AD 98-06-33 Airworthiness Directives; Fokker Model F28 Mark 1000 Through 4000 Series Airplanes

Fokker Model F28 Mark 1000 through 4000 series airplanes, equipped with flexible hydraulic hoses, part number (P/N) A71462-401; 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 (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.

Required as indicated, unless accomplished previously. To prevent pressurization of the downlock-actuator during extreme inward sideload conditions (such as touching down at a large crab angle) and consequent lifting of the toggle-links of the main landing gear (MLG), which could result in the collapse of the MLG and reduced controllability of the airplane during landing, accomplish the following: (a) Within 12 months after the effective date of this AD, replace the flexible hydraulic hoses, P/N A71462-401, that connect to the UP-port of the actuator of the MLG with new flexible hoses, P/N 97867-1, that have built-in restrictor check-valves, in accordance with Fokker Service Bulletin F28/32-123, Revision 1, dated June 30, 1994. (b) 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 requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, International Branch, ANM-116. Note 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the International Branch, ANM-116. (c) 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. (d) The actions shall be done in accordance with Fokker Service Bulletin F28/32-123, Revision 1, dated June 30, 1994. 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 Services B.V., Technical Support Department, P.O. Box 75047, 1117 ZN Schiphol Airport, the Netherlands. 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. Note 3: The subject of this AD is addressed in Dutch airworthiness directive BLA 94-095 (A), dated July 15, 1994. (e) This amendment becomes effective on April 27, 1998. Issued in Renton, Washington, on March 12, 1998. Darrell M. Pederson, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 98-7093 Filed 3-20-98; 8:45 am] BILLING CODE 4910-13-P