[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
