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###### Department of Transportation

###### Federal Aviation Administration 

          - 14 CFR Part 39 
          - [Docket No. 99-NM-164-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 certain McDonnell Douglas Model DC-9-80 series airplanes and Model MD-88 airplanes, that currently requires a one-time inspection to detect cracking of the main landing gear (MLG) pistons, and repair or replacement of the pistons with new or serviceable parts, if necessary. This action would require, among other actions, repetitive dye penetrant and magnetic particle inspections to detect cracks of the MLG pistons; repair and replacement of discrepant parts; and installation of a preventative modification; as applicable. This action also would provide for an optional terminating action for certain MLG pistons. This proposal is prompted by additional reports of failure of the MLG pistons during towing of the airplanes. The actions specified by the proposed AD are intended to prevent fatigue cracking of the MLG pistons, which could result in failure of the pistons and subsequent damage to the airplane structure or injury to airplane occupants. 

# DATES:

Comments must be received by November 20, 2000. 

# ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 99-NM-164-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. 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. 99-NM-164-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 Boeing Commercial Aircraft Group, Long Beach Division, 3855 Lakewood Boulevard, Long Beach, California 90846, Attention: Technical Publications Business Administration, Dept. C1-L51 (2-60). This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California. 

# FOR FURTHER INFORMATION CONTACT:

Brent Bandley, Aerospace Engineer, Airframe Branch, ANM-120L, FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California 90712; telephone (310) 627-5237; fax (310) 627-5210. 

# 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. 

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 notice must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 99-NM-164-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-164-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. 

## Discussion 

On September 5, 1996, the FAA issued AD 96-19-09, amendment 39-9756 (61 FR 48617, September 16, 1996), applicable to certain McDonnell Douglas Model DC-9-80 series airplanes and Model MD-88 airplanes, to require a one-time inspection to detect cracking of the main landing gear (MLG) pistons, and repair or replacement of the pistons with new or serviceable parts, if necessary. That action was prompted by reports of failure of the MLG pistons that occurred during towing of the airplanes. The requirements of that AD are intended to prevent fatigue cracking of the MLG pistons, which could result in failure of the pistons and subsequent damage to the airplane structure or injury to airplane occupants. 

## Actions Since Issuance of Previous Rule 

                    Since the issuance of AD 96-19-09, the FAA has received additional reports of cracked MLG pistons on the affected airplanes. The FAA has determined that the one-time inspection of the MLG                           ( print page 59147)                        pistons required by AD 96-19-09 does not adequately preclude fatigue cracking of the MLG pistons. Also, Boeing has completed its assessment to establish a life limit for the MLG pistons affected by this AD.                 

## Explanation of Relevant Service Information 

                    The manufacturer issued, and the FAA reviewed and approved, McDonnell Douglas Service Bulletin MD80-32-277, Revision 04, dated December 7, 1999. The service bulletin describes a new life limit (                    *i.e.,*                     30,000 or 60,000 total landings, as applicable) for the affected MLG pistons. The service bulletin also describes the following improved procedures for the affected airplanes depending on the configuration:                 
    - Performing repetitive dye penetrant and magnetic particle inspections to detect cracks of the MLG pistons. And
    - Performing a preventative modification that involves various inspections to detect cracks of the MLG pistons; repair and replacement of discrepant parts, as applicable; wet grinding the rework area; flap shot peening the rework area; and reidentifying the MLG pistons. Accomplishment of the preventative modification stops the repetitive dye penetrant and magnetic particle inspections. And
    - Flap shot peening, replacing the MLG piston with a new or serviceable MLG piston, and contacting Boeing for certain conditions.

## 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 96-19-09 to require accomplishment of the actions specified in the service bulletin described previously, except as described below. 

## Error in Referenced Service Bulletin 

For Group 1 airplanes, the referenced service bulletin incorrectly refers to paragraph 1.E. for the repetitive inspection schedule for Condition 3, Option 1 of the Accomplishment Instructions. Paragraph 1.E. does not contain such a repetitive inspection schedule. 

## Differences Between Proposed Rule and Service Bulletin 

                    The effectivity listing of the referenced service bulletin lists the affected airplanes by groups (                    *i.e.,*                     Group 1, Group 2, and Group 3). The FAA finds that Group 1 and 2 airplanes do not include all of the affected modified pistons. For Groups 1 and 2, the referenced service bulletin only refers to pistons that have been inspected, replaced, or modified per prior issues of the service bulletin. However, affected pistons may have been modified per other service documents in addition to previous revisions of the referenced service bulletin. Also, the FAA finds no need to specifically reference MLG pistons that have been inspected or replaced per prior issues of the service bulletin, because the only thing that defines Groups 1 and 2 is whether the affected piston has been modified. The FAA also finds that Groups 1 and 2 of the referenced service bulletin do not include the specific affected MLG pistons [                    *i.e.,*                     part number (P/N) 5935347-1 through 5935347-509 inclusive]. Therefore, this proposed AD references the specific affected MLG pistons and whether that piston has been modified, rather than the airplanes specified in the service bulletin.                 

Operators also should note that, although the referenced service bulletin specifies that the manufacturer may be contacted for disposition of certain repair conditions, this proposed AD would require the repair of those conditions to be accomplished in accordance with a method approved by the FAA. 

The referenced service bulletin also specifies that landing gear pistons, modified per one of the following conditions, are acceptable as having complied with the intent of the service bulletin: 

1. As a result of procedure verification; 

2. As a repair per operator's inquiry and Boeing disposition; or 

3. As a preventative modification accomplished by operators who participated in the procedure verification prior to the issuance of this service bulletin revision. However, this proposed AD would require accomplishment of the actions in accordance with the procedures specified in the referenced service bulletin. Any other procedure may be used only if approved as an alternative method of compliance in accordance with paragraph (m) of this AD. 

The referenced service bulletin recommends performing repetitive visual inspections to detect cracks in the topcoat paint of the MLG piston, performing a non-destructive testing (NDT) inspection, and contacting Boeing, if necessary. The FAA has determined that the repetitive inspections of the MLG pistons and eventual preventative modification required by this proposed AD adequately addresses the identified unsafe condition for the interim. Therefore, the repetitive visual inspections of the topcoat paint and NDT inspection are not required by the proposed AD. 

For any piston having P/N 5935347-511 that has accumulated 30,000 or more total landings, the referenced service bulletin recommends either replacing the MLG piston with a new or serviceable MLG piston or contacting Boeing. The FAA has consulted with Boeing and determined that any piston having P/N 5935347-511 that has accumulated 30,000 or more total landings must be replaced. Therefore, the proposed AD only requires replacement of those pistons. 

Operators also should note that, unlike the referenced service bulletin, the proposed AD provides for an optional terminating action for the requirements of the AD. The optional terminating action involves replacing all MLG pistons with MLG pistons having P/N 5935347-517, which are redesigned pistons that will adequately address the identified unsafe condition. 

## Interim Action 

This is considered to be interim action. The manufacturer has advised that it currently is developing a replacement schedule to eventually remove all affected MLG pistons from the fleet and replace them with redesigned MLG pistons. Once this replacement schedule is developed, approved, and available, the FAA may consider additional rulemaking. 

## Cost Impact 

There are approximately 1,200 Model DC-9-80 series airplanes and Model MD-88 airplanes of the affected design in the worldwide fleet. The FAA estimates that 700 airplanes of U.S. registry would be affected by this proposed AD. 

Should an operator be required to do the dye pernetrant and magnetic particle inspections, it would take approximately 2 work hours per MLG piston to accomplish the inspections, at an average lavor rate of $60 per work hour. Based on thes figures, the cost impact of these inspections proposed by this AD on U.S. operators is estimated to be $120 per MLG piston. 

                    Should an operator be required to do the preventative modidfication, it would take approximately 6 work hours per MLG piston to accomplish the inspections, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of these inspections proposed by this AD on U.S.                           ( print page 59148)                        operators is estimated to be $36 per MLG piston.                 

The cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the current or proposed 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. 

