FR Doc E9-6218

[Federal Register: March 23, 2009 (Volume 74, Number 54)]
[Proposed Rules]
[Page 12100-12102]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr23mr09-16]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2009-0160; Directorate Identifier 2008-NM-176-AD]
RIN 2120-AA64

Airworthiness Directives; McDonnell Douglas Model MD-90-30
Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to adopt a new airworthiness directive (AD) for all
McDonnell Douglas Model MD-90-30 airplanes. This proposed AD would
require repetitive inspections for cracks of the upper aft skin panels
on the horizontal stabilizer, and related investigative and corrective
actions if necessary. This proposed AD results from a report of cracks
found in the aft skin panels on the upper right side of the horizontal
stabilizer at the aft inboard corner. We are proposing this AD to
detect and correct cracks in the fail-safe structure that may not be
able to sustain limit load, which could result in the loss of overall
structural integrity of the horizontal stabilizer.

DATES: We must receive comments on this proposed AD by May 7, 2009.

ADDRESSES: You may send comments 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 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 or 425-227-1152.

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 proposed AD, the regulatory
evaluation, any comments received, and other information. The street
address for the Docket Office (telephone 800-647-5527) is in the
ADDRESSES section. Comments will be available in the AD docket shortly
after receipt.

FOR FURTHER INFORMATION CONTACT: Roger Durbin, Aerospace Engineer,
Airframe Branch, ANM-120L, FAA, Los Angeles Aircraft Certification
Office, 3960 Paramount Boulevard, Lakewood, California 90712-4137;
telephone (562) 627-5233; fax (562) 627-5210.

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to send any written relevant data, views, or
arguments about this proposed AD. Send your comments to an address
listed under the ADDRESSES section. Include ``Docket No. FAA-2009-0160;
Directorate Identifier 2008-NM-176-AD'' at the beginning of your
comments. We specifically invite comments on the overall regulatory,
economic, environmental, and energy aspects of this proposed AD. We
will consider all comments received by the closing date and may amend
this proposed 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 proposed AD.

Discussion

We have received a report that one operator found two instances of
a crack in the aft skin panel on the upper right side of the horizontal
stabilizer at the aft inboard corner. The airplanes had accumulated
16,659 total flight cycles/31,403 total flight hours and 18,128 total
flight cycles/33,959 total flight hours. The cause of the cracking on
the aft skin panel on the upper right side of the horizontal stabilizer
is suspected to be fatigue. This condition, if not detected and
corrected, could result in cracks in the fail-safe structure that may
not be able to sustain limit load, which could result in the loss of
overall structural integrity of the horizontal stabilizer.

Relevant Service Information

We have reviewed Boeing Alert Service Bulletin MD90-55A012, dated
September 23, 2008. The service bulletin describes procedures for
repetitive eddy current inspections to detect cracks on the upper aft
skin panels on the left and right sides of the horizontal stabilizer,
and related investigative and corrective actions. The initial
compliance time is 13,500 total flight cycles or 24 months after the
effective date of this AD, whichever occurs later. The related
investigative actions include repetitive eddy current inspections for
cracks of the rear spar upper caps of the left and right sides of the
horizontal stabilizer. The repetitive interval for the inspection is
within 1,600 or 2,100 flight cycles, depending on the previous
inspection method used.
Corrective actions include, depending on crack findings and crack
location, installing the upper aft skin panel splice of the horizontal
stabilizer, and replacing the upper aft skin panel of the horizontal
stabilizer. The service bulletin describes three options, depending on
crack findings and crack location:
(Option 1) The service bulletin describes procedures for a
high frequency eddy current inspection of the rear spar cap of the
horizontal stabilizer and installation of the upper aft skin panel
splice of the horizontal stabilizer before further flight, and an eddy
current inspection on the upper aft skin panel of the horizontal
stabilizer within 13,500 flight cycles after the installation. If the
crack is on the rear spar cap of the horizontal stabilizer, the service
bulletin specifies to contact

[[Page 12101]]

Boeing for repair instructions and do the repair before further flight.
(Option 2) The service bulletin describes procedures for a
high frequency eddy current inspection of the rear spar cap of the
horizontal stabilizer, remove and replace the upper aft skin panel of
the horizontal stabilizer before further flight, and an eddy current
inspection of the upper aft skin panel of the horizontal stabilizer
within 13,500 flight cycles. If the crack is on the rear spar cap of
the horizontal stabilizer, the service bulletin specifies to contact
Boeing for further repair instructions and do the repair before further
flight.
(Option 3) The service bulletin specifies one option is to
contact Boeing for possible temporary repair of skin cracks and do the
repair before further flight.

