[Federal Register Volume 64, Number 155 (Thursday, August 12, 1999)]
[Proposed Rules]
[Pages 43959-43961]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-20891]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-NM-324-AD]
RIN 2120-AA64
Airworthiness Directives; Bombardier Model DHC-8-311 and -315
Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: This document proposes the supersedure of an existing
airworthiness directive (AD), applicable to certain Bombardier Model
DHC-8-311 and -315 series airplanes, that currently requires
replacement of the nitrogen cylinder assemblies that inflate the
airplane's ditching dams with improved nitrogen cylinder assemblies.
This action would expand the applicability of the existing AD. 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 failure of the
ditching dams to inflate fully during an emergency water landing, which
could result in water entering the airplane.
DATES: Comments must be received by September 13, 1999.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 98-NM-324-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 Bombardier, Inc., Bombardier Regional Aircraft Division,
Garratt Boulevard, Downsview, Ontario M3K 1Y5, Canada. This information
may be examined at the FAA, Transport Airplane Directorate, 1601 Lind
Avenue, SW., Renton, Washington; or at the FAA, Engine and Propeller
Directorate, New York Aircraft Certification Office, 10 Fifth Street,
Third Floor, Valley Stream, New York.
FOR FURTHER INFORMATION CONTACT: Ezra Sasson, Aerospace Engineer,
Systems and Flight Test Branch, ANE-172, FAA, Engine and Propeller
Directorate, New York Aircraft Certification Office, 10 Fifth Street,
Third Floor, Valley Stream,
[[Page 43960]]
New York 11581; telephone (516) 256-7520; fax (516) 568-2716.
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 98-NM-324-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-114, Attention: Rules
Docket No. 98-NM-324-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
On May 22, 1998, the FAA issued AD 98-11-25, amendment 39-10550 (63
FR 30121, June 3, 1998), applicable to certain Bombardier Model DHC-8-
311 and -315 series airplanes, to require replacement of the nitrogen
cylinder assemblies that inflate the airplane's ditching dams with
improved nitrogen cylinder assemblies. That action was prompted by
information by a foreign civil airworthiness authority. The
requirements of that AD are intended to prevent failure of the ditching
dams to inflate fully during an emergency water landing, which could
result in water entering the airplane.
Actions Since Issuance of Previous Rule
Since the issuance of that AD, Transport Canada Civil Aviation
(TCA), which is the airworthiness authority for Canada, has advised the
FAA that medium and high gross weight configured airplanes on which
Bombardier Change Request CR803SO00001-1 or CR803SO00002-1 has been
incorporated may also be subject to the identified unsafe condition.
Explanation of Relevant Service Information
The manufacturer has issued de Havilland Service Bulletin S.B. 8-
25-122, dated October 10, 1997, which describes procedures for
replacing the existing nitrogen cylinder assemblies on ditching dams
with new nitrogen cylinder assemblies that incorporate an improved
valve assembly. Accomplishment of the actions specified in the service
bulletin is intended to adequately address the identified unsafe
condition. TCA classified this service bulletin as mandatory and issued
Canadian airworthiness directive CF-97-21R1, dated July 22, 1998, 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
section 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 supersede AD 98-11-25 to
continue to require replacement of the nitrogen cylinder assemblies
that inflate the airplane's ditching dams with improved nitrogen
cylinder assemblies. This action would expand the applicability of the
existing AD. The actions would be required to be accomplished in
accordance with the service bulletin described previously.
Cost Impact
There are approximately 2 airplanes of U.S. registry that would be
affected by this proposed AD.
The replacement that is currently required by AD 98-11-25 and
retained in the proposed AD would take approximately 4 work hours per
airplane to accomplish, at an average labor rate of $60 per work hour.
Required parts would be provided by the manufacturer of the nitrogen
cylinder assembly at no cost to the operator. Based on these figures,
the cost impact of the replacement currently required on U.S. operators
is estimated to be $480, or $240 per airplane.
The cost impact figure discussed above is based on assumptions that
no operator has yet accomplished any of the current or 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 12,612, 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:
[[Page 43961]]
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 removing amendment 39-10550 (63 FR
30121, June 3, 1998), and by adding a new airworthiness directive (AD),
to read as follows:
Bombardier, Inc. (Formerly de Havilland, Inc.): Docket 98-NM-324-AD.
Supersedes AD 98-11-25, Amendment 39-10550.
Applicability: Model DHC-8-311 and -315 series airplanes in the
medium and high gross weight configuration, on which Bombardier
Change Request CR803SO00001, CR803SO00001-1, CR803SO00002,
CR803SO00002-1, CR803CH00046, CR803CH00079, CR803CH00105,
CR825CH00847, or CR803CH00051 has been incorporated; 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 (e) 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 failure of the ditching dams to inflate fully during
an emergency water landing, which could result in water entering the
airplane, accomplish the following:
Restatement of the Requirements of AD 98-11-25, Amendment 39-10550
(a) For airplanes in the medium and high gross weight
configuration, on which Bombardier Change Request CR803SO00001,
CR803SO00002, CR803CH00046, CR803CH00079, CR803CH00105,
CR825CH00847, or CR803CH00051 has been incorporated: Within 6 months
after July 8, 1998 (the effective date of AD 98-11-25), replace the
existing nitrogen cylinder assembly on the ditching dams with a new
nitrogen cylinder assembly that incorporates an improved valve
assembly (reference de Havilland Modification 8/3154), in accordance
with de Havilland Service Bulletin S.B. 8-25-122, dated October 10,
1997.
(b) For airplanes in the medium and high gross weight
configuration, on which Bombardier Change Request CR803SO00001,
CR803SO00002, CR803CH00046, CR803CH00079, CR803CH00105,
CR825CH00847, or CR803CH00051 has been incorporated: As of July 8,
1998, no person shall install on any airplane any nitrogen cylinder
assembly having part number (P/N) 410870(BSC) or 410870-1.
New Requirements of This AD
Replacement
(c) For airplanes other than those identified in paragraph (a)
of this AD: Within 6 months after the effective date of this AD,
replace the existing nitrogen cylinder assembly on the ditching dams
with a new nitrogen cylinder assembly having P/N 410870-3 or -5,
that incorporates an improved valve assembly (reference de Havilland
Modification 8/3154), in accordance with de Havilland Service
Bulletin S.B. 8-25-122, dated October 10, 1997.
Spares
(d) For airplanes other than those identified in paragraph (a)
of this AD: As of the effective date of this AD, no person shall
install on any airplane any nitrogen cylinder assembly having P/N
410870(BSC) or 410870-1.
Alternative Methods of Compliance
(e) 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.
Special Flight Permits
(f) 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 3: The subject of this AD is addressed in Canadian
airworthiness directive CF-97-21R1, dated July 22, 1998.
Issued in Renton, Washington, on August 6, 1999.
D. L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 99-20891 Filed 8-11-99; 8:45 am]
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