[Federal Register Volume 64, Number 171 (Friday, September 3, 1999)]
[Proposed Rules]
[Pages 48333-48335]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-23064]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-335-AD]
RIN 2120-AA64


Airworthiness Directives; Bombardier Model DHC-8-101, -102, -103, 
-106, -201, -202, -301, -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 adoption of a new airworthiness 
directive (AD) that is applicable to all Bombardier Model DHC-8-101, -
102, -103, -106, -201, -202, -301, -311, and -315 series airplanes. 
This proposal would require repetitive detailed visual inspections and 
high frequency eddy current inspections to detect cracking of the wing 
upper skin and ladder plates at over wing access panels between certain 
stations; and repair, if necessary. 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 wing ladder 
plates, which, if not corrected, could reduce the structural integrity 
of the wing.

DATES: Comments must be received by October 4, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 98-NM-335-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

[[Page 48334]]

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 98-NM-335-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-335-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The 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-8-101, -102, -103, -
106, -201, -202, -301, -311, and -315 series airplanes. The TCCA 
advises that fatigue cracking of the wing ladder plate has been found 
on DHC-8 series airplanes. This cracking has been attributed to 
repeated fatigue load cycles. This condition, if not corrected, could 
result in reduced structural integrity of the wing.

Explanation of Relevant Service Information

    Bombardier has issued de Havilland Temporary Revision TR MTC-15, 
dated September 18, 1998, of the de Havilland Maintenance Program 
Manual PSM 1-8-7 (for Model DHC-8-100 series airplanes); de Havilland 
Temporary Revision TR MTC 2-14, dated September 18, 1998, of the de 
Havilland Maintenance Program Manual PSM 1-82-7 TC (for Model DHC-8-200 
series airplanes); and de Havilland Temporary Revision TR MTC 3-14, 
dated September 18, 1998, of the de Havilland Maintenance Program 
Manual PSM 1-83-7 TC (for Model DHC-8-300 series airplanes). These 
temporary revisions describe procedures for repetitive detailed visual 
inspections and high frequency eddy current (HFEC) inspections to 
detect cracking of the wing upper skin and ladder plates at over wing 
access panels between station YW42.00 and YW171.20.
    Bombardier also has issued de Havilland Airworthiness Limitations 
List Temporary Revision TR AWL-59, dated September 10, 1998, of the de 
Havilland Maintenance Program Manual PSM 1-8-7 (for Model DHC-8-100 
series airplanes); de Havilland Airworthiness Limitations List 
Temporary Revision TR AWL2-11, dated September 10, 1998, of de 
Havilland Maintenance Program Manual PSM 1-82-7 (for Model DHC-8-200 
series airplanes); and de Havilland Airworthiness Limitations List 
Temporary Revision TR AWL3-64, dated September 10, 1998, of de 
Havilland Maintenance Program Manual PSM 1-83-7 (for Model DHC-8-300 
series airplanes). These temporary revisions describe the compliance 
times associated with the repetitive detailed visual inspections and 
HFEC inspections described previously.
    Accomplishment of the actions specified in the temporary revisions 
is intended to adequately address the identified unsafe condition. The 
TCCA classified these temporary revisions as mandatory and issued 
Canadian airworthiness directive CF-98-30, dated August 31, 1998, in 
order to assure the continued airworthiness of these airplanes in 
Canada.

FAA's Conclusions

    These airplane models are manufactured in Canada and are 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, the TCCA has kept the FAA informed 
of the situation described above. The FAA has examined the findings of 
the 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 temporary revisions described previously, 
except as discussed below.

Differences Between Proposed Rule and Service Information

    Operators should note that, although the Canadian airworthiness 
directive and the temporary revisions specify that the manufacturer may 
be contacted for disposition of certain repair conditions, this 
proposal would require the repair of those conditions to be 
accomplished in accordance with a method approved by 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.
    Operators also should note that, although the Canadian 
airworthiness directive affects Bombardier Model DHC-8-314 series 
airplanes, Bombardier Model DHC-8-314 series airplanes are not type 
certificated in the United States. Therefore, the proposed AD does not 
affect those airplanes.

Cost Impact

    The FAA estimates that 166 airplanes of U.S. registry would be 
affected by this proposed AD, that it would take approximately 40 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 
$398,400, or $2,400 per airplane, per inspection cycle.
    The cost impact figure discussed above is based on assumptions that 
no

[[Page 48335]]

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 98-NM-335-
AD.

    Applicability: All Model DHC-8-101, -102, -103, -106, -201, -
202, -301, -311, and -315 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 of the wing ladder plates, 
which if not corrected, could reduce the structural integrity of the 
wing, accomplish the following:

Inspection for DHC-8-100 and -300 Series Airplanes

    (a) At the applicable compliance time listed in paragraph 
(a)(1), (a)(2), or (a)(3) of this AD, perform a detailed visual 
inspection to detect cracking of the skin and a high frequency eddy 
current (HFEC) inspection of the ladder plates at over wing access 
panels between station YW42.00 and YW171.20, in accordance with de 
Havilland Temporary Revision TR MTC-15, dated September 18, 1998, of 
the de Havilland Maintenance Program Manual PSM-1-8-7 TC (for Model 
DHC-8-100 series airplanes); or de Havilland Temporary Revision TR 
MTC 3-14, dated September 18, 1998, of the de Havilland Maintenance 
Program Manual PSM 1-83-7 (for Model DHC-8-300 series airplanes); as 
applicable. Repeat the inspections thereafter at intervals not to 
exceed 10,000 flight cycles.
    (1) For airplanes that have accumulated 5,000 or fewer total 
flight cycles as of the effective date of this AD, accomplish the 
inspection prior to the accumulation of 10,000 total flight cycles.
    (2) For airplanes that have accumulated more than 5,000 total 
flight cycles, but fewer than 38,501 total flight cycles as of the 
effective date of this AD, accomplish the inspection prior to the 
accumulation of [5,522 + (0.8955 x N Accumulated)] total cycles. ``N 
Accumulated'' is defined as the total number of flight cycles as of 
the effective date of this AD.
    (3) For airplanes that have accumulated 38,501 or more total 
flight cycles as of the effective date of this AD, accomplish the 
inspection within 1,500 flight cycles after the effective date of 
this AD.

    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.''

Inspection for DHC-8-200 Series Airplanes

    (b) At the applicable compliance time listed in paragraph (b)(1) 
or (b)(2) of this AD, perform a detailed visual inspection of the 
skin and an HFEC inspection to detect cracking of the ladder plates 
at over wing access panels between station YW42.00 and YW171.20, in 
accordance with de Havilland Temporary Revision TR MTC 2-14, dated 
September 18, 1998, of the de Havilland Maintenance Program Manual 
PSM 1-82-7. Repeat the inspections thereafter at intervals not to 
exceed 10,000 flight cycles.
    (1) For airplanes that have accumulated 5,000 or fewer total 
flight cycles as of the effective date of this AD, accomplish the 
inspection prior to the accumulation of 10,000 total flight cycles.
    (2) For airplanes that have accumulated more than 5,000 total 
flight cycles, but fewer than 38,501 total flight cycles as of the 
effective date of this AD, accomplish the inspection prior to the 
accumulation of [5,522 + (0.8955 x N Accumulated)] total cycles, 
where ``N Accumulated'' is defined as the total number of flight 
cycles as of the effective date of this AD.

Repair

    (c) If any crack is detected during any inspection required by 
this AD, prior to further flight, 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 (TCCA) (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.

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 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 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 
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 4: The subject of this AD is addressed in Canadian 
airworthiness directive CF-98-30, dated August 31, 1998.

    Issued in Renton, Washington, on August 30, 1999.
Vi L. Lipski,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 99-23064 Filed 9-2-99; 8:45 am]
BILLING CODE 4910-13-U