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###### Department of Transportation

###### Federal Aviation Administration 

          - 14 CFR Part 39 
          - [Docket No. 98-NM-35-AD; Amendment 39-11933; AD 2000-21-01] 
          - RIN 2120-AA64 

# AGENCY:

Federal Aviation Administration, DOT. 

# ACTION:

Final rule. 

# SUMMARY:

This amendment adopts a new airworthiness directive (AD), applicable to all Lockheed Model L-1011-385 series airplanes, that requires repetitive inspections to detect corrosion or fatigue cracking of certain structural elements of the airplane; corrective action, if necessary; and incorporation of certain structural modifications. This amendment is prompted by new recommendations related to incidents of fatigue cracking and corrosion in transport category airplanes that are approaching or have exceeded their economic design goal. The actions specified by this AD are intended to prevent corrosion or fatigue cracking of certain structural elements, which could result in reduced structural integrity of the airplane. 

# DATES:

Effective November 24, 2000. 

The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of November 24, 2000. 

# ADDRESSES:

                        The service information referenced in this AD may be obtained from Lockheed Martin Aircraft & Logistics Center, 120 Orion Street, Greenville, South Carolina 29605. 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, Atlanta Aircraft Certification Office, One Crown Center, 1895 Phoenix Boulevard, suite 450, Atlanta, Georgia; or at the Office of the Federal Register,                               ( print page 62995)                            800 North Capitol Street, NW., suite 700, Washington, DC.                     

# FOR FURTHER INFORMATION CONTACT:

Thomas Peters, Aerospace Engineer, Systems and Flight Test Branch, ACE-116A, FAA, Atlanta Aircraft Certification Office, One Crown Center, 1895 Phoenix Boulevard, suite 450, Atlanta, Georgia 30349; telephone (770) 703-6063; fax (770) 703-6097. 

# 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 Lockheed Model L-1011-385 series airplanes was published in the                     **Federal Register**                     on June 25, 1999 (64 FR 34170). That action proposed to require repetitive inspections to detect corrosion or fatigue cracking of certain structural elements of the airplane; corrective action, if necessary; and incorporation of certain structural modifications.                 

## Explanation of New Service Information 

Since the issuance of the notice of proposed rulemaking (NPRM), the FAA has reviewed and approved Lockheed Service Bulletin 093-51-040, Revision 2, dated October 21, 1999. The actions described in Revision 2 of the service bulletin are essentially similar to those described in Lockheed Service Bulletin 093-51-040, Revision 1, dated October 1, 1997 (which was referenced as the applicable source of service information for accomplishment of the actions specified in the NPRM). Revision 2 of the service bulletin corrects and updates certain references, and adds and revises certain “notes” to improve clarity. Therefore, the FAA finds that either Revision 1 or Revision 2 of Lockheed Service Bulletin 093-51-040 (hereinafter referred to as “the Collector Service Bulletin”) is an acceptable source of service information for the actions required by this AD. 

However, certain new revisions of the individual service bulletins listed in Tables I and II of Revision 2 of the Collector Service Bulletin have reduced the compliance times for certain actions below what was specified in the individual service bulletins listed in Revision 1 of the Collector Service Bulletin. The FAA finds that to reduce the compliance times in this way would necessitate issuance of a supplemental NPRM and reopening of the comment period to allow adequate time for public comment. The FAA finds that it is inappropriate to further delay issuance of the final rule in this way. Therefore, while this AD allows accomplishment of the actions in this AD in accordance with either Revision 1 or Revision 2 of the Collector Service Bulletin, the applicable compliance thresholds and repetitive intervals are those listed in the individual service bulletins listed in Tables I and II of Revision 1. Paragraphs (a)(1) and (a)(2), which specify the compliance times for paragraph (a) of this AD, reference only Revision 1 of the Collector Service Bulletin, and a new note, “Note 2,” has been added to this final rule to clarify this issue. 

## 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. 

## Support for the Proposed Rule 

One commenter supports the proposed rule. 

## Provide Grace Period for Certain Inspections in Paragraph (a) 

One commenter notes that, though paragraph (a)(2) of the proposed rule provides a grace period of “one repetitive interval after the effective date of this AD” for the inspections specified in paragraph (a) of the proposed rule, certain inspections are one-time inspections and, therefore, do not have a repetitive interval. 

