Airworthiness Directives; Cessna Aircraft Company Models 172R and 172S Airplanes

withdraw the proposed AD. The FAA does not agree. We acknowledge that the manufacturer has stated that all affected airplanes have accomplished the actions specified in Cessna Service Bulletin SB750–53–19, dated January 20, 2000 (the appropriate service information specified in the final rule). However, we have determined that it is necessary to issue a final rule to prevent an inadvertent installation of a bulkhead web doubler having part number (P/N) 6711093–38 on any airplane. As explained in the preamble of the proposed AD, installation of that doubler could cause jamming of the roll control system (ailerons and spoilers) and result in reduced controllability of the airplane. Therefore, no change to the final rule is necessary. Conclusion After careful review of the available data, including the comment noted above, the FAA has determined that air safety and the public interest require the adoption of the rule as proposed. Cost Impact The FAA estimates that approximately 95 Cessna Model 750 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. The manufacturer has committed previously to its customers that it will bear the cost of replacement parts. Based on these figures, the cost impact of the AD on U.S. operators is estimated to be $45,600, or $480 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 adding the following new airworthiness directive: 2001–07–04 Cessna Aircraft Company: Amendment 39–12169. Docket 2000– NM–63–AD. Applicability: Model 750 airplanes, having manufacturer’s serial numbers –0001 through –0102 inclusive, 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 (d) 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 prevent jamming of the roll control system (ailerons and spoilers), which could result in reduced controllability of the airplane, accomplish the following: Inspection and Removal (a) Within 200 flight hours or 180 days after the effective date of this AD, whichever occurs first, inspect the bulkhead web for an existing round bulkhead web doubler, in accordance with the Accomplishment Instructions of Cessna Service Bulletin SB750–53–19, dated January 20, 2000. If there is a round bulkhead web doubler having part number (P/N) 6711093–38, prior to further flight, remove the doubler in accordance with the service bulletin. Installation (b) Within 200 flight hours or 180 days after the effective date of this AD, whichever occurs first, install a new right bulkhead web doubler having P/N 6791213–4 and a left bulkhead web doubler having P/N 6791213– 3 and enlarge the lightening holes, in accordance with the Accomplishment Instructions of Cessna Service Bulletin SB750–53–19, dated January 20, 2000. Spares (c) As of the effective date of this AD, no person shall install a bulkhead web doubler having P/N 6711093–38, on any airplane. Alternative Method of Compliance (d) 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, Wichita 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, Wichita ACO. Note 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Wichita ACO. VerDate 11<MAY>2000 17:09 Apr 09, 2001 Jkt 194001 PO 00000 Frm 00002 Fmt 4700 Sfmt 4700 E:\FR\FM\10APR1.SGM pfrm04 PsN: 10APR1 18523 Federal Register / Vol. 66, No. 69 / Tuesday, April 10, 2001 / Rules and Regulations Special Flight Permits (e) 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 (f) The actions shall be done in accordance with Cessna Service Bulletin SB750–53–19, including Supplemental Data, dated January 20, 2000. 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 Cessna Aircraft Company, P.O. Box 7706, Wichita, Kansas 67277. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Wichita Aircraft Certification Office, 1801 Airport Road, Room 100, Mid-Continent Airport, Wichita, Kansas; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. Effective Date (g) This amendment becomes effective on May 15, 2001. Issued in Renton, Washington, on April 2, 2001. Donald L. Riggin, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 01–8611 Filed 4–9–01; 8:45 am] BILLING CODE 4910–13–P DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. 