AD 94-05-01

This amendment supersedes an existing airworthiness directive (AD), applicable to certain Lockheed Model L-1011 series airplanes, that currently requires certain structural modifications and inspections. This amendment revises certain inspections required by the existing AD, and requires additional inspections and structural modifications. This amendment is prompted by reports of recent incidents involving 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 degradation of the structural capabilities of the affected airplanes. This action also reflects the FAA's determination that long term continued operational safety should be assured by actual modification of the airframe rather than repetitive inspections.

The incorporation by reference of Lockheed Service Bulletin 093-51-035, Revision 1, dated December 16, 1991, as revised by L-1011Service Bulletin Change Notification 093-51-035, R1-CN1, dated October 27, 1992, as listed in the regulations, is approved by the Director of the Federal Register as of April 4, 1994.

The incorporation by reference of Lockheed Service Bulletin 093-51-035, dated June 28, 1990, as listed in the regulations, was approved previously by the Director of the Federal Register as of March 22, 1991 (56 FR 6556, February 19, 1991).

Final Rule

94-05-01 LOCKHEED AERONAUTICAL SYSTEMS COMPANY: Amendment 39-8839. Docket 92-NM-106-AD. Supersedes AD 91-05-05, Amendment 39-6878.

Applicability: Model L-1011-385 series airplanes; as listed in Lockheed Collector Service Bulletin 093-51-035, Revision 1, dated December 16, 1991; certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

NOTE 1: Paragraphs (a) and (d) of this AD restate the requirements of AD 91-05-05, Amendment 39-6878, paragraphs (a) and (b). As allowed by the phrase, "unless accomplished previously," if the requirements of AD 91-05-05 have been accomplished previously, paragraphs (a) and (d) of this AD do not require those inspections and modifications to be repeated.

To prevent degradation of the structural capabilities of the affected airplanes, accomplish the following:

(a) Within the threshold for inspections specified in the service bulletins listed in Tables I and II of Lockheed Service Bulletin 093-51-035, dated June 28, 1990 ("Structures - Aging Aircraft Structural Modifications and Inspections - Collector Service Bulletin"), or within one repetitive inspection period specified in those service bulletins after March 22, 1991 (the effective date of AD 91-05-05, Amendment 39-6878), whichever occurs later, inspect for cracks in accordance with those service bulletins. Repeat these inspections thereafter at intervals specified in the service bulletins listed in Lockheed Service Bulletin 093-51-035, dated June 28, 1990. The inspections specified in Lockheed Service Bulletins 093-57-184, Revision 4, dated May 16, 1990; 093-57-196, Revision 3, dated March 7, 1990; and 093-57-203, Revision 1, dated August 11, 1989; as listed in Lockheed Service Bulletin 093-51-035, dated June 28, 1990, are excluded from the requirements of this AD.

(1) If cracks are found during any inspection, prior to further flight, either accomplish the terminating modification in accordance with the applicable service bulletin, or repair in accordance with the FAA-approved repair procedures in the applicable service bulletin or in accordance with a method approved by the Manager, Atlanta Aircraft Certification Office, FAA, Small Airplane Directorate.

(2) Modification in accordance with paragraph (d) of this AD or in accordance with the applicable service bulletin listed within the inspection portion of Lockheed Service Bulletin 093-51-035, dated June 28, 1990, constitutes terminating action for the individual inspection requirements of the applicable service bulletin.

(b) Except as provided by paragraph (c) of this AD, the initial and repetitive inspections required by paragraph (a) of this AD that are performed after 12 months after the effective date of this AD must be done in accordance with the service bulletins listed in Tables I and II of Lockheed Service Bulletin 093-51-035, Revision 1, dated December 16, 1991 ("Structures - Aging Aircraft Structural Modifications and Inspections - Collector Service Bulletin;" hereinafter referred to as the "Collector Service Bulletin"), as revised by L-1011 Service Bulletin Change Notification 093-51-035,R1-CN1, dated October 27, 1992, at the thresholds and intervals specified in those service bulletins.

(1) If cracks are found during any inspection, prior to further flight, either accomplish the terminating modification in accordance with the applicable service bulletin, or repair in accordance with the FAA-approved repair procedures in the applicable service bulletin or in accordance with a method approved by the Manager, Atlanta Aircraft Certification Office, FAA, Small Airplane Directorate.

(2) Modification in accordance with paragraph (d) or (e) of this AD or in accordance with the applicable service bulletin listed within the inspection portion of Lockheed Service Bulletin 093-51-035, dated June 28, 1990, or Revision 1, dated December 16, 1991, as revised by L-1011 Service Bulletin ChangeNotification 093-51-035,R1-CN1, dated October 27, 1992, constitutes terminating action for the individual inspection requirements of the applicable service bulletin.

(c) Within the threshold for inspections specified in the service bulletins listed in paragraphs (c)(1), (c)(2), and (c)(3) of this AD, or within one repetitive inspection interval after the effective date of this AD, whichever occurs later, inspect for cracks in accordance with those service bulletins. Repeat these inspections thereafter at the intervals specified in the service bulletins. If cracks are found during any inspection, prior to further flight, either accomplish the terminating modification in accordance with the applicable service bulletin, or repair in accordance with the FAA-approved repair procedures in the applicable service bulletin or in accordance with a method approved by the Manager, Atlanta Aircraft Certification Office, FAA, Small Airplane Directorate. Modification in accordance with paragraph (d) or (e) of this AD, or in accordance with the applicable service bulletin listed within the inspection portion of the Collector Service Bulletin, constitutes terminating action for the individual inspection requirements of the applicable service bulletin.

(1) For Model L-1011-385 series airplanes, serial numbers 1013 through 1250, inclusive: Lockheed Service Bulletin 093-53-238, Revision 5, dated October 7, 1991.

(2) For Model L-1011-385 series airplanes, serial numbers 1002 through 1188, inclusive: Lockheed Service Bulletin 093-57-207, Revision 3, dated November 22, 1991.

(3) For Model L-1011-385 series airplanes, serial numbers 1131 through 1250, inclusive: Lockheed Service Bulletin 093-57-050, Revision 3, dated July 12, 1991.

(d) Structural modifications must be accomplished in accordance with the service bulletins listed in Table II of Lockheed Service Bulletin 093-51-035, dated June 28, 1990, or Revision 1, dated December 16, 1991, as revised by L-1011 Service Bulletin Change Notification 093-51-035,R1-CN1, dated October 27, 1992, within the time limits specified in paragraph (d)(1) or (d)(2) of this AD, whichever occurs later. The actions specified in Lockheed Service Bulletins 093-57-184, Revision 4, dated May 16, 1990; 093-57-196, Revision 3, dated March 7, 1990; and 093-57-203, Revision 1, dated August 11, 1989; as listed in Lockheed Service Bulletin 093-51-035, dated June 28, 1990, are excluded from the requirements of this AD. Lockheed Service Bulletin 093-52-155, Revision 1, dated October 23, 1989, is not addressed in this AD action.

(1) Prior to reaching the thresholds for modifications specified in Lockheed Service Bulletin 093-51-035, dated June 28, 1990, or Revision 1, dated December 16, 1991, as revised by L-1011 Service Bulletin Change Notification 093-51-035,R1-CN1, dated October 27, 1992. Or

(2) Within 5 years or 5,000 flight cycles after March 22, 1991 (the effective date of AD 91-05-05, Amendment39-6878), whichever occurs first.

NOTE 2: The modifications required by this paragraph do not terminate the inspection requirements of any other AD unless that AD specifies that any such modification constitutes terminating action for the inspection requirements.

NOTE 3: Lockheed Service Bulletins 093-57-184, Revision 6; 093-57-196, Revision 5; and 093-57-203, Revision 3; all dated October 28, 1991, are addressed in paragraph (e) of this AD.

(e) Accomplish structural modifications in accordance with paragraph (e)(2) of this AD at the time specified in paragraph (e)(1) of this AD.

(1) Accomplish the structural modifications at the later of the following times:

(i) Prior to reaching the thresholds for modifications specified in Table II of the Collector Service Bulletin. Or

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

(2) Accomplish the structural modifications in accordance with the following service bulletins:

(i) For Model L-1011-385-1, serial numbers 1002 through 1051, inclusive: Lockheed Service Bulletin 093-57-196, Revision 5, dated October 28, 1991.

(ii) For Model L-1011-385-1 series airplanes, serial numbers 1052 through 1245, inclusive: Lockheed Service Bulletin 093-57-184, Revision 6, dated October 28, 1991.

(iii) For Model L-1011-385-3 series airplanes, serial numbers 1157 through 1250, inclusive: Lockheed Service Bulletin 093-57-203, Revision 3, dated October 28, 1991. (Only the structural modification portion of the service bulletin is mandated by this action; the inspection portion of the service bulletin is not addressed in this AD action.)

(f) 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 Aircraft Certification Office (ACO), FAA, Small Airplane Directorate. 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 4: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Atlanta ACO.

(g) Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate the airplane to a location where the requirements of this AD can be accomplished.

(h) The actions shall be done in accordance with Lockheed Service Bulletin 093-51- 035, dated June 28, 1990; and Lockheed Service Bulletin 093-51-035, Revision 1, dated December 16, 1991, as revised by L-1011 Service Bulletin Change Notification 093-51-035,R1-CN1, dated October 27, 1992. The incorporation by reference of Lockheed Service Bulletin 093- 51-035, Revision 1, dated December 16, 1991, as revised by L-1011 Service Bulletin Change Notification 093-51-035,R1-CN1, dated October 27, 1992, was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51. The incorporation by reference of Lockheed Service Bulletin 093-51-035, dated June 28, 1990, was approved previously by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51 as of March 22, 1991 (56 FR 6556, February 19, 1991). Copies may be obtained from Lockheed Western Export Company (LWEC), Dept. 693, Zone 0755, 86 South Cobb Drive, Marietta, Georgia 30063. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Small Airplane Directorate, Atlanta Aircraft Certification Office, suite 210C, 1669 Phoenix Parkway, Atlanta, Georgia; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

(i) This amendment becomes effective on April 4, 1994.

A proposal to amend part 39 of the Federal Aviation Regulations by superseding AD 91-05-05, Amendment 39-6878 (56 FR 6556, February 19, 1991), which is applicable to certain Lockheed Model L-1011-385 series airplanes, was published in the Federal Register on December 4, 1992 (57 FR 57392). The action proposed to require certain structural modifications and inspections.

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

One commenter supports the proposed rule.

One commenter suggests that any new requirements or changes to AD's that address "collector" service bulletins (CSB) should be issued as new AD's, rather than supersedures of "old" AD's. The commenter suggests further that a "collector" AD should be issued annually to address any changes or additions to CSB's. The commenter believes that this proposed procedure would ease administrative and financial burdens to operators, particularly in the case of AD's that address CSB's, such as the proposed rule.

The FAA does not concur. The FAA's normal policy is to supersede an "old" AD by removing it from the system and adding a new AD in a case where substantive requirements must be added to the "old" AD. The FAA has determined that the changes made to the original issue of the CSB addressed in this AD are substantive, since changes have been made to certain accomplishment procedures and some new requirements have been added. The FAA finds that issuance of a supersedure is appropriate in this case to include those new or revised requirements.

The Air Transport Association (ATA) of America, on behalf of one of its members, requests that the FAA conduct a thorough review of AD 91-05-05 and this proposed rule to eliminate any references to service bulletins that are addressed in other existing AD's. The commenter contends that there is no justification for requiring operators to perform duplicate inspections and that such requirements are confusing to operators.

The FAA does not concur with the commenter's request to eliminate references to service bulletins addressed in this AD that are also addressed in other existing AD's. The FAA recognizes that certain service bulletins addressed in this AD have also been the subject of other existing AD's. However, the FAA has included references to such service bulletins in this AD only to require that operators accomplish those actions that will terminate the repetitive inspections required by other existing AD's. The FAA has also been informed by Lockheed of the necessity to revise Lockheed Service Bulletin 093-51-035 [referred to in this AD as the Collector Service Bulletin (CSB)] to fully address the required terminating actions for all affected airplanes. Subsequently, the FAA may consider further rulemaking to require that action be taken in accordance with that revised CSB; any duplicate requirements would then be eliminated by rescinding any existing AD's that address those duplicate requirements.

Two commenters suggest that the contents of the second "NOTE" in paragraph (d) of the proposal should appear in the final rule as two separate paragraphs, one to exclude the first three service bulletins cited and a second to exclude the fourth service bulletin. One of the commenters asks if a "NOTE" has legal status in an AD. Another commenter states that the actions described in the first three service bulletins should have been excluded from this AD, since such an exclusion appeared in AD 91-05-05.

The FAA concurs with the commenters' request to exclude the actions described in the service bulletins specified in the second "NOTE" in paragraph (d) of the proposal, since this was the intent of that "NOTE." The FAA clarifies that the material that appears in a "NOTE" is simply explanatory or informational. The FAA has removed the "NOTE" from the final rule andhas revised paragraphs (a) and (d) to provide an exclusion of the actions described in the first three service bulletins referenced from the requirements of this AD. In addition, the actions specified in the fourth service bulletin referenced in the "NOTE" are addressed in another existing AD; this information has been specified in paragraph (d) of the final rule.

Two commenters request that paragraphs (a) and (b) of the proposal be revised to reference Table II of Lockheed Service Bulletin 093-51-035, in addition to Table I, since Table II contains interim inspection requirements. The FAA concurs, as its intent was to include these interim inspection requirements in the AD. Paragraphs (a) and (b) of the final rule have been revised accordingly.

Two commenters request that the proposed rule be revised to permit repairs to be accomplished "in accordance with FAA-approved repair procedures" and that paragraph (g) of the proposal be revised to explain the Designated Engineering Representative's (DER) authority, including any limitations, to approve minor changes to repairs done in accordance with the proposal. One commenter states that obtaining approval from the FAA often requires extended down time and unnecessary interruptions of scheduled service. The commenter believes that operators with in-house resources for obtaining FAA approval of repairs [i.e., DER's or organizations that hold a Special Federal Aviation Regulation (SFAR) 36 authorization] should be allowed to use those sources of FAA approval to return aircraft to service in an expeditious manner, particularly when repetitive inspections are being accomplished. The second commenter indicates that the CSB references approval of deviations to repairs and modifications by normal non-AD approval procedures.

The FAA does not concur. While DER's and SFAR 36-authorized organizations are authorized to determine whether a design or repair method complies with a specific requirement, they are notauthorized currently to make the discretionary determination as to what the applicable requirement is. Further, where repair data do not exist, it is essential that the FAA have feedback as to the type of repairs being made. The FAA has determined that the Manager of the Atlanta Aircraft Certification Office should approve any such deviations to the AD's requirements. Given that possible new relevant issues might be revealed during this process, it is imperative that the FAA, at this level, have such feedback. Only by reviewing deviation approvals can the FAA be assured of this feedback and of the adequacy of the repair methods. However, the FAA is currently conducting a review of this policy and may consider revising it based upon the results of that review.

One commenter requests that the FAA revise paragraph (b) of the proposal to allow inspections to continue in accordance with the service bulletin revision levels specified in the original issue of the CSB, except for those inspections for which the procedures have been revised substantively in Revision 1 of the CSB. The commenter suggests that the excepted inspections should be addressed in a separate paragraph of the proposal and should be phased in over a period of time, rather than required as of the effective date of this AD. The commenter adds that any new inspection procedures required by this AD should have been discussed with the Airworthiness Assurance Working Group (AAWG) for these airplanes.

The FAA concurs partially. The intent of paragraph (b) is to require that, after the effective date of this AD, inspections be accomplished in accordance with the service bulletin revision levels listed in Revision 1 of the CSB. The AAWG endorsed that revision of the CSB at a conference held in November 1991. However, upon reconsideration, the FAA has determined that an acceptable level of safety can be maintained if operators are allowed a "phase-in" period to change over from accomplishing inspection procedures in accordance with the original issue of the CSB to accomplishing the updated inspection procedures specified in Revision 1 of the CSB. Therefore, the FAA has revised paragraph (b) of the final rule to allow a phase-in period of 12 months for operators with airplanes that are being inspected as of the effective date of this AD to make this change.

One commenter requests that the modification requirement specified in Lockheed Service Bulletin 093-53-237 be specifically excluded from the requirements of this AD, as recommended by the AAWG. The FAA concurs. Paragraphs (b) and (d) of the final rule have been revised to reference L-1011 Service Bulletin Change Notification 093-51-035,R1-CN1, dated October 27, 1992, which eliminates the modification specified in Lockheed Service Bulletin 093-53-237.

Two commenters request that the proposal be revised to allow credit for modifications accomplished previously in accordance with the original issue of the CSB. Oneof the commenters points out that the only revised listing that appears in Table II of Revision 1 of the CSB is Lockheed Service Bulletin 093-53-233, which describes additional inspections to be conducted after accomplishing the modification specified in the service bulletin. This commenter states further that it was not the intent of the AAWG to mandate that modifications be accomplished in accordance with the latest issues of the service bulletins.

The FAA concurs. After accomplishing the modification described in Lockheed Service Bulletin 093-53-233, certain inspections are required. Those inspections are described in Lockheed Service Bulletin 093-53-238, which is listed in Table II of the revised CSB and required by paragraph (c)(1) of the final rule. The scope of the required inspections is dependent upon which version of Lockheed Service Bulletin 093-53-233 an operator accomplished; this issue is addressed under Lockheed Service Bulletin 093-53-233 in the "Remarks" section of Table II of the revised CSB.