The commenter makes no specific request for a change to the proposed rule. However, the FAA infers that the commenter is requesting that the FAA clarify the grace period for accomplishment of the subject one-time inspections. The FAA concurs that some clarification is needed, and notes that the inspections without repetitive intervals in Table I reference “Footnote 3,” which provides a grace period of the “next 'C' check not to exceed 14 months for aircraft exceeding threshold.” The FAA finds that a grace period of 14 months is adequate to ensure that the unsafe condition is addressed in a timely manner, without adversely affecting the safety of the airplane fleet. Therefore, paragraph (a)(2) of this AD has been revised to specify a grace period of 14 months after the effective date of this AD for the service bulletins listed in Tables I and II of the Collector Service Bulletin that do not specify a repetitive interval. 

## Eliminate Duplicate Requirements 

One commenter questions whether the repetitive inspections specified in Lockheed Service Bulletin 093-53-258, Revision 1, dated April 4, 1996, as listed in Table II of the Collector Service Bulletin, should be included in the proposed rule. The commenter notes that these inspections are already required by AD 95-17-03, amendment 39-9332 (60 FR 40753, August 10, 1995). 

The commenter makes no specific request for a change to the proposed rule; however, the FAA infers that it is requesting that this AD eliminate the inspections in Lockheed Service Bulletin 093-53-258, Revision 1, from the requirements of this AD. The FAA concurs. While the AD referenced by the commenter requires inspections with the original issue of Lockheed Service Bulletin 093-53-258, dated February 20, 1990, the FAA finds that the inspections in accordance with that bulletin, as required by AD 95-17-03, are acceptable for compliance with this AD. Therefore, the FAA has revised paragraph (b) of this AD to state that the structural inspections specified in Lockheed Service Bulletin 093-53-258, Revision 1, are not required by this AD, and that equivalent inspections are already required by AD 95-17-03. The modifications of Lockheed Service Bulletin 093-53-258, Revision 1, that terminate the inspections currently required by AD 95-17-03 are required by this AD. 

The same commenter questions why the inspections in Lockheed Service Bulletin 093-57-203, Revision 5, dated April 22, 1996, are included in the requirements of paragraph (a) of the proposed AD. The commenter points out that paragraph (e) of the proposed rule would require installation of the terminating modification in Lockheed Service Bulletin 093-57-215, dated April 11, 1996, which eliminates the need for the inspections in Lockheed Service Bulletin 093-57-203, Revision 5. 

                    The FAA concurs with the commenter's intent, though not for the reason stated by the commenter. Accomplishment of the inspections described in Lockheed Service Bulletin 093-57-203 is necessary to ensure continued safety of the airplane fleet until accomplishment of Lockheed Service Bulletin 093-57-215. However, the FAA notes that inspections similar to those specified in Lockheed Service Bulletin 093-57-203, Revision 5, are currently required by AD 98-10-14, amendment 39-10526 (63 FR 26966, May 15, 1998). (AD 98-10-14 requires inspections in accordance with Lockheed Service Bulletin 093-57-203, Revision 4, dated March 27, 1995, or Revision 6, dated August 18, 1997.) Thus, including these inspections in this AD would unnecessarily duplicate compliance requirements. Therefore, paragraph (b) of this AD has been revised to state that the structural                           ( print page 62996)                        inspections specified in Lockheed Service Bulletin 093-57-203, Revision 5, are not required by this AD, and that equivalent inspections are already required by AD 98-10-14. The terminating modifications of Lockheed Service Bulletin 093-57-215 are required by this AD.                 

## Request To Acknowledge Superseding Requirement 

One commenter notes that the inspections specified in Lockheed Service Bulletin 093-53-249 are currently required as part of the requirements of AD 94-05-01, amendment 39-8839 (59 FR 10275, March 4, 1994). (AD 94-05-01 requires accomplishment of Lockheed Service Bulletin 093-51-035, dated June 28, 1990—an older “Collector” service bulletin.) However, the proposed AD would reduce the repetitive inspection interval for the inspections in that bulletin from 5,000 to 4,500 flight cycles. The commenter requests that language be added to the proposed rule to acknowledge that accomplishment of the repetitive inspections in Lockheed Service Bulletin 093-53-249, Revision 3, dated February 28, 1994, at 4,500 flight cycle intervals, in accordance with this AD, eliminates the need to record accomplishment of the inspections in that service bulletin as required by AD 94-05-01. The commenter notes that this will eliminate confusion and dual compliance tracking for operators. 