2000–NM–157–AD; Amendment 39–12170; AD 2001–07–05] RIN 2120–AA64 Airworthiness Directives; Boeing Model 767 Series Airplanes Powered by General Electric or Pratt & Whitney Engines AGENCY: Federal Aviation Administration, DOT. ACTION: Final rule. SUMMARY: This amendment adopts a new airworthiness directive (AD), applicable to certain Boeing Model 767 series airplanes powered by General Electric or Pratt & Whitney engines, that requires repetitive inspections to detect discrepancies of the aft-most fastener holes in the horizontal tangs of the midspar fitting of the strut, and corrective actions, if necessary. This AD also provides an optional terminating action for the repetitive inspections. These actions are necessary to prevent fatigue cracking in primary strut structure and reduced structural integrity of the strut, which could result in separation of the strut and engine. This action is intended to address the identified unsafe condition. DATES: Effective May 15, 2001. The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of May 15, 2001. ADDRESSES: The service information referenced in this AD may be obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124–2207. 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 Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. FOR FURTHER INFORMATION CONTACT: John Craycraft, Aerospace Engineer, Airframe Branch, ANM–120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055–4056; telephone (425) 227–2782; fax (425) 227–1181. SUPPLEMENTARY INFORMATION: 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 Boeing Model 767 series airplanes powered by General Electric or Pratt & Whitney engines was published in the Federal Register on October 10, 2000 (65 FR 60124). That action proposed to require repetitive inspections to detect discrepancies of the aft-most fastener holes in the horizontal tangs of the midspar fitting of the strut, and corrective actions, if necessary. That action also proposed to provide for optional terminating action for the repetitive inspections. Comments Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comments received. Request To Limit Area of Inspection or Give Credit for Previous Inspections Several commenters request that the FAA revise paragraph (a) of the proposed AD to limit the area of the inspections to the two aft-most holes of the horizontal tangs of the midspar fitting of the strut, as shown in Boeing Service Bulletin 767–54A0101, Revision 1, dated February 3, 2000, rather than requiring inspections of the four aft most holes. The commenters state that the two aft-most holes are the most susceptible to fatigue cracking because of the higher stresses in this area of the midspar fitting. The commenters conclude that, as long as the two aft- most holes are uncracked, the next two holes would be uncracked as well. One commenter suggests reducing the interval for the repetitive inspections of the two aft-most holes in lieu of expanding the inspection area to the four aft-most holes. Other commenters request that, if the FAA finds it necessary to require inspections beyond the area specified in the service bulletin, the initial inspection per paragraph (a) be deferred to 1,500 flight cycles if inspections of the two aft-most holes have been accomplished before the effective date of this AD per the service bulletin. The FAA partially concurs with the commenters’ requests. While, in theory, if the two aft-most holes are not cracked, the next row of holes should not be cracked either, the FAA has not found this to be the case, as discussed in the notice of proposed rulemaking (NPRM). On certain Model 747 series airplanes, which have fittings and loading conditions similar to those found on the Model 767 series airplanes subject to this AD, the aft-most row of fasteners of the midspar fittings was not cracked, but the next row of fasteners was. Based on this experience, the FAA does not concur with the commenters’ request to reduce the inspection interval in lieu of requiring inspections of both rows of fasteners. However, the FAA does concur that the initial compliance time for the inspection of the four aft-most fasteners can be extended for airplanes on which the two aft-most fasteners have been inspected per the service bulletin before the effective date of this AD. The FAA finds that, for these previously inspected airplanes only, the compliance time for paragraph (a) of this AD can be extended from 600 flight hours to 1,500 flight hours. Accordingly, a new paragraph (b) has been added to this final rule and subsequent paragraphs have been reordered. Request To Reference Revised Service Information One commenter questions whether the FAA will revise the proposed rule to reference a new revision of the service bulletin. The commenter points out that the proposed requirement to inspect the four aft-most fasteners is a difference from the service bulletin and questions whether the FAA will provide an alternative method of compliance (AMOC) for this requirement, or whether a local approved authority will VerDate 11<MAY>2000 17:09 Apr 09, 2001 Jkt 194001 PO 00000 Frm 00003 Fmt 4700 Sfmt 4700 E:\FR\FM\10APR1.SGM pfrm04 PsN: 10APR1