[Federal Register Volume 71, Number 44 (Tuesday, March 7, 2006)]
[Proposed Rules]
[Pages 11328-11333]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 06-2157]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2005-21779; Directorate Identifier 2002-NM-349-AD]
RIN 2120-AA64


Airworthiness Directives; McDonnell Douglas Model DC-9-10 Series 
Airplanes; DC-9-20 Series Airplanes; DC-9-30 Series Airplanes; DC-9-40 
Series Airplanes; and DC-9-50 Series Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Supplemental notice of proposed rulemaking (NPRM); reopening of 
comment period.

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SUMMARY: The FAA is revising an earlier NPRM for an airworthiness 
directive (AD) that applies to certain McDonnell Douglas transport 
category airplanes. The original NPRM would have superseded an existing 
AD that currently requires, among other things, revision of an existing 
program of structural inspections. The original NPRM 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. The original NPRM 
resulted from a significant number of these airplanes approaching or 
exceeding the design service goal on which the initial type 
certification approval was predicated. This new action revises the 
original NPRM by removing certain service information as acceptable 
methods of compliance. We are proposing this supplemental NPRM to 
detect and correct fatigue cracking that could compromise the 
structural integrity of these airplanes.

DATES: We must receive comments on this supplemental NPRM by April 3, 
2006.

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed 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.

[[Page 11329]]

     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 proposed AD.

FOR FURTHER INFORMATION CONTACT: Wahib Mina, Aerospace Engineer, 
Airframe Branch, ANM-120L, FAA, Los Angeles Aircraft Certification 
Office, 3960 Paramount Boulevard, Lakewood, California 90712-4137; 
telephone (562) 627-5324; fax (562) 627-5210.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to submit any relevant written data, views, or 
arguments regarding this proposal. Send your comments to an address 
listed in the ADDRESSES section. Include the docket number ``Docket No. 
FAA-2005-21779; Directorate Identifier 2002-NM-349-AD'' at the 
beginning of your comments. We specifically invite comments on the 
overall regulatory, economic, environmental, and energy aspects of this 
supplemental NPRM. We will consider all comments received by the 
closing date and may amend this supplemental NPRM in light of those 
comments.
    We will post all comments submitted, without change, to http://
http://dms.dot.gov">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 supplemental NPRM. 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://
http://dms.dot.gov">dms.dot.gov, or in person at the Docket Management Facility offices 
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 ADDRESSES. Comments will be available in the 
AD docket shortly after the Docket Management System receives them.

Discussion

    We proposed to amend part 39 of the Federal Aviation Regulations 
(14 CFR part 39) with a notice of proposed rulemaking (NPRM) for an AD 
(the ``original NPRM'') for certain McDonnell Douglas transport 
category airplanes. The original NPRM proposed to supersede AD 96-13-
03, amendment 39-9671 (61 FR 31009, June 19, 1996), which applies to 
all McDonnell Douglas Model DC-9-10, -20, -30, -40, -50, and C-9 
(military) series airplanes. (Since the issuance of that AD, the FAA 
has revised the applicability of the existing AD to identify model 
designations as published in the most recent type certificate data 
sheet for the affected models.) The original NPRM was published in the 
Federal Register on July 8, 2005 (70 FR 39435). The original NPRM 
proposed to retain the requirements of AD 96-13-03. The original NPRM 
also proposed to continue to require revision of the FAA-approved 
maintenance program. The original NPRM also proposed to require 
implementation of a structural inspection program of baseline structure 
to detect and correct fatigue cracking in order to ensure the continued 
airworthiness of airplanes as they approach the manufacturer's original 
fatigue design life goal. The original NPRM resulted from a significant 
number of these airplanes approaching or exceeding the design service 
goal on which the initial type certification approval was predicated. 
That condition, if not corrected, could result in fatigue cracking that 
could compromise the structural integrity of these airplanes.

Comments

    We have considered the following comments on the original NPRM.

Comments That Resulted in a Change to the Original NPRM

Request To Remove Paragraph (j) of the Original NPRM

    One commenter, the manufacturer, points out that the provisions of 
paragraph (j) of the original NPRM would allow for the use of older 
outdated versions of Section 2 of Volume II of Boeing Report No. L26-
008, ``DC-9 All Series, Supplemental Inspection Document (SID),'' to 
satisfy future requirements of the original NPRM. The commenter advises 
that only the November 2004 revision of Volume II should be allowed for 
compliance with the proposed new requirements, except for future 
alternative methods of compliance (AMOCs). Therefore, the commenter 
requests that paragraph (j) of the original NPRM be removed.
    We agree to remove paragraph (j) of the original NPRM for the 
reason the commenter specified, and we have identified the paragraphs 
of the supplemental NPRM accordingly.

Request To Revise Certain AMOC Language

    The same commenter also requests that paragraph (r) of the original 
NPRM be revised to extend the time during which certain AMOCs would be 
acceptable for compliance with the actions required by paragraph (f) of 
the original NPRM. (Paragraph (f) of the original NPRM is part of the 
restatement of AD 96-13-03.) The commenter points out that the 
restatement of the requirements of paragraph (f) of the original NPRM 
addresses only those revisions of the DC-9 SID that are listed in AD 
96-13-03. The commenter concludes that, since the new requirements of 
paragraph (h) of the original NPRM are required within 12 months of the 
effective date, any operator using an AMOC to AD 96-13-03 would 
potentially be out of compliance during the required compliance period 
of paragraph (h) of the original NPRM.
    We agree that paragraph (r) of the original NPRM, now identified as 
paragraph (p)(4) of the supplemental NPRM, should be revised. We infer 
that the commenter interprets the requirements of paragraph (h) of the 
supplemental NPRM to effect the accomplishment of the requirements of 
paragraph (f) of the supplemental NPRM. This is not the case and in 
order to clarify the requirements and compliance times of this 
supplemental NPRM, we have added an explanation in paragraph (f) of the 
supplemental NPRM specifying that the repetitive inspections required 
by paragraph (f) of the supplemental NPRM must be repeated until the 
requirements of paragraph (i) of the supplemental NPRM are 
accomplished. Consequently, we have revised the language of paragraph 
(p)(4) of the supplemental NPRM to specify that AMOCs approved 
previously for alternative inspection procedures and planning 
requirements of AD 96-13-03 are acceptable for compliance with the 
actions required by

[[Page 11330]]

paragraph (f) of the supplemental NPRM until the requirements, at the 
times specified in paragraph (i) of the supplemental NPRM, are 
accomplished.

Request To Clarify Paragraph (m) of the Original NPRM

    This same commenter states that paragraph (m) of the original NPRM 
(that paragraph discusses corrective actions if required) is not clear 
as to whether or not Authorized Representatives (ARs) may approve 
alternative methods of compliance (AMOCs).
    We agree that paragraph (m) of the original NPRM (identified as 
paragraph (l) of the supplemental NPRM) should be revised. Since the 
issuance of the original NPRM, we have determined that the description 
of the approval of corrective actions such as those specified in 
paragraph (l) of the supplemental NPRM can be simplified by referring 
to the ``Alternative Methods of Compliance (AMOC),'' paragraph (p) of 
this supplemental NPRM. In addition, our policy is that all future 
repairs to an airplane must meet damage tolerance requirements of 14 
CFR 25.571, amendment 45. The purpose of this policy is to detect and 
repair fatigue cracks that may occur in a repair before they become 
another unsafe condition. Therefore, we have also revised the paragraph 
addressing AMOCs, paragraph (p) of this supplemental NPRM, to include 
that requirement.

