
[Federal Register Volume 76, Number 3 (Wednesday, January 5, 2011)]
[Rules and Regulations]
[Pages 430-432]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2010-32993]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2010-0953; Directorate Identifier 2010-NM-010-AD; 
Amendment 39-16565; AD 2011-01-11]
RIN 2120-AA64


Airworthiness Directives; The Boeing Company Model MD-90-30 
Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: We are adopting a new airworthiness directive (AD) for the 
products listed above. This AD requires repetitive high frequency eddy 
current inspections for cracking on the hinge bearing lugs of the left 
and right sides of the center section ribs of the horizontal 
stabilizer, and related investigative and corrective actions if 
necessary. This AD was prompted by reports of cracks found on either 
the left or right (or in one case, both) sides of the center section 
ribs of the horizontal stabilizer. We are issuing this AD to detect and 
correct cracking in the hinge bearing lugs of the center section of the 
left and right ribs, which could result in failure of the hinge bearing 
lugs and consequent inability of the horizontal stabilizer to sustain 
the required loads.

DATES: This AD is effective February 9, 2011.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in the AD as of February 9, 
2011.

ADDRESSES: For service information identified in this AD, contact 
Boeing Commercial Airplanes, Attention: Data & Services Management, 
3855 Lakewood Boulevard, MC D800-0019, Long Beach, California 90846-
0001; telephone 206-544-5000, extension 2; fax 206-766-5683; e-mail 
dse.boecom@boeing.com; Internet https://www.myboeingfleet.com. 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 http://www.regulations.gov; 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, Aerospace Engineer, 
Airframe Branch, ANM-120L, FAA, Los Angeles Aircraft Certification 
Office (ACO), 3960 Paramount Boulevard, Lakewood, California 90712-
4137; telephone (562) 627-5233; fax (562) 627-5210.

SUPPLEMENTARY INFORMATION:

[[Page 431]]

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 to include an airworthiness directive (AD) that would apply to 
the specified products. That NPRM published in the Federal Register on 
October 1, 2010 (75 FR 60665). That NPRM proposed to require repetitive 
high frequency eddy current inspections for cracking on the hinge 
bearing lugs of the left and right sides of the center section ribs of 
the horizontal stabilizer, and related investigative and corrective 
actions if necessary.

Comments

    We gave the public the opportunity to participate in developing 
this AD. We received no comments on the NPRM or on the determination of 
the cost to the public.

Explanation of Change to Applicability

    We have revised the existing AD to identify model designations as 
published in the most recent type certificate data sheet for the 
affected models.

Conclusion

    We reviewed the relevant data and determined that air safety and 
the public interest require adopting the AD as proposed--except for 
minor editorial changes and the change described previously. We have 
determined that these minor changes:
     Are consistent with the intent that was proposed in the 
NPRM for correcting the unsafe condition; and
     Do not add any additional burden upon the public than was 
already proposed in the NPRM.

Conclusion

    We reviewed the relevant data and determined that air safety and 
the public interest require adopting the AD as proposed.

Interim Action

    We consider this AD interim action. The manufacturer is currently 
developing a modification that will address the unsafe condition 
identified in this AD. Once this modification is developed, approved, 
and available, we might consider additional rulemaking.

Costs of Compliance

    We estimate that this AD affects 16 airplanes of U.S. registry. We 
also estimate that it takes about 2 work-hours per product to comply 
with this AD. The average labor rate is $85 per work-hour. Based on 
these figures, we estimate the cost of this AD to the U.S. operators to 
be $2,720, or $170 per product.

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

0
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):

2011-01-11 The Boeing Company: Amendment 39-16565; Docket No. FAA-
2010-0953; Directorate Identifier 2010-NM-010-AD.

Effective Date

    (a) This AD is effective February 9, 2011.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to all The Boeing Company Model MD-90-30 
airplanes, certificated in any category.

Subject

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

Unsafe Condition

    (e) This AD results from reports of cracks found on either the 
left or right (or in one case, both) sides of the center section 
ribs of the horizontal stabilizer. The Federal Aviation 
Administration is issuing this AD to detect and correct cracking in 
the hinge bearing lugs of the center section of the left and right 
ribs, which could result in failure of the hinge bearing lugs and 
consequent inability of the horizontal stabilizer to sustain the 
required loads.

Compliance

    (f) You are responsible for having the actions required by this 
AD performed within the compliance times specified, unless the 
actions have already been done.

Repetitive Inspections and Corrective Actions for Cracking

    (g) At the applicable time in paragraph 1.E., ``Compliance,'' of 
Boeing Alert Service Bulletin MD90-55A016, Revision 1, dated 
February 17, 2010, except as required by paragraph (n) of this AD, 
do a high frequency eddy current (HFEC) inspection for cracking on 
the hinge bearing lugs of the left and right sides of the center 
section ribs of the horizontal stabilizer, and do all applicable 
related investigative actions, in accordance with the Accomplishment 
Instructions of Boeing Alert Service Bulletin MD90-55A016, Revision 
1, dated February 17, 2010. Do all applicable related investigative 
actions before further flight.
    (h) If during any inspection required by paragraph (g) of this 
AD, no cracking is found, repeat the inspection required by 
paragraph (g) of this AD thereafter at intervals not to exceed 1,680 
flight cycles.
    (i) If during any inspection required by paragraph (g) or (h) of 
this AD, any crack is found having a length between Points `A' and 
`B' less than or equal to 0.15 inch and crack length between Points 
`C' and `D' less than or equal to 0.05 inch, as identified in Boeing 
Alert Service Bulletin MD90-55A016, Revision 1, dated February 17, 
2010: Before further flight, blend out the crack; and within

