03-31439. Airworthiness Directives; McDonnell Douglas Model MD-90-30 Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Final rule.

SUMMARY:

This amendment revises an existing airworthiness directive (AD), applicable to all McDonnell Douglas Model MD-90-30 airplanes, that currently requires replacing the lanyards on the pressure relief door for the thrust reverser with new, improved lanyards, and doing associated modifications. The actions specified by that AD are intended to ensure that the lanyards on the pressure relief door have adequate strength. Lanyards of inadequate strength could allow the pressure relief door to detach from the thrust reverser in the event that an engine bleed air duct bursts, which could result in the detached door striking and damaging the horizontal stabilizer, and consequent reduced controllability of the airplane. This amendment is prompted by the fact that a certain paragraph of the existing AD prohibits installation of certain part numbers of lanyards; the numbers listed in that paragraph correspond to new, improved lanyards that are acceptable for installation. This amendment will correct these part numbers to prohibit installation of suspect lanyards while allowing installation of the new, improved lanyards. This action is intended to address the identified unsafe condition.

DATES:

Effective January 27, 2004.

The incorporation by reference of Boeing Service Bulletin MD90-78-048, dated February 15, 2001, as listed in the regulations, was approved previously by the Director of the Federal Register as of July 9, 2003 (68 FR 33355, June 4, 2003).

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); and Rohr, Inc., 850 Lagoon Drive, Chula Vista, California 91910-2098. This information may be examined at the Federal Aviation Administration (FAA), Transport Airplane Directorate, Rules Docket, 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.

FOR FURTHER INFORMATION CONTACT:

Stephen Kolb, Aerospace Engineer, Propulsion Branch, ANM-140L, FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California 90712-4137; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by revising AD 2003-11-15, amendment 39-13174 (68 FR 33355, June 4, 2003), which is applicable to all McDonnell Douglas Model MD-90-30 airplanes, was published in the Federal Register on August 21, 2003 (68 FR 50491). The action proposed to continue to require replacing the lanyards on the pressure relief door for the thrust reverser with new, improved lanyards, and doing associated modifications. The action also proposed to prohibit installation of certain pressure relief door lanyards.

Comments

Interested persons have been afforded an opportunity to participate in the making of this amendment. No comments were submitted in response to the proposal or the FAA's determination of the cost to the public.

Conclusion

The FAA has determined that air safety and the public interest require the adoption of the rule as proposed.

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). However, for clarity and consistency in this final rule, we have retained the language of the NPRM regarding that material.

Cost Impact

There are approximately 110 airplanes of the affected design in the worldwide fleet. The FAA estimates that 21 airplanes of U.S. registry will be affected by this AD. The changes in this action add no additional economic burden. The current costs for this AD are repeated for the convenience of affected operators, as follows:

It takes approximately 8 work hours per airplane to accomplish the actions currently required by AD 2003-11-15, at an average labor rate of $65 per work hour. Required parts are provided at no cost to the operator. Based on these figures, the cost impact of the actions currently required by AD 2003-11-15 is estimated to be $10,920, or $520 per airplane.

The cost impact figure discussed above is 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.

§ 39.13

[Amended]

2. Section 39.13 is amended by removing amendment 39-13174 ( 68 FR 33355, June 4, 2003), and by adding a new airworthiness directive (AD), amendment 39-13400, to read as follows:

2003-11-15 R1 McDonnell Douglas:  Amendment 39-13400. Docket 2003-NM-169-AD. Revises AD 2003-11-15, Amendment 39-13174.

Applicability: All Model MD-90-30 airplanes, 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 ensure that the lanyards on the pressure relief door for the thrust reverser have adequate strength so that the door will not detach from the thrust reverser in the event that an engine bleed air duct bursts, which could result in the door striking and damaging the horizontal stabilizer, accomplish the following:

Replacement of Lanyards on the Thrust Reverser Pressure Relief Door

(a) Within 18 months after the effective date of the AD, replace the lanyards on the pressure relief door for the thrust reverser with new, improved lanyards, and accomplish associated modifications, per the Accomplishment Instructions of Boeing Service Bulletin MD90-78-048, dated February 15, 2001. The associated modifications include removing the pressure relief door, modifying the pressure relief door (including replacing existing brackets with new brackets and re-identifying the door with a new part number), modifying the lower track beam (including removing terminals, replacing the aft quick-release pin with a new pin, and re-identifying the beam with a new part number), modifying the heat shield on the lanyard assembly attach lugs, and re-installing the pressure relief door.

Note 2:

Boeing Service Bulletin MD90-78-048, dated February 15, 2001, refers to International Aero Engines Service Bulletin V2500-NAC-78-0184, dated February 16, 2001, for instructions on replacing the lanyards on the pressure relief door for the thrust reverser.

Parts Installation

(b) After the effective date of this AD, no person may install a lanyard having part number (S700M1392A170) or (S700M1392A161) on the pressure relief door for the thrust reverser on any airplane.

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 Permits

(d) 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.

Incorporation by Reference

(e) Unless otherwise specified in this AD, the actions shall be done in accordance with Boeing Service Bulletin MD90-78-048, dated February 15, 2001. This incorporation by reference was approved previously by the Director of the Federal Register as of July 9, 2003 (68 FR 33355, June 4, 2003). 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

(f) This amendment becomes effective on January 27, 2004.

Issued in Renton, Washington, on December 12, 2003.

Kevin M. Mullin,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.