[Federal Register Volume 59, Number 18 (Thursday, January 27, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-1690]


[[Page Unknown]]

[Federal Register: January 27, 1994]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 93-NM-167-AD]

 

Airworthiness Directives; British Aerospace Model BAC 1-11-200 
and -400 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to all British Aerospace Model BAC 1-
11-200 and -400 series airplanes. This proposal would require that 
certain landing gear brakes be inspected for wear and replaced if the 
wear limits prescribed in this proposal are not met, and that the 
specified wear limits be incorporated into the FAA-approved maintenance 
inspection program. This proposal 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 the proposed AD are intended to 
prevent the loss of brake effectiveness during a high energy RTO.

DATES: Comments must be received by March 23, 1994.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 93-NM-167-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9 a.m. and 3 p.m., Monday through Friday, except 
Federal holidays.

FOR FURTHER INFORMATION CONTACT: 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.

SUPPLEMENTARY INFORMATION:

Comments Invited

    Interested persons are invited to participate in the making of the 
proposed rule by submitting such written data, views, or arguments as 
they may desire. Communications shall identify the Rules Docket number 
and be submitted in triplicate to the address specified above. All 
communications received on or before the closing date for comments, 
specified above, will be considered before taking action on the 
proposed rule. The proposals contained in this notice may be changed in 
light of the comments received.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the proposed rule. All 
comments submitted will be available, both before and after the closing 
date for comments, in the Rules Docket for examination by interested 
persons. A report summarizing each FAA-public contact concerned with 
the substance of this proposal will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 93-NM-167-AD.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRMs

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, Transport Airplane Directorate, ANM-103, Attention: Rules 
Docket No. 93-NM-167-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    In 1988, a McDonnell Douglas Model DC-10 series airplane was 
involved in an aborted takeoff accident in which eight of the ten 
brakes failed and the airplane ran off the end of the runway. 
Investigation revealed that there were failed pistons on each of the 
eight brakes, with O-rings damaged by over-extension due to extensive 
wear. Fluid leaking from the damaged pistons caused the hydraulic fuses 
to close, releasing all brake pressure.
    This accident prompted a review of allowable wear limits for all 
brakes installed on transport category airplanes. The FAA and the 
Aerospace Industries Association (AIA) jointly developed a set of 
dynamometer test guidelines that could be used to validate appropriate 
wear limits for all airplane brakes. It should be noted that this worn 
brake accountability determination validates brake wear limits with 
respect to brake energy capacity only and is not meant to account for 
any reduction in brake force due solely to the wear state of the brake. 
The guidelines for validating brake wear limits allow credit for use of 
reverse thrust with a critical engine inoperative to determine the 
energy level absorbed by the brake during the dynamometer test.
    The FAA has requested that airframe manufacturers of transport 
category airplanes: (1) Determine required adjustments in allowable 
wear limits for all of its brakes in use; (2) schedule dynamometer 
testing to validate wear limits as necessary; and (3) submit 
information from items (1) and (2) to the FAA so that appropriate 
rulemaking action(s) can be initiated.
    British Aerospace has conducted worn brake rejected takeoff (RTO) 
dynamometer testing and analyses on various brakes installed on Model 
BAC 1-11-200 and -400 series airplanes. Based on the results of that 
testing and analyses, the FAA has determined that the maximum brake 
wear limits currently recommended in the Component Maintenance Manual 
for Model BAC 1-11-200 series airplanes equipped with brakes 
manufactured by Allied Signal Aerospace Company (Bendix) are acceptable 
as they relate to the effectiveness of the brakes during a high energy 
RTO. The FAA also finds that the maximum brake wear limits currently 
recommended in the Component Maintenance Manual for Model BAC 1-11-400 
series airplanes equipped with Bendix brakes are not acceptable as they 
relate to the effectiveness of the brakes during a high energy RTO. 
Consequently, the FAA has determined that the brake wear limits for 
Model BAC 1-11-200 series airplanes and the new brake wear limits for 
Model BAC 1-11-400 series airplanes must be incorporated into the FAA-
approved maintenance inspection program.
    The FAA has determined that, in order to prevent loss of brake 
effectiveness during a high energy RTO, the following maximum brake 
wear limits are necessary for Model BAC 1-11-200 and -400 series 
airplanes equipped with Bendix brakes: 

 British Aerospace Model Bac 1-11-200 and -400 Series Airplanes Equipped
                           With Bendix Brakes                           
------------------------------------------------------------------------
                   Brake part                                           
 Airplane Model       No.          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).                      
------------------------------------------------------------------------

    This airplane model is manufactured in the United Kingdom and is 
type certificated for operation in the United States under the 
provisions of Section 21.29 of the Federal Aviation Regulations and the 
applicable bilateral airworthiness agreement. The FAA has determined 
that AD action is necessary for products of this type design that are 
certificated for operation in the United States.
    Since an unsafe condition has been identified that is likely to 
exist or develop on other airplanes of the same type design registered 
in the United States, the proposed AD would require that certain 
landing gear brakes be inspected for wear and replaced if the wear 
limits prescribed in this proposal are not met, and that the specified 
wear limits be incorporated into the FAA-approved maintenance 
inspection program.
    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 would be affected by this proposed 
AD. For these airplanes and operators, although the proposed rule would 
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 relative to that 
requirement would be involved; such actions are currently a part of the 
current maintenance program. However, it is estimated that it would 
take approximately 1 work hour, at an average labor rate of $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 proposed 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 would be affected by this proposed 
AD. It is estimated that it would take approximately 1 work hour, at an 
average labor rate of $55 per work hour, for each operator to 
incorporate the proposed revision of its FAA-approved maintenance 
inspection program. Based on these figures, the total cost impact of 
that proposed 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 would 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) would be 
approximately $912 per airplane. Based on these figures, the total cost 
impact of these proposed requirements on U.S. operators of Model BAC 1-
11-400 series airplanes is estimated to be $29,240, or $1,462 per 
airplane.
    These total cost figures are based on the assumption that no 
operator has yet accomplished the proposed requirements of this AD.
    The regulations proposed herein would 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 
proposal would not have sufficient federalism implications to warrant 
the preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this proposed 
regulation: (1) Is not a ``significant regulatory action'' under 
Executive Order 12866; (2) is not a ``significant rule'' under the DOT 
Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); 
and (3) if promulgated, 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 copy of the draft 
regulatory evaluation prepared for this action is contained in the 
Rules Docket. A copy of it may be obtained by contacting 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.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 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.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

British Aerospace: 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                           
------------------------------------------------------------------------
                   Brake part                                           
 Airplane model       No.          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 1.0 inch or less above the surface 
of the carrier, provided the wear 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 been issued. 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 FAR 
21.197 and 21.199 to operate the airplane to a location where the 
requirements of this AD can be accomplished.

    Issued in Renton, Washington, on January 21, 1994.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 94-1690 Filed 1-26-94; 8:45 am]
BILLING CODE 4910-13-U