93-21-01: Hydraulic Systems

93-21-01 FOKKER: Amendment 39-8715. Docket 92-NM-154-AD. Applicability: Model F28 Mark 0100 series airplanes; serial numbers 11244 through 11363, inclusive, and 11408; certificated in any category. Compliance: Required as indicated, unless accomplished previously. To prevent the occurrence of overheated brakes and blown tires, which would lead to loss of braking performance and may cause the loss of directional control of the airplane while it is on the ground, accomplish the following: (a) For the airplane having serial number 11408: Within 7 months after the effective date of this AD, remove the hydraulic system 1 return filter, having part number QA05775; and install an improved system 1 return filter, having part number QA07236; in accordance with Fokker Service Bulletin SBF100-29-021, Revision 2, dated December 22, 1992. (b) For airplanes having serial number 11244 through 11363, inclusive: Within 7 months after the effective date of this AD, removethe hydraulic systems 1 and 2 return filters, having part numbers QA05775 and QA05777, respectively; and install improved systems 1 and 2 return filters, having part numbers QA07236 and QA07237, respectively; in accordance with Fokker Service Bulletin SBF100-29- 021, Revision 1, dated July 3, 1992; or Revision 2, dated December 22, 1992. (c) As of the effective date of this AD, no person shall install hydraulic systems 1 and 2 return filters, part numbers QA05775 and QA05777, respectively, on any airplane. (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, Standardization Branch, ANM-113, 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, Standardization Branch, ANM-113. NOTE: Information concerning the existence of approvedalternative methods of compliance with this AD, if any, may be obtained from the Standardization Branch, ANM-113. (e) Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate the airplane to a location where the requirements of this AD can be accomplished. (f) The removal and installation shall be done in accordance with Fokker Service Bulletin SBF100-29-021, Revision 1, dated July 3, 1992; and Fokker Service Bulletin SBF100-29-021, Revision 2, dated December 22, 1992; as applicable. 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 Fokker Aircraft USA, Inc., 1199 North Fairfax Street, Alexandria, Virginia 22314. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.(g) This amendment becomes effective on November 26, 1993.