Airworthiness Directives; The Boeing Company Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), DC-9-87 (MD-87), and MD-88 Airplanes, 53346-53348 [2011-21853]

Download as PDF 53346 Federal Register / Vol. 76, No. 166 / Friday, August 26, 2011 / Proposed Rules across the individual methodologies? How would the FCS prepare its quarterly and annual reports to investors? Should System banks be required to develop a common risk exposure methodology? Question 7: Are there certain types of assets that would require the use of a third party to provide data to FCS institutions as part of their internal process for making creditworthiness determinations? How could the use of third-party service providers be implemented to ensure quality, transparency, and consistency? What role should third-party assessors be allowed to play in determining creditworthiness? We seek comments on the roles best played by each party. E. Burden Developing alternative measures of creditworthiness will likely require significant initial and ongoing costs. Accordingly, we are seeking comment on the burden—both financial and operational—that various alternative approaches to developing such standards might entail. Dated: August 18, 2011. Mary Alice Donner, Acting Secretary, Farm Credit Administration Board. [FR Doc. 2011–21659 Filed 8–25–11; 8:45 am] BILLING CODE 6705–01–P DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. FAA–2011–0909; Directorate Identifier 2011–NM–027–AD] RIN 2120–AA64 Airworthiness Directives; The Boeing Company Model DC–9–81 (MD–81), DC–9–82 (MD–82), DC–9–83 (MD–83), DC–9–87 (MD–87), and MD–88 Airplanes Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed rulemaking (NPRM). AGENCY: We propose to adopt a new airworthiness directive (AD) for the products listed above. This proposed AD would require repetitive high frequency eddy current (HFEC) inspections for cracking of the left and right rib hinge bearing lugs of the aft face of the center section of the horizontal stabilizer; measuring crack length and blending out cracks; and replacing the horizontal stabilizer center mstockstill on DSK4VPTVN1PROD with PROPOSALS SUMMARY: VerDate Mar<15>2010 15:45 Aug 25, 2011 Jkt 223001 section rib, if necessary. This proposed AD was prompted by reports of cracks of the hinge bearing lugs 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 horizontal stabilizer center section ribs, which would result in failure of the lugs, and consequent inability of the horizontal stabilizer to sustain the required limit loads and loss of control of the airplane. DATES: We must receive comments on this proposed AD by October 11, 2011. ADDRESSES: You may send comments by any of the following methods: • Federal eRulemaking Portal: Go to https://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: Deliver to Mail address above 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 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 https:// 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 (phone: 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; phone: 562– PO 00000 Frm 00003 Fmt 4702 Sfmt 4702 627–5233; fax: 562–627–5210; e-mail: roger.durbin@faa.gov. SUPPLEMENTARY INFORMATION: Comments Invited We invite you to send any written relevant data, views, or arguments about this proposal. Send your comments to an address listed under the ADDRESSES section. Include ‘‘Docket No. FAA– 2011–0909; Directorate Identifier 2011– NM–027–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 https:// 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 received reports of cracks on Model MD–80 series airplanes and on Model MD–90–30 airplanes. The cracks were found on the aft face of the center section left and right hinge bearing lugs on either the left or right, or in two cases, on both sides of the center section ribs of the horizontal stabilizer. Cracks were reported on Model MD–80 airplanes that had accumulated 23,700 to 41,963 total flight hours, and 23,300 to 35,294 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 required limit loads and loss of control of the airplane. Related Rulemaking The proposed AD affects Model MD– 80 series airplanes. We issued AD 2011– 01–11, Amendment 39–16565 (76 FR 430, January 5, 2011) to address the identified unsafe condition on Model MD–90–30 airplanes, on December 22, 2010. AD 2011–01–11 requires similar actions as proposed in this NPRM. Relevant Service Information We reviewed Boeing Alert Service Bulletin MD80–55A069, dated January 19, 2011. That service bulletin describes procedures for repetitive high frequency eddy current (HFEC) inspections for cracking of the left and right rib hinge bearing lugs of the aft face of the center E:\FR\FM\26AUP1.SGM 26AUP1 Federal Register / Vol. 76, No. 166 / Friday, August 26, 2011 / Proposed Rules section of the horizontal stabilizer; measuring crack length and blending out cracks; and replacement of the horizontal stabilizer center section rib, if necessary. FAA’s Determination and Proposed AD Requirements We are proposing 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 these same type designs. 