Airworthiness directives: Lockheed,

[Federal Register: December 9, 1999 (Volume 64, Number 236)]

[Proposed Rules]

[Page 68960-68963]

From the Federal Register Online via GPO Access [wais.access.gpo.gov]

[DOCID:fr09de99-17]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-129-AD]

RIN 2120-AA64

Airworthiness Directives; Lockheed Model L-1011-385 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

[[Page 68961]]

ACTION: Notice of proposed rulemaking (NPRM).

SUMMARY: This document proposes the adoption of a new airworthiness directive (AD) that is applicable to all Lockheed Model L-1011-385 series airplanes. This proposal would require repetitive inspections to detect corrosion or fatigue cracking of certain structural elements of the airplane; corrective actions, if necessary; and incorporation of certain structural modifications. This proposal 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 the proposed AD are intended to prevent corrosion or fatigue cracking of certain structural elements, which could result in reduced structural integrity of the airplane.

DATES: Comments must be received by January 24, 2000.

ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 99-NM-129-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except Federal holidays.

The service information referenced in the proposed rule may be obtained from Lockheed Martin Aircraft & Logistics Center, 120 Orion Street, Greenville, South Carolina 29605. This information may be examined 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.

FOR FURTHER INFORMATION CONTACT: 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.

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to participate in the making of the proposed rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this notice may be changed in light of the comments received.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report summarizing each FAA-public contact concerned with the substance of this proposal will be filedin the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this notice must submit a self-addressed, stamped postcard on which the following statement is made: ``Comments to Docket Number 99-NM-129-AD.'' The postcard will be date stamped and returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this NPRM by submitting a request to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 99-NM-129-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

In April 1988, a high-cycle transport category airplane (specifically, a Boeing Model 737 series airplanes) was involved in an accident in which the airplane suffered major structural damage during flight. Investigation of this accident revealed that the airplane had numerous fatigue cracks and a great deal of corrosion. Subsequent inspections conducted by the operator on other high-cycle transport category airplanes in its fleet revealed that other airplanes had extensive fatigue cracking and corrosion.

Prompted by the data gained from this accident, the FAA sponsored a conference on aging airplanes in June 1988, which was attended by representatives from the aviation industry and airworthiness authorities from around the world. It became obvious that, because of the tremendous increase in air travel, the relatively slow pace of new airplane production, and the apparent economic feasibility of operating older technology airplanes rather than retiring them, increased attention needed to be focused on the aging airplane fleet and maintaining its continued operational safety.

The Air Transport Association (ATA) of America and the Aerospace Industries Association (AIA) of America agreed to undertake the task of identifying and implementing procedures to ensure the continued structural airworthiness of aging transport category airplanes. An Airworthiness Assurance Working Group (AAWG) was established in August 1988, with members representing aircraft manufacturers, operators, regulatory authorities, and other aviation industry representatives worldwide. The objective of the AAWG was to sponsor ``Task Groups'' to:

1. Select service bulletins, applicable to each airplane model in the transport fleet, to be recommended for mandatory modification of aging airplanes;

2. Develop corrosion-directed inspections and prevention programs;

3. Review the adequacy of each operator's structural maintenance program;

4. Review and update the Supplemental Inspection Documents (SID); and

5. Assess repair quality.

   The Structures Task Group (STG) assigned to review the Lockheed Model L-1011-385 series airplanes was formed in 1988, and included operators of Model L-1011-385 series airplanes, Lockheed, the FAA, and observers from regulatory agencies. Certain recommendations made by the STG (pursuant to Item 1., described previously) are contained in Lockheed Service Bulletins 093-51-035, Revision 1, dated December 16, 1991, and 093-51-040, Revision 1, dated October 1, 1997. The FAA previously issued AD 94-05-01, amendment 39-8839 (59 FR 10275, March 4, 1994), to require the structural inspections and the modifications recommended in that document.

   Since the issuance of that AD, the STG has recommended accomplishment of certain other structural inspections to detect corrosion or fatigue cracking of certain structural elements of the airplane, and incorporation of certain structural modifications. Corrosion or fatigue cracking of certain structural elements, if not detected and corrected, could result in reduced structural integrity of the airplane.

