[Federal Register Volume 75, Number 190 (Friday, October 1, 2010)]
[Proposed Rules]
[Pages 60665-60667]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2010-24715]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2010-0953; Directorate Identifier 2010-NM-010-AD]
RIN 2120-AA64
Airworthiness Directives; McDonnell Douglas Corporation Model MD-
90-30 Airplanes
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking (NPRM).
-----------------------------------------------------------------------
SUMMARY: We propose to adopt a new airworthiness directive (AD) for all
Model MD-90-30 airplanes. This proposed AD would 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. This proposed 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. We are proposing 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: We must receive comments on this proposed AD by November 15,
2010.
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 proposed 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
[email protected]; 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 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 (ACO), 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-2010-0953;
Directorate Identifier 2010-NM-010-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.
[[Page 60666]]
Discussion
We have received seven 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. These cracks were located on the aft face of the
hinge bearing lugs on the horizontal stabilizer. Cracks were reported
on MD-90 airplanes that had accumulated 9,051 to 21,183 total flight
hours, and 8,939 to 20,893 total flight cycles. The cause of the
cracking has not been determined. Undetected cracking in the hinge
bearing lugs of the center section of the left and right ribs, if not
corrected, could result in failure of the hinge bearing lugs and
consequent inability of the horizontal stabilizer to sustain the
required loads.
Relevant Service Information
We have reviewed Boeing Alert Service Bulletin MD90-55A016,
Revision 1, dated February 17, 2010. Boeing Alert Service Bulletin
MD90-55A016, Revision 1, dated February 17, 2010, describes procedures
for doing repetitive high frequency eddy current (HFEC) inspections for
cracking on the hinge bearing lugs on the aft face of the horizontal
stabilizer center section on the left and right ribs, and doing
applicable related investigative and corrective actions. The related
investigative action is measuring the crack length. The corrective
actions include blending out cracks and replacing the rib of the center
section of the horizontal stabilizer. For airplanes on which a blend
out is done, Boeing Alert Service Bulletin MD90-55A016, Revision 1,
dated February 17, 2010, describes procedures for doing repetitive HFEC
inspections for cracking of the blend out. For airplanes on which the
replacement is done, Boeing Alert Service Bulletin MD90-55A016,
Revision 1, dated February 17, 2010, describes procedures for doing
repetitive HFEC inspections for cracking of the replaced horizontal
stabilizer rib.
For the initial HFEC inspection, Boeing Alert Service Bulletin
MD90-55A016, Revision 1, dated February 17, 2010, specifies a
compliance time of before the accumulation of 7,200 total flight cycles
or within 1,505 flight cycles after the original issue date of Boeing
Alert Service Bulletin MD90-55A016, Revision 1, dated February 17,
2010, whichever occurs later.
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 same type design.
This proposed AD would require accomplishing the actions specified in
the service information described previously, except as discussed under
``Differences Between the Proposed AD and Service Bulletin.''
Differences Between the Proposed AD and Service Bulletin
For Condition 2A specified in Boeing Alert Service Bulletin MD90-
55A016, Revision 1, dated February 17, 2010, the service bulletin
specifies doing repetitive inspections of the blend out but did not
identify corrective actions when cracks are found during those
inspections. This proposed AD would require replacing the horizontal
stabilizer center section rib when cracks are found during inspections
of the blend out. We have coordinated this difference with Boeing.
For Condition 2B specified in Boeing Alert Service Bulletin MD90-
55A016, Revision 1, dated February 17, 2010, the service bulletin
specifies doing repetitive inspections of the replaced horizontal
stabilizer center section rib at intervals not to exceed 1,680 flight
cycles. This proposed AD would require doing an inspection of the
replaced horizontal stabilizer center section rib and all applicable
corrective actions and repetitive inspections (for Condition 1, the
repetitive interval is 1,680 flight cycles; for Condition 2A, the
repetitive interval is 400 flight cycles).
Interim Action
We consider this proposed 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 proposed AD would affect 16 airplanes of U.S.
registry. We also estimate that it would take about 2 work-hours per
product to comply with this proposed AD. The average labor rate is $85
per work-hour. Based on these figures, we estimate the cost of this
proposed 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
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 Corporation: Docket No. FAA-2010-0953; Directorate
Identifier 2010-NM-010-AD.
[[Page 60667]]
Comments Due Date
(a) We must receive comments by November 15, 2010.
Affected ADs
(b) None.
Applicability
(c) This AD applies to all McDonnell Douglas Corporation 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 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.
Exceptions 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 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 Aircraft
Certification Office (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.
Issued in Renton, Washington, on September 23, 2010.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 2010-24715 Filed 9-30-10; 8:45 am]
BILLING CODE 4910-13-P