AD 98-13-25 Airworthiness Directives; Fokker Model F.28 Mark 1000, 2000, 3000, and 4000 Series Airplanes

Models named: F.28 Mark 1000, 2000, 3000, 4000 series. Read the applicability below — it usually turns on serial or part numbers too.

Model F.28 Mark 1000, 2000, 3000, and 4000 series airplanes; equipped with Menasco horizontal stabilizer actuators having part number (P/N) 11100- ( ); 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. To prevent uncommanded trimming or failure of the trim system of the horizontal stabilizer, and consequent reduced controllability of the airplane, accomplish the following: (a) Within 20 days after September 9, 1992 (the effective date of AD 92-18-04, amendment 39-8348), perform an inspection of the servo-valve sub-assembly rod-end bearing and servo-valve sub- assembly for movement, in accordance with Fokker Service Bulletin F28/27-180, dated July 3, 1992. (1) If the servo-valve sub-assembly rod-end bearing and servo- valve sub-assembly move freely within the load limits specified in the service bulletin, reassemble and conduct a functional test, in accordance with the service bulletin. (2) If the servo-valve sub-assembly rod-end bearing or servo- valve sub-assembly require higher loads for movement than specified in the service bulletin, prior to further flight, remove and replace the horizontal stabilizer control unit with a serviceable control unit that has been inspected and found to be within the load limits of the service bulletin, or that has been inspected and repaired in accordance with Chapter 27-42-4 of the Menasco Overhaul Manual (OHM), as revised by Temporary Revision Number 3, dated July 10, 1992. (b) Within 6 months after the effective date of this AD, perform a one-time inspection to determine the residual strength of the servo-valve sub-assembly of the horizontal stabilizer actuator, in accordance with Part 1 of the Accomplishment Instructions of [[Page 34571]] Fokker Service Bulletin F28/27-183, dated November 21, 1994. If any discrepancy is found, prior to further flight, replace the actuator with a new or serviceable actuator in accordance with the service bulletin. (c) Within 3 years after the effective date of this AD, replace the horizontal stabilizer actuator with an actuator that has been modified and re-marked in accordance with Part 2 of the Accomplishment Instructions of Fokker Service Bulletin F28/27-183, dated November 21, 1994. (d) As of the effective date of this AD, no person shall install a horizontal stabilizer control unit on any airplane, unless the horizontal stabilizer actuator has been modified and re-marked in accordance with Part 2 of the Accomplishment Instructions of Fokker Service Bulletin F28/27-183, dated November 21, 1994. (e) 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. (f) 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. (g) The actions shall be done in accordance with Fokker Service Bulletin F28/27-180, dated July 3, 1992, and Fokker Service Bulletin F28/27-183, dated November 21, 1994. (1) The incorporation by reference of Fokker Service Bulletin F28/27-183, dated November 21, 1994, is approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. (2) The incorporation by reference of Fokker Service Bulletin F28/27-180, dated July 3, 1992, was approved previously by the Director of the Federal Register as of September 9, 1992 (57 FR 38432, August 25, 1992). (3) 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 1992-007/2(A), dated January 31, 1995. (h) This amendment becomes effective on July 30, 1998. Issued in Renton, Washington, on June 15, 1998. Darrell M. Pederson, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 98-16451 Filed 6-24-98; 8:45 am] BILLING CODE 4910-13-U