[Federal Register Volume 69, Number 108 (Friday, June 4, 2004)]
[Rules and Regulations]
[Pages 31514-31518]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-12398]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-NM-110-AD; Amendment 39-13653; AD 2004-11-07]
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, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD),

[[Page 31515]]

applicable 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, that 
requires implementation of a program of structural inspections of 
baseline structure to detect and correct fatigue cracking in order to 
ensure the continued airworthiness of these airplanes as they approach 
the manufacturer's original fatigue design life goal. This action is 
necessary to detect and correct fatigue cracking that could compromise 
the structural integrity of these airplanes. This action is intended to 
address the identified unsafe condition.

DATES: Effective July 9, 2004.
    The incorporation by reference of a certain publication listed in 
the regulations is approved by the Director of the Federal Register as 
of July 9, 2004.

ADDRESSES: The service information referenced in this AD may be 
obtained from Boeing Commercial Airplanes, Long Beach Division, 3855 
Lakewood Boulevard, Long Beach, California 90846, Attention: Data and 
Service Management, Dept. C1-L5A (D800-0024). This information may be 
examined at the Federal Aviation Administration (FAA), Transport 
Airplane Directorate, Rules Docket, 1601 Lind Avenue, SW., Renton, 
Washington; or at the FAA, Transport Airplane Directorate, Los Angeles 
Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, 
California; 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/code_of_federal_regulations/ibr_locations.html.

FOR FURTHER INFORMATION CONTACT: Mike Lee, Aerospace Engineer, Airframe 
Branch, ANM-120L, FAA, Los Angeles Aircraft Certification Office, 3960 
Paramount Boulevard, Lakewood, California 90712-4137; telephone (562) 
627-5325; fax (562) 627-5210.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an airworthiness 
directive (AD) that is applicable 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 was published in the Federal Register on October 8, 2003 
(68 FR 58046). That action proposed to require implementation of a 
program of structural inspections of baseline structure to detect and 
correct fatigue cracking in order to ensure the continued airworthiness 
of these airplanes as they approach the manufacturer's original fatigue 
design life goal.

Comments

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.

Request To Clarify Paragraph (b) of the Notice of Proposed Rulemaking 
(NPRM)

    One commenter, the airplane manufacturer, requests that paragraph 
(b) of the NPRM be clarified to specify what an operator should do to 
inspect a discrepant principal structural element (PSE). The commenter 
states that the preamble of the NPRM alludes to what to do, but that 
the body of the NPRM does not specify what actions to accomplish. 
Specifically, the commenter requests that the following clarification 
be added to paragraph (b) of the NPRM: ``If, during the inspection of 
the PSE per Supplemental Inspection Document Volume II, a discrepancy 
is determined to exist, then the following applies: For an inspection 
prior to \3/4\Nth or Nth: The area of the PSE 
affected by the discrepancy must be inspected prior to Nth 
with a method approved by the Manager of the Los Angeles Aircraft 
Certification Office (ACO). For an inspection after Nth: The 
area of the PSE affected by the discrepancy must be inspected prior to 
the accumulation of an additional [Delta]NDI/2, measured from the last 
non-discrepant inspection finding, with a method approved by the Los 
Angeles ACO.''
    The FAA agrees that clarification is needed. We have added a new 
paragraph (c) of this AD to clarify the actions and compliance times 
required if any discrepancy is detected during the inspections required 
by paragraph (b) of this AD. Paragraphs subsequent to paragraph (b) of 
the NPRM have been renumbered accordingly in this AD.

Request To Clarify the Method for Approving a Repair

    One commenter, the airplane manufacturer, requests clarification 
concerning the multiple state approach used for approving repairs. 
Specifically, the commenter requests that a ``note'' be added after 
paragraph (d) of the NPRM to clarify that Advisory Circular AC 25.1529-
1, Instructions for Continued Airworthiness of Structural Repairs on 
Transport Airplanes, dated August 1, 1991, is appropriate guidance 
concerning the approval of repairs to PSEs.
    We agree with the commenter's request and have revised the final 
rule to add a new ``Note 2'' advising that AC 25.1529-1 provides 
additional guidance concerning the approval of repairs.

