[Federal Register Volume 59, Number 33 (Thursday, February 17, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-3576]
[[Page Unknown]]
[Federal Register: February 17, 1994]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 93-CE-52-AD]
Airworthiness Directives: de Havilland DHC-6 Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: This document proposes to adopt a new airworthiness directive
(AD) that would apply to de Havilland DHC-6 series airplanes. The
proposed action would require repetitively inspecting the horizontal
stabilizer center hinge bracket for cracks, and replacing any cracked
center hinge bracket. Several reports of cracks in the horizontal
stabilizer center hinge bracket flange on the affected airplanes
prompted the proposed action. The actions specified by the proposed AD
are intended to prevent separation of the elevator control support from
the airplane as a result of a cracked horizontal stabilizer center
hinge bracket, which could result in reduced controllability of the
airplane.
DATES: Comments must be received on or before April 22, 1994.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Central Region, Office of the Assistant Chief
Counsel, Attention: Rules Docket No. 93-CE-52-AD, room 1558, 601 E.
12th Street, Kansas City, Missouri 64106. Comments may be inspected at
this location between 8 a.m. and 4 p.m., Monday through Friday,
holidays excepted.
Service information that applies to the proposed AD may be obtained
from de Havilland, Inc., 123 Garratt Boulevard, Downsview, Ontario,
Canada, M3K 1Y5. This information also may be examined at the Rules
Docket at the address above.
FOR FURTHER INFORMATION CONTACT: Jon Hjelm, Aerospace Engineer, FAA,
New York Aircraft Certification Office, 181 South Franklin Avenue, room
202, Valley Stream, New York 11581; telephone (516) 791-6220; facsimile
(516) 791-9024.
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 should 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 that summarizes 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 No. 93-CE-52-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, Central Region, Office of the Assistant Chief Counsel,
Attention: Rules Docket No. 93-CE-52-AD, room 1558, 601 E. 12th Street,
Kansas City, Missouri 64106.
Discussion
Transport Canada, which is the airworthiness authority for Canada,
recently notified the FAA that an unsafe condition may exist on de
Havilland DHC-6 series airplanes. Transport Canada reports that the
horizontal stabilizer center hinge bracket has cracked on several of
the above referenced airplanes.
De Havilland has issued Service Bulletin (SB) 6/512, dated October
25, 1991, which specifies procedures for (1) inspecting the horizontal
stabilizer center hinge bracket for cracks; and (2) replacing this
center hinge bracket. Transport Canada classified this service bulletin
as mandatory and issued Transport Canada AD CF-92-05, dated February 7,
1992, in order to assure the continued airworthiness of these airplanes
in Canada.
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 and the applicable
bilateral airworthiness agreement. Pursuant to this bilateral
airworthiness agreement, Transport Canada has kept the FAA informed of
the situation described above. The FAA has examined the findings of
Transport Canada, 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.
Since an unsafe condition has been identified that is likely to
exist or develop in other de Havilland DHC-6 series airplanes of the
same type design, the proposed AD would require repetitively inspecting
the horizontal stabilizer center hinge bracket for cracks, and
replacing any cracked center hinge bracket. The proposed action would
be accomplished in accordance with the ACCOMPLISHMENT INSTRUCTIONS
section of de Havilland SB 6/512, dated October 25, 1991.
The FAA estimates that 169 airplanes in the U.S. registry would be
affected by the proposed AD, that it would take approximately 1
workhour per airplane to accomplish the proposed inspection, and that
the average labor rate is approximately $55 an hour. Based on these
figures, the total cost impact of the proposed AD on U.S. operators is
estimated to be $9,295. This figure only includes the cost for the
initial inspection and does not include replacement costs if a center
hinge bracket was found cracked nor does it include repetitive
inspection costs. The FAA has no way to determine how many center hinge
brackets may be cracked or how many repetitive inspections each owner/
operator may incur.
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 action (1) is
not a ``significant regulatory action'' under Executive Order 12866;
(2) is not a ``significant rule'' under 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 has been placed 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 AD to read
as follows:
De Havilland: Docket No. 93-CE-52-AD.
Applicability: Models DHC-6-1, DHC-6-100, DHC-6-200, and DHC-6-
300 airplanes (all serial numbers), certificated in any category.
Compliance: Required within the next 250 hours time-in-service
(TIS), unless already accomplished, and thereafter at intervals not
to exceed 1,200 hours TIS.
To prevent separation of the elevator control support from the
airplane as a result of a cracked horizontal stabilizer center hinge
bracket, which could result in reduced controllability of the
airplane, accomplish the following:
(a) Inspect the horizontal stabilizer center hinge bracket for
cracks in accordance with the ACCOMPLISHMENT INSTRUCTIONS section of
de Havilland Service Bulletin 6/512, dated October 25, 1991, except
that where dye penetrant inspections are specified, accomplish
visual inspections with a strong light source and 10X magnifying
glass. If any cracks are found, prior to further flight, replace the
center hinge bracket in accordance with the referenced service
bulletin.
Note 1: The repetitive inspection requirement of this AD still
applies if the center hinge bracket is replaced.
(b) Special flight permits may be issued in accordance with 14
CFR 21.197 and 21.199 to operate the airplane to a location where
the requirements of this AD can be accomplished.
(c) An alternative method of compliance or adjustment of the
initial or repetitive compliance times that provides an equivalent
level of safety may be approved by the Manager, New York Aircraft
Certification Office (ACO), FAA, 181 South Franklin Avenue, room
202, Valley Stream, New York 11581. The request shall be forwarded
through an appropriate FAA 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.
(d) All persons affected by this directive may obtain copies of
the document referred to herein upon request to de Havilland, Inc.,
123 Garratt Boulevard, Downsview, Ontario M3K 1Y5 Canada; or may
examine this document at the FAA, Central Region, Office of the
Assistant Chief Counsel, room 1558, 601 E. 12th Street, Kansas City,
Missouri 64106.
Issued in Kansas City, Missouri, on February 11, 1994.
Michael K. Dahl,
Acting Manager, Small Airplane Directorate, Aircraft Certification
Office.
[FR Doc. 94-3576 Filed 2-16-94; 8:45 am]
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