
[Federal Register: May 5, 2010 (Volume 75, Number 86)]
[Rules and Regulations]               
[Page 24389-24392]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr05my10-4]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2010-0435; Directorate Identifier 2010-NM-084-AD; 
Amendment 39-16283; AD 2010-10-04]
RIN 2120-AA64

 
Airworthiness Directives; Bombardier, Inc. Model DHC-8-400 Series 
Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Final rule; request for comments.

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SUMMARY: We are adopting a new airworthiness directive (AD) for the 
products listed above. This AD results from mandatory continuing 
airworthiness information (MCAI) originated by an aviation authority of 
another country to identify and correct an unsafe condition on an 
aviation product. The MCAI describes the unsafe condition as:

    Operators of DHC-8 400 Series aeroplanes have been reporting 
chafing of wires in the AC wire harnesses located along the lower 
wing shroud on either wing resulting in a loss of various system 
services. Chafed wires may lead to arcing, local overheating and AC 
generator failure. The AC generators provide power to the anti-icing 
heaters, including pitot/static heater, engine adapter heater, and 
propeller heater. Failure of both AC generators would result in the 
loss of these systems and poses a safety concern.
* * * * *
    Loss of both AC generators could lead to unannunciated loss of heat 
to both engine inlets, which could lead to loss of power in both 
engines during icing conditions. This AD requires actions that are 
intended to address the unsafe condition described in the MCAI.

DATES: This AD becomes effective May 20, 2010.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in the AD as of May 20, 2010.
    We must receive comments on this AD by June 21, 2010.

ADDRESSES: You may send comments by any of the following methods:
     Federal eRulemaking Portal: Go to http://
www.regulations.gov. Follow the instructions for submitting comments.
     Fax: (202) 493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue, SE., Washington, DC 20590.
     Hand Delivery: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-40, 1200 New 
Jersey Avenue, SE., Washington, DC, between 9 a.m. and 5 p.m., Monday 
through Friday, except Federal holidays.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://
www.regulations.gov; or in person at the Docket Operations office 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The AD docket contains this AD, the regulatory evaluation, 
any comments received, and other information. The street address for 
the Docket Operations office (telephone (800) 647-5527) is in the 
ADDRESSES section. Comments will be available in the AD docket shortly 
after receipt.

FOR FURTHER INFORMATION CONTACT: Craig Yates, Aerospace Engineer, 
Airframe and Mechanical Systems Branch, ANE-171, FAA, New York Aircraft 
Certification Office, 1600 Stewart Avenue, Suite 410, Westbury,

[[Page 24390]]

New York 11590; telephone (516) 228-7355; fax (516) 794-5531.

SUPPLEMENTARY INFORMATION:

Discussion

    Transport Canada Civil Aviation (TCCA), which is the aviation 
authority for Canada, has issued Canadian Airworthiness Directive CF-
2010-08, dated March 16, 2010 (referred to after this as ``the MCAI''), 
to correct an unsafe condition for the specified products. The MCAI 
states:

    Operators of DHC-8 400 Series aeroplanes have been reporting 
chafing of wires in the AC wire harnesses located along the lower 
wing shroud on either wing resulting in a loss of various system 
services. Chafed wires may lead to arcing, local overheating and AC 
generator failure. The AC generators provide power to the anti-icing 
heaters, including pitot/static heater, engine adapter heater, and 
propeller heater. Failure of both AC generators would result in the 
loss of these systems and poses a safety concern.
    Investigation has revealed that at four wiring harness tie down 
mount locations, the blind fasteners used to attach the tie down 
mount base were found to have protruding stems which chafed through 
the wire insulation leading to arcing damage. In addition, the wire 
chafing along the wing rear spar lower shroud has been attributed to 
sagging wire bundles resting on the structure and insufficient 
support in low clearance areas.
    This directive mandates the replacement of the blind fasteners 
with solid rivets, and to inspect for and rectify damaged wiring 
along the wing lower shroud.

Loss of both AC generators could lead to unannunciated loss of heat to 
both engine inlets, which could lead to loss of power in both engines 
during icing conditions. The required actions also include a detailed 
inspection for damage and chafing of the wires in the wiring harness 
installation, and the Teflon tubing if necessary. The corrective 
actions (rectifying) include replacement or repair of the chafed or 
damaged wire or Teflon tubing. You may obtain further information by 
examining the MCAI in the AD docket.