Should an operator elect to accomplish the optional terminating action that would be provided by this AD action, it would take approximately 31 work hours per MLG piston to accomplish it, at an average labor rate of $60 per work hour. The cost of required parts would be approximately $107,070 per MLG piston. Based on these figures, the cost impact of the optional terminating action would be $108,930 per MLG piston. 

## 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 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 39-9756 (61 FR 48617, September 16, 1996), and by adding a new airworthiness directive (AD), to read as follows: 

**McDonnell Douglas:**                                 Docket 99-NM-164-AD. Supersedes AD 96-19-09, Amendment 39-9756.                             

*Applicability:*                                 Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), and DC-9-87 (MD-87) series airplanes; and Model MD-88 airplanes; as listed in McDonnell Douglas Service Bulletin MD80-32-277, Revision 04, dated December 7, 1999; 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 (m)(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 fatigue cracking of the main landing gear (MLG) pistons, which could result in failure of the pistons and subsequent damage to the airplane structure or injury to airplane occupants, accomplish the following: 

## For Airplanes on Which Certain Pistons Have Not Been Modified: Inspections 

(a) For airplanes on which any MLG piston, part number (P/N) 5935347-1 through 5935347-509 inclusive, has NOT been modified: Do the actions specified in paragraph (a)(1), (a)(2), or (a)(3) of this AD, as applicable, per the Accomplishment Instructions of McDonnell Douglas Service Bulletin MD80-32-277, Revision 04, dated December 7, 1999. 

(1) For any MLG piston that has accumulated less than 5,000 total landings since date of manufacture: Prior to the accumulation of 5,000 total landings on the MLG piston, or within 12 months after the effective date of this AD, whichever occurs later, do dye penetrant and magnetic particle inspections to detect cracks of the MLG pistons. 

(2) For any MLG piston that has accumulated 5,000 or more total landings since date of manufacture, but less than 30,000 total landings since date of manufacture: Within 1,500 landings on the MLG piston or 12 months after the effective date of this AD, whichever occurs later, do dye penetrant and magnetic particle inspections to detect cracks of the MLG pistons. 

(3) For any MLG piston that has accumulated 30,000 or more total landings since date of manufacture: Within 2 years or 5,000 landings on the MLG piston after the effective date of this AD, whichever occurs first, do the preventative modification (including inspections; corrective actions, if necessary; wet grind rework area; flap shot peen rework area; and reidentify the MLG pistons); except as required by paragraph (k) of this AD. Following accomplishment of the preventative modification, do the actions specified in paragraph (e) at the time indicated in that paragraph. 

## For Airplanes on Which Certain Pistons Have Not Been Modified: Condition 1 (No Crack) 

(b) If no crack is found during any inspection required by either paragraph (a)(1) or (a)(2) of this AD, do the actions specified in either paragraph (b)(1) or (b)(2) of this AD. 

(1) Condition 1, Option 1. Do the actions specified in either paragraph (b)(1)(i) or (b)(1)(ii) of this AD, and in paragraph (b)(1)(iii) of this AD. 

(i) Repeat the inspections required by either paragraph (a)(1) or (a)(2) of this AD thereafter at intervals not to exceed 1,500 landings until the permanent modification required by paragraph (b)(1)(iii) of this AD has been done. 

(ii) Before further flight, do the flap shot peening per McDonnell Douglas Service Bulletin MD80-32-277, Revision 04, dated December 7, 1999. Repeat the inspections required by either paragraph (a)(1) or (a)(2) of this AD thereafter at intervals not to exceed 2,500 landings until the permanent modification required by paragraph (b)(1)(iii) of this AD has been done. 

(iii) Prior to the accumulation of 30,000 or more total landings on the MLG piston, do the preventative modification (including inspections; corrective actions, if necessary; wet grind rework area; flap shot peen rework area; and reidentify the MLG pistons), per the Accomplishment Instructions of McDonnell Douglas Service Bulletin MD80-32-277, Revision 04, dated December 7, 1999; except as required by paragraph (k) of this AD. Accomplishment of the permanent modification stops the repetitive inspection requirements of paragraphs (b)(1)(i) and (b)(1)(ii) of this AD. Following accomplishment of the preventative modification, do the actions specified in paragraph (e) at the time indicated in that paragraph. 

                                (2) Condition 1, Option 2. Before further flight, do the preventative modification (including inspections; corrective actions, if necessary; wet grind rework area; flap shot peen rework area; and reidentify the MLG pistons) per Condition 1, Option 2, of the Accomplishment Instructions of McDonnell                                       ( print page 59149)                                    Douglas Service Bulletin MD80-32-277, Revision 04, dated December 7, 1999; except as required by paragraph (k) of this AD. Following accomplishment of the preventative modification, do the actions specified in paragraph (e) at the time indicated in that paragraph.                             

## For Airplanes on Which Certain Pistons Have Not Been Modified: Condition 2 (Any Crack Within Limits) 

(c) If any crack is found during any inspection required by either paragraph (a)(1) or (a)(2) of this AD, and that crack is within the limits specified in McDonnell Douglas Service Bulletin MD80-32-277, Revision 04, dated December 7, 1999, before further flight, do the action(s) specified in either paragraph (c)(1) or (c)(2) of this AD. 

(1) Do the preventative modification (including inspections; corrective actions, if necessary; wet grind rework area; flap shot peen rework area; and reidentify the MLG pistons) per the Accomplishment Instructions of the service bulletin; except as required by paragraph (k) of this AD. Following accomplishment of the preventative modification, do the actions specified in paragraph (e) or (h) of this AD, as applicable, at the time indicated in that paragraph. 

(2) Replace the MLG piston with a new or serviceable MLG piston per the service bulletin. Following accomplishment of the replacement, do the actions specified in paragraph (a), (e), or (h) of this AD, as applicable, at the time indicated in that paragraph. 

## For Airplanes on Which Certain Pistons Have Not Been Modified: Condition 3 (Any Crack Outside Limits) 

(d) If any crack is found during any inspection required by either paragraph (a)(1) or (a)(2) of this AD that is outside the limits specified in McDonnell Douglas Service Bulletin MD80-32-277, Revision 04, dated December 7, 1999, before further flight, do the action(s) specified in paragraph (d)(1) or (d)(2) of this AD. 

(1) Condition 3, Option 1. Replace the MLG piston with a new or serviceable MLG piston per the service bulletin. Following accomplishment of the replacement, do the actions specified in paragraph (a), (e), or (h) of this AD, as applicable, at the time indicated in that paragraph. 

(2) Condition 3, Option 2. Repair per a method approved by the Manager, Los Angeles Aircraft Certification Office (ACO), FAA. 

## For Airplanes on Which Certain Pistons Have Been Modified: Replacement or Inspections and Corrective Actions, If Necessary 

(e) For airplanes on which any MLG piston, part number (P/N) 5935347-1 through 5935347-509 inclusive, has been modified: 

(1) For any MLG piston that has accumulated 30,000 or more landings since accomplishment of the modification: Within 6 months after the effective date of this AD, replace the MLG piston with a new or serviceable MLG piston per the service bulletin. Following accomplishment of the replacement, do the actions specified in paragraph (a), (e), or (h) of this AD, as applicable, at the time indicated in that paragraph. 

(2) For any MLG piston that has accumulated less than 30,000 landings since accomplishment of the modification: Do dye penetrant and magnetic particle inspections to detect cracks of the MLG pistons, per the Accomplishment Instructions of McDonnell Douglas Service Bulletin MD80-32-277, Revision 04, dated December 7, 1999; at the applicable time(s) specified in paragraph (e)(2)(i) or (e)(2)(ii) of this AD. 

(i) For any MLG piston that has been modified per paragraph (a)(3), (b)(1)(iii), (b)(2), or (c)(1) of this AD, or that has been replaced with a modified MLG piston per paragraph (c)(2) or (d)(1) of this AD: Inspect within 2,500 landings following accomplishment of the modification or replacement with a modified MLG piston. 

(ii) For any MLG piston that has been modified prior to the effective date of this AD: Inspect within 1,500 landings or 12 months after the effective date of this AD, whichever occurs later. 

