AD 2001-07-11 Airworthiness Directives; Learjet Model 23, 24, 25, 28, 29, 31, 35, 36, and 55 Series Airplanes

All Model 23, 24, 24A, 24B, 24B-A, 24C, 24D, 24D-A, 24E, 24F, 24F-A, 25, 25A, 25B, 25C, 25D, 25F, 28, 29, 31, 31A, 35, 35A (C-21A military), 36, 36A, 55, 55B, and 55C airplanes; 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 (c) 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 separation of the tread of main landing gear tires, which could cause damage to the structure and major systems of the airplane, and consequent reduced controllability of the airplane on the ground during takeoff and landing; accomplish the following: Inspection, and Replacement if Necessary (a) Within 5 days after the effective date of this AD: Perform a general visual inspection of the main landing gear tires to determine if any tire has Goodyear part number (P/N) 178K23-5 within the serial number range of 0148xxxx through 0152xxxx inclusive, per Bombardier (Learjet) Advisory Wire 32-021, dated February 5, 2001. Note 2: For the purposes of this AD, a general visual inspection is defined as: “A visual examination of an interior or exterior area, installation, or assembly to detect obvious damage, failure, or irregularity. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight, or drop-light, and may require removal or opening of access panels or doors. Stands, ladders, or platforms may be required to gain proximity to the area being checked.” Note 3: Bombardier (Learjet) AW 32-021 references Goodyear Service Bulletin GY SB 2001-32-001, dated February 2, 2001, as an additional source of service information. (1) If no tires have P/N 178K23-5, no further actions is required by this paragraph. (2) If any tire has P/N 178K23-5 but does not contain any serial number 0148xxxx through 0152 inclusive, no further action is required by this paragraph. (3) If any tire has P/N 178K23-5 and does contain any serial number 0148xxxx through 0152xxxx inclusive: Before further flight, replace the tire with a new or serviceable tire that does not have P/N 178K23-5 with a serial number 0148xxxx through 0152xxxx inclusive. (b) As of the effective date of this AD, no person shall install a main landing gear tire having P/N 178K23-5 that contains any serial number 0148xxxx through 0152xxxx inclusive, on any airplane. Alternative Methods of Compliance (c) 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). 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 4: 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 (d) 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. Incorporation by Reference (e) The inspection, and replacement if necessary, shall be done in accordance with Bombardier (Learjet) Advisory Wire 32-021, dated February 5, 2001. 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 67209; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. Effective Date (f) This amendment becomes effective on May 1, 2001. Issued in Renton, Washington, on April 5, 2001. Donald L. Riggin, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 01-9018 Filed 4-13-01; 8:45 am] BILLING CODE 4910-13-U