FAA's Determination and Requirements of This Proposed AD

We are proposing this AD because we evaluated all relevant
information and determined the unsafe condition described previously is
likely to exist or develop in other products of the(se) same type
design(s). This proposed AD would require accomplishing the actions
specified in the service information described previously, except as
discussed under ``Difference Between the Proposed AD and Service
Bulletin.''

Difference Between the Proposed AD and Service Bulletin

Boeing Alert Service Bulletin MD90-55A012, dated September 23,
2008, specifies to contact the manufacturer for instructions on how to
repair certain conditions, but this proposed AD would require repairing
those conditions in one of the following ways:
Using a method that we approve; or
Using data that meet the certification basis of the
airplane, and that have been approved by an Authorized Representative
for the Boeing Commercial Airplanes Delegation Option Authorization
Organization whom we have authorized to make those findings.

Costs of Compliance

We estimate that this proposed AD would affect 16 airplanes of U.S.
registry. The following table provides the estimated costs for U.S.
operators to comply with this proposed AD.

Estimated Costs
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Number of
Average U.S.-
Action Work hours labor rate Parts Cost per airplane registered Fleet cost
per hour airplanes
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Inspection........................... 4 $80 None.................... $320 per inspection 16 $5,120 per inspection
cycle. cycle.
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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

We determined that this proposed AD would not have federalism
implications under Executive Order 13132. This proposed AD would 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 this proposed
regulation:
1. Is not a ``significant regulatory action'' under Executive Order
12866,
2. Is not a ``significant rule'' under the DOT Regulatory Policies
and Procedures (44 FR 11034, February 26, 1979), and
3. 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.
You can find our regulatory evaluation and the estimated costs of
compliance in the AD Docket.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.

The Proposed Amendment

Accordingly, under the authority delegated to me by the
Administrator, the FAA proposes to amend 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

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]

2. The FAA amends Sec. 39.13 by adding the following new AD:

McDonnell Douglas: Docket No. FAA-2009-0160; Directorate Identifier
2008-NM-176-AD.

Comments Due Date

(a) We must receive comments by May 7, 2009.

Affected ADs

(b) None.

Applicability

Subject

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

Unsafe Condition

(e) This AD results from a report of cracks found in the right
upper aft skin panel of the horizontal stabilizer at the aft inboard
corner. We are issuing this AD to detect and correct cracks in the
fail-safe structure that may not be able to sustain limit load,
which could result in the loss of overall structural integrity of
the horizontal stabilizer.

Compliance

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

[[Page 12102]]

Inspections

(g) Except as required by paragraphs (h) and (i) of this AD: At
the times specified in paragraph 1.E., ``Compliance,'' of Boeing
Alert Service Bulletin MD90-55A012, dated September 23, 2008, do an
eddy current inspection for cracks of the upper aft skin panels on
the left and right sides of the horizontal stabilizer, and do all
applicable related investigative and corrective actions, in
accordance with the Accomplishment Instructions of the service
bulletin.

Exceptions to Service Bulletin Specifications

(h) Where Boeing Alert Service Bulletin MD90-55A012, dated
September 23, 2008, specifies a compliance time after the date on
the service bulletin, this AD requires compliance within the
specified compliance time after the effective date of this AD.
(i) If any crack is found during any inspection required by this
AD, and Boeing Alert Service Bulletin MD90-55A012, dated September
23, 2008, 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.

Inspections Done According to Multi-Operator Message

(j) Inspections and corrective actions done before the effective
date of this AD are acceptable for compliance with the corresponding
requirements of this AD, if done in accordance with Boeing Multi-
Operator Message 1-669017091-1, dated November 9, 2007.

Alternative Methods of Compliance (AMOCs)

(k)(1) The Manager, Los Angeles Aircraft Certification Office,
FAA, ATTN: Roger Durbin, Aerospace Engineer, Airframe Branch, ANM-
120L, FAA, Los Angeles Aircraft Certification Office, 3960 Paramount
Boulevard, Lakewood, California 90712-4137; telephone (562) 627-
5233; fax (562) 627-5210; has the authority to approve AMOCs for
this AD, if requested using the procedures found in 14 CFR 39.19.
(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, in the FAA
Flight Standards District Office (FSDO), or lacking a principal
inspector, your local FSDO. 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 an
Authorized Representative for the Boeing Commercial Airplanes
Delegation Option Authorization Organization who has been authorized
by the Manager, International Branch, 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.

Issued in Renton, WA, on March 6, 2009.
Linda Navarro,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. E9-6218 Filed 3-20-09; 8:45 am]

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