[Federal Register Volume 66, Number 31 (Wednesday, February 14, 2001)]
[Proposed Rules]
[Pages 10238-10241]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-3674]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-NM-45-AD]
RIN 2120-AA64


Airworthiness Directives; Bombardier Model DHC-8-102, -103, -106, 
-201, -202, -301, -311, -314, 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-8-102, -
103, -106, -201, -202, -301, -311, -314, and -315 series airplanes. 
This proposal would require revising the Bombardier maintenance program 
to incorporate repetitive inspections to detect fatigue cracking in 
certain structures; and corrective actions, if necessary. This proposal 
is prompted by issuance of

[[Page 10239]]

mandatory continuing airworthiness information by a foreign civil 
airworthiness authority. The actions specified by the proposed AD are 
intended to ensure that fatigue cracking of certain principal 
structural elements is detected and corrected; such fatigue cracking 
could adversely affect the structural integrity of these airplanes.

DATES: Comments must be received by March 16, 2001.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2000-NM-45-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. Comments may be submitted via fax to (425) 227-1232. 
Comments may also be sent via the Internet using the following address: 
[email protected]. Comments sent via fax or the Internet must 
contain ``Docket No. 2000-NM-45-AD'' in the subject line and need not 
be submitted in triplicate. Comments sent via the Internet as attached 
electronic files must be formatted in Microsoft Word 97 for Windows or 
ASCII text.
    The service information referenced in the proposed rule may be 
obtained from Bombardier, Inc., Bombardier Regional Aircraft Division, 
123 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, New York 
Aircraft Certification Office, 10 Fifth Street, Third Floor, Valley 
Stream, New York.

FOR FURTHER INFORMATION CONTACT: Serge Napoleon, Aerospace Engineer, 
ANE-171, FAA, New York Aircraft Certification Office, 10 Fifth Street, 
Third Floor, Valley Stream, New York 11581; telephone (516) 256-7512; 
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 action may be changed in 
light of the comments received.
    Submit comments using the following format:
     Organize comments issue-by-issue. For example, discuss a 
request to change the compliance time and a request to change the 
service bulletin reference as two separate issues.
     For each issue, state what specific change to the proposed 
AD is being requested.
     Include justification (e.g., reasons or data) for each 
request.
    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 action must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 2000-NM-45-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. 2000-NM-45-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 Model DHC-8-102, -103, -106, -201, -202, -301, -311, -314, 
and -315 series airplanes. TCCA advises that fatigue cracks have been 
found in the outer closing angles at both front and rear spar locations 
on the airplane fuselage. The closing angles consist of three segments 
(left, center, and right), which are part of the structure that 
connects the fuselage to the wing front and rear spar webs located in 
the wing/fuselage interface area. Reports received by the FAA indicate 
that cracks were detected in the closing angles on a number of in-
service Model DHC-8-102 and -103 series airplanes. Investigation 
revealed that those cracks were generated by metal fatigue due to 
cyclic loading on the wing. Cracking of any closing angles identified 
as principal structural elements (PSE's) could adversely affect the 
structural integrity of the airplanes.

Explanation of Relevant Service Information

    The manufacturer has issued de Havilland Temporary Revisions (TR's) 
to the DHC-8 Maintenance Program Manuals, as listed in Table 1 of this 
AD. The TR documents include inspection procedures of the Airworthiness 
Limitations List, Structural Inspection Program Task No. 5310/31A, 
which specify threshold and repetitive inspections. Those documents are 
to be incorporated into the DHC-8 Maintenance Program Manuals to revise 
the Bombardier maintenance program.
    TCCA has approved the TR documents and has issued Canadian 
airworthiness directive CF-2000-07, dated March 3, 2000, to assure the 
continued airworthiness of these airplanes in Canada. The Canadian 
airworthiness document includes procedures for revising the Bombardier 
maintenance program and detecting and correcting fatigue cracking in 
the wing/fuselage PSE closing angles.
    Accomplishment of the actions specified in these documents is 
intended to adequately address the identified unsafe condition.

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 determined that the DHC-8 
Maintenance Program Manuals, Airworthiness Limitations List (AWL), must 
be revised by incorporating the threshold and repetitive inspection 
intervals of the AWL, Structural Inspection Program Task No. 5310/31A, 
specified by the TR documents, into the Bombardier maintenance program. 
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

[[Page 10240]]

States, the proposed AD would require accomplishment of the actions 
specified in the TR documents and in this proposed AD, except as 
discussed below.

Difference Between Proposed Rule and Canadian Airworthiness 
Directive

    Operators should note that the previously referenced Canadian 
airworthiness directive specifies contacting the manufacturer for the 
disposition of any cracking found in any closing angle identified as a 
principal structural element. However, this proposal would require the 
repair of any such cracking or replacement of the closing angles per a 
method approved by the FAA.