The FAA partially concurs with the commenter's request. Because AD 94-05-01 requires accomplishment of another “Collector” service bulletin, which lists numerous service bulletins, the FAA is unable to revise the requirement to accomplish the actions in only one of those service bulletins without superseding that entire AD. Such an action cannot be undertaken in the context of this rulemaking action. Therefore, all of the requirements of AD 94-05-01 are still applicable. As noted by the commenter, this results in two parallel inspection requirements; operators will be responsible for tracking compliance for both requirements. However, the FAA notes that the inspection in accordance with Lockheed Service Bulletin 093-53-249, Revision 3, need only be accomplished at the 4,500-flight-cycle interval required by this AD. To clarify this, a new note “Note 3” has been added following paragraph (a)(2) of this AD, to state, “The inspections specified in Lockheed Service Bulletin 093-53-249, Revision 3, dated February 28, 1994, are included in the requirements of both AD 94-05-01, amendment 39-8839, and paragraph (a) of this AD. Inspections in accordance with Lockheed Service Bulletin 093-53-249, Revision 3, at the interval specified in Table I of Lockheed Service Bulletin 093-51-040, Revision 1, as required by this AD, are acceptable for compliance with the inspections in accordance with Lockheed Service Bulletin 093-53-249, Revision 3, required by AD 94-05-01.”

## Require Overhaul of Main Landing Gear Actuator 

One commenter states that one of the purposes of Revision 1 of the Collector Service Bulletin was to require overhaul of the main landing gear (MLG) actuator within 10 years after previous modification or overhaul. The proper procedures for the MLG overhaul are described in Change Notice (CN) 1, dated September 21, 1998, for Lockheed Service Bulletin 093-32-238, Revision 3. However, Revision 1 of the Collector Service Bulletin references Lockheed Service Bulletin 093-32-238, Revision 3, with no mention of CN 1. The commenter asserts that the proposed AD would not mandate the MLG overhaul as intended. 

The commenter makes no specific request for a change to the proposed AD. However, the FAA infers that the commenter is requesting that the proposed rule be revised to reference CN 1 of the subject service bulletin. The FAA partially concurs. The FAA acknowledges that the current version of Lockheed Service Bulletin 093-32-238 is Revision 3, as revised by CN 1. The FAA also notes that Revision 2 of the Collector Service Bulletin incorporates the correct reference. However, to revise the proposed AD to specify overhaul of the MLG actuator in accordance with Lockheed Service Bulletin 093-32-238, Revision 3, as revised by CN 1, would necessitate reopening the comment period to allow adequate time for public comment. Because of the criticality of the unsafe condition addressed in this AD, the FAA finds that to delay issuance of the final rule in this way would be inappropriate. However, the FAA is considering further rulemaking to ensure that overhaul of the MLG actuator is accomplished in a timely manner in accordance with Lockheed Service Bulletin 093-32-238, Revision 3, as revised by CN 1. A new paragraph, paragraph (e), has been added to this final rule (and subsequent paragraphs have been reordered accordingly) to specify that overhaul of the main landing gear actuator in accordance with Lockheed Service Bulletin 093-32-238, Revision 3, dated April 11, 1996, as listed in Table II of Lockheed Service Bulletin 093-51-040, Revision 1, dated October 1, 1997, is not required by paragraph (d) of this AD. 

## Extend Compliance Times 

One commenter expresses concern regarding the inspections specified in Lockheed Service Bulletin 093-53-270, Revision 1, dated August 23, 1996, and the modification specified in Lockheed Service Bulletin 093-53-271, dated October 18, 1995. The commenter operates several airplanes modified in accordance with a certain supplemental type certificate. The configuration of those airplanes will necessitate request for approval of alternative methods of compliance (AMOC) for the actions specified in these service bulletins. The commenter is concerned that it will not be able to accomplish the AMOC's within the compliance time proposed in this AD for those actions. 

