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###### Department of Transportation

###### Federal Aviation Administration

          - 14 CFR Part 39
          - [Docket No. 2000-NM-145-AD]
          - RIN 2120-AA64

# AGENCY:

Federal Aviation Administration, DOT.

# ACTION:

Notice of proposed rulemaking (NPRM).

# SUMMARY:

This document proposes the supersedure of an existing airworthiness directive (AD), applicable to all Lockheed Model L-1011 series airplanes that currently requires the implementation of a corrosion prevention and control program either by accomplishing specific tasks or by revising the maintenance inspection program to include such a program. This action would require accomplishment of new specific tasks and visual inspections to detect corrosion of certain structural areas and repair, or revision of the maintenance inspection program. This proposal relates to the recommendations of the Airworthiness Assurance Task Force assigned to review Model L-1011 series airplanes, which indicate that, to assure long term continued operational safety, various structural inspections should be accomplished.

# DATES:

Comments must be received by June 11, 2001.

# ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2000-NM-145-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9 a.m. and 3 p.m., Monday through Friday, except Federal holidays. Comments may be submitted via fax to (425) 227-1232. Comments may also be sent via the Internet using the following address: 9-anm-nprmcomment@faa.gov. Comments sent via fax or the Internet must contain “Docket No. 2000-NM-145-AD” in the subject line and need not be submitted in triplicate. Comments sent via the Internet as attached electronic files must be formatted in Microsoft Word 97 for Windows or ASCII text.

The service information referenced in the proposed rule may be obtained from Lockheed Martin & Logistics Centers, 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, Atlanta Aircraft Certification Office, One Crown Center, 1895 Phoenix Boulevard, suite 450, Atlanta, Georgia.

# FOR FURTHER INFORMATION CONTACT:

Tom Peters, Program Manager, Program Management and Services Branch, ACE-118A, 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:

## 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                           ( print page 20761)                        for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this action may be changed in light of the comments received.                

Submit comments using the following format:
    - Organize comments issue-by-issue. For example, discuss a request to change the compliance time and a request to change the service bulletin reference as two separate issues.
    - For each issue, state what specific change to the proposed AD is being requested.
    - Include justification (e.g., reasons or data) for each request.

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 filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this action must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 2000-NM-145-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. 2000-NM-145-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

## Discussion

On October 8, 1993, the FAA issued AD 93-20-03, amendment 39-8710 (58 FR 60775, November 18, 1993), applicable to all Lockheed Model L-1011 series airplanes, to require the implementation of a corrosion prevention and control program either by accomplishing specific tasks or by revising the maintenance inspection program to include such a program. That action was prompted by reports of incidents involving corrosion and fatigue cracking in transport category airplanes that were approaching or had exceeded their economic design goal; those incidents jeopardized the airworthiness of the affected airplanes. The actions of that AD are intended to prevent degradation of the structural capabilities of the airplane due to the problems associated with corrosion.

## Actions Since Issuance of Previous Rule

Since the issuance of that AD, Lockheed has issued “Corrosion Prevention and Control Program (CPCP),” Report No. LR 31889, Revision D, dated August 15, 1999. This document revises the minimum procedures for preventing and controlling corrosion problems that may jeopardize continuing airworthiness of the L-1011 fleet. A Baseline Program that was developed by the L-1011 Airworthiness Assurance Task Force (AATF) Structures Working Group, is included in the document for use by operators who do not have a proven effective program. A mandatory reporting system is also included. Reported data and other relevant information will continue to be reviewed annually by an Industry Working Group.

The FAA has reviewed and approved Revision D of the CPCP, Report No. LR 31889, which describes procedures for, among other things, removing and visually inspecting the landing gear attachment bushings for corrosion; visually inspecting the upper wing access hole flanges and dip stick hole bushings on the lower wing for corrosion; visually inspecting the structural interior adjacent to the “S” duct for corrosion, and visually inspecting the horizontal stabilizer pivot bearing for corrosion. Accomplishment of the actions specified in Revision D of the CPCP Report, or a revision of the maintenance inspection program per Revision D, 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 supersede AD 93-20-03 to continue to require the visual inspections and repair of certain structures, if necessary, or a revision of the FAA-approved maintenance inspection program. This proposal would require accomplishment of various visual inspections for corrosion of certain structures, and repair, if necessary; or incorporation of Revision D of the Corrosion Prevention and Control Program, dated August 15, 1999, into the FAA-approved maintenance inspection program. Specific visual inspection and repair procedures have been described previously.

## Cost Impact

There are approximately 187 Lockheed Model L-1011 series 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.

The actions that are currently required by AD 93-20-03 take approximately 20 work hours per inspection to accomplish, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the currently required actions on U.S. operators is estimated to be $140,400, or $1,200 per airplane, per inspection cycle.

The new visual inspections proposed in this AD action would take approximately 249 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 proposed requirements of this AD on U.S. operators is estimated to be $1,747,980, or $14,940 per airplane.

If an operator chooses to accomplish the proposed revision to the maintenance inspection program, it would 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 the proposed requirements of this AD on U.S. operators is estimated to be $7,020, or $60 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 proposed 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 proposed herein would not have a substantial direct effect on the States, on the relationship between the national Government and the States, or on the distribution of power and responsibilities among the various levels of government. Therefore, it is determined that this proposal would not have federalism implications under Executive Order 13132.

                    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                           ( print page 20762)                        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.

§ 39.13 

2. Section 39.13 is amended by removing amendment 39-8710 (58 FR 60775, November 18, 1993), and by adding a new airworthiness directive (AD), to read as follows:

**Lockheed:**                                 Docket 2000-NM-145-AD. Supersedes AD 93-20-03, Amendment 39-8710.                            

*Applicability*: All Model L-1011 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 (k) 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 structural failure of the airplane due to corrosion, accomplish the following:

## Restatement of the Requirements of AD 93-20-03

# Note 2:

This AD references Lockheed Document Number LR 31889, “Corrosion Prevention and Control Program, TriStar L-1011,” dated March 15, 1991, including “Errata Sheet, LR 31889, Corrosion Prevention and Control Program, TriStar L-1011,” issued September 29, 1992, and Revision D, dated August 15, 1999 (hereafter, those publications are referred to as “the Document”), for corrosion tasks, definitions of corrosion levels, compliance times, and reporting requirements. In addition, this AD specifies inspection and reporting requirements beyond those included in the Document. Where there are differences between the AD and the Document, the AD prevails.

# Note 3:

As used throughout this AD, the term “the FAA” is defined differently for different operators, as follows: For those operators complying with paragraph (a) or (c) of this AD, “the FAA” is defined as “the Manager of the Atlanta Aircraft Certification Office (ACO).” For those operators operating under 14 CFR part 121 or 129, and complying with paragraph (b) or (d) of this AD, “the FAA” is defined as “the cognizant Maintenance Inspector at the appropriate FAA Flight Standards office.”

(a) Except as provided in paragraph (b) of this AD, complete each of the corrosion tasks specified in Section 4 of the Document in accordance with the procedures of the Document, and the schedule specified in paragraphs (a)(1) and (a)(2) of this AD. Corrosion task numbers C-32-710-01 (nose landing gear) and C-32-730-01 (main landing gear, left and right) are not required to be accomplished as part of this AD.

# Note 4:

A “corrosion task,” as defined in Section 4 of the Document, includes inspections; procedures for a corrective action, including repairs, under identified circumstances; application of corrosion inhibitors; and other follow-on actions.

# Note 5:

Corrosion tasks completed in accordance with the Document before the effective date of this AD may be credited for compliance with the initial corrosion task requirements of paragraph (a)(1) of this AD.

# Note 6:

Where non-destructive inspection (NDI) methods are employed, in accordance with Section 4 of the Document, the standards and procedures used must be acceptable to the Administrator in accordance with 14 CFR part 43.13.

(1) Complete the initial corrosion task of each “airplane area” specified in Section 4 of the Document as follows:

(i) For airplane areas that have not yet exceeded the “implementation age” (IA) for a corrosion task as of one year after December 17, 1993 (the effective date of AD 93-20-03, amendment 39-8710): Initial compliance must occur no later than the IA plus the repeat (R) interval.

(ii) For airplane areas that have exceeded the IA for a particular corrosion task, as of one year after December 17, 1993: Initial compliance must occur within one R interval for that task, measured from a date one year after December 17, 1993.

