[Federal Register Volume 62, Number 193 (Monday, October 6, 1997)]
[Proposed Rules]
[Pages 52051-52053]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-26376]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 97-NM-120-AD]
RIN 2120-AA64
Airworthiness Directives; De Havilland Model DHC-8-100, -200, and
-300 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 certain de Havilland Model DHC-8-
100, -200, and -300 series airplanes. This proposal would require
repetitive inspections of certain refuel/defuel tube assemblies in the
engine nacelles for fuel leakage, and corrective action, if necessary.
It would also require eventual modification of all tube assemblies,
which would terminate the repetitive inspections. 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 prevent fuel leaks and consequent
increased risk of engine fires.
DATES: Comments must be received by November 5, 1997.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 97-NM-120-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.
The service information referenced in the proposed rule may be
obtained from Bombardier, Inc., Bombardier Regional Aircraft Division,
Garratt Boulevard, Downsview, Ontario M3K 1Y5, Canada.
[[Page 52052]]
This information may be examined at the FAA, Transport Airplane
Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA,
New York Aircraft Certification Office, Engine and Propeller
Directorate, 10 Fifth Street, Third Floor, Valley Stream, New York.
FOR FURTHER INFORMATION CONTACT: Richard Fiesel, Aerospace Engineer,
Airframe and Propulsion Branch, ANE-171, FAA, New York Aircraft
Certification Office, Engine and Propeller Directorate, 10 Fifth
Street, Third Floor, Valley Stream, New York 11581; telephone (516)
256-7504; fax (516) 256-2716.
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 97-NM-120-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. 97-NM-120-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
Transport Canada Aviation (TCA), which is the airworthiness
authority for Canada, notified the FAA that an unsafe condition may
exist on certain de Havilland Model DHC-8-100, -200, and -300 series
airplanes. TCA advises that it received reports of fuel leaks from the
shroud drain line located adjacent to the refuel/defuel adapter in the
engine nacelles. Investigation has revealed that some of the welds
between the outer shroud and the inner tube of the refuel/defuel
assemblies may be of poor quality. Relative motion between the shroud
and the tube can result in cracking of both the tube and the shroud.
This condition, if not corrected, could result in fuel leaks and
consequent increased risk of engine fires.
Explanation of Relevant Service Information
Bombardier has issued Alert Service Bulletin S.B. A8-28-20,
Revision `A,' dated September 10, 1996, which describes procedures for
repetitive inspections of the refuel/defuel tube assemblies in the
engine nacelles for fuel leakage, and replacement of tube assemblies
that leak with improved tube assemblies.
The alert service bulletin also describes procedures for eventual
modification of all tube assemblies to prevent potential future
leakage, which would eliminate the need for the repetitive inspections.
Part 2 of the Accomplishment Instructions of the alert service bulletin
describes replacement of the tube assembly located in the most critical
area of the engine nacelle. Part 3 of the Accomplishment Instructions
of the alert service bulletin describes replacement of the remaining
tube assemblies. Accomplishment of the actions specified in the alert
service bulletin are intended to adequately address the identified
unsafe condition.
TCA classified this alert service bulletin as mandatory and issued
Canadian airworthiness directive CF-96-14, dated August 20, 1996, in
order to assure the continued airworthiness of these airplanes in
Canada.
FAA's Conclusions
This airplane model is manufactured in Canada and is type
certificated for operation in the United States under the provisions of
Sec. 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the
applicable bilateral airworthiness agreement. Pursuant to this
bilateral airworthiness agreement, TCA has kept the FAA informed of the
situation described above. The FAA has examined the findings of TCA,
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 alert service bulletin described
previously.
Cost Impact
The FAA estimates that 95 de Havilland Model DHC-8-100, -200, and -
300 series airplanes of U.S. registry would be affected by this
proposed AD.
The proposed inspection would take approximately 6 work hours per
airplane to accomplish, at an average labor rate of $60 per work hour.
Based on these figures, the cost impact of the inspection proposed by
this AD on U.S. operators is estimated to be $34,200, or $360 per
airplane, per inspection cycle.
The proposed modification (specified in Part 2 of the
Accomplishment Instructions in the referenced alert service bulletin),
would take approximately 15 work hours per airplane to accomplish, at
an average labor rate of $60 per work hour. Required parts would cost
approximately $500. Based on these figures, the cost impact of this
modification as proposed by this AD on U.S. operators is estimated to
be $133,000, or $1,400 per airplane.
The proposed modification (specified in Part 3 of the
Accomplishment Instructions in the referenced service bulletin), would
take approximately 36 work hours per airplane to accomplish, at an
average labor rate of $60 per work hour. Required parts would cost
approximately $1,600 per airplane. Based on these figures, the cost
impact of this modification proposed by this AD on U.S. operators is
estimated to be $357,200, or $3,760 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
[[Page 52053]]
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
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:
De Havilland, Inc.: Docket 97-NM-120-AD.
Applicability: Model DHC-8-100, -200, and -300 series airplanes;
as listed in Bombardier Alert Service Bulletin S.B. A8-28-20,
Revision `A,' dated September 10, 1996; 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 (f) 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 prevent fuel leaks and consequent increased risk of engine
fires, accomplish the following:
(a) Within 30 days after the effective date of this AD, inspect
the five refuel/defuel tube assemblies in the engine nacelles to
detect fuel leaks, in accordance with Part 1 of the Accomplishment
Instructions of Bombardier Alert Service Bulletin S.B. A8-28-20,
Revision `A', dated September 10, 1996. If any fuel leak is found,
prior to further flight, replace the refuel/defuel tube assembly
with an improved assembly, in accordance with the alert service
bulletin. Thereafter, repeat the inspection at intervals not to
exceed 6 months.
(b) Within 12 months after the effective date of this AD, modify
the refuel/defuel tube assembly located under the exhaust fingernail
on the engine nacelle, as specified in Part 2 of the Accomplishment
Instructions of Bombardier Alert Service Bulletin S.B. A8-28-20,
Revision `A,' dated September 10, 1996, in accordance with the
procedures specified in the alert service bulletin.
(c) Within 24 months after the effective date of this AD, modify
the remaining refuel/defuel tube assemblies, as specified in Part 3
of the Accomplishment Instructions of Bombardier Alert Service
Bulletin S.B. A8-28-20, Revision `A,' dated September 10, 1996, in
accordance with the procedures specified in the alert service
bulletin.
(d) Accomplishment of the modifications required by paragraphs
(b) and (c) of this AD constitutes terminating action for the
repetitive inspections required by paragraph (a) of this AD.
(e) As of the effective date of this AD, no person shall install
a refuel/defuel tube assembly having part number 82820107-007,
82821015-003, 82820108-005, 82820245-001, 82820246-001, 82820247-
001, or 82821014-001, on any airplane.
(f) 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, New York Aircraft Certification
Office (ACO), FAA, Engine and Propeller Directorate. Operators shall
submit their requests through an appropriate FAA Principal
Maintenance Inspector, who may add comments and then send it to the
Manager, New York ACO.
Note 2: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the New York ACO.
(g) Special flight permits may be issued in accordance with
Sec. 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 3: The subject of this AD is addressed in Canadian
airworthiness directive CF-96-14, dated August 20, 1996.
Issued in Renton, Washington, on September 30, 1997.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 97-26376 Filed 10-3-97; 8:45 am]
BILLING CODE 4910-13-U