Request To Clarify Compliance ``Threshold'' of Paragraph (d) of the 
NPRM

    One commenter, the airplane manufacturer, requests that the 
``threshold'' specified in paragraph (d)(2) of the NPRM be clarified. 
The commenter asserts that the ``threshold'' could be interpreted as 
reaching 75% of the PSE inspection threshold and not the repair 
threshold. The commenter requests that paragraph (d)(2) of the NPRM be 
revised as follows: ``(2) Prior to reaching 75% of the threshold as 
determined in paragraph (d)(1) of the NPRM, submit the inspection 
methods and repetitive inspection intervals for the repair for approval 
by the Manager of the Los Angeles ACO.'' The commenter notes that 
paragraph (d)(3) of the NPRM is clear concerning what threshold is 
being referred to.
    We agree with the commenter that clarification is warranted. We 
have redesignated paragraph (d)(2) of the NPRM as paragraph (e)(2) of 
the final rule and revised the wording of new paragraph (e)(2) to 
clarify the threshold accordingly.

Request To Clarify the Compliance Times of Paragraph (e) of the NPRM

    One commenter, the airplane manufacturer, requests that paragraph 
(e) of the NPRM be revised to delete the phrase that limits the 
applicability of paragraph (e) of the NPRM to airplanes that have 
exceeded the compliance times specified in paragraph (b) of the NPRM. 
The commenter states that, if the airplane has not exceeded these 
times, then the operator would only be required to comply per paragraph 
(b) of the NPRM.
    We do not concur with the commenter's request. The purpose of this 
limitation is to avoid the need for air carriers to comply with this 
paragraph (redesignated as paragraph (f) in this final rule) if they 
are able to comply with paragraph (b) within the compliance times 
specified in paragraph (b) of the AD. Without this limitation, for 
example, an air carrier placing a relatively new airplane into service 
would either have to perform the inspections before placing it into 
service or obtain an FAA approval for performing them later.
    In considering this comment, however, we recognize that the only 
time that an air carrier would need to address this issue is when the 
airplane

[[Page 31516]]

has exceeded the fatigue life threshold (Nth). Before that 
time, paragraph (b) of the AD allows for performance of the inspections 
within the compliance times specified in that paragraph. Therefore, we 
have revised paragraph (f) of the AD to reference only the fatigue life 
threshold (Nth).

Request To Revise Certain Terminology

    One commenter, the airplane manufacturer, requests that the terms 
``SSIP'' and ``SSI'' be removed from the NPRM and replaced with the 
terms ``SIP'' and ``PSE,'' respectively, to be consistent with the 
terminology used in the MD-80 Supplemental Inspection Document.
    We agree with the commenter's request. We have redesignated 
paragraph (e) of the NPRM as paragraph (f) of the final rule, and where 
those terms appeared in paragraph (e) of the NPRM, paragraph (f) of the 
final rule reflects those changes. However, other sections where usage 
of those terms appeared in the preamble of the NPRM do not appear in 
the final rule, and it is not necessary to revise in the final rule in 
that regard.

Request To Clarify a Reference in the SID

    One commenter, an airline operator, requests that clarification be 
given regarding possible misinterpretation of notes (**) and (***) of 
the Boeing MD80 SID, Volume 1. The commenter states that the two PSEs 
(PSEs 53.80.004 and 54.80.005) referenced in notes (**) and (***) can 
be inspected at ``intervals specified'' in the Maintenance Review Board 
(MRB) Report, and that the MRB Report mentions ``C'' check intervals. 
Therefore, the commenter suggests that the two PSEs could mistakenly be 
inspected at intervals of every ``C'' check.
    We acknowledge the commenter's request for clarification, but note 
that no change is necessary to the final rule for the following 
reasons. The intent of notes (**) and (***) in the SID is to allow 
operators the opportunity to receive credit for MD80 SID inspections of 
the forward and aft engine pylon isolators land conebolts when 
inspections are performed at engine changes. However, the 
Nth still remains at 50,000 landings and [Delta]NDI/2 
intervals still remain at 10,000 landings even if the inspections are 
performed at engine changes per notes (**) and (***) of the SID.