(iii) For airplanes that have reached or exceeded 20 years after the date of manufacture as of one year after December 17, 1993: Initial compliance must occur for each corrosion task within one R interval for that task, but not to exceed 6 years, measured from a date one year after December 17, 1993, whichever occurs first.

(iv) Notwithstanding paragraph (a)(1)(i), (a)(1)(ii), or (a)(1)(iii) of this AD, for airplane areas that exceed the IA for that area, the operator must accomplish the initial corrosion task for each such area at a minimum rate equivalent to one such area per year, beginning one year after December 17, 1993.

# Note 7:

This paragraph does not require inspection of any area that has not exceeded the IA for that area.

# Note 8:

This minimum rate requirement may cause an undue hardship on some small operators. In those circumstances, requests for adjustments to the implementation rate will be evaluated on a case-by-case basis under the provisions of paragraph (h) of this AD.

(2) Repeat each corrosion task at a time interval not to exceed the R interval specified in the Document for that task.

(b) As an alternative to the requirements of paragraph (a) of this AD: Prior to one year after December 17, 1993, revise the FAA-approved maintenance inspection program to include the corrosion prevention and control program specified in the Document; or to include an equivalent program that is approved by the FAA. In all cases, the initial corrosion task for each airplane area must be completed in accordance with the compliance schedule specified in paragraph (a)(1) of this AD. Corrosion task numbers C-32-710-01 (nose landing gear) and C-32-730-01 (main landing gear, left and right) are not required to be accomplished as part of this AD.

(1) Any operator complying with paragraph (b) of this AD may use an alternative recordkeeping method to that otherwise required by 14 CFR part 91.417 or part 121.380 for the actions required by this AD, provided it is approved by the FAA and is included in a revision to the FAA-approved maintenance inspection program.

(2) Subsequent to the accomplishment of the initial corrosion task, extensions of R intervals specified in the Document must be approved by the FAA.

## New Requirements of This AD

(c) Except as provided in paragraph (e) of this AD, within 5 years after the effective date of this AD: Complete each of the corrosion tasks at the times specified in paragraphs (c)(1), (c)(2), (c)(3), and (c)(4) of this AD in accordance with the procedures specified in the Document. (Corrosion tasks number C-32-710-01 (nose landing gear) and C-32-730-01 (main landing gear, left and right) are not required to be accomplished as part of this AD.)

# Note 9:

A “corrosion task,” as defined in Section 4 of the Document, includes inspections; procedures for a corrective action, including repairs, under identified circumstances; application of corrosion inhibitors; and other follow-on actions.

# Note 10:

Corrosion tasks completed in accordance with the Document before the effective date of this AD may be credited for compliance with the initial corrosion task requirements of paragraph (a)(1) of this AD.

# Note 11:

                                    Where non-destructive inspection (NDI) methods are employed, in accordance with Section 4 of the Document, the                                           ( print page 20763)                                        standards and procedures used must be acceptable to the Administrator in accordance with FAR Section 43.13.                                

(1) Accomplish corrosion tasks C-55-320-05 and C-55-330-05, per Revision D of the Document. Thereafter, accomplish these corrosion tasks at intervals not to exceed 5 years.

(2) Accomplish corrosion task C-57-540-02, per Revision D of the Document. Thereafter, accomplish this corrosion task at intervals not to exceed 5 years.

(3) Accomplish corrosion task C-57-530-04, per Revision D of the Document. Thereafter, accomplish this corrosion task at intervals not to exceed 5 years.

(4) Accomplish corrosion task C-53-310-03, per Revision D of the Document. Thereafter, accomplish this corrosion task at intervals not to exceed 10 years.

## Inspection of the Horizontal Stabilizer

(d) Within 15 years time-in-service or 5 years after the effective date of this AD, whichever occurs later: Conduct a free-play inspection of the horizontal stabilizer pivot bearing, disassemble ALL horizontal stabilizer pivot bearing assemblies, and perform a detailed visual inspection of the pivot bearing assembly components to detect corrosion, in accordance with the procedures specified in Task C-55-350-01 of Revision D of the Document. Thereafter, repeat this inspection at intervals not to exceed 5 years.

# Note 12:

This paragraph does not require inspection of any area that has not exceeded the IA for that area.