The commenter makes no specific request for a change to this AD. However, the FAA infers that it is requesting extension of the compliance time for the subject requirements. The FAA does not concur that such an extension is appropriate. The inspection threshold of 13,000 or 9,000 flight cycles (depending on airplane configuration) and repetitive inspection interval of 2,500 flight cycles for the actions in Lockheed Service Bulletin 093-53-270, Revision 1, and the threshold of 20,000 flight cycles for the actions in Lockheed Service Bulletin 093-53-271, were established based on consideration of structural damage risk, damage probability, and damage growth rate. As noted by the commenter, if the commenter's unique circumstances make it impossible to comply with the requirements of this AD as written, it will need to submit a request for approval of an AMOC, in accordance with paragraph (g) of this AD. The FAA finds that the compliance time is adequate for the commenter to submit its request for approval of an AMOC and for the FAA to review the request. No change to the final rule is necessary in this regard. 

## Clarify Terminating Action 

                    One commenter requests that the proposed rule be revised to clearly indicate which revisions of the service bulletins associated with the rear spar modification are acceptable for terminating the rear spar inspections described in Lockheed Service Bulletin 093-57-203 (which, as described previously, are currently required by AD 98-10-14). The commenter notes that Revision 1 of the Collector Service Bulletin lists Lockheed Service Bulletin 093-57-184, Revisions 2 through 7, and Service Bulletin 093-57-196, Revisions                           ( print page 62997)                        1 through 6, as acceptable sources for instructions for the rear spar modifications. However, AD 98-10-14 lists only Lockheed Service Bulletin 093-57-184, Revision 6, dated October 28, 1991, and Revision 7, dated December 6, 1994, and Service Bulletin 093-57-196, Revision 5, dated October 28, 1991, and Revision 6, dated December 6, 1994, as sources of service information for the modifications of the rear spar to terminate the repetitive inspections required by AD 98-10-14.                 

The FAA does not concur and has determined that no change to the final rule is necessary relevant to the commenter's request. This determination is based on the following: 
    - As explained previously, structural inspections equivalent to those specified in Lockheed Service Bulletin 093-57-203, Revision 5, are required by AD 98-10-14. [Paragraph (b) of this final rule has been revised to clarify this information.]
    - AD 98-10-14 correctly states terminating action for the requirements of that AD. Therefore, use of any other revision to accomplish the modifications would necessitate request for approval of an AMOC in accordance with paragraph (c) of AD 98-10-14.
    - Current revisions of the referenced modification bulletins, as well as Revision 2 of the Collector Service Bulletin (described previously), correctly indicate which revisions are acceptable for terminating the inspections in Lockheed Service Bulletin 093-57-203.
    - Section 2.B. of Revisions 1 and 2 of the Collector Service Bulletin (page 9) states, “Aircraft effectivity, inspection thresholds, and repeat inspection intervals are shown for convenience, and in the event of conflicts, the individual service bulletin shall take precedence.”

## Increase Compliance Threshold 

One commenter requests an increase in the compliance threshold for the modification of the rear spar on Model L-1011-385-3 series airplanes specified in Lockheed Service Bulletin 093-57-215, dated April 11, 1996, as listed in Table II of the Collector Service Bulletin. The commenter states that the proposed compliance threshold would preclude accomplishment of the rear spar modification during a regularly scheduled maintenance visit, thus increasing the cost of the modification for operators. The commenter requests that the compliance time be increased to coincide with the compliance threshold for a similar modification on Model L-1011-385-1 series airplanes. The commenter points out that current proposed thresholds for inspection and modification of the rear spar on the Model L-1011-385-3 series airplanes are lower, in terms of accumulated flight cycles, and earlier, in terms of design-life goal, than currently required actions on the Model L-1011-385-1 series airplanes. The commenter separately notes that while the L-1011-385-1 series airplanes are approaching 83 percent of the 36,000 flight-cycle design-life goal, the L-1011-385-1-14, L-1011-385-1-15, and L-1011-385-3 series airplanes are at less than 50 percent of this goal. The commenter justifies its request on the basis that Model L-1011-385-3 series airplanes are younger and accumulate flight cycles at a lower rate than L-1011-385-1 series airplanes. 

The FAA does not concur with the commenter's request to increase the compliance threshold. The proposed compliance time for the modification of the rear spar on Model L-1011-385-3 series airplanes is based on established service history and predicted fatigue cracking. The FAA has determined that the unique characteristics of Model L-1011-385-3 series airplanes (principally, higher fuel loading than on Model L-1011-385-1 series airplanes) make it necessary to require modification of the rear spar at a lower threshold relative to the Model L-1011-385-1 series. Because of these unique characteristics, inspection thresholds and repetitive intervals are consistently lower for actions affecting the wing rear spar on Model L-1011-385-3 series airplanes than for actions affecting the same area on Model L-1011-385-1 series airplanes. No change to the final rule is necessary in this regard. 