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 the Service Information.’’ Differences Between the Proposed AD and the Service Information Although Boeing Alert Service Bulletin MD80–55A069, dated January 19, 2011, specifies to send the inspection results to the manufacturer, this proposed AD would not require any report. Interim Action We consider this proposed AD interim action since investigation is 53347 ongoing and no terminating action has been developed yet. 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 may consider additional rulemaking. Costs of Compliance We estimate that this proposed AD affects 668 airplanes of U.S. registry. We estimate the following costs to comply with this proposed AD: ESTIMATED COSTS Action Labor cost Parts cost Cost per product Cost on U.S. operators Inspection ........................................................ 6 work-hours × $85 per hour = $510 per inspection cycle. $0 $510 $340,680 mstockstill on DSK4VPTVN1PROD with PROPOSALS We have received no definitive data that would enable us to provide labor cost estimates for the on-condition actions (blend-out repair(s) or replacement of center section rib(s)) specified in this proposed AD. However, we have been advised that replacement parts would be $14,500 per horizontal stabilizer rib crack repair kit. 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 VerDate Mar<15>2010 15:45 Aug 25, 2011 Jkt 223001 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), (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. 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. § 39.13 [Amended] 2. The FAA amends § 39.13 by adding the following new airworthiness directive (AD): PO 00000 Frm 00004 Fmt 4702 Sfmt 4702 The Boeing Company: Docket No. FAA– 2011–0909; Directorate Identifier 2011– NM–027–AD. Comments Due Date (a) We must receive comments by October 11, 2011. Affected ADs (b) None. Applicability (c) This AD applies to The Boeing Company Model DC–9–81 (MD–81), DC–9– 82 (MD–82), DC–9–83 (MD–83), DC–9–87 (MD–87), and MD–88 airplanes, certificated in any category, as identified in Boeing Alert Service Bulletin MD80–55A069, dated January 19, 2011. Subject (d) Air Transport Association (ATA) of America Code 55: Stabilizers. Unsafe Condition (e) This AD was prompted by reports of cracks of the hinge bearing lugs 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 horizontal stabilizer center section ribs, which would result in failure of the lugs, and consequent inability of the horizontal stabilizer to sustain the required limit loads and loss of control of the airplane. Compliance (f) Comply with this AD within the compliance times specified, unless already done. Actions on Horizontal Stabilizer Ribs Made From 7075–T7351 Material (g) For Group 1 airplanes, as identified in Boeing Alert Service Bulletin MD80–55A069, dated January 19, 2011: Before the accumulation of 23,000 total flight cycles, or within 4,383 flight cycles after the effective E:\FR\FM\26AUP1.SGM 26AUP1 53348 Federal Register / Vol. 76, No. 166 / Friday, August 26, 2011 / Proposed Rules mstockstill on DSK4VPTVN1PROD with PROPOSALS date of this AD, whichever occurs later, do a high frequency eddy current (HFEC) inspection for cracking of the left and right rib hinge bearing lugs of the aft face of the center section of the horizontal stabilizer, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin MD80–55A069, dated January 19, 2011. For any crack-free lug, repeat the inspection on that lug thereafter at intervals not to exceed 8,200 flight cycles. (h) If, during any inspection required by paragraph (g) of this AD, any crack is found, before further flight, measure the length of the crack between the points specified in Boeing Alert Service Bulletin MD80–55A069, dated January 19, 2011. Do the action in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin MD80–55A069, dated January 19, 2011. (1) If the crack length between points ‘A’ and ‘B’ is less than or equal to 0.15 inch and the crack length between points ‘C’ and ‘D’ is less than or equal to 0.05 inch: Before further flight, blend out the crack, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin MD80–55A069, dated January 19, 2011. Within 15,600 flight cycles after doing the blend out, do an HFEC inspection of the blend out on the center section rib hinge bearing lug for cracking, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin MD80–55A069, dated January 19, 2011, and repeat that inspection thereafter at intervals not to exceed 3,900 flight cycles. (2) If the crack length between points ‘A’ and ‘B’ is greater than 0.15 inch or the crack length between points ‘C’ and ‘D’ is greater than 0.05 inch: 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 MD80–55A069, dated January 19, 2011. Repeat the inspection required by paragraph (g) of this AD one time before the accumulation of 23,000 total flight cycles on the new horizontal stabilizer center section rib, and thereafter at intervals not to exceed 11,300 flight cycles. Actions on Horizontal Stabilizer Ribs Made From 7050–T7451 Material (i) For Group 2 airplanes, as identified in Boeing Alert Service Bulletin MD80–55A069, dated January 19, 2011: Before the accumulation of 23,000 total flight cycles, or within 4,383 flight cycles after the effective date of this AD, whichever occurs later, do an HFEC inspection for cracking of the left and right rib hinge bearing lugs of the aft face of the center section of the horizontal stabilizer, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin MD80–55A069, dated January 19, 2011. For any crack-free lug, repeat the inspection on that lug thereafter at intervals not to exceed 11,300 flight cycles. (j) If, during any inspection required by paragraph (i) of this AD, any crack is found, before further flight, measure the length of the crack between the points specified in and in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin MD80–55A069, dated January 19, 2011. VerDate Mar<15>2010 15:45 Aug 25, 2011 Jkt 223001 (1) If the crack length between points ‘A’ and ‘B’ is less than or equal to 0.15 inch and the crack length between points ‘C’ and ‘D’ is less than or equal to 0.05 inch: Before further flight, blend out the crack, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin MD80–55A069, dated January 19, 2011. Within 15,600 flight cycles after doing the blend out, do an HFEC inspection of the blend out on the center section rib hinge bearing lug for cracking, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin MD80–55A069, dated January 19, 2011, and repeat that inspection thereafter at intervals not to exceed 5,800 flight cycles. (2) If the crack length between points ‘A’ and ‘B’ is greater than 0.15 inch or the crack length between points ‘C’ and ‘D’ is greater than 0.05 inch: 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 MD80–55A069, dated January 19, 2011. Repeat the inspection required by paragraph (i) of this AD one time before the accumulation of 23,000 total flight cycles on the new horizontal stabilizer center section rib, and thereafter at intervals not to exceed 11,300 flight cycles. 90712–4137; phone: 562–627–5233; fax 562– 627–5210; e-mail: roger.durbin@faa.gov. (n) 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. No Reporting Requirement (k) Although Boeing Alert Service Bulletin MD80–55A069, dated January 19, 2011, specifies to submit certain information to the manufacturer, this AD does not include that requirement. [Docket No. FAA–2011–0908; Directorate Identifier 2010–NM–251–AD] Alternative Methods of Compliance (AMOCs) (l)(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 45, and the approval must specifically refer to this AD. Related Information (m) For more information about this AD, contact Roger Durbin, Aerospace Engineer, Airframe Branch, ANM–120L, FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California PO 00000 Frm 00005 Fmt 4702 Sfmt 4702 Issued in Renton, Washington, on August 19, 2011. Ali Bahrami, Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 2011–21853 Filed 8–25–11; 8:45 am] BILLING CODE 4910–13–P DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 RIN 2120–AA64 Airworthiness Directives; BAE SYSTEMS (Operations) Limited Model BAe 146 Airplanes and Model Avro 146–RJ Airplanes Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed rulemaking (NPRM). AGENCY: We propose to adopt a new airworthiness directive (AD) for the products listed above that would supersede an existing AD. This proposed AD results from mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as: * * * * * SUMMARY: * * * BAE Systems (Operations) Limited has amended the AMM [aircraft maintenance manual] to remove the life limits on shock absorber assemblies, but not the individual shock absorber components, and amend the life limits on the different standards of Main Landing Gear (MLG) Up-Locks and MLG Door Up-Locks in sub-chapter 05–10–15. In addition BAE Systems has amended Chapter 05–10–15 of the AMM to introduce and amend life limits on MLG components. * * * * * The unsafe condition is fatigue cracking of certain structural elements which E:\FR\FM\26AUP1.SGM 26AUP1

