
[Federal Register: April 21, 2010 (Volume 75, Number 76)]
[Proposed Rules]               
[Page 20787-20790]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr21ap10-14]                         

========================================================================
Proposed Rules
                                                Federal Register
________________________________________________________________________

This section of the FEDERAL REGISTER contains notices to the public of 
the proposed issuance of rules and regulations. The purpose of these 
notices is to give interested persons an opportunity to participate in 
the rule making prior to the adoption of the final rules.

========================================================================



[[Page 20787]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2010-0382; Directorate Identifier 2009-NM-211-AD]
RIN 2120-AA64

 
Airworthiness Directives; Bombardier, Inc. Model DHC-8-400, -401, 
and -402 Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: We propose to adopt a new airworthiness directive (AD) for the 
products listed above that would supersede an existing AD. This 
proposed 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:

    Several cases have been reported where a loss of fluid in the 
No. 2 hydraulic system has caused the power transfer unit (PTU) to 
overspeed, resulting in pressure fluctuations and increased fluid 
flow within the No. 1 hydraulic system. In one case, the hydraulic 
system control logic did not shut down the PTU and the overspeed 
condition persisted, resulting in the illumination of the No. 1 HYD 
FLUID HOT caution light.
* * * * *
    The unsafe condition is possible loss of both the No. 1 and No. 2 
hydraulic systems, resulting in the potential loss of several functions 
essential for safe flight and landing of the airplane. The proposed AD 
would require actions that are intended to address the unsafe condition 
described in the MCAI.

DATES: We must receive comments on this proposed AD by June 7, 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.
    For service information identified in this proposed 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. 
You may review copies of the referenced 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.

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 proposed 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: Fabio Buttitta, Aerospace Engineer, 
Airframe and Mechanical Systems Branch, ANE-171, FAA, New York Aircraft 
Certification Office, 1600 Stewart Avenue, Suite 410, Westbury, New 
York 11590; telephone (516) 228-7303; fax (516) 794-5531.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments about this proposed AD. Send your comments to an address 
listed under the ADDRESSES section. Include ``Docket No. FAA-2010-0382; 
Directorate Identifier 2009-NM-211-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of this proposed AD. We 
will consider all comments received by the closing date and may amend 
this proposed AD based on those comments.
    We have lengthened the 30-day comment period for proposed ADs that 
address MCAI originated by aviation authorities of other countries to 
provide adequate time for interested parties to submit comments. The 
comment period for these proposed ADs is now typically 45 days, which 
is consistent with the comment period for domestic transport ADs.
    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 proposed AD.

Discussion

    On July 31, 2008, we issued AD 2008-17-06, Amendment 39-15644 (73 
FR 47818, August 15, 2008). That AD required actions intended to 
address an unsafe condition on the products listed above.
    Since we issued AD 2008-17-06, a modification of the power transfer 
unit (PTU) control logic, including the provision of automatic PTU 
shutdown in the event of loss of fluid in the No. 2 hydraulic system, 
has been developed. The modification addresses the identified unsafe 
condition. In addition, the applicability has been revised to remove 
airplanes having serial number 4185 and subsequent, since an equivalent 
modification has been installed in production on these airplanes. 
Transport Canada Civil Aviation (TCCA), which is the aviation authority 
for Canada, has issued Canadian Airworthiness Directive CF-2006-08R1, 
dated August 31, 2009 (referred to after this as ``the MCAI''), to 
correct an unsafe condition for the specified products. The MCAI 
states:

    Several cases have been reported where a loss of fluid in the 
No. 2 hydraulic system has caused the power transfer unit (PTU) to 
overspeed, resulting in pressure fluctuations and increased fluid 
flow within the No. 1 hydraulic system. In one case, the hydraulic 
system control logic did not shut down the PTU and the overspeed 
condition persisted, resulting in the illumination of the No.1 HYD 
FLUID HOT caution light.

[[Page 20788]]

    As an interim action to avoid possible loss of both the No. 1 
and No. 2 hydraulic systems, the Airplane Flight Manual (AFM) has 
been revised to include pulling the HYD PWR XFER circuit breaker in 
the event of the loss of all hydraulic fluid in the No. 2 hydraulic 
system.
    Insertion of the resultant Temporary Amendment (TA) No. 13 into 
the AFM was mandated in the original issue of this [Canadian] 
directive. This instruction * * * remains in effect until * * * this 
[revised] directive is accomplished.
    Revision 1 of this directive * * * mandates modification of the 
PTU control logic, including the provision of automatic PTU shutdown 
in the event of loss of fluid in the No. 2 hydraulic system. In 
addition, the applicability of the [Canadian] directive has been 
revised to remove aircraft Serial Number (SN) 4185 and subsequent, 
since an equivalent modification has been installed in production on 
these aircraft.

