# AD 94-09-03: Main Landing Gear Wear Limits - Type: Airworthiness directive - Status: Current - Products: BAE Systems BAe 146-100A, BAe 146-200A and BAe 146-300A - Effective: May 20, 1994 - Superseded by: Nothing supersedes this AD - Product type: Aircraft, Large airplane - Amendment: 39-8891 - Docket: 93-NM-92-AD - Registered aircraft: 8 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/C5823A9E2368F54E86256A1D006C8AAD.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/94-09-03 ## Summary This amendment adopts a new airworthiness directive (AD), applicable to certain British Aerospace Model BAe 146 series airplanes, that requires that the brake wear limits prescribed in this proposal be incorporated into the FAA-approved maintenance inspection program. This amendment is prompted by an accident in which a transport category airplane executed a rejected takeoff (RTO) and was unable to stop on the runway due to worn brakes; and the subsequent review of allowable brake wear limits for all transport category airplanes. The actions specified by this AD are intended to prevent the loss of brake effectiveness during a high energy RTO. ## The airworthiness directive 94-09-03 BRITISH AEROSPACE: Amendment 39-8891. Docket 93-NM-92-AD. Applicability: Model BAe 146 series airplanes equipped with Dunlop brakes, certificated in any category. Compliance: Required as indicated, unless accomplished previously. To prevent loss of main landing gear braking effectiveness, accomplish the following: (a) Within 180 days after the effective date of this AD, incorporate the maximum brake wear limits specified in the following table into the FAA-approved maintenance inspection program and comply with these measurements thereafter. DUNLOP BRAKES Brake Type Maximum Brake Wear Limit (inch) - Lineal Axial Wear as Measured by the Brake Part No. Brake Wear Pin (inch) Carbon AHA 1412/13 2.34" (1.5" original wear pin setting + 0.84" spacer) Carbon AHA 1558/59 2.34" (1.5" original wear pin setting + 0.84" spacer) SteelAHA 1455/56 0.866" NOTE 1: The measuring instructions for carbon and steel brake thicknesses and instructions for setting the wear pin length specified in the BAe 146 airplane maintenance manual (AMM), Section 32-42-24, or in the Dunlop component maintenance manual (CMM), Section 32-42-58, are based currently on the minimum brake thicknesses specified in the table. (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, Standardization Branch, ANM-113, FAA, Transport 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, Standardization Branch, ANM-113. NOTE 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Standardization Branch, ANM-113. (c) Special flightpermits may be issued in accordance with Federal Aviation Regulations (FAR) 21.197 and 21.199 to operate the airplane to a location where the requirements of this AD can be accomplished. (d) This amendment becomes effective on May 20, 1994 ## Rule preamble ### Supplementary information A proposal to amend part 39 of the Federal Aviation Regulations to include an airworthiness directive (AD) that is applicable to all British Aerospace Model BAe 146 series airplanes equipped with Dunlop brakes was published in the Federal Register on October 21, 1993 (58 FR 54310). That action proposed to require the incorporation of the specified maximum wear limits for the specified brakes into the FAA-approved maintenance inspection program. Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the single comment received. The commenter supports the proposed rule. After careful review of the available data, including the comment noted above, the FAA has determined that air safety and the public interest require the adoption of the rule as proposed. The FAA estimates that 45 airplanes of U.S. registry and 6 U.S. operators that will be affected by this AD.Although this amendment will require the incorporation of maximum brake wear limits into the FAA-approved maintenance inspection program, no other specific additional action, inspection, or part replacement costs are involved; such actions are currently a part of the normal maintenance program. However it is estimated that it will take approximately 20 work hours, at an average labor rate is $55 per work hour, for each operator to incorporate the requirement into its FAA-approved maintenance inspection program. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $6,600, or $1,100 per operator. The total cost impact figure discussed above is based on assumptions that no operator has yet accomplished any of the requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted. The regulations adopted herein will not have substantial direct effects on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government. Therefore, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment. For the reasons discussed above, I certify that this action (1) is not a "significant regulatory action" under Executive Order 12866; (2) is not a "significant rule" under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. A final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it may be obtained from the Rules Docket at the location provided under the caption "ADDRESSES." List of Subjects in 14 CFR Part39 Air transportation, Aircraft, Aviation safety, Safety. Adoption of the Amendment Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends 14 CFR part 39 of the Federal Aviation Regulations as follows: PART 39 - AIRWORTHINESS DIRECTIVES 1. The authority citation for part 39 continues to read as follows: Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 106(g); and 14 CFR 11.89. 39.13 - [Amended] 2. Section 39.13 is amended by adding the following new airworthiness directive: ## Affected data sheets (1) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS A49EU](https://openairdocs.org/tcds/A49EU): BAE Systems (Operations) Limited; names 3 of 6 models: BAe 146-300A, BAe 146-100A, BAe 146-200A ## Registered aircraft it may apply to (OpenAirDocs) Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment. - Aircraft: 8 (8 by airframe model, 0 by engine model) - Makers: British Aerospace 8 Models with the most aircraft: - [British Aerospace BAE 146 SERIES 200A](https://openairdocs.org/model/british-aerospace-bae-146-series-200a): 8 aircraft (airframe model) All 1 models: https://openairdocs.org/ad/94-09-03/models.md Every aircraft: https://openairdocs.org/ad/94-09-03/aircraft.md Its text cites no advisory circulars or STCs. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.