Agencies

[Federal Register Volume 76, Number 166 (Friday, August 26, 2011)]
[Proposed Rules]
[Pages 53346-53348]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-21853]

=======================================================================
-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2011-0909; Directorate Identifier 2011-NM-027-AD]
RIN 2120-AA64

Airworthiness Directives; The Boeing Company Model DC-9-81 (MD-
81), DC-9-82 (MD-82), DC-9-83 (MD-83), DC-9-87 (MD-87), and MD-88
Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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

SUMMARY: We propose to adopt a new airworthiness directive (AD) for the
products listed above. This proposed AD would require repetitive high
frequency eddy current (HFEC) inspections for cracking of the left and
right rib hinge bearing lugs of the aft face of the center section of
the horizontal stabilizer; measuring crack length and blending out
cracks; and replacing the horizontal stabilizer center section rib, if
necessary. This proposed AD was prompted by reports of cracks of the
hinge bearing lugs 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 horizontal stabilizer center section
ribs, which would result in failure of the lugs, and consequent
inability of the horizontal stabilizer to sustain the required limit
loads and loss of control of the airplane.

DATES: We must receive comments on this proposed AD by October 11,
2011.

ADDRESSES: You may send comments by any of the following methods:
Federal eRulemaking Portal: Go to https://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: Deliver to Mail address above 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
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 https://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 (phone: 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;
phone: 562-627-5233; fax: 562-627-5210; e-mail: roger.durbin@faa.gov.

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to send any written relevant data, views, or
arguments about this proposal. Send your comments to an address listed
under the ADDRESSES section. Include ``Docket No. FAA-2011-0909;
Directorate Identifier 2011-NM-027-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 https://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 received reports of cracks on Model MD-80 series airplanes and
on Model MD-90-30 airplanes. The cracks were found on the aft face of
the center section left and right hinge bearing lugs on either the left
or right, or in two cases, on both sides of the center section ribs of
the horizontal stabilizer. Cracks were reported on Model MD-80
airplanes that had accumulated 23,700 to 41,963 total flight hours, and
23,300 to 35,294 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 required limit loads and loss of
control of the airplane.

Related Rulemaking

The proposed AD affects Model MD-80 series airplanes. We issued AD
2011-01-11, Amendment 39-16565 (76 FR 430, January 5, 2011) to address
the identified unsafe condition on Model MD-90-30 airplanes, on
December 22, 2010. AD 2011-01-11 requires similar actions as proposed
in this NPRM.

Relevant Service Information

We reviewed Boeing Alert Service Bulletin MD80-55A069, dated
January 19, 2011. That service bulletin describes procedures for
repetitive high frequency eddy current (HFEC) inspections for cracking
of the left and right rib hinge bearing lugs of the aft face of the
center

[[Page 53347]]

section of the horizontal stabilizer; measuring crack length and
blending out cracks; and replacement of the horizontal stabilizer
center section rib, if necessary.

FAA's Determination and Proposed AD Requirements

We are proposing 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 these same type
designs. 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 the Service
Information.''

Differences Between the Proposed AD and the Service Information

Although Boeing Alert Service Bulletin MD80-55A069, dated January
19, 2011, specifies to send the inspection results to the manufacturer,
this proposed AD would not require any report.

Interim Action

We consider this proposed AD interim action since investigation is
ongoing and no terminating action has been developed yet. 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 may consider additional
rulemaking.

Costs of Compliance

We estimate that this proposed AD affects 668 airplanes of U.S.
registry. We estimate the following costs to comply with this proposed
AD:

Estimated Costs
----------------------------------------------------------------------------------------------------------------
Cost per Cost on U.S.
Action Labor cost Parts cost product operators
----------------------------------------------------------------------------------------------------------------
Inspection.......................... 6 work-hours x $85 per $0 $510 $340,680
hour = $510 per
inspection cycle.
----------------------------------------------------------------------------------------------------------------

We have received no definitive data that would enable us to provide
labor cost estimates for the on-condition actions (blend-out repair(s)
or replacement of center section rib(s)) specified in this proposed AD.
However, we have been advised that replacement parts would be $14,500
per horizontal stabilizer rib crack repair kit.

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),
(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.

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
airworthiness directive (AD):

The Boeing Company: Docket No. FAA-2011-0909; Directorate Identifier
2011-NM-027-AD.

Comments Due Date

(a) We must receive comments by October 11, 2011.

Affected ADs

(b) None.

Applicability

(c) This AD applies to The Boeing Company Model DC-9-81 (MD-81),
DC-9-82 (MD-82), DC-9-83 (MD-83), DC-9-87 (MD-87), and MD-88
airplanes, certificated in any category, as identified in Boeing
Alert Service Bulletin MD80-55A069, dated January 19, 2011.

Subject

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

Unsafe Condition

(e) This AD was prompted by reports of cracks of the hinge
bearing lugs 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 horizontal stabilizer center
section ribs, which would result in failure of the lugs, and
consequent inability of the horizontal stabilizer to sustain the
required limit loads and loss of control of the airplane.

