AD 93-24-10

93-24-10 LEARJET: Amendment 39-8759. Docket 93-NM-95-AD.

Applicability: Model 55, 55B, and 55C airplanes; serial numbers 55-003 through 55-147, inclusive; certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent the loss of both generators during flight, accomplish the following:

(a) Within 100 hours time-in-service or 90 days after the effective date of this AD, whichever occurs later, modify the wiring inside the left- and right-hand generator interface boxes and between these two boxes, and perform an operational test of the DC power distribution system in accordance with Learjet Service Bulletin SB 55-24-4, dated May 3, 1993.

(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 (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: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Wichita ACO.

(c) 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.

(d) The modification and operational test shall be done in accordance with Learjet Service Bulletin SB 55-24-4, dated May 3, 1993. 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 Corporation, Customer Services, P.O. Box 7707, Wichita, Kansas 67277-7707. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Small Airplane Directorate, 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.

(e) This amendment becomes effective on January 18, 1994.