Relevant Service Information

    Bombardier has issued Alert Service Bulletin A84-24-44, Revision A, 
dated February 2, 2010; and Repair Drawing 8/4-24-011, Issue 2, dated 
January 21, 2010. The actions described in this service information are 
intended to correct the unsafe condition identified in the MCAI.

FAA's Determination and Requirements of This AD

    This product has been approved by the aviation authority of another 
country, and is approved for operation in the United States. Pursuant 
to our bilateral agreement with the State of Design Authority, we have 
been notified of the unsafe condition described in the MCAI and service 
information referenced above. We are issuing this AD because we 
evaluated all pertinent information and determined the unsafe condition 
exists and is likely to exist or develop on other products of the same 
type design.

Differences Between the AD and the MCAI or Service Information

    We have reviewed the MCAI and related service information and, in 
general, agree with their substance. But we might have found it 
necessary to use different words from those in the MCAI to ensure the 
AD is clear for U.S. operators and is enforceable. In making these 
changes, we do not intend to differ substantively from the information 
provided in the MCAI and related service information.
    We might also have required different actions in this AD from those 
in the MCAI in order to follow FAA policies. Any such differences are 
highlighted in a Note within the AD.

FAA's Determination of the Effective Date

    An unsafe condition exists that requires the immediate adoption of 
this AD. The FAA has found that the risk to the flying public justifies 
waiving notice and comment prior to adoption of this rule because the 
chafing of a wire bundle could result in an electrical short and 
potential loss of several functions essential for safe flight, 
including both AC generators. Therefore, we determined that notice and 
opportunity for public comment before issuing this AD are impracticable 
and that good cause exists for making this amendment effective in fewer 
than 30 days.

Comments Invited

    This AD is a final rule that involves requirements affecting flight 
safety, and we did not precede it by notice and opportunity for public 
comment. We invite you to send any written relevant data, views, or 
arguments about this AD. Send your comments to an address listed under 
the ADDRESSES section. Include ``Docket No. FAA-2010-0435; Directorate 
Identifier 2010-NM-084-AD'' at the beginning of your comments. We 
specifically invite comments on the overall regulatory, economic, 
environmental, and energy aspects of this AD. We will consider all 
comments received by the closing date and may amend this AD because of 
those comments.
    We will post all comments we receive, without change, to http://
www.regulations.gov, including any personal information you provide. We 
will also post a report summarizing each substantive verbal contact we 
receive about this AD.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, section 106, describes the 
authority of the FAA Administrator. ``Subtitle VII: Aviation 
Programs,'' describes in more detail the scope of the Agency's 
authority.
    We are issuing this rulemaking under the authority described in 
``Subtitle VII, Part A, Subpart III, Section 44701: General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

Regulatory Findings

    We determined that this AD will not have federalism implications 
under Executive Order 13132. This AD will 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.
    For the reasons discussed above, I certify this AD:
    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. 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.
    We prepared a regulatory evaluation of the estimated costs to 
comply with this AD and placed it in the AD docket.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

0
Accordingly, under the authority delegated to me by the Administrator, 
the FAA amends 14 CFR part 39 as follows:

[[Page 24391]]

PART 39--AIRWORTHINESS DIRECTIVES

0
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]

0
2. The FAA amends Sec.  39.13 by adding the following new AD:

2010-10-04 Bombardier, Inc.: Amendment 39-16283. Docket No. FAA-
2010-0435; Directorate Identifier 2010-NM-084-AD.

Effective Date

    (a) This airworthiness directive (AD) becomes effective May 20, 
2010.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Bombardier, Inc. Model DHC-8-400, -401, 
and -402 airplanes, serial numbers 4001 through 4169 inclusive, 
certificated in any category.

Subject

    (d) Air Transport Association (ATA) of America Code 24: 
Electrical Power.

Reason

    (e) The mandatory continued airworthiness information (MCAI) 
states:

    Operators of DHC-8 400 Series aeroplanes have been reporting 
chafing of wires in the AC wire harnesses located along the lower 
wing shroud on either wing resulting in a loss of various system 
services. Chafed wires may lead to arcing, local overheating and AC 
generator failure. The AC generators provide power to the anti-icing 
heaters, including pitot/static heater, engine adapter heater, and 
propeller heater. Failure of both AC generators would result in the 
loss of these systems and poses a safety concern.
    Investigation has revealed that at four wiring harness tie down 
mount locations, the blind fasteners used to attach the tie down 
mount base were found to have protruding stems which chafed through 
the wire insulation leading to arcing damage. In addition, the wire 
chafing along the wing rear spar lower shroud has been attributed to 
sagging wire bundles resting on the structure and insufficient 
support in low clearance areas.
    This directive mandates the replacement of the blind fasteners 
with solid rivets, and to inspect for and rectify damaged wiring 
along the wing lower shroud.

Loss of both AC generators could lead to unannunciated loss of heat 
to both engine inlets, which could lead to loss of power in both 
engines during icing conditions. The required actions also include a 
detailed inspection for damage and chafing of the wires in the 
wiring harness installation, and the Teflon tubing if necessary. The 
corrective actions (rectifying) include replacement or repair of the 
chafed or damaged wire or Teflon tubing.

Compliance

    (f) You are responsible for having the actions required by this 
AD performed within the compliance times specified, unless the 
actions have already been done.

Replacement of Blind Fasteners, Inspection for Chafing at Four Wiring 
Harness Tie Down Mount Locations and Corrective Action

    (g) Within 200 flight hours after the effective date of this AD: 
Replace the blind fasteners installed at the four wiring harness tie 
down mount locations with solid rivets; and do a detailed inspection 
for chafing and damage of the wires and, as applicable, of any 
Teflon tubing and do all applicable corrective actions; in 
accordance with paragraph B.(6) of the Accomplishment Instructions 
of Bombardier Alert Service Bulletin A84-24-44, Revision A, dated 
February 2, 2010. Do all applicable corrective actions before 
further flight.

Inspection of AC Feeder Cables Along Lower Wing Shroud and Corrective 
Action

    (h) At the applicable time in paragraph (h)(1) or (h)(2) of this 
AD: Do a detailed inspection of the wiring harness installation 
along the wing rear spar lower shroud for any chafing and damage, 
and do all applicable corrective actions, in accordance with the 
Accomplishment Instructions of Bombardier Alert Service Bulletin 
A84-24-44, Revision A, dated February 2, 2010. Do all applicable 
corrective actions before further flight.
    (1) For airplanes with AC feeder cables not covered with 
protective Teflon tubing (Modsum Number IS4Q2450001 or production 
Modsum 4Q109946 not incorporated): Within 600 flight hours after the 
effective date of this AD.
    (2) For airplanes with AC feeder cables covered with protective 
Teflon tubing (Modsum Number IS4Q2450001 or production Modsum 
4Q109946 incorporated): Within 4,000 flight hours after the 
effective date of this AD.
    (i) For airplanes on which the temporary repair specified in 
Bombardier Repair Drawing 8/4-24-011, Issue 2, dated January 21, 
2010, has been done: Within 600 flight hours after accomplishing the 
temporary repair or 60 flight hours after the effective date of this 
AD, whichever occurs later, do the permanent repair or replace the 
wiring, in accordance with Bombardier Repair Drawing 8/4-24-011, 
Issue 2, dated January 21, 2010.

Actions According to Previous Issue of Service Information

    (j) Actions done before the effective date of this AD in 
accordance with Bombardier Alert Service Bulletin A84-24-44, dated 
January 27, 2010, are acceptable for compliance with the 
corresponding requirements of paragraphs (g) and (h) of this AD.
    (k) Actions done before the effective date of this AD in 
accordance with any modification summary identified in Table 1 of 
this AD are acceptable for compliance with the corresponding 
requirements of paragraph (g) of this AD.

                                         Table 1--Modification Summaries
----------------------------------------------------------------------------------------------------------------
    Bombardier modification summary--              Revision--                           Dated--
----------------------------------------------------------------------------------------------------------------
IS4Q5700013..............................  A                           January 12, 2010.
IS4Q5700013..............................  B                           January 20, 2010.
IS4Q5700013..............................  C                           January 27, 2010.
----------------------------------------------------------------------------------------------------------------

Reporting Requirement

    (l) Submit a report of the findings (both positive and negative) 
of the inspection required by paragraph (h) of this AD to Bombardier 
Technical Help Desk; telephone 416-375-4000; e-mail 
thd.qseries@aero.bombardier.com; at the applicable time specified in 
paragraph (l)(1) or (l)(2) of this AD. Use Figures 1 and 2 (Feedback 
Form) of Bombardier Alert Service Bulletin A84-24-44, Revision A, 
dated February 2, 2010, to submit the report. The report must 
include the inspection results, a description of any discrepancies 
found, the airplane serial number, and the number of landings and 
flight hours on the airplane.
    (1) If the inspection was done on or after the effective date of 
this AD: Submit the report within 14 days after the inspection.
    (2) If the inspection was accomplished prior to the effective 
date of this AD: Submit the report within 14 days after the 
effective date of this AD.

FAA AD Differences

    Note 1: This AD differs from the MCAI and/or service information 
as follows: The MCAI does not specify a compliance time for doing a 
permanent repair or replacement for airplanes on which a temporary 
repair is done. This AD requires that the temporary repair is 
replaced by a permanent repair or replacement of the wiring. We have 
coordinated this difference with Transport Canada Civil Aviation 
(TCCA).

Other FAA AD Provisions

    (m) The following provisions also apply to this AD:
    (1) Alternative Methods of Compliance (AMOCs): The Manager, ANE-
170, New York Aircraft Certification Office, FAA, has the authority 
to approve AMOCs for this AD, if requested using the procedures 
found in 14

[[Page 24392]]

CFR 39.19. Send information to Attn: Program Manager, Continuing 
Operational Safety, FAA, New York ACO, 1600 Stewart Avenue, Suite 
410, Westbury, New York, 11590; telephone 516-228-7300; fax 516-794-
5531. Before using any approved AMOC on any airplane to which the 
AMOC applies, notify your principal maintenance inspector (PMI) or 
principal avionics inspector (PAI), as appropriate, or lacking a 
principal inspector, your local Flight Standards District Office. 
The AMOC approval letter must specifically reference this AD.
    (2) Airworthy Product: For any requirement in this AD to obtain 
corrective actions from a manufacturer or other source, use these 
actions if they are FAA-approved. Corrective actions are considered 
FAA-approved if they are approved by the State of Design Authority 
(or their delegated agent). You are required to assure the product 
is airworthy before it is returned to service.
    (3) Reporting Requirements: For any reporting requirement in 
this AD, under the provisions of the Paperwork Reduction Act (44 
U.S.C. 3501 et seq.), the Office of Management and Budget (OMB) has 
approved the information collection requirements and has assigned 
OMB Control Number 2120-0056.

Related Information

    (n) Refer to MCAI Canadian Airworthiness Directive CF-2010-08, 
dated March 16, 2010; Bombardier Alert Service Bulletin A84-24-44, 
Revision A, dated February 2, 2010; and Bombardier Repair Drawing 8/
4-24-011, Issue 2, dated January 21, 2010; for related information.

Material Incorporated by Reference

    (o) You must use Bombardier Alert Service Bulletin A84-24-44, 
Revision A, dated February 2, 2010; and Bombardier Repair Drawing 8/
4-24-011, Issue 2, dated January 21, 2010; as applicable; to do the 
actions required by this AD, unless the AD specifies otherwise. 
Bombardier Repair Drawing 8/4-24-011, Issue 2, dated January 21, 
2010, contains the following effective pages:

------------------------------------------------------------------------
                                 Revision
           Page No.            level shown       Date shown on page
                                 on page
------------------------------------------------------------------------
1, 3.........................            2  January 21, 2010.*
2, 4-7.......................            1  January 18, 2010.*
------------------------------------------------------------------------
* Only the first page of this repair drawing contains the issue dates.

    (1) The Director of the Federal Register approved the 
incorporation by reference of this service information under 5 
U.S.C. 552(a) and 1 CFR part 51.
    (2) For service information identified in this AD, contact 
Bombardier, Inc., 400 C[ocirc]te-Vertu Road West, Dorval, 
Qu[eacute]bec H4S 1Y9, Canada; telephone 514-855-5000; fax 514-855-
7401; e-mail thd.qseries@aero.bombardier.com; Internet http://
www.bombardier.com.
    (3) You may review copies of the service information at the FAA, 
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington. For information on the availability of this material at 
the FAA, call 425-227-1221.
    (4) You may also review copies of the service information that 
is incorporated by reference at the National Archives and Records 
Administration (NARA). For information on the availability of this 
material at NARA, call 202-741-6030, or go to: http://
www.archives.gov/federal_register/code_of_federal_regulations/
ibr_locations.html.

    Issued in Renton, Washington, on April 27, 2010.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2010-10472 Filed 5-4-10; 8:45 am]
BILLING CODE 4910-13-P