Comments That Did Not Result in a Change to the Original NPRM

Request To Add a New Principal Structural Element (PSE)

    One commenter states that the latest revision (November 2002) of 
the DC-9 SID, Volume I, created a new PSE 53.09.059. The commenter 
states that the new PSE is not included in the latest revision 
(November 2004) of Volume II of the SID, and that operators will not be 
able to complete inspections of the PSE 53.09.059 area without proper 
definition of that PSE in Volume II. The commenter requests that the 
``oversight'' be corrected with a revision to Volume II of the DC-9 
SID, and that the latest revision be specified in the final rule.
    We do not agree. We have discussed this issue with the 
manufacturer, and it has advised us that the DC-9 SID, Volume I, page 
1.11, cross-references PSE 53.09.059 to non-destructive inspection 
(NDI) procedure 53-10-06, with a notation specified on the bottom of 
the page. The PSE inspection threshold for PSE 53.09.059 specified on 
page 1.11 states that only sequence 2 of the NDI procedure applies to 
PSE 53.09.059. Volume 1, Section 4, page 4.10, of the DC-9 SID, also 
refers to Volume II, procedure 53-10-06. We received no other requests 
from operators concerning this issue, and the manufacturer is confident 
that the previous references are sufficient to allow operators to 
satisfy the SID requirements for this PSE. No change has been made to 
the supplemental NPRM in this regard.

Request To Consider ``Advancing Thresholds''

    One commenter requests the original NPRM be revised to ``advance 
the thresholds'' prior to the implementation of the final rule (the 
100% inspection program) if supported by data collected from the SID 
sampling program. The commenter states that this would minimize the 
impact to operators that have inspected any PSE shortly after \1/
2\Nth, only to find that after that inspection the 
Nth is increased. The commenter requests that, if a revision 
to the DC-9 SID is pending, the thresholds should be revised based on 
service history.
    We do not agree to extend the thresholds. The manufacturer has 
advised us that the service data collected so far is not sufficient to 
justify extending the threshold values at this time. Additionally, the 
manufacturer has advised that there are no plans to increase any PSE 
inspection threshold values specified in Volume I of the DC-9 SID. No 
change has been made to the supplemental NPRM in this regard.

Request To Revise the Costs of Compliance

    One commenter agrees that the original NPRM would require 
approximately 20 additional hours of labor to inspect each airplane. 
However, the commenter's data show that the time required to complete 
the inspections required by existing AD 96-13-03 is 571 labor hours 
rather than 362 work hours as specified in the existing AD. The 
commenter bases these labor hours on over 2,000 NDIs performed as part 
of the SID sampling program. The commenter also notes that the 571 
hours of labor do not include time for access, since it performs these 
inspections at maintenance checks with access already opened. The 
commenter is requesting that the costs of compliance be revised 
accordingly.
    We do not agree that the Costs of Compliance section needs to be 
revised. Although we acknowledge that the work hours for the 
commenter's fleet is more than the work hours estimated in the original 
NPRM, we also recognize that other operators' fleets may not require 
the same amount of work hours for the inspections. The work hours 
specified in the Costs of Compliance section are simply estimates based 
on the information that we have available from the manufacturer. 
Because of the differences involved with various airplane 
configurations and differences in airline maintenance procedures, there 
may be a significant difference in work hours necessary for operators 
to accomplish the inspections. Even if additional work hours are 
necessary for some airplanes, we do not have sufficient information to 
evaluate the number of airplanes that may be so affected or the number 
of additional work hours that may be required. Consequently, attempting 
to estimate work hours for each operator would be futile. No change is 
necessary to the supplemental NPRM in this regard.

Editorial Change

    We have revised this supplemental NPRM to clarify the appropriate 
procedure for notifying the principal inspector before using any 
approved AMOC on any airplane to which the AMOC applies.
    Additionally, we have determined that accomplishment of the 
requirements of paragraph (o) of the supplemental AD (inspection/
replacement for certain repairs to the fuselage pressure shell in 
accordance with Boeing Report No. MDC 91K0263, ``DC-9/MD-80 Aging 
Aircraft Repair Assessment Program Document,'' Revision 1, dated 
October 2000), are also acceptable for compliance with the requirements 
of paragraph (m) of the supplemental AD and have revised paragraph (o) 
of the supplemental AD accordingly.

Explanation of Change Made to This AD

    We have simplified paragraph (l) of the supplemental AD of this AD 
by referring to the ``Alternative Methods of Compliance (AMOCs)'' 
paragraph of this AD for repair methods.

FAA's Determination and Proposed Requirements of the Supplemental NPRM

    Certain changes discussed above expand the scope of the original 
NPRM; therefore, we have determined that it is necessary to reopen the 
comment period to provide additional opportunity for public comment on 
this supplemental NPRM. For the purposes of this proposed AD, a PSE is 
defined as an element that contributes significantly to the carrying of 
flight, ground or pressurization loads, and the integrity of that 
element is essential in maintaining

[[Page 11331]]

the overall structural integrity of the airplane.

Costs of Compliance

    There are about 710 McDonnell Douglas transport category airplanes 
worldwide of the affected design. This supplemental NPRM would affect 
about 477 airplanes of U.S. registry, or 26 U.S. airline operators.
    The recurring inspection costs, as required by AD-96-13-03, take 
362 work hours per airplane, at an average labor rate of $65 per work 
hour. Based on these figures, the estimated cost of the currently 
required actions is $11,223,810, or $23,530 per airplane, per 
inspection cycle.
    The incorporation of the revised procedures in this AD action will 
require approximately 20 additional work hours per operator to 
accomplish, at an average labor rate of $65 per work hour. Based on 
these figures, the cost to the 26 affected U.S. operators to 
incorporate these revised procedures into the SID program is estimated 
to be $33,800, or $1,300 per operator.
    Additionally, the number of required work hours for each proposed 
inspection (and the SID program), as indicated above, is presented as 
if the accomplishment of those actions were 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. Further, any costs associated with special airplane scheduling 
are expected to be minimal.

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 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 that the proposed 
regulation:
    1. Is not a ``significant regulatory action'' under Executive Order 
12866;
    2. Is not a ``significant rule'' under the DOT Regulatory Policies 
and Procedures (44 FR 11034, February 26, 1979); and
    3. Will not have a significant economic impact, positive or 
negative, on a substantial number of small entities under the criteria 
of the Regulatory Flexibility Act.
    We prepared a regulatory evaluation of the estimated costs to 
comply with this supplemental NPRM 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, 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 Federal Aviation Administration (FAA) amends Sec.  39.13 by 
removing amendment 39-9671 (61 FR 31009, June 19, 1996) and adding the 
following new airworthiness directive (AD):

McDonnell Douglas: Docket No. FAA-2005-21779; Directorate Identifier 
2002-NM-349-AD.

Comments Due Date

    (a) The FAA must receive comments on this AD action by April 3, 
2006.

Affected ADs

    (b) This AD supersedes AD 96-13-03.

Applicability

    (c) This AD applies to all McDonnell Douglas Model DC-9-11, DC-
9-12, DC-9-13, DC-9-14, DC-9-15, and DC-9-15F airplanes; DC-9-21 
airplanes; DC-9-31, DC-9-32, DC-9-32 (VC-9C), DC-9-32F, DC-9-33F, 
DC-9-34, DC-9-34F, and DC-9-32F (C-9A, C-9B) airplanes; DC-9-41 
airplanes; and DC-9-51 airplanes; certificated in any category.

Unsafe Condition

    (d) This AD was prompted by a significant number of these 
airplanes approaching or exceeding the design service goal on which 
the initial type certification approval was predicated. We are 
issuing this AD to detect and correct fatigue cracking that could 
compromise the structural integrity of these airplanes.

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.

Requirements of AD 96-13-03

Revision of the FAA-Approved Maintenance Inspection Program

    (f) Within 6 months after July 24, 1996 (the effective date of 
AD 96-13-03, amendment 39-9671), replace the FAA-approved 
maintenance inspection program with a revision that provides for 
inspection(s) of the principal structural elements (PSEs) defined in 
McDonnell Douglas Report No. L26-008, ``DC-9 Supplemental Inspection 
Document (SID),'' Section 2 of Volume I of McDonnell Douglas Report 
No. L26-008, ``DC-9 Supplemental Inspection Document (SID),'' 
Revision 4, dated July 1993, in accordance with Section 2 of Volume 
III-95, dated September 1995, of the SID.

    Note 1: Operators should note that certain visual inspections of 
fleet leader operator sampling PSE's that were previously specified 
in earlier revisions of Volume III of the SID are no longer 
specified in Volume III-95 of the SID.

    (1) Prior to reaching the threshold (Nth), but no 
earlier than one-half of the threshold (\1/2\Nth), 
specified for all PSE's listed in Volume III-95, dated September 
1995, of the SID, inspect each PSE sample in accordance with the 
non-destructive inspection (NDI) procedures set forth in Section 2 
of Volume II, dated July 1993. Thereafter, repeat the inspection for 
that PSE at intervals not to exceed [Delta]NDI/2 of the NDI 
procedure that is specified in Volume III-95, dated September 1995, 
of the SID, until the requirements of paragraph (i) of this AD are 
accomplished.
    (2) The NDI techniques set forth in Section 2 of Volume II, 
dated July 1993, of the SID provide acceptable methods for 
accomplishing the inspections required by this paragraph.
    (3) All inspection results (negative or positive) must be 
reported to McDonnell Douglas, in accordance with the instructions 
contained in Section 2 of Volume III-95, dated September 1995, 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.


[[Page 11332]]


    Note 2: Volume II of the SID, dated July 1993, is comprised of 
the following:


                                 Table 1
------------------------------------------------------------------------
                                                          Revision level
                   Volume designation                        shown on
                                                              volume
------------------------------------------------------------------------
Volume II-10/20.........................................               4
Volume II-20/30.........................................               5
Volume II-40............................................               4
Volume II-50............................................               4
------------------------------------------------------------------------


    Note 3: NDI inspections accomplished in accordance with the 
following Volume II of the SID provide acceptable methods for 
accomplishing the inspections required by this paragraph:


                                 Table 2
------------------------------------------------------------------------
        Volume  designation          Revision level    Date of  revision
------------------------------------------------------------------------
Volume II-10/20...................  4...............  July 1993.
Volume II-10-20...................  3...............  Apr. 1991.
Volume II-10/20...................  2...............  Apr. 1990.
Volume II-10/20...................  1...............  June 1989.
Volume II-20......................  Original........  Nov. 1987.
Volume II-20/30...................  5...............  July 1993.
Volume II-20/30...................  4...............  Apr. 1991.
Volume II-20/30...................  3...............  Apr. 1990.
Volume II-20/30...................  2...............  June 1989.
Volume II-20/30...................  1...............  Nov. 1987.
Volume II-40......................  4...............  July 1993.
Volume II-40......................  3...............  Apr. 1991.
Volume II-40......................  2...............  Apr. 1990.
Volume II-40......................  1...............  June 1989.
Volume II-40......................  Original........  Nov. 1987.
Volume II-50......................  4...............  July 1993.
Volume II-50......................  3...............  Apr. 1991.
Volume II-50......................  2...............  Apr. 1990.
Volume II-50......................  1...............  June 1989.
Volume II-50......................  Original........  Nov. 1987.
------------------------------------------------------------------------

    (g) Any cracked structure detected during the inspections 
required by paragraph (f) of this AD must be repaired before further 
flight, in accordance with a method approved by the Manager, Los 
Angeles Aircraft Certification Office (ACO), FAA, Transport Airplane 
Directorate.

    Note 4: Requests for approval of any PSE repair that would 
affect the FAA-approved maintenance inspection program that is 
required by this AD should include a damage tolerance assessment for 
that PSE.

New Requirements of This AD

Revision of the Maintenance Inspection Program

    (h) 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 PSEs, in accordance 
with Boeing Report L26-008, ``DC-9 All Series, Supplemental 
Inspection Document (SID),'' Volume I, Revision 6, dated November 
2002. Unless otherwise specified, all further references in this AD 
to the ``SID'' are to Revision 6, dated November 2002.

Non-Destructive Inspections (NDIs)

    (i) For all PSEs listed in Section 2 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, dated 
November 2004 of the SID, at the times specified in paragraph 
(i)(1), (i)(2), or (i)(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 60 months after the effective date of this AD, whichever 
occurs later. Inspect again prior to reaching the threshold 
(Nth) or [Delta]NDI/2, whichever occurs later, 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.

    Note 5: Volume II of the SID, dated November 2004 comprises the 
following:


                                 Table 3
------------------------------------------------------------------------
                                                          Revision level
                   Volume designation                        shown on
                                                              volume
------------------------------------------------------------------------
Volume II-10/20.........................................               6
Volume II-20/30.........................................               7
Volume II-40............................................               6
Volume II-50............................................               6
------------------------------------------------------------------------

Discrepant Findings

    (j) If any discrepancy (e.g., a PSE cannot be inspected as 
specified in Volume II of the SID or does not match rework, repair, 
or modification description in Volume I of the SID) is detected 
during any inspection required by paragraph (i) of this AD, 
accomplish the action specified in paragraph (j)(1) or (j)(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 or within 18 months of the discovery of the 
discrepancy, whichever is later, in accordance with a method 
approved by the Manager, Los Angeles 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, or within 18 months of the discovery of the 
discrepancy, whichever occurs later, in accordance with a method 
approved by the Manager of the Los Angeles ACO.

Reporting Requirements

    (k) All negative, positive, or discrepant (discrepant finding 
examples are described in paragraph (j) of this AD) findings of the 
inspections accomplished under paragraph (i) of this AD must be 
reported to Boeing, at the times specified in, and in accordance 
with the instructions contained in, Section 4 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

    (l) Any cracked structure of a PSE detected during any 
inspection required by paragraph (i) of this AD must be repaired 
before further flight in accordance with a method approved by the 
Manager, Los Angeles ACO, or by using a method approved in 
accordance with procedures specified in paragraph (p) of this AD. 
Accomplish follow-on actions described in paragraphs (l)(1), (l)(2), 
and (l)(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.
    (2) Before reaching 75% of the repair threshold as determined in 
paragraph (l)(1) of this AD, submit the inspection methods and 
repetitive inspection intervals for the repair for approval.
    (3) Before the repair threshold, as determined in paragraph 
(l)(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 6: For the purposes of this AD, we anticipate that 
submissions of the DTA of the repair, if acceptable, should be 
approved within six months after submission.


    Note 7: 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

    (m) 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 
(m)(1) or (m)(2) of this AD, as applicable.
    (1) For airplanes that have been inspected in accordance with 
this AD, the inspection of each PSE must be accomplished by the new 
operator in accordance with 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

[[Page 11333]]

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 in accordance with the new operator's schedule and 
inspection method.
    (2) For airplanes that have not been inspected in accordance 
with 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 in accordance with 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

    (n) Inspections accomplished prior to the effective date of this 
AD in accordance with Boeing Report No. L26-008, ``DC-9 All Series 
Supplemental Inspection Document (SID),'' Volume I, Revision 6, 
dated November 2002, are acceptable for compliance with the 
requirements of paragraph (i) of this AD.

Acceptable for Compliance

    (o) Boeing Report MDC 91K0263, ``DC-9/MD-80 Aging Aircraft 
Repair Assessment Program Document,'' Revision 1, dated October 
2000, 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 (i), (l), and (m) of this AD for 
repairs subject to that document.

Alternative Methods of Compliance (AMOCs)

    (p)(1) The Manager, Los Angeles ACO, has the authority to 
approve AMOCs for this AD, if requested in accordance with the 
procedures found in 14 CFR 39.19.
    (2) Before using any AMOC approved in accordance with CFR 39.19 
on any airplane to which the AMOC applies, notify the appropriate 
principal inspector in the FAA Flight Standards 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 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.
    (4) AMOCs approved previously for alternative inspection 
procedures per AD 87-14-07 R1, amendment 39-6019; AD 94-03-01, 
amendment 39-8807; and AD 96-13-03, amendment 39-9671; are 
acceptable for compliance with the actions required by paragraph (f) 
of this AD for inspections performed before the requirements of 
paragraph (i) are accomplished.
    (5) AMOCs approved previously for repairs per AD 87-14-07 R1, 
amendment 39-6019; AD 94-03-01, amendment 39-8807; and AD 96-13-03, 
amendment 39-9671; are acceptable for compliance with the 
requirements of paragraph (l) of this AD.

    Issued in Renton, Washington, on February 23, 2006.
Michael J. Kaszycki,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 06-2157 Filed 3-6-06; 8:45 am]
BILLING CODE 4910-13-P