    The unsafe condition is possible loss of both the No. 1 and No. 2 
hydraulic systems, resulting in the potential loss of several functions 
essential for safe flight and landing of the airplane. You may obtain 
further information by examining the MCAI in the AD docket.

Relevant Service Information

    Bombardier has issued Service Bulletin 84-29-22, Revision A, dated 
February 24, 2009. 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 Proposed 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 proposing this AD because we 
evaluated all pertinent information and determined an unsafe condition 
exists and is likely to exist or develop on other products of the same 
type design.

Differences Between This 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 proposed 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 proposed AD.

Costs of Compliance

    Based on the service information, we estimate that this proposed AD 
would affect about 42 products of U.S. registry.
    The actions that are required by AD 2008-17-06 and retained in this 
proposed AD take up about 1 work-hour per product, at an average labor 
rate of $85 per work hour. Required parts cost about $0 per product. 
Based on these figures, the estimated cost of the currently required 
actions is up to $85 per product.
    We estimate that it would take up to 165 work-hours per product to 
comply with the new basic requirements of this proposed AD. The average 
labor rate is $85 per work-hour. Required parts would cost about 
$10,982 per product. Where the service information lists required parts 
costs that are covered under warranty, we have assumed that there will 
be no charge for these costs. As we do not control warranty coverage 
for affected parties, some parties may incur costs higher than 
estimated here. Based on these figures, we estimate the cost of the 
proposed modification on U.S. operators to be up to $1,050,294, or up 
to $25,007 per product.

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 proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD 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.
    For the reasons discussed above, I certify 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. 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 proposed 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.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 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. The FAA amends Sec.  39.13 by removing Amendment 39-15644 (73 FR 
47818, August 15, 2008) and adding the following new AD:

Bombardier, Inc.: Docket No. FAA-2010-0382; Directorate Identifier 
2009-NM-211-AD.

Comments Due Date

    (a) We must receive comments by June 7, 2010.

Affected ADs

    (b) This AD supersedes AD 2008-17-06, Amendment 39-15644.

Applicability

    (c) This AD applies to Bombardier, Inc. Model DHC-8-400, -401, 
and -402 airplanes, certificated in any category; serial numbers 
4001, 4003, 4004, 4006, and 4008 through 4184 inclusive.

Subject

    (d) Air Transport Association (ATA) of America Code 29: 
Hydraulic power.

Reason

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

    ``Several cases have been reported where a loss of fluid in the 
No.2 hydraulic system has caused the power transfer unit (PTU) to

[[Page 20789]]

overspeed, resulting in pressure fluctuations and increased fluid 
flow within the No. 1 hydraulic system. In one case, the hydraulic 
system control logic did not shut down the PTU and the overspeed 
condition persisted, resulting in the illumination of the No.1 HYD 
FLUID HOT caution light.
    ``As an interim action to avoid possible loss of both the No. 1 
and No. 2 hydraulic systems, the Airplane Flight Manual (AFM) has 
been revised to include pulling the HYD PWR XFER circuit breaker in 
the event of the loss of all hydraulic fluid in the No. 2 hydraulic 
system.
    ``Insertion of the resultant Temporary Amendment (TA) No. 13 
into the AFM was mandated in the original issue of this [Canadian] 
directive. This instruction * * * remains in effect until * * * this 
[revised] directive is accomplished.
    ``Revision 1 of this directive * * * mandates modification of 
the PTU control logic, including the provision of automatic PTU 
shutdown in the event of loss of fluid in the No. 2 hydraulic 
system. In addition, the applicability of the [Canadian] directive 
has been revised to remove aircraft Serial Number (SN) 4185 and 
subsequent, since an equivalent modification has been installed in 
production on these aircraft.''

    The unsafe condition is possible loss of both the No. 1 and No. 
2 hydraulic systems, resulting in the potential loss of several 
functions essential for safe flight and landing of the airplane.

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.

