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Proposed Rule

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

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes the adoption of a new airworthiness directive (AD) that is applicable to Start Printed Page 48385certain McDonnell Douglas Model DC-9-10, −20, −30, −40, and −50 series airplanes, and C-9 airplanes. This proposal would 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 proposal also would require modification of the ventral aft pressure bulkhead. This action is necessary 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:

Comments must be received by November 5, 2001.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2000-NM-324-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. 2000-NM-324-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:

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

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-324-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-324-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

The FAA has received reports indicating that the repetitive x-ray inspections required by AD 85-01-02 R1, amendment 39-5241 (51 FR 6101, February 20, 1986), do not adequately detect fatigue cracks in all layers of a repaired or modified aft pressure bulkhead. Fatigue cracks in the corners and upper center of the door cutout of the aft pressure bulkhead, if not detected and corrected, could result in rapid decompression of the fuselage and consequent reduced structural integrity of the airplane.

Other Relevant Rulemaking

The FAA normally would issue a proposed AD to supersede AD 85-01-02 R1 to continue to require the existing requirements, until the new proposed actions that address the identified unsafe condition are done. This would involve restating the existing requirements of AD 85-01-02 R1 in the new proposed AD. Because of the complexity of the requirements of AD 85-01-02 R1, we plan to issue this proposed AD as a “stand-alone” AD that would not supersede AD 85-01-02 R1. We have included a paragraph in this proposed AD that terminates the repetitive inspection requirements of AD 85-01-02 R1. Once a final rule has been issued and it becomes effective, we plan to rescind AD 85-01-02 R1.

The FAA has previously issued AD 96-10-11, amendment 39-9618 (61 FR 24675, May 16, 1996), which requires certain inspections and structural modifications. Accomplishment of the modification (reference Boeing (McDonnell Douglas) Service Bulletin DC9-53-166) 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, as the appropriate source of service information for accomplishing the modification) terminates the repetitive inspection requirements of paragraphs (b) and (c) of this AD.

Explanation of Relevant Service Information

The FAA has reviewed and approved McDonnell Douglas Service Bulletin DC9-53-137, Revision 07, dated February 6, 2001, which describes procedures for 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. The corrective actions include modification of the bulkhead; trim forward facing flange; stop drill ends of cracks; install repair kit; replacement of cracked part with new parts; and installation of additional doublers. The follow-on actions include repetitive visual and eddy current inspections of the upper and lower corners and upper center of the door cutout of the aft pressure bulkhead door. Accomplishment of the general visual and x-ray inspections would eliminate the need for the Start Printed Page 48386repetitive inspection requirements of AD 85-01-02 R1.

The FAA also has reviewed and approved McDonnell Douglas DC-9 Service Bulletin 53-165, Revision 3, dated May 3, 1989, which describes procedures for modification of the ventral aft pressure bulkhead structure (including cutting and removing flange of the upper; cutting and removing the lower flange of formers and replacing it with a clip; installing pads at the outboard end clips of formers; and replacing clearance fit bolts at the upper corner doubler angles with interference fit Hi-Lok pins and monel rivets).

In addition, the FAA has reviewed and approved McDonnell Douglas DC-9 Service Bulletin 53-157, Revision 1, dated January 7, 1985, which describes, for certain airplanes, procedures for modification of the ventral aft pressure bulkhead (including encapsulating the head and nut of the attachments and applying a fillet seal of sealant around parts located on the forward and aft sides of the aft pressure bulkhead; and applying a soft film corrosion inhibiting compound to the forward and aft sides of the aft pressure bulkhead. For certain airplanes, these procedures must be done in conjunction with those in McDonnell Douglas DC-9 Service Bulletin 53-165.

FAA's Determination

The FAA finds that if, after the effective date of this AD, the airplane is operated without cabin pressurization and a placard that prohibits operation with cabin pressurization is installed in the cockpit in full view of the pilot, the inspections and modification specified in the service bulletins described previously are not necessary.

Explanation of Requirements of Proposed Rule

Since an unsafe condition has been identified that is likely to exist or develop on other products of this same type design, the proposed AD would require accomplishment of the actions specified in the service bulletins described previously; except if, after the effective date of this AD, the airplane is operated without cabin pressurization and a placard that prohibits operation with cabin pressurization is installed in the cockpit in full view of the pilot.

Differences Between the Proposed AD and a Certain Referenced Service Bulletin

McDonnell Douglas DC-9 Service Bulletin 53-165, Revision 3, dated May 3, 1989, and McDonnell Douglas Service Bulletin DC9-53-137, Revision 07, dated February 6, 2001, recommend compliance times with only a “threshold” (i.e., before the airplane accumulates 15,000 total landings, within 15,000 landings after the bulkhead modification, and at the earliest practical maintenance period feasible on airplanes that have accumulated more than 15,000 landings, respectively). These service bulletins do not provide a “grace period” for airplanes that have already reached (or will soon reach) the 15,000-landing threshold, which would result in some airplanes being in immediate non-compliance with the rule upon reaching the stated number of landings. Therefore, the compliance times specified in paragraphs (a), (d)(1), and (d)(2) of this proposed AD include a grace period of “within 4,000 landings after the effective date of this AD.” The FAA finds such a grace period for completing the required actions to be warranted, in that it represents an appropriate interval of time allowable for affected airplanes to continue to operate without compromising safety.

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 would be affected by this proposed AD.

It would take approximately 5 work hours per airplane to accomplish the proposed inspections, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the proposed AD on U.S. operators is estimated to be $119,100, or $300 per airplane, per inspection cycle.

For certain airplanes, it would take approximately between 21 and 26 work hours per airplane depending on the airplane configuration to accomplish the proposed 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 would cost approximately between $3,470 and $11,831 per airplane, depending on the airplane configuration. Based on these figures, the cost impact of this proposed modification AD on U.S. operators is estimated to be between $4,730, or $13,391 per airplane.

For certain airplanes, it would take approximately 9 work hours per airplane to accomplish the proposed 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 proposed modification AD 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 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

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
Start Printed Page 48387
[Amended]

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

McDonnell Douglas: Docket 2000-NM-324-AD.

Applicability: Model DC-9-10, -20, -30, -40, and -50 series airplanes, and C-9 airplanes, 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; certificated in any category; 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 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) 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) 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 general visual and 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.

Note 2:

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 under normally available lighting conditions such as daylight, hangar lighting, flashlight, or drop-light, 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.”

No Crack Detected: Repetitive Inspections

(b) If no crack is detected during any inspection required by paragraph (a) of this AD, within 8,000 landings after accomplishment of the general visual and x-ray inspections required by paragraph (a) of this AD, do a general visual inspection and eddy current inspection of the upper and lower corners and upper center of the door cutout of the aft pressure bulkhead door, per McDonnell Douglas Service Bulletin DC9-53-137, Revision 07, dated February 6, 2001. Repeat the general visual and eddy current inspections required by this paragraph every 8,000 landings.

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 the action specified in paragraph (d) or (g) of this AD has been done.

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 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 3:

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.

(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 requirements of paragraph (e) of this AD.

(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: Within 18 months after the effective date of this AD, modify the ventral aft pressure bulkhead per the service bulletin.

Note 4:

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, amendment 39-9618 (61 FR 24675, May 16, 1996) (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, 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) The inspections and modifications required by this AD do NOT need to be done if, after the effective date of this AD, 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

(i) 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 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.

Note 5:

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 Permit

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

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Start Printed Page 48388

Issued in Renton, Washington, on September 14, 2001.

Ali Bahrami,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

End Signature End Part End Supplemental Information

[FR Doc. 01-23417 Filed 9-19-01; 8:45 am]

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