Airworthiness Directives; McDonnell Douglas Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), DC-9-87 (MD-87), and MD-88 Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes the supersedure of an existing airworthiness directive (AD), applicable to certain McDonnell Douglas Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), DC-9-87 (MD-87), MD-88, and MD-90-30 airplanes. That AD currently requires repetitive inspections to detect cracking of the main landing gear (MLG) shock strut pistons, and replacement of a cracked piston with a new or serviceable part. This action would remove certain airplanes but would require that the existing inspections, and corrective actions if necessary, be accomplished on additional MLG shock strut pistons. This action also would require replacing the MLG shock strut pistons with new improved parts, which would terminate the repetitive inspections. This action is necessary to prevent fatigue cracking of the MLG pistons, which could result in failure of the pistons and consequent damage to the airplane structure or injury to airplane occupants. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by June 21, 2004.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2001-NM-293-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. 2001-NM-293-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 or 2000 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.

FOR FURTHER INFORMATION CONTACT:

Mike Lee, Aerospace Engineer, Airframe Branch, ANM-120L, FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California 90712-4137; telephone (562) 627-5325; fax (562) 627-5210.

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to participate in the making of the proposed rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this 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 2001-NM-293-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. 2001-NM-293-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

On June 15, 1999, the FAA issued AD 99-13-07, amendment 39-11201 (64 FR 33392, June 23, 1999), applicable to certain McDonnell Douglas Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), DC-9-87 (MD-87), MD-88, and MD-90-30 airplanes. That action requires repetitive inspections to detect cracking of the main landing gear (MLG) shock strut pistons, and replacement of a cracked piston with a new or serviceable part. That action was prompted by reports indicating that, while an airplane was positioned on the taxiway, the right MLG shock strut piston failed due to fatigue cracking. The requirements of that AD are intended to detect and correct such fatigue cracking, which could result in failure of the piston, and consequent damage to the airplane structure or injury to the passengers and flightcrew.

In the preamble of the notice of proposed rulemaking (NPRM) for AD 99-13-07, we stated that the proposed AD was considered interim action, and that the manufacturer was developing a modification to address the unsafe condition. We indicated that we might consider further rulemaking action once the modification was developed, approved, and available. The manufacturer now has developed such a modification, and we have determined that further rulemaking action is indeed necessary. This proposed AD follows from that determination.

Actions Since Issuance of Previous Rule

Since the issuance of AD 99-13-07, we have issued AD 2002-10-03, amendment 39-12749 (67 FR 34823), which applies to certain McDonnell Douglas Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), DC-9-87 (MD-87), MD-88, and MD-90-30 airplanes. That AD requires replacement of certain MLG shock strut piston assemblies with new or serviceable improved assemblies, in accordance with Boeing Service Bulletin MD80-32-309, Revision 01, dated April 25, 2001 (for Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), DC-9-87 (MD-87), and MD-88 airplanes); or Boeing Service Bulletin MD90-32-031, Revision 01, dated April 25, 2001 (for Model MD-90-30 airplanes). Accomplishment of that replacement will terminate the requirements of this AD, as noted in paragraph (b) of AD 2002-10-03. Therefore, we have included in paragraph (h) of this proposed AD the requirements of paragraph (a) of AD 2002-10-03 that apply to airplanes subject to this proposed AD. The compliance time for the replacement specified in this proposed AD (“Before the accumulation of 30,000 total landings on the MLG shock strut piston assemblies, or within 5,000 landings after June 20, 2002 (the effective date of AD 2002-10-03, amendment 39-12749), whichever occurs later”) is the same as the compliance time in paragraph (a) of AD 2002-10-03. Once this proposed AD becomes effective, we may consider further rulemaking to revise or rescind AD 2002-10-03 to remove the duplicate requirement.

Explanation of Related AD

Since the issuance of AD 99-13-07, we have issued AD 2004-05-18, amendment 39-13513 (69 FR 10915, March 9, 2004). That AD requires certain actions for certain McDonnell Douglas Model MD-90-30 airplanes. The actions required by that AD include:

• Repetitive fluorescent penetrant and magnetic particle inspections to detect fatigue cracking of the MLG piston, and repair if necessary.
• Repetitive inspections for evidence of cracking in the paint topcoat of the MLG pistons.
• Replacement of certain MLG shock strut piston assemblies with new or serviceable improved assemblies.

We find that the actions required by that AD for Model MD-90-30 airplanes overlap with the requirements of AD 99-13-07 for the same airplanes. Thus, we have not included Model MD-90-30 airplanes in the applicability of this proposed AD.

Explanation of Relevant Service Information

Since the issuance of AD 99-13-07, the FAA has reviewed and approved Boeing Alert Service Bulletin MD80-32A308, Revision 04, dated June 12, 2001 (for Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), DC-9-87 (MD-87), and MD-88 airplanes). (AD 99-13-07 refers to McDonnell Douglas Alert Service Bulletins MD80-32A308, dated March 5, 1998, and Revision 01, dated May 12, 1998; as appropriate sources of service information for accomplishing the actions in that AD.) That service bulletin describes procedures for repetitive fluorescent dye penetrant and fluorescent magnetic particle inspections to detect cracking of the MLG shock strut piston, and replacement of any cracked piston with a new or serviceable improved assembly. Revision 04 of the service bulletin includes additional part numbers of MLG shock strut pistons subject to the inspections described therein.

