[Federal Register Volume 62, Number 228 (Wednesday, November 26, 1997)]
[Proposed Rules]
[Pages 63042-63044]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-31023]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 96-NM-200-AD]
RIN 2120-AA64
Airworthiness Directives; British Aerospace BAe Model ATP
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 certain British Aerospace BAe
Model ATP airplanes. This proposal would require repetitive inspections
to detect uneven wear of the heat pack of the main landing gear (MLG)
brake unit; measurement and setting of the wear remaining length (WRL)
of the wear indicator pin (WIP); and replacement of the brake heat pack
unit with a serviceable unit, if necessary. This proposal is prompted
by issuance of mandatory continuing airworthiness information by a
foreign civil airworthiness authority. The actions specified by the
proposed AD are intended to detect uneven wear of the brake heat pack
unit and prevent failure of the pressure stator of the MLG brake unit,
which could result in reduced braking efficiency and consequent longer
stopping distances upon landing.
DATES: Comments must be received by December 26, 1997.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 96-NM-200-AD, 1601 Lind Avenue, SW.,
Renton, Washington 98055-4056. Comments may be inspected at this
location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except
Federal holidays.
The service information referenced in the proposed rule may be
obtained from AI(R) American Support, Inc., 13850 McLearen Road,
Herndon, Virginia 20171. This information may be examined at the FAA,
Transport
[[Page 63043]]
Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington.
FOR FURTHER INFORMATION CONTACT: International Branch, ANM-116, FAA,
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton,
Washington 98055-4056; telephone (425) 227-2110; fax (425) 227-1149.
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 96-NM-200-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. 96-NM-200-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
The Civil Aviation Authority (CAA), which is the airworthiness
authority for the United Kingdom, notified the FAA that an unsafe
condition may exist on certain British Aerospace BAe Model ATP
airplanes. The CAA advises it received reports indicating that the heat
pack unit of the main landing gear (MLG) brake unit has exhibited
uneven wear at the pressure stator/first rotor interface in some
instances, which has resulted in a small number of failures of the
pressure stator. The pressure stator failures have been attributed to
incorrect wear remaining length (WRL) indicated by the wear indicator
pin (WIP). Such uneven wear and/or failure of the pressure stator/first
rotor interface of the brake units, if not corrected, could result in
reduced braking efficiency and consequent longer stopping distances
upon landing.
Explanation of Relevant Service Information
Jetstream has issued Service Bulletin ATP/J61-32-71, dated May 23,
1996, and Revision 1, dated June 18, 1996, which describe procedures
for repetitive inspections to detect uneven wear of the heat pack of
the MLG brake unit at the pressure stator/first rotor interface;
measurement and setting of the WRL of the WIP to indicate the correct
amount of allowable remaining wear of the brake heat pack unit; and
replacement of the brake heat pack unit with a serviceable unit, if
necessary. (The Jetstream service bulletin references Dunlop service
Bulletin AHA1612/AHA2004-32-1122, dated April 16, 1996, as an
additional source of service information for inspecting the brakes,
measuring the WRL of the WIP, and setting the corrected length of the
pin.
The CAA classified the Jetstream service bulletin as mandatory and
issued British airworthiness directive 002-05-96 in order to assure the
continued airworthiness of these airplanes in the United Kingdom.
FAA's Conclusions
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 (14 CFR
21.29) and the applicable bilateral airworthiness agreement. Pursuant
to this bilateral airworthiness agreement, the CAA has kept the FAA
informed of the situation described above. The FAA has examined the
findings of the CAA, reviewed all available information, and determined
that AD action is necessary for products of this type design that are
certificated for operation in the United States.
Explanation of Requirements of Proposed Rule
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 accomplishment of
the actions specified in the service bulletin described previously.
Differences Between Proposed AD and Service Information
Operators should note that certain procedures described in the
referenced Dunlop Service Bulletin are not included in this AD. Those
procedures address the possible delay in the accomplishment of some of
the work tasks due to the lack of qualified persons to set the WRL of
the WIP. However, this AD permits no delay in setting the corrected
length of the pin.
Cost Impact
The FAA estimates that 10 airplanes of U.S. registry would be
affected by this proposed AD, that it would take approximately 5 work
hours per airplane to accomplish the proposed actions, and that the
average labor rate is $60 per work hour. Based on these figures, the
cost impact of the proposed AD on U.S. operators is estimated to be
$3,000, or $300 per airplane.