Request To Correct ``SIP Inspection Requirements'' of the Discussion

    One commenter, the airplane manufacturer, points out that the first 
sentence of the ``SIP Inspection Requirements'' of the Discussion 
section of the NPRM should be revised to reflect the correct threshold 
requirements. Specifically, the commenter requests that the first 
sentence be revised to read, ``Paragraph (b) of this proposed AD also 
would require, for airplanes that have exceeded the Nth/2, 
that each PSE be inspected prior to reaching the established thresholds 
(\3/4\Nth and Nth) or within 18 months after the 
effective date of this AD.'' The commenter notes that inspection of a 
PSE that exceeds Nth cannot be inspected prior to 
Nth.
    We acknowledge the commenter's request to revise that paragraph of 
the Discussion section. Since that section of the preamble does not 
reappear in the final rule, no change to the final rule is necessary in 
that regard.

Conclusion

    After careful review of the available data, including the comments 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule with the changes previously 
described. The FAA has determined that these changes will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.

Interim Action

    This is considered to be interim action. The FAA is currently 
considering requiring damage tolerance-based inspections and procedures 
that include all major structural repairs and modifications (RAMs), 
which may result in additional rulemaking.

Cost Impact

    There are approximately 1,167 Model DC-9-80 and MD-88 airplanes of 
the affected design in the worldwide fleet. The FAA estimates that 665 
airplanes of U.S. registry will be affected by this AD.
    Incorporation of the SIP into an operator's maintenance program is 
estimated to require 1,062 work hours (per operator), at an average 
labor rate of $65 per work hour. Based on these figures, the cost to 
the 18 affected U.S. operators to incorporate the SIP is estimated to 
be $1,242,540.
    The recurring inspection costs in this AD are estimated to be 362 
work hours per airplane per year, at an average labor rate of $65 per 
work hour. Based on these figures, the recurring inspection costs are 
estimated to be $23,530 per airplane, per inspection, or $15,647,450 
for the affected U.S. fleet.
    Based on the above figures, the total cost impact of this AD on 
U.S. operators is estimated to be $1,242,540 for the first year, and 
$15,647,450 for each year thereafter. These ``total cost impact'' 
figures assume that no operator has yet accomplished any of the 
requirements of this AD.
    Additionally, the number of required work hours for each required 
inspection (and the SIP), as indicated above, is presented as if the 
accomplishment of those actions are to be conducted as ``stand alone'' 
actions. However, in actual practice, these actions for the most part 
will be accomplished coincidentally or in combination with normally 
scheduled airplane inspections and other maintenance program tasks. 
Therefore, the actual number of necessary additional work hours will be 
minimal in many instances. Further, any cost associated with special 
airplane scheduling can be expected to be minimal.

Regulatory Impact

    The regulations adopted herein 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. Therefore, it 
is determined that this final rule does not have federalism 
implications under Executive Order 13132.
    For the reasons discussed above, I certify that this action (1) is 
not a ``significant regulatory action'' under Executive Order 12866; 
(2) is not a ``significant rule'' under 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. A final evaluation has been prepared for this action 
and it is contained in the Rules Docket. A copy of it may be obtained 
from the Rules Docket at the location provided under the caption 
ADDRESSES.

List of Subjects in 14 CFR Part 39

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

Adoption of the Amendment

0
Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends part 39 of 
the Federal Aviation Regulations (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.

[[Page 31517]]

Sec.  39.13  [Amended]

0
2. Section 39.13 is amended by adding the following new airworthiness 
directive:

2004-11-07 McDonnell Douglas: Amendment 39-13653. Docket 2000-NM-
110-AD.