   Explanation of Relevant Service Information

   The FAA has reviewed and approved Lockheed Tristar L-1011 Service Bulletin 093-51-041, dated April 27, 1998 (hereinafter referred to as the ``Collector Service Bulletin''). The Collector Service Bulletin describes

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   certain repetitive inspections to detect corrosion or fatigue cracking of certain structural elements of the airplane, including areas around the wing/root joint of the fuselage, aft pressure bulkhead of the fuselage, and the center section wing box in the wings. The Collector Service Bulletin also describes structural modifications of various elements of the airplane that have been recommended by the STG, including modification of the C1A cargo door, modification of the actuator support fitting for the horizontal stabilizer, reinforcement of the mid beam longeron at fuselage station 1363 and waterline 168.4, and reinforcement of the intermediate spar shear web of the center box in the wings. The Collector Service Bulletin also references appropriate sources of accomplishment instructions for the structural inspections and modifications.

   Accomplishment of the actions specified in the Collector Service Bulletin is intended to adequately address the identified unsafe condition.

   Explanation of Requirements of Proposed Rule

   Since an unsafe condition has been identified that is likely to exist or develop on other products of this same type design, the proposed AD would require accomplishment of the actions specified in the Collector Service Bulletin described previously, except as discussed below.

   Other Relevant Rulemaking

   The FAA has previously issued notice of proposed rulemaking (NPRM), Rules Docket 98-NM-35-AD (64 FR 34170, June 25, 1999), to require the structural inspections and modifications recommended in Lockheed Service Bulletin 093-51-040, Revision 1, dated October 1, 1997. However, this proposed AD would not affect the requirements of that previously issued proposed 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 would be affected by this proposed AD.

   It would take approximately 32 work hours per airplane (for Table I) and 97 work hours per airplane (for Table II) to accomplish the proposed inspections, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the proposed AD on U.S. operators is estimated to be $224,640, or $1,920 per airplane, per inspection cycle (for Table I), and $680,940, or $5,820 per airplane, per inspection cycle (for Table II).

   It would take approximately 614 work hours per airplane to accomplish the proposed modifications, at an average labor rate of $60 per work hour. Required parts would cost approximately $142,275 per airplane. Based on these figures, the cost impact of the proposed AD on U.S. operators is estimated to be $20,956,455, or $179,115 per airplane.

   The cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the proposed requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted.

   Regulatory Impact

   The regulations proposed herein would 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 proposal would not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.

   For the reasons discussed above, I certify that this 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) if promulgated, 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 copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption ADDRESSES.

   List of Subjects in 14 CFR Part 39

   Air transportation, Aircraft, Aviation safety, Safety.

   The Proposed Amendment

   Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend 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.

   Sec. 39.13 [Amended]

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

   Lockheed: Docket 99-NM-129-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 (d) 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) 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 Tristar L-1011 Service Bulletin 093-51-041, dated April 27, 1998. Perform the initial inspections at the later of the times specified in paragraphs (a)(1) and (a)(2) of this AD. Thereafter, repeat the inspections at intervals not to exceed those specified in the applicable service bulletin.

   (1) Prior to the threshold specified in the individual service bulletin as listed in Table I or II of Lockheed Tristar L-1011 Service Bulletin 093-51-041, dated April 27, 1998, 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 Tristar L-1011 Service Bulletin 093-51- 041, dated April 27, 1998, as applicable.

   Corrective Action

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

   (1) Repair in accordance with the applicable service bulletin referenced in Table I or II of Lockheed Tristar L-1011 Service Bulletin 093-51-041, dated April 27, 1998.

   (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

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   applicable service bulletin referenced in Table I or II of Lockheed Tristar L-1011 Service Bulletin 093-51-041, dated April 27, 1998.

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

   Terminating Action

   (c) Install the terminating modification referenced in each service bulletin listed in Table II of Lockheed Tristar L-1011 Service Bulletin 093-51-041, dated April 27, 1998; in accordance with the applicable service bulletin listed under ``Service Bulletin Number, Revision, and Date'' in Table II of Lockheed Tristar L-1011 Service Bulletin 093-51-041; at the later of the times specified in paragraphs (c)(1) and (c)(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 Tristar L-1011 Service Bulletin 093-51-041, dated April 27, 1998.

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

   Alternative Methods of Compliance

   (d) 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 2: 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

   (e) 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.

   Issued in Renton, Washington, on December 3, 1999. D.L. Riggin, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

   [FR Doc. 99-31876Filed12-8-99; 8:45 am]

   BILLING CODE 4910-13-P