## Remove Inspection Requirement for Certain Airplanes 

One commenter requests that any airplane on which a rear spar modification has been installed previously be excluded from the requirement to accomplish Lockheed Service Bulletin 093-57-194, Revision 3, dated April 11, 1994, as listed in Table II of the Collector Service Bulletin. The commenter states that it sees little benefit in listing this requirement for any airplanes subject to AD 94-05-01, and the requirement should only apply to airplanes on which the rear spar has not been modified. 

The FAA does not concur that any change to this AD is necessary. For the service bulletin referenced by the commenter, Table II of the Collector Service Bulletin clearly states, “Rear spar web replacement per Service Bulletin 093-57-184, 093-57-196, or 093-57-215 terminates these requirements.” The FAA finds that no clarification and no change to the final rule is necessary in this regard. 

## Remove Terminating Modification Requirement 

One commenter requests that Lockheed Service Bulletin 093-53-256, Revision 1, dated October 7, 1991, be removed from the listing of structural modifications in Table II of the Collector Service Bulletin. The commenter points out that there are certain inspection findings addressed by repetitive inspections and not by the immediate installation of a terminating modification. 

The FAA does not concur with the commenter's request. The intent of this AD is that the inspections specified in Table II of the Collector Service Bulletin be accomplished according to the schedule cited in that bulletin, and that the specified terminating or corrective action be accomplished, unless otherwise noted in this AD. For the specific service bulletin referenced by the commenter, Table II states, “Terminate repeat inspections of Part I by performing Part II inspection and disposition of inspection findings per Service Bulletin 093-53-256 R1.” The FAA finds that these instructions are clear, and no change to the final rule is necessary in this regard. 

## Acknowledge Incorrect Reference to Service Bulletin in Table II 

One commenter points out that Lockheed Service Bulletin 093-53-271, dated October 18, 1995, listed in Table II of the Collector Service Bulletin, is not an inspection bulletin. The commenter notes that inspections are contained in Lockheed Service Bulletin 093-53-A271, as required by AD 95-10-17, amendment 39-9234 (60 FR 26683, May 18, 1995). 

                    The commenter makes no specific request for a change to the proposal. The FAA infers that the commenter is requesting that the FAA acknowledge that there are no inspections in accordance with Lockheed Service Bulletin 093-53-271. The FAA does not concur with the commenter's request. The listing in Table II of the Collector Service Bulletin for Lockheed Service Bulletin 093-53-271 refers to Lockheed Service Bulletin 093-53-A271, dated April 25, 1995, as the correct source of information for accomplishment of the inspections. The commenter is correct that AD 95-10-17 does require inspections in accordance with Lockheed Service Bulletin 093-53-A271, dated April 25, 1995. However, Revision 2 of the Collector Service Bulletin correctly notes that the                           ( print page 62998)                        inspections required by that AD are one-time only. The FAA now finds that it is necessary for the inspections in that bulletin to be accomplished repetitively. For the inspections associated with Lockheed Service Bulletin 093-53-271 (meaning the inspections of Lockheed Service Bulletin 093-53-A271, dated April 25, 1995), Revision 1 of the Collector Service Bulletin specifies repetitive intervals varying from 3,500 to 6,500 flight cycles, depending on the method of inspection. The FAA has determined that the inspections and repetitive intervals specified in Revision 1 of the Collector Service Bulletin are adequate to ensure the safety of the airplane fleet. No change to the final rule is necessary in this 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. 

## Cost Impact 

There are approximately 214 Model L-1011-385 series airplanes of the affected design in the worldwide fleet. The FAA estimates that 107 airplanes of U.S. registry will be affected by this AD. 

It will take approximately 315 work hours per airplane to accomplish the required inspections, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the inspections required by this AD on U.S. operators is estimated to be $2,022,300, or $18,900 per airplane, per inspection cycle. 

It will take approximately 3,385 work hours per airplane to accomplish the required modifications, at an average labor rate of $60 per work hour. Required parts will cost approximately $242,000 per airplane. Based on these figures, the cost impact of the modifications required by this AD on U.S. operators is estimated to be $47,625,700, or $445,100 per airplane. 

The cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted. The cost impact figures discussed in AD rulemaking actions represent only the time necessary to perform the specific actions actually required by the AD. These figures typically do not include incidental costs, such as the time required to gain access and close up, planning time, or time necessitated by other administrative actions. 

## 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 

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 

1. The authority citation for part 39 continues to read as follows: 

Authority:49 U.S.C. 106(g), 40113, 44701.

§ 39.13

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

**2000-21-01 Lockheed:**                             Amendment 39-11933. Docket 98-NM-35-AD.                         

*Applicability:*                             All Model L-1011-385 series airplanes, certificated in any category.                         

# Note 1:

This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (g) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

*Compliance:*                             Required as indicated, unless accomplished previously.                         

To prevent corrosion or fatigue cracking of certain structural elements, which could result in reduced structural integrity of the airplane, accomplish the following: 

## Inspections 

(a) Except as provided by paragraph (b) of this AD, perform structural inspections to detect corrosion or fatigue cracking of certain structural elements of the airplane, in accordance with the applicable service bulletins listed under “Service Bulletin Number, Revision, and Date” in Tables I and II of Lockheed Service Bulletin 093-51-040, Revision 1, dated October 1, 1997, or Revision 2, dated October 21, 1999. Perform the initial inspections at the later of the times specified in paragraphs (a)(1) and (a)(2) of this AD. Thereafter, repeat each inspection at an interval not to exceed that specified in the applicable service bulletin listed in Revision 1 of Lockheed Service Bulletin 093-51-040. 

(1) Prior to the threshold specified in the individual service bulletin listed in Table I or II of Lockheed Service Bulletin 093-51-040, Revision 1, as applicable. 

(2) Within one repetitive interval after the effective date of this AD, as specified in the individual service bulletin listed in Table I or II of Lockheed Service Bulletin 093-51-040, Revision 1, as applicable; or within 14 months after the effective date of this AD for the service bulletins in Tables I and II that do not specify a repetitive interval; as applicable. 

# Note 2:

Operators should note that paragraphs (a)(1) and (a)(2) of this AD reference only Revision 1 of Lockheed Service Bulletin 093-51-040. Certain new revisions of the individual service bulletins listed in Tables I and II of Lockheed Service Bulletin 093-51-040, Revision 2, have reduced the compliance times below those specified in the service bulletin revision levels listed in Lockheed Service Bulletin 093-51-040, Revision 1. While this AD allows accomplishment of the actions in this AD in accordance with either Lockheed Service Bulletin 093-51-040, Revision 1, or Revision 2, the applicable compliance thresholds and repetitive intervals are those listed in the individual service bulletins listed in Table I or II of Lockheed Service Bulletin 093-51-040, Revision 1.

# Note 3:

                                The inspections specified in Lockheed Service Bulletin 093-53-249, Revision 3, dated February 28, 1994, are included in the requirements of both AD 94-05-01, amendment 39-8839, and paragraph (a) of this AD. Inspections in accordance with Lockheed Service Bulletin 093-53-249, Revision 3, at the interval specified in Table I of Lockheed Service Bulletin 093-51-040,                                       ( print page 62999)                                    Revision 1, as required by this AD, are acceptable for compliance with the inspections in accordance with Lockheed Service Bulletin 093-53-249, Revision 3, required by AD 94-05-01.                            

(b) The following service bulletins listed in Table II of Lockheed Service Bulletin 093-51-040, Revision 1, dated October 1, 1997, and Revision 2, dated October 21, 1999, are excluded from the requirements of paragraph (a) of this AD.

(1) The structural inspections specified in Lockheed Service Bulletins 093-53-268, Revision 1, dated July 2, 1996, and 093-53-272, Revision 1, dated March 17, 1997, are not required by this AD. The inspections specified in these service bulletins are required by AD 99-08-20, amendment 39-11128.

(2) The structural inspections specified in Lockheed Service Bulletin 093-53-258, Revision 1, dated April 4, 1996, are not required by this AD. Inspections equivalent to those specified in that bulletin are required by AD 95-17-03, amendment 39-9332. 

(3) The structural inspections specified in Lockheed Service Bulletin 093-57-203, Revision 5, dated April 22, 1996, are not required by this AD. Inspections equivalent to those specified in that bulletin are required by AD 98-10-14, amendment 39-10526. 