    Applicability: 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.
    Compliance: Required as indicated, unless accomplished 
previously.
    To detect and correct fatigue cracking that could compromise the 
structural integrity of these airplanes, accomplish the following:

Revision of the Maintenance Inspection Program

    (a) Within 12 months after the effective date of this AD, 
incorporate a revision into the FAA-approved maintenance inspection 
program that provides for inspection(s) of the Principal Structural 
Elements (PSEs), in accordance with Section 3 of Volume I , Revision 
B, dated March 2003, of Boeing Report No. L26-022, ``MD-80 
Supplemental Inspection Document (SID).'' PSEs are also specified in 
the SID. Unless otherwise specified, all references in this AD to 
the ``SID'' are to Revision B, dated March 2003.

Non-Destructive Inspections (NDIs)

    (b) For all PSEs listed in Section 3 of Volume I of the SID, 
perform an NDI for fatigue cracking of each PSE in accordance with 
the NDI procedures specified in Section 2 of Volume II of the SID, 
at the times specified in paragraph (b)(1), (b)(2), or (b)(3) of 
this AD, as applicable.
    (1) For airplanes that have less than three quarters of the 
fatigue life threshold (\3/4\Nth) as of the effective 
date of the AD: Perform an NDI for fatigue cracking no earlier than 
one-half of the threshold (\1/2\Nth) but prior to 
reaching three-quarters of the threshold (\3/4\Nth), or 
within 18 months after the effective date of this AD, whichever 
occurs later. Inspect again prior to reaching the threshold 
(Nth), but no earlier than (\3/4\Nth). 
Thereafter, after passing the threshold (Nth), repeat the 
inspection for that PSE at intervals not to exceed [Delta]NDI/2.
    (2) For airplanes that have reached or exceeded three-quarters 
of the fatigue life threshold (\3/4\Nth), but less than 
the threshold (Nth), as of the effective date of the AD: 
Perform an NDI prior to reaching the threshold (Nth), or 
within 18 months after the effective date of this AD, whichever 
occurs later. Thereafter, after passing the threshold 
(Nth), repeat the inspection for that PSE at intervals 
not to exceed [Delta]NDI/2.
    (3) For airplanes that have reached or exceeded the fatigue life 
threshold (Nth) as of the effective date of the AD: 
Perform an NDI within 18 months after the effective date of this AD. 
Thereafter, repeat the inspection for that PSE at intervals not to 
exceed [Delta]NDI/2.

Discrepant Findings

    (c) If any discrepancy (e.g., differences on the airplane from 
the NDI reference standard, such as PSEs that have been repaired, 
altered, or modified) is detected during any inspection required by 
paragraph (b) of this AD, accomplish the action specified in 
paragraph (c)(1) or (c)(2) of this AD, as applicable.
    (1) If a discrepancy is detected during any inspection performed 
prior to \3/4\Nth or Nth: The area of the PSE 
affected by the discrepancy must be inspected prior to 
Nth per a method approved by the Manager, Los Angeles 
Aircraft Certification Office (ACO), FAA.
    (2) If a discrepancy is detected during any inspection performed 
after Nth: The area of the PSE affected by the 
discrepancy must be inspected prior to the accumulation of an 
additional [Delta]NDI/2, measured from the last non-discrepant 
inspection finding, per a method approved by the Manager of the Los 
Angeles ACO.

Reporting Requirements

    (d) All negative, positive, or discrepant (discrepant finding 
examples are described in paragraph (c) of this AD) findings of the 
inspections accomplished under paragraph (b) of this AD must be 
reported to Boeing, at the times specified in, and in accordance 
with the instructions contained in, Section 3 of Volume I of the 
SID. Information collection requirements contained in this 
regulation have been approved by the Office of Management and Budget 
(OMB) under the provisions of the Paperwork Reduction Act of 1980 
(44 U.S.C. 3501 et seq.) and have been assigned OMB Control Number 
2120-0056.

Corrective Actions

    (e) Any cracked structure of a PSE detected during any 
inspection required by paragraph (b) of this AD must be repaired 
before further flight in accordance with an FAA-approved method. 
Accomplish follow-on actions described in paragraphs (e)(1), (e)(2), 
and (e)(3) of this AD, at the times specified.
    (1) Within 18 months after repair, perform a damage tolerance 
assessment (DTA) that defines the threshold for inspection of the 
repair and submit the assessment for approval to the Manager of the 
Los Angeles ACO.
    (2) Prior to reaching 75% of the threshold as determined in 
paragraph (e)(1) of this AD, submit the inspection methods and 
repetitive inspection intervals for the repair for approval by the 
Manager of the Los Angeles ACO.
    (3) Prior to the threshold as determined in paragraph (e)(1) of 
this AD, incorporate the inspection method and repetitive inspection 
intervals into the FAA-approved structural maintenance or inspection 
program for the airplane.

