2001-12-02: Brake Valve

2001-12-02 Learjet: Amendment 39-12257. Docket 2000-NM-128-AD. Applicability: Model 55 series airplanes, serial numbers 55-003 through 55-147 inclusive, and Model 60 airplanes, serial numbers 60-002 through 60-189 inclusive; 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.Compliance: Required as indicated, unless accomplished previously. To prevent bottoming of the valve components before contact of the brake valve lever with the stop, which could result in loss of all hydraulic fluid and consequent loss of normal braking; accomplish the following: Replacement of Brake Valve Lever Stop Switch (a) Within 300 flight hours or one year after the effective date of this AD, whichever occurs first, accomplish the actions specified in paragraph (a)(1), (a)(2), or (a)(3) of this AD, as applicable. (1) For Learjet Model 60 airplanes having serial numbers 60-002 through 60-093 inclusive, and 60-095 through 60-188 inclusive: Replace the existing brake valve lever stop switch with a new brake valve lever stop switch, and replace the brake valve adjustment screws with new improved screws, per Bombardier Service Bulletin 60-32-10, Revision 1, dated June 22, 2000. (2) For Learjet Model 60 airplanes having serial number 60-094 or 60-189: Replace the brake valve adjustment screws with new improved screws, per Bombardier Service Bulletin 60-32-10, Revision 1, dated June 22, 2000. (3) For Learjet Model 55 series airplanes having serial numbers 55-003 through 55-147 inclusive: Replace the existing brake valve lever stop with a new brake valve lever stop, and replace the brake valve adjustment screws with new improved screws, per Bombardier Service Bulletin 55-32-14, dated November 9, 1999. Alternative Methods of Compliance (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, Wichita Aircraft Certification Office, FAA. 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. Special Flight Permits (c) Special flight permits may be issued in accordance with Secs. 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. Incorporation by Reference (d) The actions shall be done in accordance with Bombardier Service Bulletin 60-32-10, Revision 1, dated June 22, 2000; and Bombardier Service Bulletin 55-32-14, dated November 9, 1999; 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 Learjet, Inc., One Learjet Way, Wichita, Kansas 67209-2942. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Wichita Aircraft Certification Office, 1801 Airport Road, Room 100, Mid-Continent Airport, Wichita, Kansas;or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. Effective Date (e) This amendment becomes effective on July 18, 2001.