[Federal Register Volume 61, Number 170 (Friday, August 30, 1996)]
[Proposed Rules]
[Pages 45914-45916]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-22143]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 95-NM-163-AD]
RIN 2120-AA64
Airworthiness Directives; de Havilland Model DHC-8-102 and -103
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-
102 and -103 series airplanes. This proposal would require repetitive
external inspections to detect cracks in the skin exterior of the
fuselage at floor level, and repair, if necessary. This proposal also
would require repetitive internal inspections to detect cracks of the
subject area, which terminates the repetitive external inspections.
This proposal is prompted by a report that one of the tasks in the
Maintenance Program Airworthiness Limitations List inadvertently
excluded certain airplanes from the instructions for the inspections.
The actions specified by the proposed AD are intended to prevent
undetected cracking of the frames and skin panels of the fuselage,
which could result in reduced structural integrity of the airplane.
DATES: Comments must be received by October 8, 1996.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 95-NM-163-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.
FOR FURTHER INFORMATION CONTACT: Jon Hjelm, 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) 256-7523; 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 95-NM-163-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. 95-NM-163-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
Transport Canada Aviation, which is the airworthiness authority for
Canada, has notified the FAA that an unsafe condition may exist on
certain de Havilland Model DHC-8-102 and -103 series airplanes.
Transport Canada advises that, in a previous issue of the Maintenance
Program Airworthiness Limitations List (ALL), certain modified
airplanes were inadvertently excluded from instructions for performing
one of the required maintenance tasks.
The ALL contains mandatory damage tolerance inspections of the
fuselage [required by section 25.571 (``Damage tolerance and fatigue
evaluation of structure'') of the Federal Aviation Regulations (14 CFR
25.571), amendment 25-45] that are part of the type certificate of
these airplanes. The instructions for these inspections are in the form
of inspection ``maintenance task cards'' and are contained in the Dash
8 Maintenance Program Manual PSM 1-8-7.
Maintenance Task Card 5310/30C contains instructions for performing
internal visual inspections to detect cracks of the left- and right-
hand fuselage frames at the floor level. It also contains an
effectivity listing, which specifies those airplanes on which the
inspection is necessary. The effectivity of this task card lists
airplanes on which de Havilland Modification 8/0427 has not been
installed, but inadvertently
[[Page 45915]]
excludes from the list the airplanes on which that modification has
been installed. Both the modified and unmodified airplanes must receive
these inspections, however.
Since the ALL is incorporated into the Dash 8 Maintenance Program
Manual, and since the ALL's effectivity for this necessary inspection
is incorrect, the fuselage frames of the modified airplanes may not
have been inspected. Without these necessary inspections, cracking
could occur and go undetected. Additionally, cracking of the fuselage
frames is often associated with secondary cracking of the fuselage
skin. Such cracking of the frames and skin panels of the fuselage at
the floor level, if not detected and corrected, could result in reduced
structural integrity of the airplane.
Explanation of Relevant Service Information
De Havilland has issued Service Bulletin 8-53-48, dated August 26,
1994, which describes procedures for repetitive external detailed
visual inspections to detect cracks in the left-and right-hand skin
exterior of the fuselage at the floor level on Model DHC-8 series
airplanes on which de Havilland Modification 8/0427 has been installed.
The service bulletin also describes procedures for repetitive internal
visual inspections to detect cracks of the fuselage frames.
Accomplishment of the internal inspection eliminates the need for the
repetitive external inspections. In addition, the service bulletin
describes procedures for reporting all cracks to Bombardier Regional
Aircraft Division.
Transport Canada Aviation classified this service bulletin as
mandatory and issued Canadian airworthiness directive CF-94-17, dated
September 9, 1994, in order to assure the continued airworthiness of
these airplanes in Canada.
FAA's Conclusion
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, Transport Canada Aviation has kept
the FAA informed of the situation described above. The FAA has examined
the findings of Transport Canada Aviation, 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, the
proposed AD would require repetitive external detailed visual
inspections to detect cracks in the left-and right-hand skin exterior
of the fuselage at the floor level. The proposed AD also would require
repetitive internal visual inspections to detect cracks of the fuselage
frames; initiation of these inspections would constitute terminating
action for the repetitive external inspection requirements. The actions
would be required to be accomplished in accordance with the service
bulletin described previously.
This proposed AD would be applicable only to airplanes on which de
Havilland Modification 8/0427 has been installed, and on which
Maintenance Program Manual PSM 1-8-7, Task 5310/30C (Section 3-53, page
12, dated August 10, 1993) has not been accomplished.