    Note 1: For the purposes of this AD, the FAA anticipates that 
submissions of the damage tolerance assessment of the repair, if 
acceptable, should be approved within six months after submission.


    Note 2: Advisory Circular AC 25.1529-1, Instructions for 
Continued Airworthiness of Structural Repairs on Transport 
Airplanes, dated August 1, 1991, is considered to be additional 
guidance concerning the approval of repairs to PSEs.

Inspection for Transferred Airplanes

    (f) Before any airplane that has exceeded the fatigue life 
threshold (Nth) can be added to an air carrier's 
operations specifications, a program for the accomplishment of the 
inspections required by this AD must be established per paragraph 
(f)(1) or (f)(2) of this AD, as applicable.
    (1) For airplanes that have been inspected per this AD, the 
inspection of each PSE must be accomplished by the new operator per 
the previous operator's schedule and inspection method, or the new 
operator's schedule and inspection method, at whichever time would 
result in the earlier accomplishment date for that PSE inspection. 
The compliance time for accomplishment of this inspection must be 
measured from the last inspection accomplished by the previous 
operator. After each inspection has been performed once, each 
subsequent inspection must be performed per the new operator's 
schedule and inspection method.
    (2) For airplanes that have not been inspected per this AD, the 
inspection of each PSE required by this AD must be accomplished 
either prior to adding the airplane to the air carrier's operations 
specification, or per a schedule and an inspection method approved 
by the Manager, Los Angeles ACO. After each inspection has been 
performed once, each subsequent inspection must be performed per the 
new operator's schedule.

Inspections Accomplished Before the Effective Date of This AD

    (g) Inspections per Boeing Report No. L26-022, ``MD-80 
Supplemental Inspection Document (SID),'' Revision A, dated 
September 2000, accomplished prior to the effective date of this AD, 
are acceptable for compliance with the requirements of paragraph (b) 
of this AD.

Acceptable for Compliance

    (h) McDonnell Douglas Report No. MDC 91K0263, ``DC-9/MD-80 Aging 
Aircraft Repair Assessment Program Document,'' dated July 1997, 
provides inspection/replacement programs for certain repairs to the 
fuselage pressure shell. These repairs and inspection/replacement 
programs are considered acceptable for compliance with the 
requirements of paragraphs (b) and (e) of this AD for repairs 
subject to that document.

Alternative Methods of Compliance

    (i) In accordance with 14 CFR 39.19, the Manager, Los Angeles 
ACO, is authorized to approve alternative methods of compliance 
(AMOCs) for this AD.

Incorporation by Reference

    (j) Unless otherwise specified in this AD, the actions shall be 
done in accordance with Section 3 of Volume I, Revision B, dated 
March 2003, of Boeing Report No. L26-022, ``MD-80 Supplemental 
Inspection Document (SID).'' This incorporation by reference was 
approved by the Director of the Federal Register in accordance with 
5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from 
Boeing Commercial Airplanes, Long Beach Division, 3855 Lakewood 
Boulevard, Long Beach, California 90846, Attention:

[[Page 31518]]

Data and Service Management, Dept. C1-L5A (D800-0024). Copies may be 
inspected at the FAA, Transport Airplane Directorate, 1601 Lind 
Avenue, SW., Renton, Washington; or at the FAA, Los Angeles Aircraft 
Certification Office, 3960 Paramount Boulevard, Lakewood, 
California; 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/code_of_federal_regulations/ibr_locations.html.

Effective Date

    (k) This amendment becomes effective on July 9, 2004.

    Issued in Renton, Washington, on May 5, 2004.
Ali Bahrami,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service
[FR Doc. 04-12398 Filed 6-3-04; 8:45 am]
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