## Corrective Action 

(c) If any cracking is detected during any inspection required by paragraph (a) of this AD, prior to further flight, accomplish the actions specified in paragraph (c)(1), (c)(2), (c)(3), or (c)(4) of this AD. 

(1) Repair in accordance with the applicable service bulletin referenced in Table I or II of Lockheed Service Bulletin 093-51-040, Revision 1, dated October 1, 1997, or Revision 2, dated October 21, 1999. 

(2) Repair in accordance with the applicable section of the Lockheed L-1011 Structural Repair Manual. 

(3) Accomplish the terminating modification in accordance with the applicable service bulletin referenced in Table I or II of Lockheed Service Bulletin 093-51-040, Revision 1, dated October 1, 1997, or Revision 2, dated October 21, 1999. 

(4) Repair in accordance with a method approved by the Manager, Atlanta Aircraft Certification Office (ACO), FAA. 

## Terminating Action 

(d) Except as provided by paragraph (e) of this AD, install the terminating modification referenced in each service bulletin listed in Table II of Lockheed Service Bulletin 093-51-040, Revision 1, dated October 1, 1997, or Revision 2, dated October 21, 1999; in accordance with the applicable service bulletin listed under “Service Bulletin Number, Revision, and Date” in Table II of Lockheed Service Bulletin 093-51-040, Revision 1 or Revision 2. Except as provided by paragraph (f) of this AD, install each modification at the later of the times specified in paragraphs (d)(1) and (d)(2) of this AD. Such installation constitutes terminating action for the applicable structural inspection required by paragraph (a) of this AD. 

(1) Prior to the threshold specified in the applicable service bulletin listed in Table II of Lockheed Service Bulletin 093-51-040, Revision 1 or Revision 2.

(2) Within 5 years or 5,000 flight cycles after the effective date of this AD, whichever occurs first. 

# Note 4:

Installation of the terminating modifications specified in Lockheed Service Bulletin 093-53-268, Revision 1, dated July 2, 1996, and Lockheed Service Bulletin 093-53-272, dated November 12, 1996, does not constitute terminating action for the repetitive inspection requirements of AD 99-08-20, amendment 39-11128.

(e) Overhaul of the main landing gear actuator in accordance with Lockheed Service Bulletin 093-32-238, Revision 3, dated April 11, 1996, as listed in Table II of Lockheed Service Bulletin 093-51-040, Revision 1, dated October 1, 1997, is not required by paragraph (d) of this AD. 

(f) At the later of the times specified in paragraphs (f)(1) and (f)(2) of this AD: Install the terminating modification listed in Lockheed Service Bulletin 093-57-215, as referenced in Table II of Lockheed Service Bulletin 093-51-040, Revision 1, dated October 1, 1997, or Revision 2, dated October 21, 1999. Such installation constitutes terminating action for the inspections required by AD 98-10-14, amendment 39-10526. 

(1) Prior to the threshold specified in Lockheed Service Bulletin 093-57-203, Revision 5, dated April 22, 1996.

(2) Within 2 years or 2,000 flight cycles after the effective date of this AD, whichever occurs first. 

## Alternative Methods of Compliance 

(g) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Atlanta ACO. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Atlanta ACO. 

# Note 5:

Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Atlanta ACO.

## Special Flight Permits 

(h) Special flight permits may be issued in accordance with §§ 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished. 

## Incorporation by Reference 

(i) Except as provided by paragraphs (c)(2) and (c)(4) of this AD, the actions shall be done in accordance with Lockheed Service Bulletin 093-51-040, Revision 1, dated October 1, 1997; or Lockheed Service Bulletin 093-51-040, Revision 2, dated October 21, 1999. 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 Lockheed Martin Aircraft & Logistics Center, 120 Orion Street, Greenville, South Carolina 29605. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; at the FAA, Atlanta Aircraft Certification Office, One Crown Center, 1895 Phoenix Boulevard, suite 450, Atlanta, Georgia; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. 

## Effective Date 

(j) This amendment becomes effective on November 24, 2000.

Issued in Renton, Washington, on October 11, 2000. 

Donald L. Riggin, 

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. 

[FR Doc. 00-26590 Filed 10-19-00; 8:45 am] 

BILLING CODE 4910-13-P