(f) If no crack is found during any inspection required by paragraph (e)(2) of this AD, repeat the dye penetrant and magnetic particle inspections required by paragraph (e)(2) of this AD thereafter at intervals not to exceed 2,500 landings. Prior to the accumulation of 30,000 or more total landings on the MLG piston, replace the MLG piston with a new or serviceable MLG piston per the Accomplishment Instructions of McDonnell Douglas Service Bulletin MD80-32-277, Revision 04, dated December 7, 1999. Following accomplishment of the replacement, do the actions specified in paragraph (a), (e), or (h) of this AD, as applicable, at the time indicated in that paragraph. 

(g) If any crack is found during any inspection required by paragraph (e)(2) of this AD, before further flight, do the action(s) specified in either paragraph (d)(1) or (d)(2) of this AD. 

## For Airplanes on Which a Certain Piston Has Been Installed 

(h) For airplanes on which any MLG piston, P/N 5935347-511, has been installed: Do the actions specified in paragraph (h)(1), (h)(2), or (h)(3) of this AD, as applicable, per the Accomplishment Instructions of McDonnell Douglas Service Bulletin MD80-32-277, Revision 04, dated December 7, 1999. 

(1) For any MLG piston that has accumulated less than 5,000 total landings since date of manufacture: Prior to the accumulation of 5,000 total landings on the MLG piston, or within 12 months after the effective date of this AD, whichever occurs later, do dye penetrant and magnetic particle inspections to detect cracks of the MLG pistons. 

(2) For any MLG piston that has accumulated 5,000 or more total landings since date of manufacture, but less than 30,000 total landings since date of manufacture: Within 1,500 landings on the MLG piston or 12 months after the effective date of this AD, whichever occurs later, do dye penetrant and magnetic particle inspections to detect cracks of the MLG pistons. 

(3) For any MLG piston that has accumulated 30,000 or more total landings since date of manufacture: Within 6 months after the effective date of this AD, replace the MLG piston with a new or serviceable MLG piston per the service bulletin. Following accomplishment of the replacement, do the actions specified in paragraph (a), (e), or (h) of this AD, as applicable, at the time indicated in that paragraph. 

(i) If no crack is found during any inspection required by either paragraph (h)(1) or (h)(2) of this AD, repeat the dye penetrant and magnetic particle inspections required by either paragraph (h)(1) or (h)(2) of this AD thereafter at intervals not to exceed 2,500 landings. Prior to the accumulation of 30,000 or more total landings on the MLG piston, do the actions specified in paragraph (d)(1) of this AD. 

(j) If any crack is found during any inspection required by either paragraph (h)(1) or (h)(2) of this AD, before further flight, do the action(s) specified in either paragraph (d)(1) or (d)(2) of this AD. 

## Exception to Actions Referenced in Service Bulletin 

(k) If any discrepancy is found during any inspection while accomplishing the preventative modification required by this AD, prior to further flight, do applicable corrective action(s) per McDonnell Douglas Service Bulletin MD80-32-277, Revision 04, dated December 7, 1999. If the service bulletin specifies to contact the manufacturer for appropriate  action: Prior to further flight, repair in accordance with a method approved by the Manager, Los Angeles ACO. For a repair method to be approved by the Manager, Los Angeles ACO, as required by this paragraph, the Manager's approval letter must specifically reference this AD. 

## Optional Terminating Action 

(l) Replacement of any MLG piston with a MLG piston, P/N 5935347-517, per McDonnell Douglas Service Bulletin MD80-32-277, Revision 04, dated December 7, 1999; constitutes terminating action for the requirements of this AD for that MLG piston. 

## Alternative Methods of Compliance 

(m)(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, Los Angeles ACO. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Los Angeles ACO. 

# Note 2:

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

(2) Alternative methods of compliance, approved previously in accordance with AD 96-19-09, amendment 39-9756, are approved as alternative methods of compliance with this AD. 

## Special Flight Permits 

                                (n) Special flight permits may be issued in accordance with sections 21.197 and 21.199                                       ( print page 59150)                                    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 September 28, 2000. 

Donald L. Riggin, 

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. 

[FR Doc. 00-25434 Filed 10-3-00; 8:45 am] 

BILLING CODE 4910-13-P