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Proposed Rule

Airworthiness Directives; McDonnell Douglas Model DC-9-10, -20, -30, -40, and -50 Series Airplanes

Document Details

Information about this document as published in the Federal Register.

Published Document

This document has been published in the Federal Register. Use the PDF linked in the document sidebar for the official electronic format.

Start Preamble

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Supplemental notice of proposed rulemaking; reopening of comment period.

SUMMARY:

This document revises an earlier proposed airworthiness directive (AD), applicable to certain McDonnell Douglas Model DC-9-10, -20, -30, -40, and -50 series airplanes, and C-9 (military) airplanes, that would have required, among other actions, various inspections to detect cracks of the cockpit enclosure window sill, and follow-on and corrective actions, as applicable. This new action revises the proposed rule by revising certain procedures and clarifying the proposed requirements. The actions specified by this new proposed AD are intended to prevent fatigue cracking of the internal doublers and frame structure of the fuselage skin of the cockpit enclosure window sill, which could result in rapid decompression of the fuselage and consequent reduced structural integrity of the airplane. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by August 6, 2002.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2000-NM-57-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-57-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: Data and Service Management, Dept. C1-L5A (D800-0024). 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.

Start Further Info

FOR FURTHER INFORMATION CONTACT:

Technical Information: Wahib Mina, Aerospace Engineer, Airframe Branch, ANM-120L, FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California 90712; telephone (562) 627-5324; fax (562) 627-5210.

Other Information: Judy Golder, Airworthiness Directive Technical Editor/Writer; telephone (425) 687-4241, fax (425) 227-1232. Questions or comments may also be sent via the Internet using the following address: judy.golder@faa.gov. Questions or comments sent via the Internet as attached electronic files must be formatted in Microsoft Word 97 for Windows or ASCII text.

End Further Info End Preamble Start Supplemental Information

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 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-57-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-57-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to add an airworthiness directive (AD) applicable to certain McDonnell Douglas Model DC-9-10, -20, -30, -40, and -50 series airplanes and C-9 (military) airplanes was published as a notice of proposed rulemaking (NPRM) in the Federal Register on September 18, 2000 (65 FR 56270). That NPRM would have required, among other actions, various inspections to detect cracks of the cockpit enclosure window sill, and follow-on and corrective actions, as Start Printed Page 46933applicable. That NPRM was prompted by reports of cracking of the internal doublers and frame structure of the fuselage skin of the cockpit enclosure window sill. That condition, if not corrected, could result in rapid decompression of the fuselage and consequent reduced structural integrity of the airplane.

Actions Since Issuance of NPRM

Since the issuance of that NPRM, the FAA has reviewed and approved Boeing Service Bulletin DC9-53-290, Revision 01, dated March 15, 2002. (The original NPRM referred to McDonnell Douglas Service Bulletin DC9-53-290, dated December 14, 1999, as the appropriate source of service information for the proposed actions.) Revision 01 of the service bulletin incorporates changes made to a certain service rework drawing based on Non-Destructive Testing analysis and operator experience. These changes have resulted in the following revisions in Revision 01 of the service bulletin:

  • Changes to certain inspection methods and parts to be inspected.
  • Clarification of certain inspection procedures, criteria, and areas.
  • Revision of kit information and the addition of new kits and parts.
  • Deferral of the inspection of certain parts that cannot be inspected without extensive disassembly of the airplane until the permanent repair is done.

Revision 01 of the service bulletin now describes the following procedures:

  • A visual inspection to determine if certain temporary repairs have been installed.
  • A visual inspection to detect loose or missing fasteners or cracks of the upper nose skins of the cockpit.
  • A high frequency eddy current (HFEC) inspection for cracking of Zees, and replacement of cracked Zees with new parts.
  • Visual, borescope, and HFEC inspections for cracking of the skins and frames.

The service bulletin also describes applicable follow-on and corrective actions, which include:

  • If no cracks and no previous repairs are found—Repeating the previously accomplished visual, borescope, and HFEC inspections for cracking (Condition 1, Option 1).
  • If cracks within certain limits are found—Accomplishing a temporary repair (including installation of external doublers), and performing repetitive visual inspections for cracking of skins and external doublers and repetitive borescope and HFEC inspections for cracking of internal structure (Condition 2, Option 1).
  • If certain existing temporary repairs are found—Performing repetitive visual inspections for cracking of skins and external doublers and repetitive borescope and HFEC inspections for cracking of internal structure, accomplishing a one-time inspection of existing repairs of certain frames for growth of cracks beyond the repair angles, and replacing frames with new frames if necessary (Condition 3, Option 1).

For all airplanes except those on which no cracking or previous temporary repair is found, the service bulletin recommends accomplishing a permanent repair (including visual and eddy current inspections, and repair replacement, or rework of various parts, if necessary). The recommended compliance time for such permanent repair varies by condition. Installing the permanent repair eliminates the need to perform repetitive inspections at the pre-permanent-repair intervals, but the service bulletin recommends eventual accomplishment of certain inspections to find cracks of the permanent repair area.

Accomplishment of the actions specified in Revision 01 of the service bulletin is intended to adequately address the identified unsafe condition.

Comments

Due consideration has been given to the comments received in response to the original NPRM.

No Objection to Proposed AD

One commenter, an operator, states that the proposed AD would not apply to its fleet and offers no additional comments on the original NPRM.

Another commenter states that it has no objection to the proposed AD because it is anticipating that all affected airplanes in its fleet will be retired before the compliance time. However, the commenter did offer several comments on the original NPRM.

Refer to Revised Service Information and Clarify Requirements of Proposed AD

One commenter makes numerous suggestions for revisions to the original NPRM. The commenter requests that the FAA revise the proposed AD to refer to Revision 01 of the service bulletin, described previously, “or later approved revisions” as the appropriate source of service information for the proposed actions. The commenter also suggests numerous editorial changes to the original NPRM.

We concur that it is necessary to revise this supplemental NPRM to refer to Revision 01 of the service bulletin. Based on the new service bulletin and for further clarification, we have reordered and reidentified many of the paragraphs in this supplemental NPRM. We also have considered the commenter's editorial suggestions and, where we agree that they provide clarification, we have incorporated such changes. (Due to the extensive revisions of the original NPRM, we find it is necessary to reopen the comment period to give interested parties additional opportunity to comment on the proposal.)

With regard to the commenter's request to refer to “later approved revisions” of the service bulletin, we do not concur. The use of that phrase violates Office of the Federal Register (OFR) regulations regarding approval of materials that are incorporated by reference. An AD may only refer to a service document that is submitted and approved by the OFR for “incorporation by reference.” For operators to use later revisions of the referenced document (issued after the publication of the AD), either the AD must be revised to refer to the specific later revisions, or request for approval of the use of the later revisions must be requested as an alternative method of compliance (AMOC) with the AD (e.g., under the provisions of paragraph (j)(1) of this supplemental NPRM). We have made no change to the supplemental NPRM in this regard.

Clarify Compliance Time for Airplanes With Previously Installed Repairs

One commenter requests that we clarify the compliance time in paragraph (g)(1) of the original NPRM. (The provisions of paragraph (g)(1) of the original NPRM are included under paragraph (d)(1) of this supplemental NPRM.) Paragraph (g)(1) of the original NPRM applies to airplanes on which certain temporary repairs have been installed previously. That paragraph refers to other paragraphs in the original NPRM that specify accomplishment of various inspections within 2,000 and 3,500 landings after installation of the temporary repair. The commenter points out that this proposed compliance time may conflict with the initial compliance time in paragraph (a)(1) of the original NPRM—i.e., the later of 40,000 total landings or 5,000 landings after the effective date of the AD. The commenter provides the example that, if a temporary repair was installed before the effective date of the proposed AD, and the initial inspection in the proposed AD was not done until after 3,500 landings after the effective date of the AD, the airplane would be out of Start Printed Page 46934compliance with the proposed AD. The commenter states that the original NPRM should be revised to direct operators to accomplish repetitive inspections of existing temporary repairs at the applicable intervals, commencing at the time of the initial inspections specified in paragraph (a) of the proposed AD.

We have reviewed paragraph (g)(1) of the original NPRM and concur that we need to clarify the compliance time for the requirements proposed in that paragraph. We have revised the relevant paragraphs in this supplemental NPRM to specify a compliance time for the general visual inspection of 2,000 landings after the temporary repair, or before further flight after accomplishment of the initial inspections specified in paragraph (a) of this supplemental NPRM, whichever is later, and a compliance time for the borescope and HFEC inspections of 3,500 landings after the temporary repair, or before further flight after accomplishment of the initial inspections specified in paragraph (a) of this supplemental NPRM, whichever is later.

Clarify Appropriate Source of Repair Instructions

One commenter requests that we revise several paragraphs of the original NPRM to refer to the correct section of the service bulletin for repair instructions. As an example, the commenter notes that paragraph (c) of the original NPRM, which describes actions for airplanes with cracking within certain limits, specifies to repair cracks per paragraph (b)(2) of the original NPRM. That paragraph, in turn, specifies accomplishment of the permanent repair specified in Condition 1, Option 2. However, Condition 1, Option 2 of the accomplishment instructions of the service bulletin provides repair instructions for airplanes with no cracks and no previous repairs. The commenter requests that we revise paragraphs (c), (f), (g)(2), and (i) of the original NPRM to refer to the correct source of repair instructions in the service bulletin.

We concur. As explained previously, we have restructured this supplemental NPRM to take into account the changes in Revision 01 of the service bulletin, and this supplemental NPRM contains correct references to the repair instructions in the service bulletin.

Explanation of Other Change Made to the Proposed AD

Paragraph (j) of this supplemental NPRM (which appeared as paragraph (k) of the original NPRM) includes a new subparagraph. Paragraph (j)(2) of this supplemental NPRM is added to specify that “an AMOC for any inspection or repair required by this [proposed] AD that provides an acceptable level of safety may be used per data meeting the type certification basis of the airplane approved by a Boeing Company Designated Engineering Representative who has been authorized by the Manager, Los Angeles ACO, to make such findings.” For a repair method to be approved, the approval must specifically reference this AD.

Explanation of New Requirements of Proposed AD

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 Revision 01 of the service bulletin described previously, except as discussed below.

Differences Between Supplemental NPRM and Service Information

Operators should note that, although the service bulletin specifies that the manufacturer should 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.

Also, the service bulletin specifies a “visual” inspection for cracking of the skins and frames. We find that the procedures involved in that inspection constitute a “detailed” inspection. A definition of “detailed inspection” is included in Note 4 of this supplemental NPRM.

Further, though the service bulletin describes procedures for inspections to eventually be performed following installation of the permanent repair, the service bulletin does not clearly identify procedures for addressing any crack found in these follow-on inspections. Therefore, if any crack is found during the follow-on inspections after installation of the permanent repair, the proposed AD would require a repair to be accomplished in accordance with a method approved by the FAA.

Conclusion

Since the changes described previously may expand the scope of the originally proposed rule, the FAA has determined that it is necessary to reopen the comment period to provide additional opportunity for public comment.

Cost Impact

There are approximately 809 Model DC-9-10, -20, -30, -40, and -50 series airplanes and C-9 (military) airplanes of the affected design in the worldwide fleet. The FAA estimates that 572 airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately 4 work hours per airplane to accomplish the proposed initial inspections, and that the average labor rate is $60 per work hour. Based on these figures, the cost impact of the proposed AD on U.S. operators is estimated to be $137,280, or $240 per airplane.

The cost impact figure discussed above is 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 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.

Start List of Subjects

List of Subjects in 14 CFR Part 39

End List of Subjects Start Printed Page 46935

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:

Start Part

PART 39—AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

Start Authority

Authority: 49 U.S.C. 106(g), 40113, 44701.

End Authority
[Amended]

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

McDonnell Douglas: Docket 2000-NM-57-AD.

Applicability: Model DC-9-11, DC-9-12, DC-9-13, DC-9-14, DC-9-15, DC-9-15F, DC-9-21, DC-9-31, DC-9-32, DC-9-32 (VC-9C), DC-9-32F, DC-9-32F (C-9A, C-9B), DC-9-33F, DC-9-34, DC-9-34F, DC-9-41, and DC-9-51 airplanes; listed in Boeing Service Bulletin DC9-53-290, Revision 01, dated March 15, 2002; 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 (j) 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 internal doublers and frame structure of the fuselage skin of the cockpit enclosure window sill, which could result in rapid decompression of the fuselage and consequent reduced structural integrity of the airplane, accomplish the following:

Note 2:

Where there are differences between the AD and the referenced service bulletin, the AD prevails.

Initial Inspections

(a) Before the accumulation of 40,000 total landings, or within 5,000 landings after the effective date of this AD, whichever occurs later, do the actions specified in paragraphs (a)(1) AND (a)(2) of this AD per the Accomplishment Instructions of Boeing Service Bulletin DC9-53-290, Revision 01, dated March 15, 2002.

(1) Do a general visual inspection to determine if any existing repair of the internal doublers and frame structure of the fuselage skin of the cockpit enclosure window sill has been accomplished before the effective date of this AD.

Note 3:

For the purposes of this AD, a general visual inspection is defined as: “A visual examination of an interior or exterior area, installation, or assembly to detect obvious damage, failure, or irregularity. This level of inspection is made from within touching distance unless otherwise specified. A mirror may be necessary to enhance visual access to all exposed surfaces in the inspection area. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight, or droplight and may require removal or opening of access panels or doors. Stands, ladders, or platforms may be required to gain proximity to the area being checked.”

(2) Do inspections to detect cracks or loose or missing fasteners of the cockpit enclosure window sill per paragraphs 3.B.1. through 3.B.6. of the Accomplishment Instructions of the service bulletin. The inspections include a general visual inspection to detect loose or missing fasteners or cracks of the upper nose skins of the cockpit; a high frequency eddy current (HFEC) inspection for cracking of Zees; and detailed, borescope, and HFEC inspections for cracking of the skins and frames.

Note 4:

For the purposes of this AD, a detailed 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.”

Note 5:

If any cracked Zee is found during any inspection per paragraph (a)(2) of this AD, refer to paragraph (h) of this AD.

Condition 1 (No Previous Repair and No Crack)

(b) If no previous repair and no crack is found during the inspections required by paragraphs (a)(1) and (a)(2) of this AD: Do the actions specified in paragraph (b)(1) or (b)(2) of this AD, at the times specified in those paragraphs.

Condition 1, Option 1: Repetitive Inspections

(1) Condition 1, Option 1: Repeat the inspections required by paragraph (a)(2) of this AD every 5,000 landings, until paragraph (b)(2) of this AD is done. If any crack is found, determine the applicable Condition as specified in the Accomplishment Instructions of Boeing Service Bulletin DC9-53-290, Revision 01, dated March 15, 2002, and do the applicable actions required by this AD.

Condition 1, Option 2: Permanent Repair

(2) Condition 1, Option 2: Do paragraphs (b)(2)(i) and (b)(2)(ii) of this AD.

(i) Before further flight, do all actions associated with the permanent repair (including detailed and eddy current inspections of various parts; and repair, replacement, or rework of those parts, as applicable) per Condition 1, Option 2 of the Accomplishment Instructions of Boeing Service Bulletin DC9-53-290, Revision 01, dated March 15, 2002. This terminates the repetitive inspections per paragraph (b)(1) of this AD.

Note 6:

Boeing Service Bulletin DC9-53-290, Revision 01, dated March 15, 2002, refers to Boeing Service Rework Drawing SR09530268, Revision D, dated November 29, 2001, as an additional source of service information for identifying parts to be inspected, and repairing, replacing, or reworking those parts.

(ii) Within 40,000 landings after doing the permanent repair required by paragraph (b)(2)(i) of this AD, repeat the inspections specified in paragraph (a)(2) of this AD to detect any crack of the completed repair, per the Accomplishment Instructions of the service bulletin. If no crack is found, repeat the inspections specified in paragraph (a)(2) of this AD every 5,000 landings. If any crack is found, do paragraph (g) of this AD.

Condition 2 (Any Crack Within Flyable Limits for Temporary Repair)

(c) If any crack is found during the initial inspection required by paragraph (a)(2) of this AD or during any repetitive inspection required by paragraph (b)(1) of this AD, and that crack is WITHIN the flyable limits specified in Condition 2 of the Accomplishment Instructions of Boeing Service Bulletin DC9-53-290, Revision 01, dated March 15, 2002: Do the actions specified in paragraph (c)(1) OR (c)(2) of this AD.

Note 7:

Boeing Service Bulletin DC9-53-290, Revision 01, dated March 15, 2002, refers to Boeing Service Rework Drawing SR09530268, Revision D, dated November 29, 2001, as the source for determining flyable limits.

Condition 2, Option 1: Temporary Repair and Repetitive Inspections

(1) Condition 2, Option 1: Do paragraphs (c)(1)(i), (c)(1)(ii), (c)(1)(iii), and (c)(1)(iv) of this AD, at the times specified in those paragraphs.

(i) Before further flight, do the temporary repair (including installation of doublers) per Condition 2, Option 1, of the Accomplishment Instructions of the service bulletin.

(ii) Within 2,000 landings after doing the temporary repair, do a general visual inspection to detect cracks of the skins and external doublers. If NO crack is found that is outside the flyable limits specified in Condition 2 of the Accomplishment Instructions of the service bulletin, repeat the inspection every 2,000 landings until paragraph (c)(2)(i) of this AD is done.

Note 8:

If any crack is found during any inspection per paragraph (c)(1)(ii) or (c)(1)(iii) of this AD, refer to paragraph (f) of this AD.

(iii) Within 3,500 landings after doing the temporary repair, do borescope and HFEC inspections to detect cracks of the internal structure. If NO crack is found that is outside the flyable limits specified in Condition 2 of the Accomplishment Instructions of the Start Printed Page 46936service bulletin, repeat the inspection every 3,500 landings until paragraph (c)(2)(i) of this AD is done.

(iv) Except as provided by paragraph (f) of this AD, within 8,000 landings after doing the temporary repair, do the permanent repair specified in paragraph (c)(2) of this AD.

Condition 2, Option 2: Permanent Repair

(2) Condition 2, Option 2: Do paragraphs (c)(2)(i) and (c)(2)(ii) of this AD at the times specified in those paragraphs.

(i) Before further flight, do all actions associated with the permanent repair (including detailed and eddy current inspections of various parts; and repair, replacement, or rework of those parts, as applicable) per Condition 2, Option 2, of the Accomplishment Instructions of the service bulletin. This terminates the repetitive inspections required by paragraphs (c)(1)(ii) and (c)(1)(iii) of this AD.

(ii) Within 40,000 landings after doing the permanent repair required by paragraph (c)(2)(i) of this AD, repeat the inspections specified in paragraph (a)(2) of this AD to detect any crack of the completed repair, per the Accomplishment Instructions of the service bulletin. If no crack and no crack progression is found, repeat the inspections specified in paragraph (a)(2) of this AD every 5,000 landings. If any crack or crack progression is found, do paragraph (g) of this AD.

Condition 3 (Existing Temporary Repairs Per Certain Service Information)

(d) If any temporary repair is found during any inspection required by paragraph (a)(1) of this AD and that repair WAS accomplished per the service information identified in Condition 3 of the Accomplishment Instructions of Boeing Service Bulletin DC9-53-290, Revision 01, dated March 15, 2002: Do the actions specified in paragraph (d)(1) or (d)(2) of this AD. Also, if the Station Y=83.550 frames have been repaired before the effective date of this AD per DC-9/MD-80 Structural Repair Manual, Section 53-03, Figure 34, or Boeing Service Rework Drawing S509530127, do a one-time inspection of the frames for crack growth emanating beyond the repair angles. If any crack progression is found, before further flight, replace the frames with new frames per the Accomplishment Instructions of the service bulletin.

Condition 3, Option 1: Repetitive Inspections

(1) Condition 3, Option 1: Do paragraphs (d)(1)(i), (d)(1)(ii), and (d)(1)(iii) of this AD at the times specified in those paragraphs.

(i) Within 2,000 landings after doing the temporary repair, or before further flight after accomplishment of the initial inspections in paragraph (a) of this AD, whichever is later, do a general visual inspection to detect cracks of the skins and external doublers. If NO crack is found that is outside the flyable limits specified in Condition 2 of the Accomplishment Instructions of the service bulletin, repeat the inspection every 2,000 landings until paragraph (d)(2)(i) of this AD is done.

Note 9:

If any crack outside the flyable limits is found during any inspection per paragraph (d)(1)(i) or (d)(1)(ii) of this AD, refer to paragraph (f) of this AD.

(ii) Within 3,500 landings after doing the temporary repair, or before further flight after accomplishment of the initial inspections in paragraph (a) of this AD, whichever is later, do borescope and HFEC inspections to detect cracks of the internal structure. If NO crack is found that is outside the flyable limits specified in Condition 2 of the Accomplishment Instructions of the service bulletin, repeat the inspection every 3,500 landings until paragraph (d)(2)(i) of this AD is done.

(iii) Except as provided by paragraph (f) of this AD, within 8,000 landings after doing the temporary repair, or before further flight if more than 8,000 landings have been accumulated since the temporary repair, do the permanent repair specified in paragraph (d)(2)(i) of this AD.

Condition 3, Option 2: Permanent Repair

(2) Condition 3, Option 2: Do paragraphs (d)(2)(i) and (d)(2)(ii) of this AD at the times specified in those paragraphs.

(i) Before further flight, do all actions associated with the permanent repair (including detailed and eddy current inspections of various parts; and repair, replacement, or rework of those parts, as applicable) per Condition 3, Option 2 of the Accomplishment Instructions of the service bulletin. This terminates the repetitive inspections required by paragraphs (d)(1)(i) and (d)(1)(ii) of this AD.

(ii) Within 40,000 landings after doing the permanent repair required by paragraph (d)(2)(i) of this AD, repeat the inspections specified in paragraph (a)(2) of this AD to detect any crack of the completed repair, per the Accomplishment Instructions of the service bulletin. If no crack and no crack progression is found: Repeat the inspections specified in paragraph (a)(2) of this AD every 5,000 landings. If any crack or crack progression is found, do paragraph (g) of this AD.

Condition 4 (Existing Repairs Per Other Service Information)

(e) If any repair is found during any inspection required by paragraph (a)(1) of this AD, and the repair was not accomplished per the service information identified in Condition 4 of the Accomplishment Instructions of Boeing Service Bulletin DC9-53-290, Revision 01, dated March 15, 2002: Before further flight, repair per a method approved by the Manager, Los Angeles Aircraft Certification Office (ACO), FAA.

Condition 5 (Crack Outside Flyable Limits for Temporary Repair)

(f) If any crack is found during any inspection required by paragraph (a)(2), (b)(1), (c)(1)(ii), (c)(1)(iii), (d)(1)(i), or (d)(1)(ii) of this AD; AND that crack is OUTSIDE the limits specified in Condition 2 of the Accomplishment Instructions of Boeing Service Bulletin DC9-53-290, Revision 01, dated March 15, 2002; AND a permanent repair was NOT previously accomplished per this AD: Do paragraphs (f)(1) and (f)(2) of this AD at the times specified in those paragraphs.

(1) Before further flight, do all actions associated with the permanent repair (including detailed and eddy current inspections of various parts; and repair, replacement, or rework of those parts, as applicable) per Condition 5 of the Accomplishment Instructions of the service bulletin.

(2) Within 40,000 landings after doing the permanent repair required by paragraph (f)(1) of this AD, repeat the inspections specified in paragraph (a)(2) of this AD to detect any crack of the completed repair, per the Accomplishment Instructions of the service bulletin. If no crack and no crack progression is found, repeat the inspections specified in paragraph (a)(2) of this AD every 5,000 landings. If any crack or crack progression is found, do paragraph (g) of this AD.

Corrective Actions: Cracking Following Permanent Repair

(g) If any crack or crack progression is found during any inspection required by paragraph (b)(2)(ii), (c)(2)(ii), (d)(2)(ii), or (f)(2) of this AD: Before further flight, repair per a method approved by the Manager, Los Angeles ACO.

Corrective Action for Cracked Zee

(h) If any cracked Zee is found during any inspection performed per paragraph (a)(2) of this AD: Before further flight, replace the cracked Zee with a new part per the Accomplishment Instructions of Boeing Service Bulletin DC9-53-290, Revision 01, dated March 15, 2002.

Previously Accomplished Inspections and Repairs

(i) Inspections and repairs accomplished before the effective date of this AD per the Accomplishment Instructions of Boeing Service Bulletin DC9-53-290, dated December 14, 1999, are acceptable for compliance with the corresponding actions in this AD.

Alternative Methods of Compliance

(j)(1) An alternative method of compliance (AMOC) 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.

(2) An AMOC for any inspection or repair required by this AD that provides an acceptable level of safety may be used per data meeting the type certification basis of the airplane approved by a Boeing Company Designated Engineering Representative who has been authorized by the Manager, Los Angeles ACO, to make such findings.

Note 10:

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

Special Flight Permits

(k) Special flight permits may be issued in accordance with §§ 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a Start Printed Page 46937location where the requirements of this AD can be accomplished.

Start Signature

Issued in Renton, Washington, on July 11, 2002.

Lirio Liu-Nelson,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

End Signature End Part End Supplemental Information

[FR Doc. 02-18025 Filed 7-16-02; 8:45 am]

BILLING CODE 4910-13-U