The U.S. aircraft register, updated daily
FAA orders · airworthiness directive · current

2001-07-11: Main Landing Gear Tires

FAA order 2001-07-11 is an airworthiness directive in force since May 1, 2001. The FAA's subject line: Main Landing Gear Tires. It names Learjet 23, Learjet 24, Learjet 25, Learjet 31, Learjet 35, Learjet 55: about 392 aircraft on the U.S. register today across them, though an order usually covers particular versions or serial numbers rather than every one. System: landing gear.

What it applies to as the FAA lists it

Kind of product
Aircraft
Makes
Learjet Inc.
Models
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), 36, 36A, 55, 55B, 55C
On this site
Learjet 23 6 registered
Learjet 24 16 registered
Learjet 25 23 registered
Learjet 31 119 registered
Learjet 35 161 registered
Learjet 55 67 registered

Dates and paperwork

In force since
May 1, 2001
Published
April 16, 2001 (signed April 5, 2001)
Docket
2001-NM-76-AD
Status
Current
The FAA's document
Read the order on the FAA's site

The FAA's summary their words, unchanged

This amendment adopts a new airworthiness directive (AD) that is applicable to all Learjet Model 23, 24, 25, 28, 29, 31, 35, 36, and 55 series airplanes. This action requires an inspection to determine if tires on the main landing gear have a certain part number and certain serial numbers, and replacement with a tire having a part number that does not contain those certain serial numbers, if necessary. This action is necessary 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. This action is intended to address the identified unsafe condition.

The order itself the regulatory text, as published

Show the full text (4,811 characters)
2001-07-11 LEARJET INC.: Amendment 39-12177. Docket 2001-NM-76-AD. Applicability: 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. Compliance: 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 ADcan 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.

Related safety bulletins advice on the same designs, not orders

2026-03-192026-07 · MAIN LANDING GEAR ATTACH SECTION, Trunnion Pins
2016-09-15NM-16-24 · Fuselage: Main Plate/Skin
2013-06-24NM-13-38 · Flight Controls Control Column Section
2011-08-22NM-11-48 · Ice and Rain Protection: Wing Transverse Duct Assembly
2004-05-06CE-04-67 ·

Source: FAA Dynamic Regulatory System, airworthiness directives. The FAA's document is the authority; the register counts are this site's, from the FAA register of October 7, 2026. Connections as data: /graph/directive/2001-07-11.json · aircraft systems.