[Federal Register Volume 67, Number 55 (Thursday, March 21, 2002)]
[Proposed Rules]
[Pages 13108-13111]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-6794]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001-NM-69-AD]
RIN 2120-AA64


Airworthiness Directives; Bombardier Model DHC-8-100, -200, and -
300 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 Bombardier Model DHC-8-
100, -200, and ``300 series airplanes. This proposal would require 
revision of the applicable maintenance program manual, repetitive 
inspections for corrosion or cracking of the hook roller shafts of the 
flap carriage, and eventual replacement of the hook roller shafts with 
new or serviceable hook roller shafts. This replacement would extend 
the interval for the repetitive inspections. This action is necessary 
to prevent cracking of the hook roller shafts of the flap carriage and 
consequent reduced structural integrity of the flap, which could result 
in jamming of the flap. This action is intended to address the 
identified unsafe condition.

DATES: Comments must be received by April 22, 2002.

ADDRESSES: Submit comments in triplicate to the Federal Aviation

[[Page 13109]]

Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2001-NM-69-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. 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. 2001-NM-69-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: Dan Parrillo, Aerospace Engineer, 
Airframe and Propulsion Branch, ANE-172, FAA, New York Aircraft 
Certification Office, 10 Fifth Street, Third Floor, Valley Stream, New 
York 11581; telephone (516) 256-7505; 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 2001-NM-69-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. 2001-NM-69-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 certain Bombardier Model DHC-8-100, -200, and -300 series 
airplanes. TCCA advises that corroded hook roller shafts have been 
found on the flap carriages of several in-service airplanes. During its 
investigation, the airplane manufacturer has identified discrepancies 
in the manufacturing process that may have resulted in inadequate 
corrosion protection on some hook roller shafts. This condition, if not 
corrected, could cause cracking of the hook roller shafts of the flap 
carriage and consequent reduced structural integrity of the flap, which 
could result to jamming of the flap.

Explanation of Relevant Service Information

    Bombardier, Inc., has issued De Havilland Inc. Dash 8 Airworthiness 
Limitations List Temporary Revisions (TRs) AWL-75 and AWL-76 (for Model 
DHC-8-100 series airplanes), AWL 2-19 (for Model DHC-8-200 series 
airplanes), and AWL 3-83 (for Model DHC-8-300 series airplanes), all 
dated July 14, 2000. Those TRs specify new thresholds and repetitive 
intervals for existing structural inspections of the hook roller shafts 
of the flap carriage according to De Havilland Inc. Dash 8 Maintenance 
Program Manual PSM 1-8-7 (for Model DHC-8-100 series airplanes), PSM 1-
82-7 (for Model DHC-8-200 series airplanes), or PSM 1-83-7 (for Model 
DHC-8-300 series airplanes), as applicable. TCCA classified these TRs 
as mandatory and issued Canadian airworthiness directive CF-1999-10R2, 
dated September 12, 2000, in order to assure the continued 
airworthiness of these airplanes in Canada. Canadian airworthiness 
directive CF-1999-10R2 also requires replacement of existing hook 
roller shafts with new or serviceable hook roller shafts.

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 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 revision of De 
Havilland Inc. Dash 8 Maintenance Program Manual PSM 1-8-7 (for Model 
DHC-8-100 series airplanes), PSM 1-82-7 (for Model DHC-8-200 series 
airplanes), or PSM 1-83-7 (for Model DHC-8-300 series airplanes), as 
applicable, repetitive detailed inspections for corrosion or cracking 
of the hook roller shafts of the flap carriage, and eventual 
replacement of the hook roller shafts with new or serviceable hook 
roller shafts. This replacement would extend the interval for the 
repetitive inspections. The inspections would be required to be 
accomplished according to the applicable De Havilland Inc. Dash 8 
Maintenance Program Manual and at the compliance times specified in the 
TRs described previously. The replacement of the hook roller shafts 
would be required to be accomplished in accordance with certain 
sections of the applicable De Havilland Inc. Dash 8 Aircraft 
Maintenance Manual.

Differences Between the Proposed Rule and Service Information

    The service information identifies the inspection described 
previously only as

[[Page 13110]]

a ``structural inspection.'' For clarity, this proposed AD refers to 
that structural inspection as a ``detailed inspection.'' Note 2 of this 
proposed AD defines such an inspection.

Cost Impact

    The FAA estimates that 183 airplanes of U.S. registry would be 
affected by this proposed AD.
    It would take approximately 4 work hours per airplane to accomplish 
the proposed inspection, at an average labor rate of $60 per work hour. 
Based on these figures, the cost impact of the proposed inspection on 
U.S. operators is estimated to be $43,920, or $240 per airplane, per 
inspection cycle.
    It would take approximately 4 work hours per airplane to accomplish 
the proposed replacement, at an average labor rate of $60 per work 
hour. Required parts would cost approximately $460 per airplane. Based 
on these figures, the cost impact of the proposed AD on U.S. operators 
is estimated to be $128,100, or $700 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 proposed 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 2001-NM-69-
AD.

    Applicability: Model DHC-8-100, -200, and ``300 series 
airplanes; serial numbers 3 through 555 inclusive; 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 (e) 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 cracking of the hook roller shafts of the flap 
carriage and consequent reduced structural integrity of the flap, 
which could result in jamming of the flap, accomplish the following:

Revision of Maintenance Program Manual

    (a) Within 30 days after the effective date of this AD, 
accomplish paragraph (a)(1), (a)(2), or (a)(3) of this AD, as 
applicable.
    (1) For Model DHC-8-100 series airplanes: Insert De Havilland 
Inc. Dash 8 Airworthiness Limitations List Temporary Revisions (TRs) 
AWL-75 and AWL-76, both dated July 14, 2000, into De Havilland Inc. 
Dash 8 Series 100 Maintenance Program Manual PSM 1-8-7.
    (2) For Model DHC-8-200 series airplanes: Insert De Havilland 
Inc. Airworthiness Limitations List TR AWL 2-19, dated July 14, 
2000, into De Havilland Inc. Dash 8 Series 200 Maintenance Program 
Manual PSM 1-82-7.
    (3) For Model DHC-8-300 series airplanes: Insert De Havilland 
Inc. Airworthiness Limitations List TR AWL 3-83, dated July 14, 
2000, into De Havilland Inc. Dash 8 Series 300 Maintenance Program 
Manual PSM 1-83-7.

Repetitive Inspections

    (b) Do a detailed inspection for corrosion or cracking of the 
hook roller shafts of the flap carriage, at the times specified in 
paragraph (b)(1), (b)(2), or (b)(3) of this AD, as applicable, and 
according to the service information in paragraph (b)(1), (b)(2), or 
(b)(3) of this AD, as applicable.

    Note 2: For the purposes of this AD, a detailed 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.''

    (1) For Model DHC-8-100 series airplanes: For Pre Mod 8Q101103 
roller shafts having part number (P/N) 85750362-103 or 85750362-105, 
do the initial inspection at the compliance time specified in the 
``Threshold'' column of the table in De Havilland Inc. Airworthiness 
Limitations List TRs AWL-75 and AWL-76, both dated July 14, 2000, or 
within 12 months after the effective date of this AD, whichever 
occurs later, according to De Havilland Inc. Dash 8 Series 100 
Maintenance Program Manual PSM 1-8-7. Thereafter, repeat the 
inspection at the applicable interval specified in the ``Initial 
Interval'' column of the table in TR AWL-75 and AWL-76, until the 
airplane reaches the applicable threshold listed in the ``Repeat 
Cut-In'' column of the table in TR AWL-75 and AWL-76. Thereafter, 
repeat the inspections at the applicable interval listed in the 
``Repeat Interval'' column of the table in TR AWL-75 and AWL-76, 
until paragraph (c) of this AD has been accomplished on all affected 
hook roller shafts. Where the TR specifies compliance intervals in 
``flights,'' for the purposes of this AD, ``flights'' means ``flight 
cycles.''
    (2) For Model DHC-8-200 series airplanes: For Pre Mod 8Q101103 
hook roller shafts having part number (P/N) 85750362-103 or 
85750362-105, do the initial inspection at the compliance time 
specified in the ``Threshold'' column of the table in De Havilland 
Inc. Airworthiness Limitations List TR AWL 2-19, dated July 14, 
2000, or within 12 months after the effective date of this AD, 
whichever occurs later, according to De Havilland Inc. Dash 8 Series 
200 Maintenance Program Manual PSM 1-82-7. Thereafter, repeat the 
inspection at the applicable interval specified in the ``Initial 
Interval'' column of the table in TR AWL 2-19, until the airplane 
reaches the applicable threshold listed in the ``Repeat Cut-In'' 
column of the table in TR AWL 2-19.

[[Page 13111]]

Thereafter, repeat the inspections at the applicable interval listed 
in the ``Repeat Interval'' column of the table in TR AWL 2-19, until 
paragraph (c) of this AD has been accomplished on all affected hook 
roller shafts. Where the TR specifies compliance intervals in 
``flights,'' for the purposes of this AD, ``flights'' means ``flight 
cycles.''
    (3) For Model DHC-8-300 series airplanes: For Pre Mod 8Q101103 
hook roller shafts having part number (P/N) 85750362-103 or 
85750362-105, do the initial inspection at the compliance time 
specified in the ``Threshold'' column of the table in De Havilland 
Inc. Airworthiness Limitations List TR AWL 3-83, or within 12 months 
after the effective date of this AD, whichever occurs later, 
according to De Havilland Inc. Dash 8 Series 300 Maintenance Program 
Manual PSM 1-83-7. Thereafter, repeat the inspection at the 
applicable interval specified in the ``Initial Interval'' column of 
the table in TR AWL 3-83, until the airplane reaches the applicable 
threshold listed in the ``Repeat Cut-In'' column of the table in TR 
AWL 3-83. Thereafter, repeat the inspections at the applicable 
interval listed in the ``Repeat Interval'' column of the table in TR 
AWL 3-83 until paragraph (c) of this AD has been accomplished on all 
affected hook roller shafts. Where the TR specifies compliance 
intervals in ``flights,'' for the purposes of this AD, ``flights'' 
means ``flight cycles.''

Replacement

    (c) At the applicable time specified in paragraph (c)(1) or 
(c)(2) of this AD, replace hook roller shafts having P/N 85750362-
103 or 85750362-105 with new or serviceable hook roller shafts 
having P/N 85750362-107, according to Sections 57-50-44 and 57-50-53 
of the De Havilland Inc. Dash 8 Aircraft Maintenance Manual, as 
applicable. Replacement of all hook roller shafts, P/N 85750362-103 
or 85750362-105, with new hook roller shafts, P/N 85750362-107, ends 
the repetitive inspections at the intervals required by paragraph 
(a) of this AD.
    (1) For hook roller shafts on which any corrosion or crack is 
found during any inspection per paragraph (b) of this AD: Do the 
replacement before further flight.
    (2) For uncracked or uncorroded hook roller shafts: Do the 
replacement within 20,000 flight cycles or 5 years after the 
effective date of this AD, whichever is first.

Post-Replacement Inspections

    (d) Following the replacement of hook roller shafts according to 
paragraph (c) of this AD, do the Structural Inspection Program for 
the hook roller shafts of the flap carriage, as specified in 
paragraph (d)(1), (d)(2), or (d)(3) of this AD, as applicable.
    (1) For Model DHC-8-100 series airplanes: Using the criteria for 
Mod 8Q101103 hook roller shafts having P/N 85750362-107, do the 
initial inspection at the compliance time specified in the 
``Threshold'' column of the table in De Havilland Inc. Airworthiness 
Limitations List TR AWL-75 and AWL ``76, both dated July 14, 2000, 
according to De Havilland Inc. Dash 8 Series 100 Maintenance Program 
Manual PSM 1-8-7. Thereafter, repeat the inspection at the 
applicable interval specified in the ``Initial Interval'' column of 
the table in TRs AWL-75 and AWL -76, until the airplane reaches the 
applicable threshold listed in the ``Repeat Cut-In'' column of the 
table in TRs AWL-75 and AWL-76. Thereafter, repeat the inspections 
at the applicable interval listed in the ``Repeat Interval'' column 
of the table in TRs AWL-75 and AWL-76. Where the TR specifies 
compliance intervals in ``flights,'' for the purposes of this AD, 
``flights'' means ``flight cycles.''
    (2) For Model DHC-8-200 series airplanes: Using the criteria for 
Mod 8Q101103 hook roller shafts having P/N 85750362-107, do the 
initial inspection at the compliance time specified in the 
``Threshold'' column of the table in De Havilland Inc. Airworthiness 
Limitations List TR AWL 2-19, dated July 14, 2000, according to De 
Havilland Inc. Dash 8 Series 200 Maintenance Program Manual PSM 1-
82-7. Thereafter, repeat the inspection at the applicable interval 
specified in the ``Initial Interval'' column of the table in TR AWL 
2-19, until the airplane reaches the applicable threshold listed in 
the ``Repeat Cut-In'' column of the table in TR AWL 2-19. 
Thereafter, repeat the inspections at the applicable interval listed 
in the ``Repeat Interval'' column of the table in TR AWL 2-19. Where 
the TR specifies compliance intervals in ``flights,'' for the 
purposes of this AD, ``flights'' means ``flight cycles.''
    (3) For Model DHC-8-300 series airplanes: Using the criteria for 
Mod 8Q101103 hook roller shafts having P/N 85750362-107, do the 
initial inspection at the compliance time specified in the 
``Threshold'' column of the table in De Havilland Inc. Airworthiness 
Limitations List TR AWL 3-83, according to De Havilland Inc. Dash 8 
Series 300 Maintenance Program Manual PSM 1-83-7. Thereafter, repeat 
the inspection at the applicable interval specified in the ``Initial 
Interval'' column of the table in TR AWL 3-83, until the airplane 
reaches the applicable threshold listed in the ``Repeat Cut-In'' 
column of the table in TR AWL 3-83. Thereafter, repeat the 
inspections at the applicable interval listed in the ``Repeat 
Interval'' column of the table in TR AWL 3-83. Where the TR 
specifies compliance intervals in ``flights,'' for the purposes of 
this AD, ``flights'' means ``flight cycles.''

Alternative Methods of Compliance

    (e) 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. 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

    (f) 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-1999-10R2, dated September 12, 2000.


    Issued in Renton, Washington, on March 14, 2002.
Ali Bahrami,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 02-6794 Filed 3-20-02; 8:45 am]
BILLING CODE 4910-13-U