[[Page 432]]

1,000 flight cycles after doing the blend out, do an HFEC inspection 
of the blend out on the center section rib hinge bearing lug; in 
accordance with the Accomplishment Instructions of Boeing Alert 
Service Bulletin MD90-55A016, Revision 1, dated February 17, 2010. 
Repeat the HFEC inspection of the blend out thereafter at intervals 
not to exceed 400 flight cycles until the replacement specified by 
paragraph (j) is done.
    (j) If any cracking is detected during any inspection required 
by paragraph (i) of this AD, before further flight, replace the 
horizontal stabilizer center section rib with a new horizontal 
stabilizer center section rib, in accordance with the Accomplishment 
Instructions of Boeing Alert Service Bulletin MD90-55A016, Revision 
1, dated February 17, 2010.
    (k) If during any inspection required by paragraph (g) or (h) of 
this AD, any crack is found having a length between Points `A' and 
`B' greater than 0.15 inch or crack length between Points `C' and 
`D' greater than 0.05 inch, as identified in Boeing Alert Service 
Bulletin MD90-55A016, Revision 1, dated February 17, 2010: Before 
further flight, replace the horizontal stabilizer center section rib 
with a new horizontal stabilizer center section rib, in accordance 
with the Accomplishment Instructions of Boeing Alert Service 
Bulletin MD90-55A016, Revision 1, dated February 17, 2010.
    (l) For any airplane having a horizontal stabilizer center 
section rib replaced during the actions required by paragraph (j) or 
(k) of this AD: Before the accumulation of 7,200 total flight cycles 
on the new horizontal stabilizer center section rib, do the actions 
required by paragraph (g) of this AD, and do all applicable actions 
specified in paragraphs (h), (i), (j), and (k) of this AD.

Credit for Actions Accomplished According to Previous Issue of Service 
Bulletin

    (m) Actions accomplished before the effective date of this AD 
according to Boeing Alert Service Bulletin MD90-55A016, dated 
December 16, 2009, are considered acceptable for compliance with the 
corresponding actions required by paragraphs (g), (h), (i), (j), and 
(k) of this AD.

Exception to the Service Bulletin

    (n) Where Boeing Alert Service Bulletin MD90-55A016, Revision 1, 
dated February 17, 2010, specifies a compliance time ``after the 
original issue date on the service bulletin,'' this AD requires 
compliance within the specified compliance time after the effective 
date of this AD.

Alternative Methods of Compliance (AMOCs)

    (o)(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. Send 
information to ATTN: Roger Durbin, Aerospace Engineer, Airframe 
Branch, ANM-120L, FAA, Los Angeles ACO, 3960 Paramount Boulevard, 
Lakewood, California 90712-4137; telephone (562) 627-5233; fax (562) 
627-5210.
    (2) To request a different method of compliance or a different 
compliance time for this AD, follow the procedures in 14 CFR 39.19. 
Before using any approved AMOC on any airplane to which the AMOC 
applies, notify your principal maintenance inspector (PMI) or 
principal avionics inspector (PAI), as appropriate, or lacking a 
principal inspector, your local Flight Standards District Office. 
The AMOC approval letter must specifically reference this AD.
    (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 the approval 
must specifically refer to this AD.

Related Information

    (p) For more information about this AD, contact Roger Durbin, 
Aerospace Engineer, Airframe Branch, ANM-120L, FAA, Los Angeles ACO, 
3960 Paramount Boulevard, Lakewood, California 90712-4137; telephone 
(562) 627-5233; fax (562) 627-5210.

Material Incorporated by Reference

    (q) You must use Boeing Alert Service Bulletin MD90-55A016, 
Revision 1, dated February 17, 2010, to do the actions required by 
this AD, unless the AD specifies otherwise.
    (1) The Director of the Federal Register approved the 
incorporation by reference of Boeing Alert Service Bulletin MD90-
55A016, Revision 1, dated February 17, 2010, under 5 U.S.C. 552(a) 
and 1 CFR part 51.
    (2) For service information identified in this AD, contact 
Boeing Commercial Airplanes, Attention: Data & Services Management, 
3855 Lakewood Boulevard, MC D800-0019, Long Beach, California 90846-
0001; telephone 206-544-5000, extension 2; fax 206-766-5683; e-mail 
dse.boecom@boeing.com; Internet https://www.myboeingfleet.com.
    (3) You may review copies of the 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.
    (4) You may also review copies of the service information that 
is incorporated by reference at the National Archives and Records 
Administration (NARA). For information on the availability of this 
material at an NARA facility, call 202-741-6030, or go to http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.

    Issued in Renton, Washington, on December 22, 2010.
Jeffrey E. Duven,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2010-32993 Filed 1-4-11; 8:45 am]
BILLING CODE 4910-13-P


