AD 94-11-07 ACTIVE

This amendment adopts a new airworthiness directive (AD), applicable to all British Aerospace Model BAC 1-11-200 and -400 series airplanes, that requires inspection of the landing gear brakes for wear, and replacement of the brakes if the wear limits prescribed in this amendment are not met. This amendment also requires that the specified maximum brake wear limits 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.

Final rule

94-11-07 BRITISH AEROSPACE: Amendment 39-8923. Docket 93-NM-167-AD.
Applicability: All Model BAC 1-11-200 and -400 series airplanes, certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent the loss of brake effectiveness during a high energy rejected takeoff (RTO), accomplish the following:

(a) Within 180 days after the effective date of this AD, accomplish paragraphs (a)(1) and (a)(2) of this AD.

(1) Inspect main landing gear brakes having the brake part numbers listed below for wear. Any brake worn more than the maximum wear limit specified below must be replaced, prior to further flight, with a brake within that limit.

British Aerospace
Model BAC 1-11-200 And -400 Series Airplanes
Equipped With Bendix Brakes
Airplane
Model
Brake
Part Number
Maximum Brake
Wear Limit (inch/mm)
BAC 1-11-200
2601225-1
0.75 inch (19.1 mm)
BAC 1-11-400
2601240-1
1.0 inch (25.4 mm)

NOTE 1: Measuring instructions for Bendix brakes can be found in Revision 4 of the Allied Signal Component Maintenance Manual.

NOTE 2: Revision 4 of the Allied Signal Component Maintenance Manual specifies a brake wear limit of 1.06 inch for brake part number 2601240-1. That brake wear limit is superseded by the brake wear limit of 1.0 inch specified above for that brake part number. Revision 5 of the Allied Signal Component Maintenance Manual will reflect the revised brake wear limit of 1.0 inch. Brake units having wear indicators set at 1.06 inch will be considered to be fully worn when either wear indicator pin is 0.06 inch or less above the surface of the carrier, provided the wear indicator pin has not been shortened on that brake unit.

NOTE 3: Each operator should provide a method of identifying modified brakes until Revision 5 of the Allied Signal Component Maintenance Manual has beenissued. Revision 5 of the manual will define a method of brake identification and reflect the brake wear limits specified above. A paint scheme similar to that used to differentiate between new and refurbished brakes could be used, for example, if a different color is used.

(2) Incorporate into the FAA-approved maintenance inspection program the maximum brake wear limits specified in paragraph (a)(1) of this AD.

(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 4: 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 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.

(d) This amendment becomes effective on July 5, 1994.

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 BAC 1-11-200 and -400 series airplanes was published in the Federal Register on January 27, 1994 (59 FR 3798). That action proposed to require the inspection of certain landing gear brakes for wear, and the replacement of brakes if the wear limits prescribed in the proposal are not met. That action also proposed that the specified maximum brake wear limits be incorporated 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 comments received.

One commenter supports the proposal.

Another commenter requests that NOTE 2 of the proposal be clarified. This commenter points out that proposed NOTE 2 states, ". . .Brake units having wear indicators setat 1.06 inch will be considered to be fully worn when either wear indicator pin is 1.0 inch or less above the surface of the carrier. . ." In effect, this wording permits a total brake wear (from new to fully worn brake) of only 0.06 inch. This clearly is incorrect. This commenter states that a correctly set wear indicator pin protrudes above the surface of the carrier when in normal operation, but will be flush with the surface when the brake is fully worn. Thus, the dimension by which the pin protrudes above the surface of the carrier is the amount of wear still available. Therefore, a wear indicator pin set for the existing limit of 1.06 inch will protrude above the surface of the carrier by 0.06 inch when the new wear limit of 1.00 inch is reached. The FAA concurs and has revised NOTE 2 of the final rule to clarify this point.

After careful review of the available data, including the comments noted above, the FAA has determined that air safety and the public interest require the adoption of the rule with the change previously described. The FAA has determined that this change will neither increase the economic burden on any operator nor increase the scope of the AD.

There are approximately 100 Model BAC 1-11-200 and -400 series airplanes of the affected design in the worldwide fleet.

The FAA estimates that 10 Model BAC 1-11-200 series airplanes of U.S. registry and 2 U.S. operators of these airplanes will be affected by this proposed AD. For these airplanes and operators, although the rule requires the incorporation of maximum brake wear limits into the FAA-approved maintenance inspection program, no other specific additional action, inspection, or part replacement costs relative to that requirement is involved; such actions are currently a part of the current maintenance program. However, it is estimated that it will take approximately 1 work hour, at an average labor rate of $55 per work hour, for each operator to incorporate the revision into its FAA-approved maintenance inspection program. Based on these figures, the total cost impact of the requirement to revise the FAA-approved maintenance inspection program on U.S. operators of Model BAC 1-11-200 series airplanes is estimated to be $110, or $55 per operator.

The FAA estimates that 20 Model BAC 1-11-400 series airplanes of U.S. registry and 19 U.S. operators of these airplanes will be affected by this AD. It is estimated that it will take approximately 1 work hour, at an average labor rate of $55 per work hour, for each operator to incorporate the revision into its FAA-approved maintenance inspection program. Based on these figures, the total cost impact of that requirement on U.S. operators of Model BAC 1-11-400 series airplanes is estimated to be $1,045, or $55 per operator.

Additionally, the FAA estimates that for operators of Model BAC 1-11-400 series airplanes, it will take approximately 2 work hours per airplane to shorten the wear pins for replacement brakes, and 8 work hours per airplane to change the brakes, at an average labor rate of $55 per work hour. The cost of required parts to accomplish the change in wear limits for these airplanes (that is, the cost resulting from the requirement to change the brakes before they are worn to their previously approved limits for a one-time change) is estimated to be $912 per airplane. Based on these figures, the total cost impact of these requirements on U.S. operators of Model BAC 1-11-400 series airplanes is estimated to be $29,240, or $1,462 per airplane.

The total cost impact figures discussed above are 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 Part 39
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:

Information pertaining to this rulemaking action may be examined at the Federal Aviation Administration (FAA), Transport Airplane Directorate, Rules Docket, 1601 Lind Avenue, SW., Renton, Washington.

Mark Quam, Aerospace Engineer, Standardization Branch, ANM-113, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206) 227-2145; fax (206) 227-1320.