Differences Between the Proposal and the Related Service
Information
Operators should note that, although the service bulletin specifies
that operators are to contact Bombardier Regional Aircraft Division for
``disposition of all cracks,'' this proposed AD would require that
operators accomplish the repair of any cracking in accordance with the
de Havilland DHC-8 Structural Repair Manual, or in accordance with a
method approved by Transport Canada Aviation or the FAA.
Cost Impact
The FAA estimates that 80 airplanes of U.S. registry would be
affected by this proposed AD.
The proposed external inspections would take approximately 1 work
hour per airplane to accomplish, at an average labor rate of $60 per
work hour. Based on these figures, the cost impact of the proposed AD
on U.S. operators is estimated to be $4,800, or $60 per airplane, per
inspection.
The proposed internal inspections would take approximately 3 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 proposed AD
on U.S. operators is estimated to be $14,400, or $180 per airplane, per
inspection.
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 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 95-NM-163 AD.
Applicability: Model DHC-8-102 and 103 series airplanes having
serial numbers 101 through 180, inclusive; on which de Havilland
Modification 8/0427 has been installed, and on which Maintenance
Program Manual PSM 1-8-7, Task 5310/30C (Section 3-53, page 12,
dated August 10, 1993) has not been accomplished; certificated in
any category.
Note 1: This AD applies to each airplane identified in the
preceding applicability
[[Page 45916]]
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 (c) 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 undetected cracking of the frames and skin panels of
the fuselage, which could result in reduced structural integrity of
the airplane, accomplish the following:
(a) Prior to the accumulation of 15,343 total flight cycles, or
within 200 landings after the effective date of this AD, whichever
occurs later, perform an external detailed visual inspection to
detect cracks in the left- and right-hand skin exterior of the
fuselage at floor level, in accordance with paragraph III, External
Inspection, of the Accomplishment Instructions of de Havilland
Service Bulletin S.B. 8-53-48, dated August 26, 1994.
(1) If no crack is detected, repeat the external detailed visual
inspection thereafter at intervals not to exceed 750 landings.
(2) If any crack is detected, prior to further flight, perform
an internal visual inspection to detect cracks of the fuselage
frames in accordance with the service bulletin. Accomplishment of
this internal visual inspection constitutes terminating action for
the repetitive external detailed visual inspections required by of
paragraph (a)(1) of this AD.
(i) If no crack is detected during the internal inspection,
prior to further flight, repair the cracked area(s) found during the
external inspection, in accordance with the de Havilland DHC-8
Structural Repair Manual; or in accordance with a method approved by
Transport Canada; or in accordance with a method approved by the
Manager, New York Aircraft Certification Office (ACO), FAA, Engine
and Propeller Directorate. Repeat the internal inspection thereafter
at intervals specified in accordance with the Dash 8 Maintenance
Program Manual.
(ii) If any crack is detected during the internal inspection,
prior to further flight, repair all cracks found during both the
external and internal inspections, in accordance with the de
Havilland DHC-8 Structural Repair Manual, or in accordance with a
method approved by Transport Canada Aviation; or in accordance with
a method approved by the Manager, New York ACO, FAA, Engine and
Propeller Directorate. Repeat the internal inspection thereafter at
intervals specified in accordance with the Dash 8 Maintenance
Program Manual.
(b) Prior to the accumulation of 31,000 flight cycles, or within
12 months after the effective date of this AD, whichever occurs
later, perform an internal visual inspection to detect cracking of
the fuselage frames, in accordance with de Havilland Service
Bulletin S.B. 8-53-48, dated August 26, 1994. Accomplishment of the
internal visual inspection constitutes terminating action for the
repetitive external detailed visual inspections required by
paragraph (a)(1) of this AD.
(1) If no cracking is detected during the internal inspection,
repeat the internal inspection thereafter at intervals specified in
accordance with the Dash 8 Maintenance Program Manual.
(2) If any cracking is detected during the internal inspection,
prior to further flight, repair it in accordance with the de
Havilland DHC-8 Structural Repair Manual, or in accordance with a
method approved by Transport Canada Aviation; or in accordance with
a method approved by the Manager, New York ACO, FAA, Engine and
Propeller Directorate. Repeat the internal inspection thereafter at
intervals specified in accordance with the Dash 8 Maintenance
Program Manual.
(c) 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 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.
(d) 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.
Issued in Renton, Washington, on August 23, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 96-22143 Filed 8-29-96; 8:45 am]
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