95-19-04: Omega Navigation System

95-19-04 LEARJET: Amendment 39-9365. Docket 95-NM-25-AD. Applicability: Model 35, 35A, 36, 36A, 55, 55B, and 55C airplanes; equipped with Global Wulfsburg GNS 500, GNS-1000, and GNS-X Flight Management Systems, 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 use the authority provided in paragraph (d) of this AD to request approval from the FAA. This approval may address either no action, if the current configuration eliminates the unsafe condition; or different actions necessary to address the unsafe condition described in this AD. Such a request should include an assessment of the effect of the changed configuration on the unsafe condition addressed by this AD. In no case does the presence of any modification, alteration, or repair remove any airplane from the applicability of this AD. Compliance: Required as indicated, unless accomplished previously. To prevent excessive deviation from the intended flight path which, if the aircraft is on an extended overwater operation, may lead to a potential low-fuel condition or a traffic conflict operation, accomplish the following: (a) Within 60 days after the effective date of this AD, install a placard in a prominent location on the instrument panel that states: "VLF/OMEGA MAY BE INOPERATIVE AT 92.5% N2" (b) For Model 35 airplanes, serial numbers 35-001 through 35-603 inclusive; and Model 36, serial numbers 36-001 through 36-053 inclusive: Installation of a GNS 500/1000 generator band reject filter in accordance with Gates Learjet Airplane Accessory Kit Model AAK 85-1, dated January 14, 1986, as revised by Airplane Accessory Kit ChangeNotice AAK-85-1, Change 1 (undated), constitutes terminating action for the placard requirement of paragraph (a) of this AD. Following installation of the filter, the placard required by paragraph (a) of this AD may be removed. (c) For Model 55 airplanes, serial numbers 55-003 through 55-124 inclusive: Installation of a GNS 500/1000 generator band reject filter in accordance with Gates Learjet Airplane Accessory Kit Model 55 AAK 55-85-2, dated January 14, 1986, as revised by Airplane Accessory Kit Change Notice AAK No. AAK55-85-2, Change 1 (undated), constitutes terminating action for the placard requirement of paragraph (a) of this AD. Following installation of the filter, the placard required by paragraph (a) of this AD may be removed. (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, Small 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, 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. (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. (f) This amendment becomes effective on October 12, 1995.