The cost impact figures discussed above are based on assumptions
that no operator has yet accomplished any of the proposed requirements
of this AD action, and that no operator would accomplish those actions
in the future if this AD were not adopted.
Regulatory Impact
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.
[[Page 63044]]
The Proposed Amendment
Accordingly, pursuant to the authority delegated to me by the
Administrator, the Federal Aviation Administration proposes to amend
part 39 of the Federal Aviation Regulations (14 CFR part 39) as
follows:
PART 39--AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
British Aerospace Regional Aircraft [Formerly Jetstream Aircraft
Limited; British Aerospace (Commercial Aircraft) Limited]: Docket
96-NM-200-AD.
Applicability: BAe Model ATP airplanes having constructors
numbers 2002 through 2067 inclusive, certificated in any category.
Note 1: This AD applies to each airplane identified in the
preceding applicability provision, regardless of whether it has been
otherwise 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 detect uneven wear of the brake heat pack unit and prevent
failure of the pressure stator of the main landing gear (MLG) brake
unit, which could result in reduced braking efficiency and
consequent longer stopping distances upon landing, accomplish the
following:
(a) Within 300 hours time-in-service (TIS) after the effective
date of this AD: Perform an inspection of the brake units of the
left and right MLG to detect uneven wear at the pressure stator/
first rotor interface, measure the wear remaining length (WRL) of
the wear indicator pin (WIP), and accomplish the action specified in
paragraph (a)(1) or (a)(2) of this AD, as applicable; in accordance
with Jetstream Service Bulletin ATP/J61-32-71, dated May 23, 1996,
or Revision 1, dated June 18, 1996.
Note 2: Jetstream Service Bulletin ATP/J61-32-71, dated May 23,
1996, and Revision 1, dated June 18, 1996, reference Dunlop Service
Bulletin AHA1612/AHA2004-32-1122, dated April 16, 1996, as an
additional source of service information for procedures to inspect
the brakes, measure the wear remaining length (WRL) of the wear
indicator pin (WIP), and set the corrected length of the pin.
(1) If the WRL of the WIP is greater than or equal to 0.5
inches: Repeat the action required in paragraph (a) of this AD
thereafter at intervals not to exceed 300 hours TIS.
(2) If the WRL of the WIP is less than 0.5 inches: Prior to
further flight, measure the thickness of the pressure stator and
accomplish the action specified in paragraph (a)(2)(i) or (a)(2)(ii)
of this AD, as applicable; and repeat the action required in
paragraph (a) of this AD thereafter at intervals not to exceed 300
hours TIS.
(i) If the pressure stator is less than or equal to 0.31 inches
thick: Replace the heat pack of the MLG brake unit with a
serviceable unit and set the WRL of the WIP to indicate the
corrected WRL measurement.
(ii) If the pressure stator exceeds 0.31 inches thick: Set the
WRL of the WIP to indicate the corrected WRL measurement.
(b) If, during any inspection required by this AD, the WRL of
the WIP on any brake unit shows that the wear status of the brake
heat pack is outside the acceptable limits specified in Jetstream
Service Bulletin ATP/J61-32-71, dated May 23, 1996, or Revision 1,
dated June 18, 1996: Prior to further flight, replace the brake heat
pack unit with a serviceable unit in accordance with the referenced
service bulletin; and repeat the action required in paragraph (a) of
this AD thereafter at intervals not to exceed 300 hours TIS.
(c) An alternative method of compliance or adjustment of the
initial compliance time that provides an acceptable level of safety
may be used if approved by the Manager, International Branch, ANM-
116, FAA, Transport Airplane Directorate. Operators shall submit
their requests through an appropriate FAA Principal Maintenance
Inspector, who may add additional comments, and then send it to the
Manager, International Branch, ANM-116.
Note 3: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the International Branch, ANM-116.
(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 AD can be accomplished.
Note 4: The subject of this AD is addressed in British
airworthiness directive 002-05-96.
Issued in Renton, Washington, on November 19, 1997.
Stewart R. Miller,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 97-31023 Filed 11-25-97; 8:45 am]
BILLING CODE 4910-13-U
