AD 98-08-01 Airworthiness Directives; Fokker Model F28 Mark 0070 and Mark 0100 Series Airplanes

Models named: F28 Mark 0070, Mark 0100. Read the applicability below — it usually turns on serial or part numbers too.

Model F28 Mark 0070 and Mark 0100 airplanes; as listed in Fokker Service Bulletin SBF100-53-084, dated July 6, 1996; if equipped with any corrujoint seal having part number (P/N) BE20061 (Rolls-Royce P/N 3405891); 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 (e) 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.

Required as indicated, unless accomplished previously.'' That language reappears in this final rule. Therefore, no change to the final rule is necessary. Similarly, the ATA requests that a provision be added to exclude airplanes on which the intent of the proposed AD has already been accomplished, including repairs that were generated to repair damaged structure, in accordance with Fokker Service Bulletin SBF100-53-081, which is not referenced in the proposed rule. The FAA concurs that replacements and repairs accomplished prior to the effective date of this AD in accordance with the service bulletin referenced by the commenter are acceptable provided that no seal has been subsequently replaced with a seal having part number BE20061 (Rolls-Royce part number 3405891). This final rule, therefore, includes a note stating that inspections for heat damage, leak tests, seal replacements, and repairs accomplished prior to the effective date of this AD, in accordance with Fokker Service Bulletin SBF100-53-081, dated July 7, 1995, are considered acceptable for compliance with the requirements of this AD, provided that no seal has been subsequently replaced with a seal having part number BE20061 (Rolls-Royce part number 3405891). The ATA, on behalf of another commenter, requests that a provision be added to allow the leak tests to be omitted if the inspection reveals no heat damage and if, prior to further flight, the corrujoint seals at the seventh stage low pressure check valve and twelfth stage high pressure check valves are replaced with the improved corrujoint seals. The commenter states that accomplishment of these actions is similar to the optional method of complying with Fokker Service Bulletin SBF100-53-084. The FAA concurs with the commenter's request. The FAA agrees that, if the inspection required by paragraph (a) of this AD reveals no heat damage, and if, prior to further flight, all affected corrujoint seals are replaced with the improved corrujoint seals, then accomplishment of the leak tests is not necessary. The FAA has revised and [[Page 17319]] reformatted paragraph (b) of this final rule to include this provision. The ATA also requests that the compliance time be extended from 12 to 18 months. The commenter states that 18 months is the accepted industry standard and further notes that, because of the areas to which access is needed, the work must be accomplished while an airplane is out of service for maintenance. The FAA does not concur. 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 a number of other factors as well. Those included the recommendations of the manufacturer and foreign airworthiness authority, the availability of required parts, and the practical aspect of accomplishing the required actions within an interval of time coinciding with normal scheduled maintenance for the majority of the affected operators. Considering all of those factors, the FAA determined that the proposed compliance time represents the maximum interval in which the affected airplanes could continue to operate without compromising safety. In that regard, the commenter did not provide any data to substantiate that an extension of the compliance time would not compromise safety. In view of those factors, and the amount of time that has already elapsed since issued of the original notice of proposed rulemaking, the FAA has determined that further delay of these actions is, in general, not appropriate. The FAA may, however, approve a request for an adjustment of the compliance time under the provisions of this final rule if data are submitted to substantiate that such an adjustment would provide an equivalent level of safety. Conclusion After 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 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. Cost Impact The FAA estimates that 131 Fokker Model F28 Mark 0070 and Mark 0100 series airplanes of U.S. registry will be affected by this AD. The inspection will take approximately 3 work hours per airplane to accomplish, 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 $23,580, or $180 per airplane. The replacement of the corrujoint seals will take approximately 7 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Required parts will cost approximately $80 per airplane. Based on these figures, the cost impact of the replacement required by this AD on U.S. operators is estimated to be $65,500, or $500 per airplane. The 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. Regulatory Impact The 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. 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. Sec. 39.13 [Amended] 2. Section 39.13 is amended by adding the following new airworthiness directive: 98-08-01 Fokker: Amendment 39-10450. Docket 97-NM-249-AD.