# Note 13:

For the purposes of this AD, a detailed visual inspection is defined as: “An intensive visual examination of a specific structural area, system, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at intensity deemed appropriate by the inspector. Inspection aids such as mirror, magnifying lenses, etc., may be used. Surface cleaning and elaborate access procedures may be required.”

## Acceptable Alternative Compliance With Certain Requirements

(e) As an alternative to the requirements of paragraph (c) and (d) of this AD: Within 90 days after the effective date of this AD, revise the FAA-approved maintenance program to incorporate and implement Revision D of Lockheed Document Number LR 31889, “Corrosion and Protection Control Program, TriStar L-1011”, dated August 15, 1999.

## Accommodating Scheduling Requirements

(f) To accommodate unanticipated scheduling requirements of paragraph (c) or (d) of this AD, it is acceptable for an R interval to be increased by up to 10%, but not to exceed 6 months. The FAA must be informed, in writing, of any such extension within 30 days after such adjustment of the schedule.

                                (g)(1) If, during any inspection conducted in accordance with this AD, Level 3 corrosion is determined to exist in any airplane area, accomplish the actions specified in either paragraph (g)(1)(i) or (g)(1)(ii) of this AD within 7 days after such determination. Information collection requirements contained in this regulation have been approved by the Office of Management and Budget (OMB) under the provisions of the Paperwork Reduction Act of 1980 (44 U.S.C. 3501*et seq.*) and have been assigned OMB Control Number 2120-0056.                            

(i) Submit a report of that determination to the FAA and complete the corrosion task in the affected areas on all Model L-1011 series airplanes in the operator's fleet; or

(ii) Submit to the FAA for approval one of the following:

(A) A proposed schedule for performing the corrosion tasks in the affected areas on the remaining Model L-1011 series airplanes in the operator's fleet, which is adequate to ensure that any other Level 3 corrosion is detected in a timely manner, along with substantiating data for that schedule; or

(B) Data substantiating that the Level 3 corrosion found is an isolated occurrence.

# Note 14:

                                    Notwithstanding the provisions of Section 1 of the Document, which would permit corrosion that otherwise meets the definition of Level 3 corrosion (                                    *i.e.,*                                     which is determined to be a potentially urgent airworthiness concern requiring expeditious action) to be treated as Level 1 if the operator finds that it “can be attributed to an event not typical of the operator's usage of other airplanes in the same fleet,” this paragraph requires that data substantiating any such finding be submitted to the FAA for approval.                                

(2) The FAA may impose schedules other than those proposed, upon finding that such changes are necessary to ensure that any other Level 3 corrosion is detected in a timely manner.

(3) Within the time schedule approved under paragraph (g)(1) or (g)(2) of this AD, accomplish the corrosion tasks in the affected areas of the remaining Model L-1011 series airplanes in the operators' fleet.

(h) If, as a result of any inspection after an initial inspection conducted in accordance with the requirements of this AD, it is determined that corrosion findings exceed Level 1 in any area, within 60 days after such determination, implement a means, approved by the FAA, to reduce future findings of corrosion in that area to Level 1 or better.

(i) Before any operator places into service any airplane subject to the requirements of this AD, a schedule for the accomplishment of corrosion tasks required by this AD must be established in accordance with paragraph (i)(1) or (i)(2) of this AD, as applicable:

(1) For airplanes previously maintained in accordance with this AD, the first corrosion task in each airplane area to be performed by the new operator must be accomplished in accordance with the previous operator's schedule or with the new operator's schedule, whichever would result in the earlier accomplishment date for that task. After each corrosion task has been performed once, each subsequent task must be performed in accordance with the new operator's schedule.

(2) For airplanes that have not been previously maintained in accordance with this AD, the first corrosion task for each airplane area to be performed by the new operator must be accomplished prior to further flight or in accordance with a schedule approved by the FAA.

(j) Reports of Level 2 and Level 3 corrosion must be submitted at least quarterly to Lockheed Aeronautical Systems in accordance with Section 5 of Revision 4 of the Document.

# Note 15:

Reporting of Level 2 and Level 3 corrosion found as a result of any opportunity inspections is highly desirable.

## Alternative Methods of Compliance

(k) 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. 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 16:

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

(l) 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 April 18, 2001.

Donald L. Riggin,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

[FR Doc. 01-10181 Filed 4-24-01; 8:45 am]

BILLING CODE 4910-13-P