
[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]


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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).

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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 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: 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 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 (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 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 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