Restatement of Requirements of AD 2007-12-03: Airplane Flight Manual 
(AFM) Revision

    (g) Within 14 days after July 10, 2007 (the effective date of AD 
2007-12-03, Amendment 39-15081, which was superseded by AD 2008-17-
06), revise the Limitations section of the applicable AFM to include 
the information in the applicable Bombardier temporary amendment 
specified in Table 1 of this AD, as specified in the temporary 
amendment. These temporary amendments introduce procedures for 
pulling the ``HYD PWR XFER'' circuit breaker in the event of the 
loss of all hydraulic fluid in the No. 1 or No. 2 hydraulic system. 
Operate the airplane according to the limitations and procedures in 
the applicable temporary amendment.

                                        Table 1--AFM Temporary Amendments
----------------------------------------------------------------------------------------------------------------
                                         Use
                                     Bombardier                                           To Bombardier  Dash 8
           For Model--                Temporary        Issue--           Dated--          Q400  Airplane Flight
                                     Amendment--                                                Manual--
----------------------------------------------------------------------------------------------------------------
DHC-8-400 airplanes..............              13               1  July 14, 2005......  PSM 1-84-1A.
DHC-8-401 airplanes..............              13               1  July 14, 2005......  PSM 1-84-1A.
DHC-8-402 airplanes..............              13               1  July 14, 2005......  PSM 1-84-1A.
----------------------------------------------------------------------------------------------------------------


    Note 1: This may be done by inserting a copy of the applicable 
temporary amendment into the applicable AFM. When the applicable 
temporary amendment has been included in general revisions of the 
AFM, the general revisions may be inserted into the AFM, provided 
the relevant information in the general revisions is identical to 
that in the temporary amendment.

Restatement of Requirements of AD 2008-17-06: AFM Revision

    (h) Within 14 days after September 2, 2008 (the effective date 
of AD 2008-17-06), revise the applicable AFM Normal and Abnormal 
Procedures section to include the information in the applicable 
Bombardier temporary amendment specified in Table 2 of this AD, as 
specified in the temporary amendment. These temporary amendments 
introduce additional procedures for ensuring that the ``PTU CNTRL'' 
switch is Normal, the ``PTU CNTRL ON'' advisory light is out, and 
the ``HYD PWR XFER'' circuit breaker is pulled in the event of the 
illumination of the ``2 HYD ISO VALVE'' caution light. 
After accomplishing the AFM revision, the AFM limitation required by 
paragraph (g) in this AD may be removed from the AFM.

                                        Table 2--AFM Temporary Amendments
----------------------------------------------------------------------------------------------------------------
                                         Use
                                     Bombardier                                           To Bombardier  Dash 8
           For Model--                Temporary        Issue--           Dated--          Q400  Airplane Flight
                                     Amendment--                                                Manual--
----------------------------------------------------------------------------------------------------------------
DHC-8-400 airplanes..............              13               3  June 9, 2008.......  PSM 1-84-1A.
DHC-8-401 airplanes..............              13               3  June 9, 2008.......  PSM 1-84-1A.
DHC-8-402 airplanes..............              13               3  June 9, 2008.......  PSM 1-84-1A.
----------------------------------------------------------------------------------------------------------------

New Requirements of This AD: Actions

    (i) Within 6,000 flight hours after the effective date of this 
AD, modify the PTU control logic, in accordance with the 
Accomplishment Instructions of Bombardier Service Bulletin 84-29-22, 
Revision A, dated February 24, 2009. Doing this modification 
terminates the requirements of paragraphs (g) and (h) of this AD, 
and after the modification has been done, the AFM limitation 
required by paragraphs (g) and (h) of this AD may be removed from 
the AFM.
    (j) Modifying the PTU control logic is also acceptable for 
compliance with the requirements of paragraph (i) of this AD if done 
before the effective date of this AD, in accordance with Bombardier 
Service Bulletin 84-29-22, dated December 5, 2008.

FAA AD Differences

    Note 2:  This AD differs from the MCAI and/or service 
information as follows: No differences.

Other FAA AD Provisions

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

[[Page 20790]]

    (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

    (l) Refer to MCAI Canadian Airworthiness Directive CF-2006-08R1, 
dated August 31, 2009; and Bombardier Service Bulletin 84-29-22, 
Revision A, dated February 24, 2009; for related information.

    Issued in Renton, Washington, on April 9, 2010.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2010-9110 Filed 4-20-10; 8:45 am]
BILLING CODE 4910-13-P