Difference Between TR Document, and Canadian Airworthiness 
Directive and Proposed Rule

    Operators should note that TR AWL-71, dated September 3, 1999, 
lists Model DHC-8-101 series airplanes in the table of the Structural 
Inspection Program included in that TR. However, that airplane model is 
not cited in the Canadian airworthiness directive or in the 
applicability of the proposed rule. In addition, the manufacturer has 
informed the FAA that Model DHC-8-101 no longer exists, as it was 
converted into Model DHC-8-102 in 1986.

Cost Impact

    The FAA estimates that 195 Model DHC-8-102, -103, -106, -201, -202, 
-301, -311, -314, and -315 series airplanes of U.S. registry would be 
affected by this proposed AD.
    It would take approximately 1 work hour per airplane to revise the 
Bombardier maintenance program, 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 $11,700, or $60 per airplane.
    It would take approximately 5 work hours per airplane to accomplish 
the structural inspections, 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 $58,500, or $300 per airplane.
    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. The cost impact figures 
discussed in AD rulemaking actions represent only the time necessary to 
perform the specific actions actually required by the AD. These figures 
typically do not include incidental costs, such as the time required to 
gain access and close up, planning time, or time necessitated by other 
administrative actions.

Regulatory Impact

    The regulations proposed herein would not have a substantial direct 
effect 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, it 
is determined that this proposal would not have federalism implications 
under Executive Order 13132.
    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 2000-NM-45-
AD.

    Applicability: Model DHC-8-102, -103, -106, -201, -202, -301, -
311, -314, 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 ensure continued structural integrity of these airplanes, 
accomplish the following:
    (a) Within 30 days after the effective date of this AD, 
accomplish the actions required by either paragraph (a)(1) or (a)(2) 
of this AD, as applicable.

Maintenance Program Revisions

    (1) Revise the Bombardier maintenance program by incorporating 
the threshold and repetitive inspection intervals specified in the 
Temporary Revisions (TR's) to the DHC-8 Maintenance Program Manuals, 
Airworthiness Limitations List (AWL), Structural Inspection Program 
Task No. 5310/31A, into the Bombardier maintenance program. The TR's 
for specific airplane models are listed in Table 1, as follows:

                  Table 1.--List of Temporary Revisions
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       Bombardier models              TR number              Date
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DHC-8-102, -103, and -106        TR AWL-71            September 3, 1999.
 series airplanes.
DHC-8-102, -103, -106, -201, -   TR AWL 2-15          September 3, 1999.
 202, -301, -311, -314, and -
 315 series airplanes.
DHC-8-301, -311, -314, and -315  TR AWL 3-78          November 19, 1999.
 series airplanes.
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    Note 2: When the TR documents listed in Table 1 in paragraph 
(a)(1) of thisAD are incorporated into the general revisions of the 
DHC-8 Maintenance Program Manual, you may insert the general 
revisions into the Bombardier maintenance program, provided

[[Page 10241]]

that the information contained in the general revisions is identical 
to that specified in the TR documents.

Structural Inspections

    (2) For airplanes having closing angles that are identified as 
principal structural elements: Do the inspections specified by the 
applicable TR listed in Table 1 of paragraph (a) of this AD. 
Thereafter, repeat the inspection at intervals not to exceed 10,000 
flight cycles at the time specified in paragraph (a)(2)(i), 
(a)(2)(ii), or (a)(2)(iii) of this AD, as applicable.
    (i) For airplanes that have accumulated less than 8,000 flight 
cycles as of the effective date of this AD: Do the threshold 
inspection prior to the accomplishment of 10,000 flight cycles, or 
within 2,000 flight cycles after the effective date of this AD, 
whichever occurs later.
    (ii) For airplanes that have accumulated 8,000 flight cycles or 
more as of the effective date of this AD: Do the threshold 
inspection within 2,000 flight cycles after the effective date of 
this AD.
    (iii) For airplanes on which a 40,000 flight cycle inspection 
specified by the applicable TR listed in Table 1 of paragraph (a) of 
this AD has been done, no cracks have been found, and/or the closing 
angles have been replaced: Start the 10,000 flight cycle repetitive 
inspection at the time specified by either paragraph (a)(2)(iii)(A) 
or (a)(2)(iii)(B) of this AD, as applicable.
    (A) From the date at which the 40,000 flight cycle inspection 
was done.
    (B) From the date the closing angles were replaced.

Corrective Actions

    (b) If any crack is detected during any structural inspection 
required by paragraph (a)(2) of this AD, before further flight, 
repair any such cracking or replace the closing angles per a method 
approved by the Manager, New York Aircraft Certification Office 
(ACO), FAA, or the Transport Canada Civil Aviation (or its delegated 
agent). For a repair or replacement 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) Except as provided by paragraph (d) of this AD: After the 
actions specified in paragraphs (a) and (b) of this AD have been 
accomplished, no alternative inspections or inspection intervals may 
be approved for the structural elements specified by the documents 
listed in Table 1 of paragraph (a)(1) of 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 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 
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-2000-07, dated March 3, 2000.


    Issued in Renton, Washington, on February 7, 2001.
Dorenda D. Baker,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 01-3674 Filed 2-13-01; 8:45 am]
BILLING CODE 4910-13-P