[Federal Register Volume 63, Number 115 (Tuesday, June 16, 1998)]
[Proposed Rules]
[Pages 32771-32772]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-15885]
[[Page 32771]]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-NM-70-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 to revise an existing airworthiness
directive (AD), applicable to certain de Havilland Model DHC-8-100, -
200, and -300 series airplanes, that currently requires modification of
the attitude and heading reference systems (AHRS). That AD was prompted
by a report of loss of power to both AHRS's during flight due to a
faulty terminal block to which the signal ground for the AHRS's is
connected. The actions specified by that AD are intended to prevent
simultaneous power loss to both AHRS's, which could result in reduced
controllability of the airplane. This action would reduce the
applicability of the existing AD.
DATES: Comments must be received by July 16, 1998.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 98-NM-70-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: Luciano Castracane, Aerospace
Engineer, Systems and Equipment Branch, ANE-172, FAA, New York Aircraft
Certification Office, Engine and Propeller Directorate, 10 Fifth
Street, Third Floor, Valley Stream, New York 11581; telephone (516)
256-7535; 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-70-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-70-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
On September 19, 1997, the FAA issued AD 97-20-10, amendment 39-
10147 (62 FR 50861, September 29, 1997), applicable to certain de
Havilland Model DHC-8-100, -200, and -300 series airplanes, to require
modification of the attitude and heading reference systems (AHRS). That
action was prompted by a report of loss of power to both AHRS's during
flight due to a faulty terminal block to which the signal ground for
the AHRS's are connected. The requirements of that AD are intended to
prevent simultaneous power loss to both AHRS's, which could result in
reduced controllability of the airplane.
Actions Since Issuance of Previous Rule
Since issuance of that AD, the Transport Canada Aviation (TCA),
which is the airworthiness authority for Canada, has issued Canadian
airworthiness directive CF-97-01R2, dated August 13, 1997. This
revision supersedes Canadian airworthiness directive CF-97-01R1, dated
February 3, 1997, which was referenced in AD 97-20-10 as the parallel
Canadian airworthiness directive for AD 97-20-10. The only change
effected by CF-97-01R2 is to reduce the list of affected airplanes to
serial numbers 3 through 472 inclusive. The effectivity listing of CF-
97-01R2 limits accomplishment of the modification of the AHRS to those
airplanes on which the modification was not accomplished in production.
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 the
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 revise AD 97-20-10 to
continue to require modification of the AHRS. The proposed AD also
would reduce the applicability of that AD to airplanes having serial
numbers 3 through 472 inclusive.
Cost Impact
The FAA estimates that 167 de Havilland Model DHC-8-100, -200, and
-300 series airplanes of U.S. registry would be affected by this
proposed AD, that it would take approximately 4 work hours per airplane
to accomplish the proposed actions, and that the average labor rate is
$60 per work hour. Required parts would cost approximately $10 per
airplane. Based on these figures, the cost impact of the proposed AD on
U.S. operators is estimated to be $41,750, or $250 per airplane.
[[Page 32772]]
The cost impact figure discussed above is 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.
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 removing amendment 39-10147 (62 FR
50861, September 29, 1997), and by adding a new airworthiness directive
(AD), to read as follows:
De Havilland, Inc.: Docket 98-NM-70-AD. Revises AD 97-20-10,
Amendment 39-10147.
Applicability: Model DHC-8-100, -200, and -300 series airplanes,
serial numbers 3 through 472 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
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 (b) 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 simultaneous power loss to both attitude and heading
reference systems (AHRS), which could result in reduced
controllability of the airplane, accomplish the following:
(a) Within 400 hours time-in-service after November 3, 1997 (the
effective date of AD 97-20-10, amendment 39-10147), modify the
AHRS's, in accordance with Bombardier Alert Service Bulletin S.B.
A8-34-117, Revision `C', dated February 14, 1997.
(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, 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.
(c) 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-97-01R2, dated August 13, 1997.
Issued in Renton, Washington, on June 9, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 98-15885 Filed 6-15-98; 8:45 am]
BILLING CODE 4910-13-U
