[Federal Register Volume 63, Number 72 (Wednesday, April 15, 1998)] [Proposed Rules] [Pages 18342-18344] From the Federal Register Online via the Government Publishing Office [www.gpo.gov] [FR Doc No: 98-9875] ----------------------------------------------------------------------- DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. 98-NM-98-AD] RIN 2120-AA64 Airworthiness Directives; Fokker Model F27 Mark 100, 200, 300, 400, 500, 600, and 700 Series Airplanes AGENCY: Federal Aviation Administration, DOT. ACTION: Notice of proposed rulemaking (NPRM). ----------------------------------------------------------------------- SUMMARY: This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Fokker Model F27 Mark 100, 200, 300, 400, 500, 600, and 700 series airplanes. This proposal would require replacement of the actuating ram bobbin and O-ring seals of the main landing gear (MLG), with new bobbins and improved O-ring seals. This proposal is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by the proposed AD are intended to prevent loss of dampening of the MLG actuating ram, which could result in failure of the MLG lockstruts, and consequent structural damage to the airplane. DATES: Comments must be received by May 15, 1998. ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 98-NM-98-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except Federal holidays. The service information referenced in the proposed rule may be obtained from Fokker Services B.V., Technical Support Department, P.O. Box 75047, 1117 ZN Schiphol Airport, the Netherlands. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington. FOR FURTHER INFORMATION CONTACT: Norman B. Martenson, Manager, [[Page 18343]] International Branch, ANM-116, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-2110; fax (425) 227-1149. SUPPLEMENTARY INFORMATION: Comments Invited Interested persons are invited to participate in the making of the proposed rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this notice may be changed in light of the comments received. Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report summarizing each FAA-public contact concerned with the substance of this proposal will be filed in the Rules Docket. Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this notice must submit a self-addressed, stamped postcard on which the following statement is made: ``Comments to Docket Number 98-NM-98-AD.'' The postcard will be date stamped and returned to the commenter. Availability of NPRMs Any person may obtain a copy of this NPRM by submitting a request to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 98-NM-98-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Discussion The Rijksluchtvaartdienst (RLD), which is the airworthiness authority for the Netherlands, notified the FAA that an unsafe condition may exist on certain Fokker Model F27 Mark 100, 200, 300, 400, 500, 600, and 700 series airplanes. The RLD advises that it received reports of broken lockstruts on the main landing gear (MLG) due to loss of dampening of the MLG actuating ram, which extends and retracts the MLG. The actuating ram is equipped with a dampening chamber filled with silicon fluid (oil), which is forced through a restrictor to dampen gear movement. The existing design of the O-ring seals could allow fluid to leak gradually, which may not be noticed during regular maintenance inspections, and could lead to loss of dampening of the MLG actuating ram. This condition, if not corrected, could result in failure of the MLG lockstruts, and consequent structural damage to the airplane. Explanation of Relevant Service Information The manufacturer has issued Fokker Service Bulletin F27/32-168, dated October 23, 1996, which describes procedures for replacing the actuating ram bobbin, O-ring seals, and back-up O-ring seals of the MLG, with new bobbins and improved O-ring seals. The service bulletin references Dunlop Equipment Division Service Bulletin SB 32-1142, dated October 22, 1996, as an additional source of service information to accomplish the modification. Accomplishment of the actions specified in the service bulletin is intended to adequately address the identified unsafe condition. The RLD classified this service bulletin as mandatory and issued Dutch airworthiness directive 1996-142 (A), dated November 29, 1996, in order to assure the airworthiness of these airplanes in the Netherlands. FAA's Conclusions These airplane models are manufactured in the Netherlands and are type certificated for operation in the United States under the provisions of Section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the applicable bilateral airworthiness agreement. Pursuant to this bilateral airworthiness agreement, the RLD has kept the FAA informed of the situation described above. The FAA has examined the findings of the RLD, reviewed all available information, and determined that AD action is necessary for products of this type design that are certificated for operation in the United States. Explanation of Requirements of Proposed Rule Since an unsafe condition has been identified that is likely to exist or develop on other airplanes of the same type design registered in the United States, the proposed AD would require accomplishment of actions specified in the service bulletin described previously. Cost Impact The FAA estimates that 34 airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately 26 work hours per airplane to accomplish the proposed replacement, at an average labor rate of $60 per work hour. Required parts would be furnished by the manufacturer at no cost to the operators. Based on these figures, the cost impact of the replacement proposed by this AD on U.S. operators is estimated to be $53,040, or $1,560 per airplane. The cost impact figure discussed above is based on assumptions that no operator has yet accomplished any of the proposed 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 proposed herein would 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 proposal would not have sufficient federalism implications to warrant the preparation of a Federalism Assessment. For the reasons discussed above, I certify that this proposed regulation (1) is not a `significant regulatory action' under Executive Order 12866; (2) is not a `significant rule' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) if promulgated, 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 copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption ADDRESSES. List of Subjects in 14 CFR Part 39 Air transportation, Aircraft, Aviation safety, Safety. The Proposed Amendment Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend 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. [[Page 18344]] Sec. 39.13 [Amended] 2. Section 39.13 is amended by adding the following new airworthiness directive: Fokker Services B.V.: Docket 98-NM-98-AD. Applicability: Model F27 Mark 100, 200, 300, 400, 500, 600, and 700 series airplanes; equipped with Dunlop main landing gear (MLG) actuating rams having part number (P/N) AC67132, AC67134, AC67848, or AC67850; 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 (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. Compliance: Required as indicated, unless accomplished previously. To prevent loss of dampening of the MLG actuating ram, which could result in failure of the MLG lockstruts, and consequent structural damage to the airplane, accomplish the following: (a) Within 4,000 flight hours or 2 years after the effective date of this AD, whichever occurs first, replace the actuating ram bobbin, O-ring seals, and back-up O-ring seals of the MLG, with new bobbins and improved O-ring seals, in accordance with Fokker Service Bulletin F27/32-168, dated October 23, 1996. Note 2: Dunlop Equipment Division Service Bulletin SB 32-1142, dated October 22, 1996, and Revision 1, dated January 14, 1997, provide service information for accomplishment of the modification. (b) As of the effective date of this AD, no person shall install on any airplane a Dunlop Main Undercarriage Ram, part number (P/N) AC67132, AC67134, AC67848, or AC67850, unless it has been modified in accordance with Fokker Service Bulletin F27/32-168, dated October 23, 1996. (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, International Branch, ANM-116, FAA, Transport Airplane Directorate. Operators shall submit their request through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, International Branch, ANM-116. Note 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the International Branch, ANM-116. (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. Note 4: The subject of this AD is addressed in Dutch airworthiness directive 1996-142(A), dated November 29, 1996. Issued in Renton, Washington, on April 8, 1998. Darrell M. Pederson, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 98-9875 Filed 4-14-98; 8:45 am] BILLING CODE 4910-13-U