air safety and the public interest require adopting the 
AD as proposed--except for minor editorial changes. We have determined 
that these minor changes:
    <bullet> Are consistent with the intent that was proposed in the 
NPRM (77 FR 45515, August 1, 2012) for correcting the unsafe condition; 
and
    <bullet> Do not add any additional burden upon the public than was 
already proposed in the NPRM (77 FR 45515, August 1, 2012).

Costs of Compliance

    We estimate that this AD affects 52 airplanes of U.S. registry.
    We estimate the following costs to comply with this AD:

[[Page 65804]]



                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                 Cost on U.S.
             Action                  Labor cost           Parts cost       Cost per product        operators
----------------------------------------------------------------------------------------------------------------
Inspection.....................  13 work-hours x     None...............  $1,105 per          $57,460 per
                                  $85 per hour =                           inspection cycle.   inspection cycle
                                  $1,105 per
                                  inspection cycle.
Post-repair inspection.........  13 work-hours x     None...............  $1,105............  $57,460.
                                  $85 per hour =
                                  $1,105.
----------------------------------------------------------------------------------------------------------------

    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
----------------------------------------------------------------------------------------------------------------
                   Action                              Labor cost               Parts cost      Cost per product
----------------------------------------------------------------------------------------------------------------
Splice repair per wing.....................  93 work-hours x $85 per hour            $28,126            $36,031
                                              = $7,905.
----------------------------------------------------------------------------------------------------------------

    We have received no definitive data that would enable us to provide 
cost estimates for the on-condition actions of the post-repair 
inspection specified in this AD.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, section 106, describes the 
authority of the FAA Administrator. Subtitle VII: Aviation Programs, 
describes in more detail the scope of the Agency's authority.
    We are issuing this rulemaking under the authority described in 
Subtitle VII, Part A, Subpart III, Section 44701: ``General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

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):

2012-21-18 The Boeing Company: Amendment 39-17234; Docket No. FAA-
2012-0728; Directorate Identifier 2012-NM-050-AD.

(a) Effective Date

    This AD is effective December 5, 2012.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to The Boeing Company Model MD-90-30 airplanes, 
certificated in any category, as identified in Boeing Alert Service 
Bulletin MD90-57A030, dated February 14, 2012.

(d) Subject

    Joint Aircraft System Component (JASC)/Air Transport Association 
(ATA) of America Code 57, Wings.

(e) Unsafe Condition

    This AD was prompted by reports of fatigue cracks found in 
Stringer 11 at the outboard flap, inboard drive hinge at Station 
Xrs=164.000. We are issuing this AD to detect and correct such 
cracking, which could result in the wing structure not supporting 
the limit load condition, which could lead to loss of the structural 
integrity of the wing.

(f) Compliance

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

(g) Repetitive Inspections

    Before the accumulation of 14,000 total flight cycles, or within 
9,470 flight cycles after the effective date of this AD: Whichever 
occurs later, do an in-tank eddy current high frequency (ETHF) 
inspection for cracks in Stringer 11 at the outboard flap, inboard 
drive hinge at Station Xrs=164.000 of the left and right wings, in 
accordance with the Accomplishment Instructions of Boeing Alert 
Service Bulletin MD90-57A030, dated February 14, 2012. If no 
cracking is found, repeat the inspection thereafter at intervals not 
to exceed 31,000 flight cycles.

(h) Splice Repair

    If any cracking is found during any inspection required by 
paragraph (g) of this AD: Before further flight, do a splice repair, 
in accordance with the Accomplishment Instructions of Boeing Alert 
Service Bulletin MD90-57A030, dated February 14, 2012.

(i) Post-Repair Inspection

    Within 42,000 flight cycles after doing the splice repair 
specified in paragraph (h) of this AD: Do an ETHF inspection for 
cracks in Stringer 11 at the outboard flap, inboard drive hinge at 
Station Xrs=164.000, in accordance with the Accomplishment 
Instructions of Boeing Alert Service Bulletin MD90-57A030, dated 
February 14, 2012. Repeat the inspection thereafter at intervals

[[Page 65805]]

not to exceed 31,000 flight cycles. If any crack is found: Before 
further flight, repair the crack using a method approved in 
accordance with the procedures specified in paragraph (j) of this 
AD.

(j) 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 the Related Information 
section of this AD.
    (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, Los Angeles ACO to 
make those findings. For a repair method to be approved, the repair 
must meet the certification basis of the airplane, and 14 CFR 
25.571, Amendment 54, and the approval must specifically refer to 
this AD.

(k) Related Information

    For more information about this AD, contact Roger Durbin, 
Airframe Branch, ANM-120L, FAA, Los Angeles Aircraft Certification 
Office (ACO), 3960 Paramount Boulevard, Lakewood, California 90712-
4137; phone: (562) 627-5233; fax: (562) 627-5210; email: 
<a href="/cdn-cgi/l/email-protection#b0c2dfd7d5c29ed4c5c2d2d9def0d6d1d19ed7dfc6"><span class="__cf_email__" data-cfemail="c3b1aca4a6b1eda7b6b1a1aaad83a5a2a2eda4acb5">[email&#160;protected]</span></a>.

(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 MD90-57A030, dated February 
14, 2012.
    (ii) Reserved.
    (3) For The Boeing Company Airplanes service information 
identified in this AD, contact Boeing Commercial Airplanes, 
Attention: Data & Services Management, 3855 Lakewood Boulevard, MC 
D800-0019, Long Beach, CA 90846-0001; telephone 206-544-5000, 
extension 2; fax 206-766-5683; Internet <a href="https://www.myboeingfleet.com">https://www.myboeingfleet.com</a>.
    (4) You may view this service information at FAA, Transport 
Airplane Directorate, 1601 Lind Avenue SW., Renton, Washington. 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 October 12, 2012.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2012-26187 Filed 10-30-12; 8:45 am]
BILLING CODE 4910-13-P

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