Compliance

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

Actions on Horizontal Stabilizer Ribs Made From 7075-T7351 Material

(g) For Group 1 airplanes, as identified in Boeing Alert Service
Bulletin MD80-55A069, dated January 19, 2011: Before the
accumulation of 23,000 total flight cycles, or within 4,383 flight
cycles after the effective

[[Page 53348]]

date of this AD, whichever occurs later, do a high frequency eddy
current (HFEC) inspection for cracking of the left and right rib
hinge bearing lugs of the aft face of the center section of the
horizontal stabilizer, in accordance with the Accomplishment
Instructions of Boeing Alert Service Bulletin MD80-55A069, dated
January 19, 2011. For any crack-free lug, repeat the inspection on
that lug thereafter at intervals not to exceed 8,200 flight cycles.
(h) If, during any inspection required by paragraph (g) of this
AD, any crack is found, before further flight, measure the length of
the crack between the points specified in Boeing Alert Service
Bulletin MD80-55A069, dated January 19, 2011. Do the action in
accordance with the Accomplishment Instructions of Boeing Alert
Service Bulletin MD80-55A069, dated January 19, 2011.
(1) If the crack length between points `A' and `B' is less than
or equal to 0.15 inch and the crack length between points `C' and
`D' is less than or equal to 0.05 inch: Before further flight, blend
out the crack, in accordance with the Accomplishment Instructions of
Boeing Alert Service Bulletin MD80-55A069, dated January 19, 2011.
Within 15,600 flight cycles after doing the blend out, do an HFEC
inspection of the blend out on the center section rib hinge bearing
lug for cracking, in accordance with the Accomplishment Instructions
of Boeing Alert Service Bulletin MD80-55A069, dated January 19,
2011, and repeat that inspection thereafter at intervals not to
exceed 3,900 flight cycles.
(2) If the crack length between points `A' and `B' is greater
than 0.15 inch or the crack length between points `C' and `D' is
greater than 0.05 inch: 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 MD80-55A069, dated
January 19, 2011. Repeat the inspection required by paragraph (g) of
this AD one time before the accumulation of 23,000 total flight
cycles on the new horizontal stabilizer center section rib, and
thereafter at intervals not to exceed 11,300 flight cycles.

Actions on Horizontal Stabilizer Ribs Made From 7050-T7451 Material

(i) For Group 2 airplanes, as identified in Boeing Alert Service
Bulletin MD80-55A069, dated January 19, 2011: Before the
accumulation of 23,000 total flight cycles, or within 4,383 flight
cycles after the effective date of this AD, whichever occurs later,
do an HFEC inspection for cracking of the left and right rib hinge
bearing lugs of the aft face of the center section of the horizontal
stabilizer, in accordance with the Accomplishment Instructions of
Boeing Alert Service Bulletin MD80-55A069, dated January 19, 2011.
For any crack-free lug, repeat the inspection on that lug thereafter
at intervals not to exceed 11,300 flight cycles.
(j) If, during any inspection required by paragraph (i) of this
AD, any crack is found, before further flight, measure the length of
the crack between the points specified in and in accordance with the
Accomplishment Instructions of Boeing Alert Service Bulletin MD80-
55A069, dated January 19, 2011.
(1) If the crack length between points `A' and `B' is less than
or equal to 0.15 inch and the crack length between points `C' and
`D' is less than or equal to 0.05 inch: Before further flight, blend
out the crack, in accordance with the Accomplishment Instructions of
Boeing Alert Service Bulletin MD80-55A069, dated January 19, 2011.
Within 15,600 flight cycles after doing the blend out, do an HFEC
inspection of the blend out on the center section rib hinge bearing
lug for cracking, in accordance with the Accomplishment Instructions
of Boeing Alert Service Bulletin MD80-55A069, dated January 19,
2011, and repeat that inspection thereafter at intervals not to
exceed 5,800 flight cycles.
(2) If the crack length between points `A' and `B' is greater
than 0.15 inch or the crack length between points `C' and `D' is
greater than 0.05 inch: 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 MD80-55A069, dated
January 19, 2011. Repeat the inspection required by paragraph (i) of
this AD one time before the accumulation of 23,000 total flight
cycles on the new horizontal stabilizer center section rib, and
thereafter at intervals not to exceed 11,300 flight cycles.

No Reporting Requirement

(k) Although Boeing Alert Service Bulletin MD80-55A069, dated
January 19, 2011, specifies to submit certain information to the
manufacturer, this AD does not include that requirement.

Alternative Methods of Compliance (AMOCs)

(l)(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 45, and the approval must specifically refer to this AD.

Related Information

(m) For more information about this AD, contact Roger Durbin,
Aerospace Engineer, Airframe Branch, ANM-120L, FAA, Los Angeles
Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood,
California 90712-4137; phone: 562-627-5233; fax 562-627-5210; e-
mail: roger.durbin@faa.gov.
(n) 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.

Issued in Renton, Washington, on August 19, 2011.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 2011-21853 Filed 8-25-11; 8:45 am]
BILLING CODE 4910-13-P

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