[Federal Register Volume 64, Number 224 (Monday, November 22, 1999)]
[Proposed Rules]
[Pages 63760-63762]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-30369]
[[Page 63760]]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 99-NM-107-AD]
RIN 2120-AA64
Airworthiness Directives; Bombardier Model DHC-7-100 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 all Bombardier Model DHC-7-100
series airplanes. This proposal would require repetitive high frequency
eddy current inspections to detect cracks on the locking pin fittings
of the baggage door and locking pin housings of the fuselage;
repetitive detailed visual inspections to detect cracks of the inner
door structure on all four door locking attachment fittings; and
corrective actions, if necessary. In lieu of accomplishing the
corrective actions, this proposal also would provide a temporary
option, for certain cases, for revising the Airplane Flight Manual
(AFM), and installing a placard. 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 and correct fatigue cracking of the baggage door
fittings and the support structure, which could result in structural
failure, and consequent rapid decompression of the airplane during
flight.
DATES: Comments must be received by December 22, 1999.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 99-NM-107-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. 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: Franco Pieri, Aerospace Engineer,
Airframe and Propulsion Branch, ANE-171, FAA, Engine and Propeller
Directorate, New York Aircraft Certification Office, 10 Fifth Street,
Third Floor, Valley Stream, New York 11581; telephone (516) 256-7526;
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 99-NM-107-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. 99-NM-107-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
Transport Canada Civil Aviation (TCCA), which is the airworthiness
authority for Canada, notified the FAA that an unsafe condition may
exist on all Bombardier Model DHC-7-100 series airplanes. TCCA advises
that fatigue cracks have been reported in the door stop fittings
mounted on the baggage door. Failure of a door stop fitting would
appreciably degrade the structural integrity of the baggage door
installation. This condition, if not corrected, could result in
structural failure, and consequent rapid decompression of the airplane
during flight.
Explanation of Relevant Service Information
Bombardier has issued de Havilland Temporary Revision (TR) 5-100,
dated
December 23, 1998, for Supplementary Inspection Task 52-1 to the de
Havilland Dash 7 Maintenance Manual PSM 1-7-2. The service information
describes procedures for repetitive high frequency eddy current
inspections to detect cracks on the locking pin fittings of the baggage
door and locking pin housings of the fuselage; and repetitive detailed
visual inspections to detect cracks of the inner door structure on all
four door locking attachment fittings. TCCA classified this service
information as mandatory and issued Canadian airworthiness directive
CF-99-03, dated February 22, 1999, 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, TCCA has kept the FAA informed of
the situation described above. The FAA has examined the findings of
TCCA, 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 information described previously,
except as discussed below. The proposed AD also would require
corrective actions to be accomplished in accordance with de Havilland
Dash 7 Maintenance Manual PSM 1-7-2. The corrective actions, for
certain cases, involve replacement of any cracked fitting or housing
with a new fitting or housing, as applicable. For certain other
[[Page 63761]]
cases, the corrective actions involve replacement of any cracked
structure with a new support structure, or repair as described below.
In lieu of accomplishing the corrective actions, this proposal also
would provide a temporary option, for certain cases, for revising the
Airplane Flight Manual (AFM), and installing a placard.
Differences Between Proposed Rule and Service Information
Operators should note that, although the service information
specifies that the manufacturer may be contacted for disposition of
certain cracks, this proposal would require the repair of those
conditions to be accomplished in accordance with a method approved by
either the FAA, or the TCCA (or its delegated agent). In light of the
type of repair that would be required to address the identified unsafe
condition, and in consonance with existing bilateral airworthiness
agreements, the FAA has determined that, for this proposed AD, a repair
approved by either the FAA or the TCCA would be acceptable for
compliance with this proposed AD.
Interim Action
This is considered to be interim action until final action is
identified, at which time the FAA may consider further rulemaking.
Cost Impact
The FAA estimates that 32 airplanes of U.S. registry would be
affected by this proposed AD, that it would take approximately 3 work
hours per airplane to accomplish the proposed inspections, 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
$5,760, or $180 per airplane, per inspection cycle.
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 adding the following new
airworthiness directive:
Bombardier, Inc. (Formerly de Havilland, Inc.): Docket 99-NM-107-AD.
Applicability: All Model DHC-7-100 series airplanes,
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 (d) 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 and correct fatigue cracking in the baggage door
fittings and the support structure, which could result in structural
failure, and consequent rapid decompression of the airplane during
flight, accomplish the following:
Repetitive Inspections
(a) At the latest of the times specified in paragraphs (a)(1)
and (a)(2) of this AD, perform a high frequency eddy current
inspection to detect fatigue cracks of the locking pin fittings of
the baggage door and locking pin housings of the fuselage; and a
detailed visual inspection to detect fatigue cracks of the inner
door structure on all four locking attachment fittings of the
baggage door; in accordance with de Havilland Temporary Revision
(TR) 5-100, dated December 23, 1998, for Supplementary Inspection
Task 52-1 to the de Havilland Dash 7 Maintenance Manual PSM 1-7-2.
Thereafter, repeat the inspections at intervals not to exceed 1,000
flight cycles.
(1) Inspect prior to the accumulation of 12,000 total flight
cycles.
(2) Inspect within 600 flight cycles or 3 months after the
effective date of this AD, whichever occurs later.
Note 2: For the purposes of this AD, a detailed visual
inspection is defined as: ``An intensive visual examination of a
specific structural area, system, installation, or assembly to
detect damage, failure, or irregularity. Available lighting is
normally supplemented with a direct source of good lighting at
intensity deemed appropriate by the inspector. Inspection aids such
as mirror, magnifying lenses, etc., may be used. Surface cleaning
and elaborate access procedures may be required.''
Corrective Actions
(b) If any crack is detected during any inspection required by
paragraph (a) of this AD, prior to further flight, accomplish the
requirements of paragraphs (b)(1) and (b)(2) of this AD, as
applicable, except as provided in paragraph (c) of this AD. For
operators that elect to accomplish the actions specified in
paragraph (c) of this AD: After accomplishment of the replacement
required by paragraph (b)(1) or (b)(2) of this AD, the AFM revision
and placard required by paragraph (c) of this AD may be removed.
(1) If a crack is detected in a baggage door locking pin fitting
or fuselage locking pin housing: Replace the fitting or housing with
a new fitting or housing, as applicable, in accordance with de
Havilland Dash 7 Maintenance Manual PSM 1-7-2.
(2) If a crack is detected in the inner baggage door structure
at the locking attachment fittings: Replace the structure with a new
support structure in accordance with de Havilland Dash 7 Maintenance
Manual PSM 1-7-2, or repair in accordance with a method approved by
the Manager, New York Aircraft Certification Office (ACO), FAA,
Engine and Propeller Directorate, or the Transport Canada Civil
Aviation (or its delegated agent). For a repair method to be
approved by the Manager, New York ACO, as required by this
paragraph, the Manager's approval letter must specifically reference
this AD.
(c) For airplanes on which only one baggage door stop fitting or
its support structure is found cracked at one location, and on which
the pressurization system ``Dump'' function is operational: Prior to
further flight, accomplish the requirements of paragraphs (c)(1) and
(c)(2) of this AD.
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Within 1,000 flight cycles after accomplishment of the requirements
of paragraphs (c)(1) and (c)(2) of this AD, accomplish the
requirements of paragraph (b)(1) or (b)(2) of this AD, as
applicable.
(1) Revise the Limitations Section of the FAA-approved DHC-7
Airplane Flight Manual (AFM), PSM 1-71A-1A, to include the following
statement. This AFM revision may be accomplished by inserting a copy
of this AD into the AFM.
Flight is restricted to unpressurized flight below 10,000 feet
mean sea level (MSL). The airplane must be operated in accordance
with DHC-7 AFM, PSM 1-71A-1A, Supplement 20.
(2) Install a placard on the cabin pressure control panel or in
a prominent location that states the following:
DO NOT PRESSURIZE THE AIRCRAFT UNPRESSURIZED FLIGHT PERMITTED
ONLY IN ACCORDANCE WITH DHC-7 AFM PSM 1-71A-1A, SUPPLEMENT 20 FLIGHT
ALTITUDE LIMITED TO 10,000 FEET MSL OR LESS.
Alternative Methods of Compliance
(d) 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 ACO. 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 3: 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
(e) Special flight permits may be issued in accordance with
Secs. 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 Canadian
airworthiness directive CF-99-03, dated February 22, 1999.
Issued in Renton, Washington, on November 16, 1999.
D.L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 99-30369 Filed 11-19-99; 8:45 am]
BILLING CODE 4910-13-U
