AD 99-09-14 ACTIVE

This amendment supersedes an existing airworthiness directive (AD), applicable to all Lockheed Model L-1011-385 series airplanes, that currently requires inspections to detect cracking of fuselage station (FS) 983 main frame (left and right sides), and repair, if necessary. That AD was prompted by reports of cracks found in the left and right sides of the FS 983 main frame, below the level of the cabin floor. This amendment adds a new requirement to review the airplane maintenance records to determine if a crack within the FS 983 main frame web was detected previously, and if repair of any such crack was deferred; and repetitive inspections, if necessary, until accomplishment of a repair. This amendment also adds terminating action for the repetitive inspections. The actions specified by this AD are intended to prevent cracking of the FS 983 frame, which could result in reduced structural integrity of the fuselage.

Final rule

99-09-14 LOCKHEED: Amendment 39-11147. Docket 98-NM-199-AD. Supersedes AD 91-21-51, amendment 39-8099.

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 (h)(1) 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 cracking in the fuselage station (FS) 983 frame, which could result in reduced structural integrity of the fuselage, accomplish the following:

RESTATEMENT OF REQUIREMENTS OF AD 91-21-51, AMENDMENT 39-8099:
(a) Within 20 days after December 18, 1991 (the effective date of AD 91-21-51, amendment 39-8099), inspect the left and right sides of FS 983 main frame from waterline (WL) 175 to WL 200 to detect cracks using a high frequency eddy current procedure, in accordance with paragraph A. of the Accomplishment Instructions of Lockheed Service Bulletin 093-53-264, dated October 4, 1991. At the operator's option, the internal inspection required by paragraph (d) below may be used in lieu of the external inspection.

(b) If cracks that extend into the main frame caps are found during the inspection performed in accordance with paragraph (a) of this AD, prior to further flight, repair in accordance with a method approved by the Manager, Atlanta AircraftCertification Office (ACO), FAA, Small Airplane Directorate.

(c) Within 60 days after December 18, 1991, perform an internal visual and an eddy current inspection of the FS 983 main frame cap and web in accordance with paragraph B. of the Accomplishment Instructions of Lockheed Service Bulletin 093-53-264, dated October 4, 1991.

(d) If cracks in the following locations are found during the inspection required by paragraph (c) of this AD, prior to further flight, repair in accordance with a method approved by the Manager, Atlanta ACO.

(1) Any crack extending into the main frame caps.

(2) Any crack extending into the web-to-cap radius.

(3) Any crack extending into a web area outside the shaded area shown in Figure 1, Sheet 3, of Lockheed Service Bulletin 093-53-264, dated October 4, 1991.

(4) More than 1 crack within the main frame web area shown in Figure 1, Sheet 3, of Lockheed Service Bulletin 093-53-264, dated October 4, 1991.

(e) If, during the inspection required by paragraph (c) of this AD, a single crack is found that is completely contained within the main frame web area shown in Figure 1, Sheet 3, of Lockheed Service Bulletin 093-53-264, dated October 4, 1991: Prior to further flight, treat the cracked section of the web with corrosion inhibitor in accordance with the service bulletin. Thereafter, repeat the inspections at intervals not to exceed 90 days, using the internal inspection procedure required by paragraph (c) of this AD.

NEW REQUIREMENTS OF THIS AD:
(f) Within 18 months after the effective date of this AD: Review the airplane maintenance records to determine if a crack within the main frame web area has been detected previously, and to determine if repair of any such crack was deferred in accordance with paragraph (e) of AD 91-21-51, amendment 39-8099. For airplanes having cracks for which a repair has been deferred, continue the repetitive inspections in accordance with the requirements of paragraph (e) of this AD, until accomplishment of paragraph (g) of this AD.

(g) Within 18 months after the effective date of this AD: Repair any crack for which repair has been deferred as specified in paragraph (e) of this AD, in accordance with Lockheed Tristar L-1011 Service Bulletin 093-53-266, dated March 2, 1992; as revised by Change Notification CN1, dated July 10, 1992. Accomplishment of such repair constitutes terminating action for the repetitive inspections required by paragraph (e) of this AD.

NOTE 2: Lockheed Tristar L-1011 Service Bulletin 093-53-266, dated March 2, 1992; as revised by Change Notification CN1, dated July 10, 1992; references Lockheed Drawings LCC-7622-325, LCC-7622-326, and LCC-7622-327, as additional sources of service information to accomplish repairs.

Alternative Methods of Compliance
(h) (1) 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.

(2) Alternative methods of compliance, approved previously in accordance with AD 91-21-51, amendment 39-8099, are approved as alternative methods of compliance with the inspection requirements of paragraphs (a) and (c) of this AD, and the repair/modification requirements of paragraphs (b) and (d) of this AD.

NOTE 3: 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
(i) Special flight permits may be issued in accordance with sections 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
(j) Except as provided by paragraphs (b) and (d) of this AD, the actions shall be done in accordance with Lockheed Tristar L-1011 Service Bulletin 093-53-266, dated March 2, 1992; as revised by Change Notification 093-53-266, CN1, dated July 10, 1992; and Lockheed Service Bulletin 093-53-264, dated October 4, 1991.

(1) The incorporation by reference of Lockheed Tristar L-1011 Service Bulletin 093-53-266, dated March 2, 1992; as revised by Change Notification 093-53-266, CN1, dated July 10, 1992, is approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51.

(2) The incorporation by reference of Lockheed Service Bulletin 093-53-264, dated October 4, 1991, was approved previously by the Director of the Federal Register as of December 18, 1991 (56 FR 61361, December 3, 1991).

(3) Copies may be obtained from Lockheed Martin Aircraft & Logistics Centers, 120 Orion Street, Greenville, South Carolina 29605. 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, 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.

(k) This amendment becomes effective on June 1, 1999.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by superseding AD 91-21-51, amendment 39-8099 (56 FR 61361, December 3, 1991), which is applicable to all Lockheed Model L-1011-385 series airplanes, was published in the Federal Register on August 19, 1998 (63 FR 44411). The action proposed to require inspections to detect cracking of fuselage station (FS) 983 main frame (left and right sides), and repair, if necessary. The action also proposed to add a new requirement to review the airplane maintenance records to determine if a crack within the FS 983 main frame web was detected previously, and if repair of any such crack was deferred; and repair, prior to further flight, if necessary.

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.

Request to Revise Certain Requirements of Proposed Rule
One commenter requests that paragraph (f) of the proposed rule be revised to read, "For aircraft with previously deferred cracks, continue the current repetitive inspection at the limits given in AD 91-21-51, paragraph (e). Repair of these cracks must be accomplished in accordance with Lockheed Service Bulletin 093-53-266, dated March 2, 1992, within 18 months after the effective date of this AD." The commenter states that, as paragraph (f) is worded in the proposed rule, the operator would have to repair any cracks that were deferred in accordance with the requirements in paragraph (e), prior to further flight. This could result in airplanes being immediately out of compliance as of the effective date of the final rule.

The FAA concurs that paragraph (f) of the proposed rule could be misinterpreted as suggested by the commenter. The FAA s intent was that the repair be accomplished prior to further flightafter the determination that is required by the first sentence of paragraph (f). to accommodate the commenter s concern, the FAA has revised paragraph (f) of this AD to require the repetitive inspections to continue until accomplishment of the repair. In addition, a new paragraph (g) has been added to require accomplishment of the repair within 18 months after the effective date of this AD.

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 described previously. 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 235 airplanes of the affected design in the worldwide fleet. The FAA estimates that 117 airplanes of U.S. registry will be affected by this AD.

The external eddy current inspection that currently is required by AD 91-21-51, and is retained in this AD, takes approximately 1 work hour per airplane to accomplish, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the currently required inspection on U.S. operators is estimated to be $7,020, or $60 per airplane.

The internal visual and eddy current inspections that currently are required by AD 91-21-51, and retained in this AD, take approximately 1 work hour per airplane to accomplish, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of these inspections on U.S. operators is estimated to be $7,020, or $60 per airplane, per inspection cycle.

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.

Should an operator be required to accomplish the necessary repair of cracking, it would take approximately 30 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the repair required by this AD on U.S. operators is estimated to be $1,800 per airplane.

Regulatory Impact
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 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 [Amended]
2. Section 39.13 is amended by removing amendment 39-8099 (56 FR 61361, December 3, 1991), and by adding a new airworthiness directive (AD), amendment 39-11147, to read as follows:

The service information referenced in this AD may be obtained from Lockheed Martin Aircraft & Logistics Centers, 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, Small Airplane Directorate, 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.

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