Explanation of Requirements of Proposed Rule

Since an unsafe condition has been identified that is likely to exist or develop on other products of this same type design, the proposed AD would supersede AD 99-13-07 to continue to require repetitive inspections to detect cracking of the MLG shock strut pistons, and replacement of a cracked piston with a new or serviceable part. The proposed AD would remove Model MD-90-30 airplanes from the applicability, but would require the existing inspections, and corrective actions if necessary, to be accomplished on additional MLG shock strut pistons. The inspections would be required to be accomplished in accordance with Boeing Alert Service Bulletin MD80-32A308, Revision 04, except as discussed below. The proposed AD also would require replacing the MLG shock strut pistons with new improved assemblies, which would terminate the repetitive inspections. The replacement would be required to be accomplished in accordance with Boeing Service Bulletin MD80-32-309, Revision 01.

Differences Between Service Bulletins and Proposed AD

Although Boeing Alert Service Bulletin MD80-32A308, Revision 04, describes procedures for fluorescent penetrant and magnetic particle inspections, this service bulletin does not emphasize the sequence of these inspections. We find that, in each inspection cycle, it is necessary for the fluorescent penetrant inspection to precede the magnetic particle inspection. This sequencing is important because we are aware of cases in which accomplishment of a magnetic particle inspection before a fluorescent penetrant inspection interfered with the results of the fluorescent penetrant inspection. Therefore, a new paragraph (d) has been included in this proposed AD to clarify that, for inspections performed after the effective date of this AD, accomplishment of the fluorescent penetrant inspection must precede accomplishment of the magnetic particle inspection.

Although Boeing Alert Service Bulletin MD80-32A308, Revision 04, specifies that operators may contact the manufacturer for disposition of certain repair conditions, this proposed AD would require operators to repair those conditions per a method approved by the FAA.

Operators should note that, although Figure 1 of Boeing Alert Service Bulletin MD80-32A308, Revision 04, specifies to report certain inspection results to the airplane manufacturer, this proposed AD would not require such reporting. We do not need this information from operators.

Explanation of Change to Existing Requirements

We have revised certain wording from the existing AD to identify model designations as they are published in the most recent type certificate data sheet for the affected models.

Changes to 14 CFR Part 39/Effect on the AD

On July 10, 2002, the FAA issued a new version of 14 CFR part 39 (67 FR 47997, July 22, 2002), which governs the FAA's airworthiness directives system. The regulation now includes material that relates to altered products, special flight permits, and alternative methods of compliance (AMOCs). Because we have now included this material in part 39, only the office authorized to approve AMOCs is identified in each individual AD. Therefore, Note 1 and paragraph (f) of AD 99-13-07 are not included in this proposed AD, and paragraph (e) of AD 99-13-07 (which appears as paragraph (m)(1) of this proposed AD) has been revised in this proposed AD. Also, we have added paragraph (m)(2) to this AD to provide credit for AMOCs approved previously per AD 99-13-07.

Cost Impact

There are approximately 1,364 airplanes of the affected design in the worldwide fleet. The FAA estimates that 849 airplanes of U.S. registry would be affected by this proposed AD.

The inspections that are currently required by AD 99-13-07 take approximately 4 work hours per airplane to accomplish, at an average labor rate of $65 per work hour. Based on these figures, the cost impact of the currently required inspections on U.S. operators is estimated to be $220,740, or $260 per airplane, per inspection cycle.

The new inspections that are proposed in this AD action would take approximately 4 work hours per airplane to accomplish, at an average labor rate of $65 per work hour. Based on these figures, the cost impact of the currently required inspections on U.S. operators is estimated to be $220,740, or $260 per airplane, per inspection cycle.

As explained previously, the new replacement included in this AD action is already required by AD 2002-10-03. Therefore, the new proposed requirement will not add any additional economic burden on affected operators. The current costs associated with this proposed AD are reiterated in their entirety (as follows) for the convenience of affected operators.

The replacement of MLG pistons that is included in this AD action and currently required by AD 2002-10-03 takes approximately 28 work hours per airplane to accomplish, at an average labor rate of $65 per work hour. Required parts cost approximately $263,438 per airplane. Based on these figures, the cost impact of this requirement on U.S. operators subject to this proposed AD is estimated to be $225,204,042, or $265,258 per airplane.

The cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the current or proposed requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted. The cost impact figures discussed in AD rulemaking actions represent only the time necessary to perform the specific actions actually required by the AD. These figures typically do not include incidental costs, such as the time required to gain access and close up, planning time, or time necessitated by other administrative actions. The manufacturer may cover the cost of replacement parts associated with this proposed AD, subject to warranty conditions. Manufacturer warranty remedies may also be available for labor costs associated with this proposed AD. As a result, the costs attributable to the proposed AD may be less than stated above.

Regulatory Impact

The regulations proposed herein would not have a substantial direct effect on the States, on the relationship between the national Government and the States, or on the distribution of power and responsibilities among the various levels of government. Therefore, it is determined that this proposal would not have federalism implications under Executive Order 13132.

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

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Safety

The Proposed Amendment

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

PART 39—AIRWORTHINESS DIRECTIVES

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

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