AD 2003-08-16

This amendment adopts a new airworthiness directive (AD), applicable to certain McDonnell Douglas Model MD-90-30 airplanes, that requires a one-time inspection for chafing of the RDB wire bundle against the No. 2 automatic direction finder (ADF) receiver located at the aft end of the forward right radio rack; repair or replacement, if necessary; and modification of the wire bundle. The actions specified by this AD are intended to prevent chafing of the RDB wire bundle against the No. 2 ADF receiver, which could result in electrical arcing and consequent smoke and/or fire in the cockpit. This action is intended to address the identified unsafe condition.

Final rule.

2003-08-16 McDonnell Douglas: Amendment 39-13129. Docket 2001-NM-173-AD. \n\n\tApplicability: Model MD-90-30 airplanes equipped with a No. 2 automatic direction finder (ADF) receiver, and listed in McDonnell Douglas Alert Service Bulletin MD90-24A051, Revision 02, dated August 14, 2002; certificated in any category. \n\n\tNote 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. \n\n\tCompliance: Required as indicated, unless accomplished previously. \n\n\tTo prevent chafing of the RDB wire bundle against the No. 2 ADF receiver, which could result in electrical arcing and consequent smoke and/or fire in the cockpit, accomplish the following: \n\nInspection/Repair or Replacement/Modification \n\n\t(a) Within 6 months after the effective date of this AD, do the requirements specified in paragraphs (a)(1) and (a)(2) of this AD, per McDonnell Douglas Alert Service Bulletin MD90-24A051, Revision 02, excluding Evaluation Form, dated August 14, 2002. \n\n\t(1) Do a one-time general visual inspection for chafing of the RDB wire bundle against the No. 2 ADF receiver located at the aft end of the forward right radio rack. If any chafing is found, before further flight, repair or replace the affected wire bundle. \n\n\tNote 2: For the purposes of this AD, a general visual inspection is defined as: "A visual examination ofan interior or exterior area, installation, or assembly to detect obvious damage, failure, or irregularity. This level of inspection is made from within touching distance unless otherwise specified. A mirror may be necessary to enhance visual access to all exposed surfaces in the inspection area. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight, or droplight 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." \n\n\t(2) Modify the RDB wire bundle (including installation of three new tie mounts using new screws and clip nuts, removal of the existing tie straps and splitting the wire bundle into two separate bundles, installation of six new straps, and verification of adequate clearance between the wire bundle and the ADF receiver), and do the return-to-service test. \n\n\t(b) Accomplishment of the actions specifiedin paragraphs (a)(1) and (a)(2) of this AD, per McDonnell Douglas Alert Service Bulletin MD90-24A051, dated October 28, 1999; or Revision 01, dated March 26, 2001; before the effective date of this AD, is considered acceptable for compliance with the requirements of this AD. \n\nAlternative Methods of Compliance \n\n\t(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. \n\n\tNote 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Los Angeles ACO. \n\nSpecial Flight Permits \n\n\t(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. \n\nIncorporation by Reference \n\n\t(e) The actions shall be done in accordance with McDonnell Douglas Alert Service Bulletin MD90-24A051, Revision 02, excluding Evaluation Form, dated August 14, 2002. This incorporation by reference was approved 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 \n\n\t(f) This amendment becomes effective on May 30, 2003.

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 MD-90-30 airplanes was published in the Federal Register on September 23, 2002 (67 FR 59481). That action proposed to require a one-time inspection for chafing of the RDB wire bundle against the automatic direction finder (ADF) receiver located at the aft end of the forward right radio rack; repair or replacement, if necessary; and modification of the wire bundle. \n\nComment \n\n\tInterested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the single comment received. \n\n\tThe commenter states that the unsafe condition corrected by the proposed AD only exists when the No. 2 ADF receiver is installed on the airplane, and asks that explicit relief be included in the proposed AD to preclude action if the operator doesnot use the No. 2 ADF receiver. The commenter notes that without the No. 2 ADF receiver installed, there is no unsafe condition. \n\n\tThe FAA agrees with the commenter, and notes that the referenced service bulletin specified that the chafing condition could exist only on airplanes equipped with the No. 2 ADF receiver. We have changed the applicability in this final rule to add that it is only applicable to airplanes equipped with the No. 2 ADF receiver. In addition, we have changed the term, "ADF receiver" to "No. 2 ADF receiver" throughout the final rule. \n\nExplanation of Editorial Change \n\n\tWe have changed the service bulletin citation throughout this final rule to exclude the Evaluation Form. The form is intended to be completed by operators and submitted to the manufacturer to provide input on the quality of the service bulletin; however, this AD does not include such a requirement. \n\nConclusion \n\n\tAfter careful review of the available data, including the comment and change noted above, the FAA has determined that air safety and the public interest require the adoption of the rule with the changes previously described. The FAA has determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD. \n\nCost Impact \n\n\tThere are approximately 96 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. \n\n\tIt will take approximately 1 work hour per airplane to accomplish the inspection, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the inspection required by this AD on U.S. operators is estimated to be $1,260, or $60 per airplane. \n\n\tIt will take approximately 4 work hours per airplane to accomplish the modification of the RDB wire bundle, at an average labor rate of $60 per work hour. Parts cost is minimal. Based on these figures, the cost impact of the modification required by this AD on U.S. operators is estimated to be $5,040, or $240 per airplane. \n\n\tShould an operator be required to accomplish the repair or replacement of the wire bundle, it will take approximately 2 work hours per airplane to accomplish the actions, at an average labor rate of $60 per work hour. Parts cost is minimal. Based on these figures, the cost impact of the repair or replacement required by this AD is estimated to be $120 per airplane. \n\n\tThe 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 necessitatedby other administrative actions. \n\nRegulatory Impact \n\n\tThe 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. \n\n\tFor 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. \n\nList of Subjects in 14 CFR Part 39 \n\n\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. \n\nAdoption of the Amendment \n\n\tAccordingly, 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: \n\nPART 39-AIRWORTHINESS DIRECTIVES \n\n\t1. The authority citation for part 39 continues to read as follows: \n\n\tAuthority: 49 U.S.C. 106(g), 40113, 44701. \n\n§ 39.13 (Amended) \n\n\t2. Section 39.13 is amended by adding the following new airworthiness directive: