AD 96-11-04

This amendment adopts a new airworthiness directive (AD), applicable to certain McDonnell Douglas Model DC-9 and Model DC-9-80 series airplanes, Model MD-88 airplanes, and C-9 (military) series airplanes, that requires modification of the slant panel insulation blankets on the slant pressure panel of the main landing gear. The amendment also requires a visual inspection to detect discrepancies of the left and right seal assemblies of the overwing emergency exit door, and replacement of any discrepant door seal. This amendment is prompted by a report that the flaps and landing gear did not extend or retract properly due to water accumulation in the slant pressure panel area. The actions specified by this AD are intended to prevent such water accumulation, which could result in the failure of the flaps or landing gear to properly extend or retract.

Final rule.

96-11-04 MCDONNELL DOUGLAS: Amendment 39-9629. Docket 95-NM-185-AD. \n\n\tApplicability: Model DC-9-10, -20, -30, -40, and -50 series airplanes; Model DC-9-81 (MD- 81), -82 (MD-82), -83 (MD-83), -87 (MD-87) series airplanes; Model MD-88 airplanes; and C-9 (military) series airplanes; as listed in McDonnell Douglas Service Bulletin DC9-53-268, dated August 11, 1995; 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 otherwise 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 (b) 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 water accumulation in the slant pressure panel area, which could result in the failure of the flaps or landing gear to properly extend or retract, accomplish the following: \n\n\t(a)\tWithin 24 months after the effective date of this AD, accomplish paragraphs (a)(1) and (a)(2) of this AD, in accordance with McDonnell Douglas Service Bulletin DC9-53-268, dated August 11, 1995. \n\n\t\t(1)\tModify the slant panel insulation blankets on the slant pressure panel of the main landing gear. \n\n\t\t(2)\tPerform a visual inspection to detect discrepancies (i.e., defects and constant gap) of the left and right seal assemblies of the overwing emergency exit door. If any discrepancy is detected, prior to further flight, replace door seal in accordance with the service bulletin. \n\n\t(b)\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 Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. 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(c)\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(d)\tThe modification, inspection, and replacement shall be done in accordance with McDonnell Douglas Service Bulletin DC9-53-268, dated August 11, 1995.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 McDonnell Douglas Corporation, 3855 Lakewood Boulevard, Long Beach, California 90846, Attention: Technical Publications Business Administration, Department C1-L51 (2-60). 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, Transport Airplane Directorate, 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(e)\tThis amendment becomes effective on June 26, 1996.

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 and Model DC-9-80 series airplanes, Model MD-88 airplanes, and C-9 (military) series airplanes was published in the Federal Register on January 31, 1996 (61 FR 3341). That action proposed to require modification of the slant panel insulation blankets on the slant pressure panel of the main landing gear. That action also proposed to require a visual inspection to detect discrepancies of the left and right seal assemblies of the overwing emergency exit door, and replacement of the discrepant door seal. \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 Proposal \n\n\tTwo commenters support the proposed rule. \n\nRequests to Extend the Compliance Time \n\n\tSeveral commenters request that the compliance time for accomplishment of the modification be extended from the proposed 24 months. These commenters request an extension to as much as 36 months, which will allow the modification to be accomplished during a regularly scheduled heavy maintenance check when the airplanes are brought to main base for an extended hold. Two of these commenters state that they would have to special schedule their fleet in order to accomplish the modification within the proposed compliance time; this would entail considerable additional expenses. \n\n\tAfter consideration of all the available information, the FAA cannot conclude that an extension of the proposed compliance time is warranted. In developing an appropriate compliance time for this action, the FAA considered not only the degree of urgency associated with addressing the subject unsafe condition, but the availability of required parts and the practical aspect of accomplishing the requiredmodification within an interval of time that parallels normal scheduled maintenance for the majority of affected operators. Further, the proposed compliance time of 24 months was arrived at initially with the concurrence of affected operators, the manufacturer, and the FAA. In light of this, and in consideration of the amount of time that has already elapsed since issuance of the original notice, the FAA has determined that further delay of accomplishment of the requirements of this final rule is not appropriate. However, under the provisions of paragraph (b) of the final rule, the FAA may approve requests for adjustments to the compliance time if data are submitted to substantiate that such an adjustment would provide an acceptable level of safety. \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\tThereare approximately 1,500 McDonnell Douglas Model DC-9 and Model DC-9-80 series airplanes, Model MD-88 airplanes, and C-9 (military) series airplanes of the affected design in the worldwide fleet. The FAA estimates that 1,000 airplanes of U.S. registry will be affected by this AD, that it will take approximately 8 work hours per airplane to accomplish the required actions, and that the average labor rate is $60 per work hour. Based on these figures, the cost impact of the AD on U.S. operators is estimated to be $480,000, or $480 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 ofpower 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.\tThe authority citation for part 39 continues to read as follows: \n\nAuthority: 49 USC 106(g), 40113, 44701. \n\n§ 39.13 - (Amended) \n\n\t2.\tSection 39.13 is amended by adding the following new airworthiness directive: