AD 99-07-14

This amendment adopts a new airworthiness directive (AD), applicable to certain McDonnell Douglas Model DC-9-80 series airplanes, and Model MD-88 airplanes, that requires a one-time inspection to detect corrosion of the lug bores and the surface of the hinge plates of the vertical-to-horizontal stabilizer; and corrective actions, if necessary. This amendment is prompted by reports of corrosion of the lug bores and the surface of the hinge plates of the vertical-to-horizontal stabilizer, apparently due to the improper brushing of cadmium on the hinge plates during manufacture. The actions specified by this AD are intended to detect and correct corrosion of the lug bores and the surface of the hinge plates of the vertical-to-horizontal stabilizer, which could result in reduced structural integrity of the airplane.

Final rule.

99-07-14 MCDONNELL DOUGLAS: Amendment 39-11099. Docket 98-NM-166-AD. \n\n\tApplicability: Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), and DC-9-87 (MD-87) series airplanes, and Model MD-88 airplanes; as listed in McDonnell Douglas Service Bulletin MD80-55-054, dated March 3, 1998; 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 detect and correct corrosion of the lug bores and the surface of the hinge plates of the vertical-to-horizontal stabilizer, which could result in reduced structural integrity of the airplane, accomplish the following: \n\n\t(a)\tWithin 18 months after the effective date of this AD, perform a one-time visual inspection to detect corrosion of the lug bores and the surface of the hinge plates of the vertical-to-horizontal stabilizer, in accordance with McDonnell Douglas Service Bulletin MD80-55-054, dated March 3, 1998. \n\n\t\t(1)\tCondition 1: If no corrosion is detected, no further action is required by this paragraph. \n\n\t\t(2)\tCondition 2: If any corrosion is detected that is within the limits specified in the Structural Repair Manual, prior to further flight, remove the corrosion in accordance with the service bulletin. \n\n\t\t(3)\tCondition3: If any corrosion is detected that exceeds the limits specified in the Structural Repair Manual, prior to further flight, replace the hinge plates with new parts, in accordance with the service bulletin. \n\n\t(b)\tWithin 10 days after accomplishing the inspection required by paragraph (a) of this AD, or within 10 days after the effective date of this AD, whichever occurs later, submit a report of the inspection results (both positive and negative findings) to the Manager, Los Angeles Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate, 3960 Paramount Boulevard, Lakewood, California 90712-4137; fax (562) 627-5210. Information collection requirements contained in this regulation have been approved by the Office of Management and Budget (OMB) under the provisions of the Paperwork Reduction Act of 1980 (44 U.S.C. 3501 et seq.) and have been assigned OMB Control Number 2120-0056. \n\n\t(c)\tAn 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 ACO. 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 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Los Angeles ACO. \n\n\t(d)\tSpecial 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\n\t(e)\tExcept as provided by paragraph (b) of this AD, the actions shall be done in accordance with McDonnell Douglas Service Bulletin MD80-55-054, dated March 3, 1998. 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 beobtained from Boeing Commercial Aircraft Group, Long Beach Division, 3855 Lakewood Boulevard, Long Beach, California 90846, Attention: Technical Publications Business Administration, Dept. C1-L51 (2-60). Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Transport Airplane Directorate, 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. \n\n\t(f)\tThis amendment becomes effective on May 6, 1999.

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 Model DC-9-80 series airplanes, and Model MD-88 airplanes was published in the Federal Register on June 26, 1998 (63 FR 34832). That action proposed to require a one-time inspection to detect corrosion of the lug bores and the surface of the hinge plates of the vertical-to-horizontal stabilizer; and corrective actions, if necessary. \n\nComments Received \n\n\tInterested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comments received. \n\nSupport for the Proposed Rule \n\n\tTwo commenters support the proposed rule. \n\nRequests to Revise Initial Inspection Method \n\n\tSeveral commenters request that the FAA require, within 18 months, an "external" visual inspection for evidence of corrosion of the hinge plates with fairings removed. If corrosion is found during the "external" visual inspection, the commenters suggest that, prior to further flight, the one-time visual inspection specified in paragraph (a) of the proposed AD then be accomplished. If no corrosion is found during the "external" visual inspection, the commenters suggest that operators repeat the "external" visual inspection thereafter at intervals not to exceed 18 months, until the one-time visual inspection is accomplished within 6 years. The commenters state that because removing the pivot pin and horizontal stabilizer to conduct the proposed one-time visual inspection is very time consuming, it will cause an undue burden on operators. One commenter states that it will have to special schedule its fleet of airplanes to accomplish the proposed visual inspection within 18 months. In addition, one commenter states that Boeing supports its inspection procedures and is prepared to revise McDonnell Douglas Service Bulletin MD80-55-054, dated March 3, 1998 (which was referenced in the proposed AD as the appropriate source of service information for accomplishment of the proposed actions). \n\n\tThe FAA concurs partially. The FAA acknowledges that the procedures recommended by the commenters could be developed and implemented by the manufacturer in a revised service bulletin. However, because a revised service bulletin does not exist at this time, the FAA finds that no change to the final rule is warranted. When the manufacturer does revise the existing service bulletin, the FAA may approve that service bulletin as an alternative method of compliance (AMOC) to the requirements of this final rule. \n\nRequest to Include a Provision for Certain Inspections Performed Previously \n\n\tOne commenter requests that the FAA revise the proposed AD to include a provision for inspections of Significant Structural Items (SSI) 55.11.053, 55.11.054, and 55.51.066 accomplished previously within the last 18 months. The commenter states that the subject hinge plates are inspected when SSI's are inspected. The FAA does not concur. The FAA finds that the SSI inspections proposed by the commenter do not adequately address the identified unsafe condition of this AD, because they are much less rigorous than the inspections required in this AD. However, under the provisions of paragraph (c) of the final rule, the FAA may approve requests for alternative methods of compliance if data are submitted to substantiate that such an alternative would provide an acceptable level of safety. \n\nRequest to Delay Issuance of Final Rule \n\n\tOne commenter requests that the Structural Repair Manual (SRM) be revised prior to issuance of the final rule. The commenter contends that the SRM does not provide procedures for any protective finish after corrosion removal is accomplished. The commenter suggests a protective finish of fluid-resistant primer. The FAA concurs. The FAA has verified with the manufacturer that a Temporary Revision to Chapter 55 of the SRM has been issued, which describes procedures for a protective finish of fluid-resistant primer after corrosion removal and deletes cadmium plating from the repair procedures. Accordingly, no change to the final rule is necessary. \n\nConclusion \n\n\tAfter careful review of the available data, including the comments noted above, the FAA has determined that air safety and the public interest require the adoption of the rule as proposed. \n\nCost Impact \n\n\tThere are approximately 1,059 airplanes of the affected design in the worldwide fleet. The FAA estimates that 706 airplanes of U.S. registry will be affected by this AD. It will take approximately 117 work hours per airplane (which includes removal and installation) to accomplish the required inspection, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the AD on U.S. operators is estimated to be $4,956,120, or $7,020 per airplane. \n\n\tThe 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. \n\nRegulatory Impact \n\n\tThe regulations adopted herein will not have substantial direct effects 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, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment. \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\nAuthority: 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: