[Federal Register Volume 72, Number 88 (Tuesday, May 8, 2007)]
[Rules and Regulations]
[Pages 25960-25962]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E7-8768]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-28100; Directorate Identifier 2007-NM-103-AD; 
Amendment 39-15045; AD 2007-10-04]
RIN 2120-AA64


Airworthiness Directives; McDonnell Douglas 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), Department of 
Transportation (DOT).

ACTION: Final rule; request for comments.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for all 
McDonnell Douglas 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. This AD requires repetitive 
inspections to detect cracks in the horizontal stabilizer, and related 
investigative/corrective actions if necessary. This AD results from 
reports of cracks found in the horizontal stabilizer--in the upper and 
lower aft skin panels at the aft inboard corner at station XH = 8.2, 
and in the rear spar upper caps adjacent to the aft skin panel at 
station XH = 10.0. We are issuing this AD to detect and correct cracks 
in the upper and lower aft skin panels and rear spar upper caps, which, 
if not corrected, could lead to the loss of overall structural 
integrity of the horizontal stabilizer.

DATES: This AD becomes effective May 23, 2007.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in the AD as of May 23, 2007.
    We must receive comments on this AD by July 9, 2007.

ADDRESSES: Use one of the following addresses to submit comments on 
this AD.
     DOT Docket Web site: Go to http://dms.dot.gov and follow 
the instructions for sending your comments electronically.
     Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your 
comments electronically.
     Mail: Docket Management Facility; U.S. Department of 
Transportation, 400 Seventh Street SW., Nassif Building, Room PL-401, 
Washington, DC 20590.
     Fax: (202) 493-2251.
     Hand Delivery: Room PL-401 on the plaza level of the 
Nassif Building, 400 Seventh Street SW., Washington, DC, between 9 a.m. 
and 5 p.m., Monday through Friday, except Federal holidays.
    Contact Boeing Commercial Airplanes, Long Beach Division, 3855 
Lakewood Boulevard, Long Beach, California 90846, Attention: Data and 
Service Management, Dept. C1-L5A (D800-0024), for service information 
identified in this AD.

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: 

Discussion

    We have received reports of cracks found in the horizontal 
stabilizer--in the upper and lower aft skin panels at the aft inboard 
corner at station XH = 8.2, and in the rear spar upper caps adjacent to 
the aft skin panel at station XH = 10.0. These cracks were found during 
maintenance visual inspections.
    The cause of the cracking is still under investigation. If not 
corrected, the cracked upper and lower aft skin panels and rear spar 
upper caps could lead to the loss of overall structural integrity of 
the horizontal stabilizer.

Relevant Service Information

    We have reviewed Boeing Alert Service Bulletin MD80-55A065, dated 
April 25, 2007. The service bulletin describes procedures for 
repetitive low- and high-frequency eddy current inspections to detect 
cracks of the horizontal stabilizer's upper and lower aft skin panels 
and rear spar upper caps. The service bulletin provides options for 
corrective action based on crack length, location, and repairability; 
these options include some combination of the following actions:
     Stop drilling the end of the crack;
     Trimming the crack and installing a filler;
     Installing a skin panel splice or rear spar upper cap 
splice;
     Replacing the skin panel or rear spar upper cap with a new 
part; and
     Repeating the inspection of the cracked area (including 
aft skin panels, skin panel splice, and rear spar upper cap).
    The repetitive inspection intervals, which range from 200 to 2,600 
flight cycles, depend on the option used.
    Accomplishing the actions specified in the service information is 
intended to adequately address the unsafe condition.

FAA's Determination and Requirements of This AD

    The unsafe condition described previously is likely to exist or 
develop on other airplanes of the same type design. For this reason, we 
are issuing this AD to detect and correct cracks in the upper and lower 
aft skin panels and rear spar upper caps, which, if not corrected, 
could lead to the loss of overall structural integrity of the 
horizontal stabilizer. This AD requires accomplishing the actions 
specified in the service information described previously, except as 
discussed under ``Differences Between the AD and the Service Bulletin'' 
below.

Differences Between the AD and the Service Bulletin

    The service bulletin specifies that any splice installed as part of 
a crack repair option be inspected within 20,000 flight cycles after 
the repair. But the service bulletin notes that the type, method, and 
repetitive interval for this inspection will be identified by Boeing at 
a later date. (See paragraph 1.E., note (a) of Tables 1 and 2 of the 
service bulletin.) To ensure continued safety, we have determined that 
this inspection and its repetitive interval must be adequately defined. 
Therefore, this AD requires that the inspection type, method, and 
repetitive interval be approved either by the FAA, or in accordance 
with 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.
    For a crack that meets the Condition 2 criteria specified in Table 
1 or Table 3 in paragraph 1.E. of the service bulletin, Options 1 and 2 
specify temporary repairs followed by repetitive inspections of the 
area, but provide no

[[Page 25961]]

terminating action for these repetitive inspections. In this case, this 
AD requires, within 4,000 flight cycles after the crack is detected, 
either installing a horizontal stabilizer aft skin panel splice or 
removing and replacing the horizontal stabilizer aft skin panel, in 
accordance with Option 3 or 4 of the applicable table, followed by the 
applicable repetitive inspections specified in Option 3 or 4. We have 
determined that this action is necessary to maintain the safety of the 
fleet.
    We have coordinated these differences with Boeing.

FAA's Determination of the Effective Date

    Since an unsafe condition exists that requires the immediate 
adoption of this AD, we have found that notice and opportunity for 
public comment before issuing this AD are impracticable, and that good 
cause exists to make this AD effective in less than 30 days.

Comments Invited

    This AD is a final rule that involves requirements that affect 
flight safety and was not preceded by notice and an opportunity for 
public comment; however, we invite you to submit any relevant written 
data, views, or arguments regarding this AD. Send your comments to an 
address listed in the ADDRESSES section. Include ``Docket No. FAA-2007-
28100; Directorate Identifier 2007-NM-103-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of the AD that might 
suggest a need to modify it.
    We will post all comments we receive, without change, to http://dms.dot.gov, including any personal information you provide. We will 
also post a report summarizing each substantive verbal contact with FAA 
personnel concerning this AD. Using the search function of that Web 
site, anyone can find and read the comments in any of our dockets, 
including the name of the individual who sent the comment (or signed 
the comment on behalf of an association, business, labor union, etc.). 
You may review the DOT's complete Privacy Act Statement in the Federal 
Register published on April 11, 2000 (65 FR 19477-78), or you may visit 
http://dms.dot.gov.

Examining the Docket

    You may examine the AD docket on the Internet at http://dms.dot.gov, or in person at the Docket Management Facility office 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The Docket Management Facility office (telephone (800) 647-
5227) is located on the plaza level of the Nassif Building at the DOT 
street address stated in the ADDRESSES section. Comments will be 
available in the AD docket shortly after the Docket Management System 
receives them.

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 have determined that 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 the 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.
    We prepared a regulatory evaluation of the estimated costs to 
comply with this AD and placed it in the AD docket. See the ADDRESSES 
section for a location to examine the regulatory evaluation.

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 Federal Aviation Administration (FAA) amends Sec.  39.13 by 
adding the following new airworthiness directive (AD):

2007-10-04 McDonnell Douglas: Amendment 39-15045. Docket No. FAA-
2007-28100; Directorate Identifier 2007-NM-103-AD.

Effective Date

    (a) This AD becomes effective May 23, 2007.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to all McDonnell Douglas 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.

Unsafe Condition

    (d) This AD results from reports of cracks found in the 
horizontal stabilizer--in the upper and lower aft skin panels at the 
aft inboard corner at station XH = 8.2, and in the rear spar upper 
caps adjacent to the aft skin panel at station XH = 10.0. We are 
issuing this AD to detect and correct cracks in the upper and lower 
aft skin panels and rear spar upper caps, which, if not corrected, 
could lead to the loss of overall structural integrity of the 
horizontal stabilizer.

Compliance

    (e) 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

    (f) Do eddy current inspections to detect cracks in the 
horizontal stabilizer, in accordance with the Accomplishment 
Instructions of Boeing Alert Service Bulletin MD80-55A065, dated 
April 25, 2007.
    (1) Do the initial inspections before the accumulation of 20,000 
total flight cycles, or within 854 flight cycles after the effective 
date of this AD, whichever occurs later.
    (2) Except as required by paragraphs (g) and (h) of this AD: Do 
all applicable repetitive inspections and related investigative and 
corrective actions in accordance with, and at the times specified 
in, the service bulletin.

Exceptions to Service Bulletin Specifications

    (g) Where Boeing Alert Service Bulletin MD80-55A065, dated April 
25, 2007, specifies inspecting any skin panel splice or cap splice 
installed as part of a crack repair

[[Page 25962]]

option: This AD requires the initial inspection within the 
compliance time specified in the service bulletin, but the 
inspection type, method, and repetitive interval must be done with 
FAA approval in accordance with the procedures specified in 
paragraph (i) of this AD.
    (h) For airplanes on which any detected crack meets the 
Condition 2 criteria specified in Table 1 or Table 3 in paragraph 
1.E. of Boeing Alert Service Bulletin MD80-55A065, dated April 25, 
2007: If Option 1 or 2 is selected as the corrective action, either 
install a horizontal stabilizer aft skin panel splice or remove and 
replace the horizontal stabilizer aft skin panel within 4,000 flight 
cycles after accomplishing Option 1 or 2, in accordance with Option 
3 or 4 of the applicable table, and repeat the inspection thereafter 
at the time specified in Option 3 or 4, as applicable.

Alternative Methods of Compliance (AMOCs)

    (i)(1) The Manager, Los Angeles Aircraft Certification Office 
(ACO), FAA, has the authority to approve AMOCs for this AD, if 
requested in accordance with 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 appropriate principal inspector (PI) in the FAA 
Flight Standards District Office (FSDO), or lacking a PI, your local 
FSDO.
    (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, 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.

Material Incorporated by Reference

    (j) You must use Boeing Alert Service Bulletin MD80-55A065, 
dated April 25, 2007, to perform the actions that are required by 
this AD, unless the AD specifies otherwise. The Director of the 
Federal Register approved the incorporation by reference of this 
document in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. 
Contact Boeing Commercial Airplanes, Long Beach Division, 3855 
Lakewood Boulevard, Long Beach, California 90846, Attention: Data 
and Service Management, Dept. C1-L5A (D800-0024), for a copy of this 
service information. You may review copies at the FAA, Transport 
Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or 
at the National Archives and Records Administration (NARA). For 
information on the availability of this material at NARA, call 202-
741-6030, or go to: http://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued in Renton, Washington, on May 1, 2007.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
 [FR Doc. E7-8768 Filed 5-7-07; 8:45 am]
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