The FAA finds that accomplishment of modifications in accordance with Table II of the original issue of the CSB may continue. Accordingly, paragraph (e) of the proposal, which would have required certain structural modifications in accordance with the service bulletins listed in Table II of the CSB, has been removed from the final rule. The contents of the first sentence of the second "NOTE" that appeared in paragraph (e) of the proposal, which indicated that Lockheed Service Bulletins 093-57-184, Revision 6; 093-57-196, Revision 5; and 093-57-203, Revision 3; are addressed in paragraph (f) of the proposal, are specified in "NOTE 3" under paragraph (d) of the final rule.

In addition, paragraph (d) of the final rule has been revised to specify that modifications accomplished in accordance with Table II of either the original issue or Revision 1 of the CSB are acceptable for compliance with the requirements of that paragraph. Further, paragraphs (b)(2) and (c) of the final rule have been revised to specify that modification in accordance with paragraph (d) or (e) of this AD or in accordance with the applicable service bulletin listed within the inspection portion of either the original issue or Revision 1 of the CSB constitutes terminating action for the individual inspection requirements of the applicable service bulletin.

One commenter asks that the number of Model L-1011 series airplanes of the affected airplanes in the worldwide fleet be revised, since the actual number is larger than that reflected in the economic impact information specified in the proposal. The FAA concurs. The FAA has verified that the correct number of affected airplanes in the worldwide fleet is 241 and has revised the economic impact information, below, accordingly.

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.

There are approximately 241 Model L-1011 series airplanes of the affected design in the worldwide fleet. The FAA estimates that 112 airplanes of U.S. registry will be affected by this AD. The actions required previously by AD 91-05-05 necessitate 1,200 work hours per airplane to accomplish, at an average labor rate of $40 per work hour. The cost for parts required by that AD is $52,000 per airplane. Based on these figures, the total cost of AD 91-05-05 to affected U.S. operators over an initial 5-year time period was estimated to be approximately $11,200,000, or $100,000 per airplane.

The actions required by this AD will require an additional 549 work hours per airplane to accomplish at an average labor rate of $55 per work hour. (Note that, in order to account for various inflationary costs in theairline industry, the FAA has increased the labor rate used in calculating the economic impact of this AD activity from $40 per work hour to $55 per work hour.) Required parts will cost approximately $21,000 per airplane. Based on these figures, the additional costs to U.S. operators with regard to the actions required by this AD is estimated to be $5,733,840, or $51,195 per airplane.

Based on the figures discussed above, the total cost impact of this AD action on U.S. operators is estimated to be $16,933,840, or $151,195 per airplane. The total cost impact figure(s) discussed above is based on assumptions that no operator has yet accomplished any of the requirements of either this new AD action or the previous AD, and that no operator would accomplish those actions in the future if this AD were not adopted.

The FAA recognizes that the obligation to maintain aircraft in an airworthy condition is vital, but sometimes expensive. Because AD's require specific actions to address specific unsafe conditions, they appear to impose costs that would not otherwise be borne by operators. However, because of the general obligation of operators to maintain aircraft in an airworthy condition, this appearance is deceptive. Attributing those costs solely to the issuance of this AD is unrealistic because, in the interest of maintaining safe aircraft, most prudent operators would accomplish the required actions even if they were not required to do so by the AD.

A full cost-benefit analysis has not been accomplished for this AD. As a matter of law, in order to be airworthy, an aircraft must conform to its type design and be in a condition for safe operation. The type design is approved only after the FAA makes a determination that it complies with all applicable airworthiness requirements. In adopting and maintaining those requirements, the FAA has already made the determination that they establish a level of safety that is cost-beneficial. When the FAA, as in this AD, makes a finding of an unsafe condition, this means that this cost-beneficial level of safety is no longer being achieved and that the required actions are necessary to restore that level of safety. Because this level of safety has already been determined to be cost-beneficial, a full cost-benefit analysis for this AD would be redundant and unnecessary.

The regulations adopted herein will not have substantial direct effects 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, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.

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 14 CFR part 39 of the Federal Aviation Regulations as follows:

PART 39 - AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 106(g); and 14 CFR 11.89.

39.13 - [Amended]
2. Section 39.13 is amended by removing amendment 39-6878 (56 FR 6556, February 19, 1991), and by adding a new airworthiness directive (AD), amendment 39-8839, to read as follows: