01-21750. Airworthiness Directives; McDonnell Douglas Model DC-9-81, -82, -83, and -87 Series Airplanes; Model MD-88 Airplanes; and Model MD-90-30 Series Airplanes

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 certain McDonnell Douglas Model DC-9-81, -82, -83, and -87 series airplanes; Model MD-88 airplanes; and Model MD-90-30 series airplanes. This proposal would require replacement of certain main landing gear (MLG) shock strut piston assemblies with new or serviceable, improved assemblies, which would constitute terminating action for the requirements of certain other ADs. This action is necessary to prevent fatigue cracking of the MLG shock strut pistons, which could result in failure of the MLG shock strut pistons during landing or jacking of the airplane, and consequent damage to the airplane structure and injury to the passengers, flightcrew, or ground personnel. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by September 28, 2001.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2001-NM-197-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 [phone]. Comments may also be sent via the Internet using the following address: [e-mail]. Comments sent via fax or the Internet must contain “Docket No. 2001-NM-197-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.

FOR FURTHER INFORMATION CONTACT:

David Y. J. Hsu, Aerospace Engineer, Airframe Branch, ANM-120L, FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California 90712-4137; telephone [phone]; fax [phone].

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-197-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-197-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

The FAA has received reports of three instances of failure of a main landing gear (MLG) shock strut piston on McDonnell Douglas Model DC-9-82 series airplanes and a Model MD-88 airplane. Subsequent inspections required by ADs 96-19-09, amendment 39-9756 (61 FR 48617, September 16, 1996); 99-13-07, amendment 39-11201 (64 FR 33392, June 23, 1999); and 2000-03-08, amendment 39-11567 (65 FR 7719, February 16, 2000) also revealed numerous fatigue cracks in the areas of the torque link lugs and small radius on the base of the jackball of the MLG shock strut pistons. Such fatigue cracking, if not corrected, could result in failure of the MLG shock strut pistons during landing or jacking of the airplane, and consequent damage to the airplane structure and injury to the passengers, flightcrew, or ground personnel.

The MLG shock strut pistons installed on McDonnell Douglas Model MD-90-30 series airplanes are similar in design to those installed on the affected Model DC-9-81, -82, -83, and -87 series airplanes, and Model MD-88 airplanes. Therefore, all of these airplanes may be subject to the same unsafe condition.

Other Relevant Rulemaking

The FAA has previously issued three other ADs that concern the MLG shock strut pistons on McDonnell Douglas Model DC-9-81, -82, -83, and -87 series airplanes; Model MD-88 airplanes; and Model MD-90-30 series airplanes:

1. AD 99-13-07, which is applicable to certain Model DC-9-81, -82, -83, and -87 series airplanes, Model MD-88 airplanes, and Model MD-90-30 series airplanes, requires repetitive inspections to detect cracking of the MLG shock strut pistons, and replacement of a cracked piston with a new or serviceable part.

2. AD 2000-03-08, which is applicable to certain Model MD-90-30 series airplanes, requires repetitive fluorescent penetrant and magnetic particle inspection to detect fatigue cracking of the MLG shock strut pistons, and repair, if necessary.

3. AD 2001-09-18, which is applicable to certain Model DC-9-81, -82, -83, and -87 series airplanes, and Model MD-88 airplanes, requires, among other actions, repetitive dye penetrant and magnetic particle inspection to detect cracks of the MLG shock strut pistons; repair and replacement of discrepant parts; and installation of a preventative modification; as applicable. (This AD superseded AD 96-19-09.)

This proposed AD would constitute terminating action for the requirements of those ADs.

Explanation of Relevant Service Information

The FAA has reviewed and approved Boeing Service Bulletin MD80-32-309, Revision 01, dated April 25, 2001 (for Model DC-9-81, -82, -83, and -87 series airplanes, and Model MD-88 airplanes), and Boeing Service Bulletin MD90-32-031, Revision 01, dated April 25, 2001 (for Model MD-90-30 series airplanes); as applicable. The service bulletins describe procedures for replacement of the MLG shock strut piston assemblies, left and right-hand side, with new or serviceable, improved assemblies, which would eliminate the need for the requirements of certain ADs (described above). Accomplishment of the actions specified in the service bulletins is intended to adequately address the identified unsafe condition.

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.

Cost Impact

There are approximately 1,380 McDonnell Douglas Model DC-9-81, -82, -83, and -87 series airplanes; Model MD-88 airplanes; and Model MD-90-30 series airplanes of the affected design in the worldwide fleet. The FAA estimates that 820 airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately 28 work hours per airplane to accomplish the proposed actions, and that the average labor rate is $60 per work hour. The manufacturer has committed previously to its customers that it will bear the cost of replacement parts, subject to the conditions in the warranty. As a result, the cost of those parts is not attributable to this proposed AD. Based on these figures, the cost impact of the proposed AD on U.S. operators is estimated to be $1,377,600, or $1,680 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.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Safety

The Proposed Amendment

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

PART 39—AIRWORTHINESS DIRECTIVES

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

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

§ 39.13

[Amended]

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

McDonnell Douglas: Docket 2001-NM-197-AD.

Applicability: Model DC-9-81, -82, -83, and -87 series airplanes, and Model MD-88 airplanes, as listed in Boeing Service Bulletin MD80-32-309, Revision 01, dated April 25, 2001; and Model MD-90-30 series airplanes, as listed in Boeing Service Bulletin MD90-32-031, Revision 01, dated April 25, 2001; 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 (c) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Compliance: Required as indicated, unless accomplished previously.

To prevent fatigue cracking of the main landing gear (MLG) shock strut pistons, which could result in failure of the MLG shock strut pistons during landing or jacking of the airplane, and consequent damage to the airplane structure and injury to the passengers, flightcrew, or ground personnel, accomplish the following:

Replacement

(a) Before the accumulation of 30,000 total landings, or within 5,000 landings after the effective date of this AD, whichever occurs later: Replace the MLG shock strut piston assemblies, left and right-hand sides, with new or serviceable, improved assemblies, per the Accomplishment Instructions of Boeing Service Bulletin MD80-32-309, Revision 01, dated April 25, 2001 (for Model DC-9-81, -82, -83, and -87 series airplanes, and Model MD-88 airplanes); or Boeing Service Bulletin MD90-32-031, Revision 01, dated April 25, 2001 (for Model MD-90-30 series airplanes); as applicable.

Note 2:

Accomplishment of the replacement specified in Boeing Service Bulletin MD80-32-309, dated January 31, 2000 (for Model DC-9-81, -82, -83, and -87 series airplanes, and Model MD-88 airplanes); or Boeing Service Bulletin MD90-32-031, dated January 31, 2000 (for Model MD-90-30 series airplanes); as applicable; before the effective date of this AD, is considered acceptable for compliance with the requirement of paragraph (a) of this AD.

Compliance With Requirements of Other ADs

(b) Accomplishment of the replacement required by paragraph (a) of this AD constitutes terminating action for the requirements of ADs 99-13-07, amendment 39-11201, 2000-03-08, amendment 39-11567, and 2001-09-18, amendment 39-12225.

Alternative Methods of Compliance

(c) 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 3:

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

(d) 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.

Issued in Renton, Washington, on August 22, 2001.

Ali Bahrami,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.