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

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Final rule.

SUMMARY:

This amendment adopts a new airworthiness directive (AD), applicable to certain McDonnell Douglas Model DC-9-10, -20, -30, -40, and -50 series airplanes; and C-9 airplanes; that requires repetitive visual and x-ray inspections to detect cracks of the upper and lower corners and upper center of the door cutout of the aft pressure bulkhead; corrective actions, if necessary; and follow-on actions. For certain airplanes, the amendment also requires modification of the ventral aft pressure bulkhead. The actions specified by this AD are intended to detect and correct fatigue cracks in the corners and upper center of the door cutout of the aft pressure bulkhead, 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:

Effective May 14, 2002.

The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of May 14, 2002.

ADDRESSES:

The service information referenced in this AD 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.

FOR FURTHER INFORMATION CONTACT:

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.

SUPPLEMENTARY INFORMATION:

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an airworthiness directive (AD) that is applicable to certain McDonnell Douglas Model DC-9-10, -20, -30, -40, and -50 series airplanes; and C-9 airplanes; was published in the Federal Register on September 20, 2001 (66 FR 48384). That action proposed to require repetitive general visual and x-ray inspections to detect cracks of the upper and lower corners and upper center of the door cutout of the aft pressure bulkhead; corrective actions, if necessary; and follow-on actions. For certain airplanes, the amendment also requires modification of the ventral aft pressure bulkhead.

Comments

Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comments received.

Requests To Revise Certain Inspection Requirements

Three commenters request revision of the inspection requirements in paragraph (b) of the proposed rule. The rationales for these requests are as follows:

• One commenter suggests revising paragraph (b) of the proposed rule to specify the same inspections cited in McDonnell Douglas Service Bulletin DC9-53-137, Revision 07, dated February 6, 2001, which was cited as the appropriate source of service information for this AD. The commenter states that paragraph (b) of the proposed rule is misleading because it incorrectly implies that a repair will always be required or that a preventive modification is required. In addition, that paragraph does not allow for continuing visual and x-ray inspections as specified in the previously referenced service bulletin.
• One commenter requests clarification of the inspection procedures specified in the proposed rule. Paragraph (b) of the proposed rule specifies visual and eddy current inspections within 8,000 landings after accomplishment of the visual and x-ray inspections required by paragraph (a) of this AD. However, Service Bulletin DC9-53-137, Revision 07, specifies visual and eddy current inspections after a repair or preventive modification is installed. The proposed rule would not require a preventive modification if no cracks are found. However, the no-crack procedures specified in the service bulletin provide the option of either accomplishing the preventive modification and thereafter a visual and eddy current inspection, or not accomplishing the modification and continuing the visual and x-ray inspections at various intervals depending on the condition.
• One commenter considers that the proposed rule should require visual and eddy current inspections only if no cracks are found and interim preventive repairs are performed per Service Bulletin DC9-53-137, Revision 07. The commenter suggests clarifying that interim preventive repairs are to be performed per the service bulletin, and that continued visual and x-ray inspections are required for unmodified corners. The inspection requirements of paragraph (b) are different from those specified in the previously referenced service bulletin. Although paragraph (b) of the proposed rule requires inspections at intervals of 8,000 landings after accomplishment of the inspections required by paragraph (a) of the proposed rule, the service bulletin specifies inspections after accomplishment of a repair or preventive modification. The service bulletin also provides the option of either accomplishing the preventive modification followed by the inspections, or not accomplishing the modification and continuing the inspections at specific intervals.

The FAA concurs with the commenter's requests to revise and clarify the inspection requirements. In making this decision, we have reviewed the Accomplishment Instructions of the service bulletin and the inspection requirements of paragraph (b) of the proposed rule. We point out that the intent of paragraph (b) of the proposed rule is to require the same inspections as those specified by the service bulletin. Therefore, we have revised paragraph (b) in the final rule to also include paragraphs (b)(1) and (b)(2). We consider that this change provides an acceptable level of safety for the fleet.

Request To Clarify the Repetitive Inspection Intervals

One commenter states that, if no crack is detected, paragraph (b) in the proposed rule requires visual and eddy current inspections per Revision 07 of Service Bulletin DC9-53-137, within 8,000 landings after accomplishing the visual and x-ray inspections required by paragraph (a) of the proposed rule. The commenter states that it had previously accomplished modifications per Revision 04, or earlier, of McDonnell Douglas DC-9 Service Bulletin 53-137, and that an alternative method of compliance (AMOC) to AD 85-01-02 R1, amendment 39-5241 (51 FR 6101, February 20, 1986), permits repetitive inspections at intervals of 15,000 landings until accomplishment of the terminating action per McDonnell Douglas DC-9 Service Bulletin 53-166. With this in mind, the commenter asks whether the repetitive intervals of previously modified airplanes will be reduced from 15,000 landings to 8,000 landings regardless of modification/repair status.

The FAA concurs that clarification of the repetitive inspection intervals for previously repaired or modified airplanes (interim preventive repairs) is necessary. We point out that McDonnell Douglas DC-9 Service Bulletin 53-137, Revision 05, dated August 29, 2000, changed the inspection method and the inspection intervals for the aft pressure bulkhead corners that previously have been repaired or modified per earlier revisions of the service bulletin. In addition, the inspection procedures specified in Revision 05 of the service bulletin also were approved as an AMOC for the accomplishment of AD 85-01-02 R1. Although earlier revisions of the service bulletin specify “visual and x-ray” inspections of previously repaired or modified corners, Revision 05 and later revisions of the service bulletin specify “visual and eddy current” inspections for those airplanes. After the type of inspection was changed, the manufacturer reconsidered the inspection intervals necessary for previously repaired or modified corners if no cracks are detected. As a result, for those airplanes, the manufacturer recommends inspection intervals of 8,000 landings for “visual and eddy current” inspections instead of 15,000 landings for “visual and x-ray” inspections.

After reconsidering the manufacturer's recommendation, we have determined that the compliance times recommended in Revision 07 of the service bulletin are adequate in maintaining the safety of the fleet. It is necessary to revise paragraph (b) of the proposed rule to clarify our intent regarding the type of inspection and inspection intervals that are specified in paragraph 3.B. (“Work Instructions”) of the service bulletin (which was cited in the proposed rule as the appropriate source of service information). We point out that the compliance times specified in Revision 07 of the service bulletin vary according to the conditions and groups of airplanes specified in paragraph 3.B. (“Work Instructions”) of the service bulletin. As a result, we have reformatted paragraph (b) of the final rule to include paragraphs (b)(1) and (b)(2), which require accomplishment of the inspections at the times specified in Revision 07 of the service bulletin, as applicable. We consider that these changes only clarify the required inspections and related compliance times, and do not impose an additional burden on any operator or necessitate providing an additional opportunity for public comment.

Request To Revise Type of Inspection per the Service Information

One commenter states that the definition of a “general visual inspection” in Note 2 of the proposed rule is not the same as that of a “visual inspection” in Service Bulletin DC9-53-137, Revision 07. The commenter states that the service bulletin has specific visual inspection requirements that are included in Service Sketch 2934E and SN09530002. The commenter considers that the proposed rule should reflect the same type of inspection as that cited in the service information.

The FAA concurs and agrees that the final rule should reflect the same inspections specified by the service information. In the final rule we have deleted Note 2 to remove the definition of a “general visual inspection.” We also have changed all references throughout the final rule, including paragraphs (a) and (b), to specify a “visual inspection” instead of a “general visual inspection.”

Request To Give Credit for Previously Accomplished Alternative Methods of Compliance (AMOCs)

One commenter requests that credit be given to operators who have accomplished previously approved AMOCs per AD 85-01-02 R1 or AD 96-10-11, amendment 39-9618 (61 FR 24675, May 16, 1996). Another commenter asks how the requirements of this AD affect previous AMOC approvals for inspections, repairs, and modifications per AD 85-01-02 R1 and AD 96-10-11. In addition, this commenter asks whether AMOCs issued per AD 90-18-03, amendment 39-6701 (55 FR 34704, August 24, 1990), are still considered valid.

The FAA concurs. In addition, we point out that AD 90-18-03 was superseded by AD 96-10-11, which gave credit for AMOCs previously issued per AD 90-18-03. However, because AD 90-18-03 was removed from the regulations, it is only necessary to give credit for the prior accomplishment of AD 85-01-02 R1 and AD 96-10-11 in paragraph (i)(2) of the final rule. We have revised the final rule accordingly.

Request To Clarify Previously Issued ADs and Effect on Compliance Times in Follow-on ADs

One commenter requests clarification of the difference between a standalone AD that supersedes an earlier AD, and a separate AD with a later action to rescind that AD. The commenter also asks the following questions:

• If the FAA rescinds AD 85-01-02 R1, what happens to AD 80-10-03, amendment 39-3769 (45 FR 31052, May 15, 1980), that was superseded by AD 85-01-02, amendment 39-4978 (50 FR 2043, January 15, 1985), and how are the concurrent service bulletin requirements affected by this decision?
• AD 85-01-02 R1 requires that the procedures specified by the service bulletins be accomplished within landing or time limits that have already passed for most applicable airplanes. How does rescinding AD 85-01-02 R1 affect this compliance?

The FAA concurs and agrees that it is necessary to clarify the difference between the two types of ADs. In response, we point out that in the preamble of the proposed AD, in “Other Relevant Rulemaking,” we stated that the FAA normally would issue a proposed AD to supersede AD 85-01-02 R1. However, because of the complexity of the requirements in AD 85-01-02 R1, we issued a standalone AD, which includes terminating action for the repetitive inspection requirements of AD 85-01-02 R1. Once a final rule has been issued and becomes effective, we plan to rescind AD 85-01-02 R1. After considering the commenter's two questions, we infer that the commenter wants us to clarify how previously issued ADs affect the compliance times in follow-on ADs. In response, we point out that AD 80-10-03 was superseded by AD 85-01-02, which removed AD 80-10-03 from the regulations. As a result, the concurrent service bulletin procedures required by AD 80-10-03 are no longer in effect. Likewise, after AD 85-01-02 R1 is rescinded, the compliance times required by that AD per the service bulletins are no longer a factor. No change to the final rule is necessary in this regard.

Request To Include Additional Corrective Actions

The commenter states that the proposed rule needs to address what happens if an operator finds “something on a corner of an airplane” that they are unable to inspect per Revision 07 of Service Bulletin DC9-53-137. The commenter adds that guidance is needed when the proposed rule cannot be complied with, and operators need to know what to do. After contacting the manufacturer for clarification of what was meant by “something on a corner of an airplane,” the commenter stated that the phrase refers to any previous repair on the aft pressure bulkhead that any operator may not be able to inspect per the service bulletin.

The FAA does not concur. We point out that the proposed rule does not need to include additional corrective actions because paragraph (i)(1) of this AD includes a provision for operators to request an AMOC for such an inspection requirement. No change to the final rule is necessary in this regard.

Request To Cite an Additional Service Bulletin

The commenter asks why some of the Boeing service bulletins listed in AD 85-01-02 R1 are included in the proposed rule and others are not. For example, McDonnell Douglas DC-9 Service Bulletin A53-144 is cited in AD 85-01-02 R1, but is not cited in this proposed rule. The commenter considers that, if certain other service bulletins specified in that AD are included in this proposed rule, we also need to include DC-9 Service Bulletin A53-144. This is necessary in case any airplane that has not been modified per the AD is brought into the United States, and to prevent any operator from performing a repair in the area and not also accomplishing the modification.

The FAA does not concur. We point out that it is unnecessary to include a reference to a service bulletin unless the specified procedures are required by the proposed rule. Because the procedures specified in DC-9 Service Bulletin A53-144 are not required by the final rule, no change to the final rule is necessary in this regard.

Explanation of Changes Made to the Proposal

The FAA has determined that it is necessary to revise the final rule and has made the following changes:

• In the “Cost Impact” section, we have clarified that 5 work hours per airplane is required for accomplishment of the required “inspections” instead of the required “actions.”
• Paragraph (a) specifies that the requirements of that paragraph also apply to airplanes on which the modification has not been accomplished per paragraph (g) of this AD, which specifies terminating action for the repetitive inspections required by paragraphs (b) and (c) of this AD. This change clarifies that if the specified modification has not been done, visual and x-ray inspections must be done within the compliance time specified in paragraph (a) of this AD.
• Paragraph (d)(2) specifies that accomplishment of the modification specified by paragraph (d)(2) constitutes terminating action for the repetitive inspection requirements of paragraphs (b) and (c)(2) of this AD.
• Paragraph (i) includes two new subparagraphs. Paragraph (i)(2) is added to give credit for AMOCs previously accomplished in accordance with AD 85-01-02 R1 or AD 96-10-11. Paragraph (i)(3) is added to specify that, if an inspection of the aft pressure bulkhead cannot be accomplished per the service bulletin, operators also may accomplish the inspection per data meeting the type certification basis of the airplane approved by a Boeing Company Designated Engineering Representative who has been authorized by the FAA to make such findings.

Conclusion

After careful review of the available data, including the comments noted above, the FAA has determined that air safety and the public interest require the adoption of the rule with the changes previously described. We also have determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD.

Cost Impact

There are approximately 700 Model DC-9-10, -20, -30, -40, and -50 series airplanes; and C-9 airplanes of the affected design in the worldwide fleet. The FAA estimates that 397 airplanes of U.S. registry will be affected by this AD.

It will take approximately 5 work hours per airplane to accomplish the required inspections, and that the average labor rate is $60 per work hour. Based on these figures, the cost impact of the AD on U.S. operators is estimated to be $119,100, or $300 per airplane.

For certain airplanes, it will take approximately between 21 and 26 work hours per airplane depending on the airplane configuration to accomplish the modification specified in McDonnell Douglas DC-9 Service Bulletin 53-165, Revision 3, dated May 3, 1989, at an average labor rate of $60 per work hour. Required parts will cost approximately between $3,470 and $11,831 per airplane, depending on the airplane configuration. Based on these figures, the cost impact of this modification on U.S. operators is estimated to be between $4,730, or $13,391 per airplane.

For certain airplanes, it will take approximately 9 work hours per airplane to accomplish the modification specified in McDonnell Douglas DC-9 Service Bulletin 53-157, Revision 1, dated January 7, 1985, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of this modification on U.S. operators is estimated to be $540 per airplane.

The cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted. 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 adopted herein will 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 final rule does not have federalism implications under Executive Order 13132.

For the reasons discussed above, I certify that this action (1) is not a “significant regulatory action” under Executive Order 12866; (2) is not a “significant rule” under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. A final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it may be obtained from the Rules Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Incorporation by reference
• Safety

Adoption of the Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows:

PART 39—AIRWORTHINESS DIRECTIVES

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

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

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

2002-07-06 McDonnell Douglas: Amendment 39-12700. Docket 2000-NM-324-AD.

Applicability: Model DC-9-10, -20, -30, -40, and -50 series airplanes, and C-9 airplanes; certificated in any category; equipped with a floor level hinged (ventral) door of the aft pressure bulkhead; as listed in McDonnell Douglas Service Bulletin DC9-53-137, Revision 07, dated February 6, 2001; except for those airplanes on which the modification required by paragraph (d) or (e) of AD 96-10-11, amendment 39-9618, or paragraph K. of AD 85-01-02 R1, amendment 39-5241, has been done.

Note 1:

This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been otherwise 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 (i)(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 detect and correct fatigue cracks in the corners and upper center of the door cutout of the aft pressure bulkhead, which could result in rapid decompression of the fuselage and consequent reduced structural integrity of the airplane, accomplish the following:

Visual and X-Ray Inspection

(a) For airplanes on which the modification has NOT been accomplished per paragraph (g) of this AD: Except as provided by paragraph (h) of this AD, prior to the accumulation of 15,000 total landings, or within 4,000 landings after the effective date of this AD, whichever occurs later, do a visual inspection and an x-ray inspection to detect cracks of the upper and lower corners and upper center of the door cutout of the aft pressure bulkhead, per McDonnell Douglas Service Bulletin DC9-53-137, Revision 07, dated February 6, 2001.

No Crack Detected: Repetitive Inspections

(b) If no crack is detected during any inspection required by paragraph (a) of this AD, do the action specified in either paragraph (b)(1) or (b)(2) of this AD per paragraph 3.B. “Work Instructions” of McDonnell Douglas Service Bulletin DC9-53-137, Revision 07, dated February 6, 2001, as applicable:

(1) If interim preventive repairs have been performed per the service bulletin; AD 85-01-02 R1 or AD 96-10-11: Do a visual inspection and an eddy current inspection at the times specified in the service bulletin. Repeat the applicable repetitive inspections at intervals not to exceed the times specified in the service bulletin, until accomplishment of the action required by paragraph (d) or (g) of this AD; or

(2) If interim preventive repairs have NOT been performed per the service bulletin, do either paragraph (b)(2)(i) or (b)(2)(ii) of this AD:

(i) Before further flight, install an interim preventive repair identified in Conditions I through XLIII inclusive, excluding Conditions XXI, XXXVII, and XXXVIII (not used at this time), per the service bulletin. At the times specified in the service bulletin, do a visual inspection and an eddy current inspection. At intervals not to exceed the times specified in the service bulletin, repeat the visual and eddy current inspections until accomplishment of the action specified in paragraph (d) or (g) of this AD; or

(ii) At intervals not to exceed the times specified in the service bulletin, repeat the visual inspection and x-ray inspection required by paragraph (a) of this AD, until accomplishment of the action specified in paragraph (d) or (g) of this AD.

Any Crack Detected: Corrective Actions and Repetitive Inspections

(c) If any crack is detected during any inspection required by paragraph (a) or (b) of this AD, do the actions specified in paragraphs (c)(1) and (c)(2) of this AD per McDonnell Douglas Service Bulletin DC9-53-137, Revision 07, dated February 6, 2001.

(1) Before further flight, do the applicable corrective actions (i.e., modification of the bulkhead; trim forward facing flange; stop drill ends of cracks; install repair kit; replacement of cracked part with new parts; and install additional doublers) identified in Conditions I through XLIII inclusive, excluding Conditions XXI, XXXVII, and XXXVIII (not used at this time), of the Accomplishment Instructions of the service bulletin; and

(2) At the times specified in the Accomplishment Instructions of the service bulletin, do the applicable repetitive inspections, until accomplishment of the action specified in paragraph (d) or (g) of this AD.

Concurrent Requirements

(d) Except as provided by paragraph (h) of this AD, modify the ventral aft pressure bulkhead structure by accomplishing all actions specified in the Accomplishment Instructions of McDonnell Douglas DC-9 Service Bulletin 53-165, Revision 3, dated May 3, 1989, per the service bulletin; at the applicable time specified in paragraph (d)(1), (d)(2), or (d)(3) of this AD.

Note 2:

Modification before the effective date of this AD per McDonnell Douglas DC-9 Service Bulletin 53-165, dated January 31, 1983; Revision 1, dated February 20, 1984; or Revision 2, dated August 29, 1986; is considered acceptable for compliance with the requirements of paragraph (d) of this AD.

(1) For airplanes on which the bulkhead modification specified in McDonnell Douglas DC-9 Service Bulletin 53-139, dated September 26, 1980, or Revision 1, dated April 30, 1981, has been done, except as provided by paragraph (d)(3) of this AD: Modify within 15,000 landings after accomplishment of the bulkhead modification, or within 4,000 landings after the effective date of this AD, whichever occurs later. Accomplishment of this modification constitutes terminating action for the repetitive inspection requirements of paragraphs (b) and (c)(2) of this AD.

(2) For airplanes on which the production equivalent of the modification specified in paragraph (d)(1) of this AD has been done before delivery, except as provided by paragraph (d)(3) of this AD: Modify before the accumulation of 15,000 total landings, or within 4,000 landings after the effective date of this AD, whichever occurs later. Accomplishment of this modification constitutes terminating action for the repetitive inspection requirements of paragraphs (b) and (c)(2) of this AD.

(3) For airplanes listed in McDonnell Douglas DC-9 Service Bulletin 53-165, Revision 3, dated May 3, 1989, that are specified in paragraph (e) of this AD: Modify in conjunction with the requirements of paragraph (e) of this AD, or within 18 months after accomplishment of the requirements of paragraph (e) of this AD.

Modification: Ventral Aft Pressure Bulkhead

(e) For Model DC-9-30 and “50 series airplanes, and C-9 airplanes, as listed in McDonnell Douglas DC-9 Service Bulletin 53-157, Revision 1, dated January 7, 1985: Except as provided by paragraph (h) of this AD, within 18 months after the effective date of this AD, modify the ventral aft pressure bulkhead per the service bulletin.

Note 3:

Modification before the effective date of this AD per McDonnell Douglas DC-9 Service Bulletin 53-157, dated August 11, 1981, is considered acceptable for compliance with the requirements of paragraph (e) of this AD.

Compliance with AD 85-01-02 R1

(f) Accomplishment of the visual and x-ray inspections required by paragraph (a) of this AD constitutes terminating action for the repetitive inspection requirements of AD 85-01-02 R1.

Terminating Modification

(g) Accomplishment of the modification (reference McDonnell Douglas DC-9 Service Bulletin 53-166) required by paragraph (d) or (e) of AD 96-10-11 (which references “DC-9/MD-80 Aging Aircraft Service Action Requirements Document” (SARD), McDonnell Douglas Report No. MDC K1572, Revision A, dated June 1, 1990; or Revision B, dated January 15, 1993; as the appropriate source of service information for accomplishing the modification) terminates the repetitive inspection requirements of paragraphs (b) and (c) of this AD.

Exception to Inspections and Modifications

(h) As of the effective date of this AD, the inspections and modifications required by this AD do NOT need to be done during any period that the airplane is operated without cabin pressurization and a placard is installed in the cockpit in full view of the pilot that states the following: “OPERATION WITH CABIN PRESSURIZATION IS PROHIBITED.”

Alternative Methods of Compliance (AMOC)

(i)(1) An AMOC or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Los Angeles 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, Los Angeles ACO.

(2) AMOCs approved previously in accordance with AD 85-01-02 R1, amendment 39-4978; or AD 96-10-11, amendment 39-9618; are approved as AMOCs for paragraph (a) or (c) of this AD, as appropriate.

(3) An AMOC for any inspection required by paragraph (a) or (c) of 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 4:

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

Special Flight Permit

(j) 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 location where the requirements of this AD can be accomplished.

Incorporation by Reference

(k) The actions shall be done in accordance with McDonnell Douglas Service Bulletin DC9-53-137, Revision 07, dated February 6, 2001; McDonnell Douglas DC-9 Service Bulletin 53-165, Revision 3, dated May 3, 1989; and McDonnell Douglas DC-9 Service Bulletin 53-157, Revision 1, dated January 7, 1985; as applicable. This incorporation by reference was approved previously by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies 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). Copies may be inspected 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; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

Effective Date

(l) This amendment becomes effective on May 14, 2002.