
[Federal Register: August 15, 2008 (Volume 73, Number 159)]
[Rules and Regulations]               
[Page 47818-47822]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr15au08-3]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2008-0864; Directorate Identifier 2008-NM-120-AD; 
Amendment 39-15644; AD 2008-17-06]
RIN 2120-AA64

 
Airworthiness Directives; Bombardier 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: The FAA is superseding an existing airworthiness directive 
(AD) that applies to certain Bombardier Model DHC-8-400 series 
airplanes. The existing AD currently requires revising the Limitations 
section of the airplane flight manual (AFM) to include 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. This AD 
requires a revision to the AFM to include 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. This AD resulted from low No. 2 hydraulic 
pressure in-flight, which caused the power transfer unit to overspeed, 
and the fluid flow within the No. 1 hydraulic system to increase. We 
are issuing this AD to prevent 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.

DATES: This AD becomes effective September 2, 2008.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in the AD as of September 2, 
2008.
    On July 10, 2007 (72 FR 30968, June 5, 2007), the Director of the 
Federal Register approved the incorporation by reference of certain 
other publications.
    We must receive any comments on this AD by September 15, 2008.

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-

[[Page 47819]]

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 W12-140, 1200 New 
Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m., 
Monday through Friday, except Federal holidays.
    For service information identified in this AD, contact Bombardier, 
Inc., Bombardier Regional Aircraft Division, 123 Garratt Boulevard, 
Downsview, Ontario M3K 1Y5, Canada.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://
www.regulations.gov; or in person at the Docket Management Facility 
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 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, 
Systems and Flight Test Branch, ANE-172, 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: 

Discussion

    On May 25, 2007, the FAA issued AD 2007-12-03, amendment 39-15081 
(72 FR 30968, June 5, 2007). That AD applies to certain Bombardier 
Model DHC-8-400 series airplanes. That AD requires revising the 
airplane flight manual (AFM) to include 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. That AD 
resulted from low No. 2 hydraulic pressure in-flight, which caused the 
power transfer unit (PTU) to overspeed, and the fluid flow within the 
No. 1 hydraulic system to increase. The actions specified in that AD 
are intended to prevent 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.

Actions Since AD Was Issued

    Since we issued AD 2007-12-03, Transport Canada Civil Aviation 
(TCCA), which is the airworthiness authority for Canada, advises that 
it has received an additional report of loss of the No. 2 hydraulic 
system on a Model DHC-8-402 airplane, causing the PTU to overspeed, 
increasing the fluid flow within the No. 1 hydraulic system. 
Investigation revealed that, after the caution light for the No. 2 
hydraulic system had illuminated, the PTU was left in the ``ON'' 
position. The flightcrew had followed AFM procedures, as specified in 
the AFM revision required by AD 2007-12-03, and did not pull the 
circuit breaker because the hydraulic fluid from the No. 2 system was 
not completely depleted.
    Therefore, we find that the AFM revision required by AD 2007-12-03 
does not adequately prevent 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 hydraulic 
power transfer system on the Model DHC-8-400 and DHC-8-401 airplanes 
are similar to those on the affected Model DHC-8-402 airplanes. 
Therefore, all of the models are subject to the same unsafe condition.

Relevant Service Information

    Bombardier has issued the temporary amendments specified in the 
following table (AD 2007-12-03 refers to Issue 1 of Bombardier 
Temporary Amendments 13, all dated July 14, 2005, as appropriate 
sources of service information for accomplishing the required AFM 
revision).

                                        Revised 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.
----------------------------------------------------------------------------------------------------------------

    The procedures specified in Issue 3 for addressing the loss of all 
hydraulic fluid in the No. 1 and No. 2 hydraulic systems are identical 
to those specified in Issue 1. Issue 3 has been revised to include 
procedures for ensuring that the PTU is disabled when the fluid level 
in the No. 2 hydraulic system falls to a value where the PTU becomes a 
hazard to the No. 1 hydraulic system. This is achieved by 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. 
TCCA previously mandated Issue 1 (``or later'') of the service 
information and issued Canadian airworthiness directive CF-2006-08, 
dated April 26, 2006 (referred to after this as ``the MCAI''), to 
ensure the continued airworthiness of these airplanes in Canada.

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 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.
    Therefore, we are issuing this AD to supersede AD 2007-12-03. This 
new AD retains the requirements of the existing AD. This AD also 
requires a revision to the Normal and Abnormal Procedures section of 
the AFM to include 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.
    In addition, AD 2007-12-03 specifies to revise the Limitations 
section of the AFM; however, this AD specifies to revise the Normal and 
Abnormal Procedures section.

[[Page 47820]]

 Interim Action

    We consider this AD interim action. The manufacturer is currently 
developing a modification that will address the unsafe condition 
identified in this AD. Once this modification is developed, approved, 
and available, we might consider additional rulemaking.

FAA's Justification and Determination of the Effective Date

    Fluid loss in the No. 2 hydraulic system causing a PTU overspeed 
and increased fluid flow in the No. 1 hydraulic system could cause the 
loss of several functions essential for safe flight and landing of the 
airplane. Because of our requirement to promote safe flight of civil 
aircraft, and thus the critical need to ensure the proper functioning 
of the No.1 and No. 2 hydraulic systems and the short compliance time 
involved with this action, this AD must be issued immediately.
    Because an unsafe condition exists that requires the immediate 
adoption of this AD, we find that notice and opportunity for prior 
public comment hereon are impracticable and that good cause exists for 
making this amendment effective in less than 30 days.

Comments Invited

    This AD is a final rule that involves requirements affecting flight 
safety, and we did not provide you with notice and an opportunity to 
provide your comments before it becomes effective. However, we invite 
you to send any written data, views, or arguments about this AD. Send 
your comments to an address listed under the ADDRESSES section. Include 
``Docket No. FAA-2008-0864; Directorate Identifier 2008-NM-120-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 have 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 that the 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 AD and placed it in the AD docket. See the ADDRESSES 
section for a location to examine the regulatory evaluation.

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 part 39 of the Federal Aviation Regulations (14 CFR part 
39) as follows:

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 Federal Aviation Administration (FAA) amends Sec.  39.13 by 
removing amendment 39-15081 (72 FR 30968, June 5, 2007) and adding the 
following new AD:

2008-17-06 Bombardier, Inc. (Formerly de Havilland, Inc.): Docket 
No. FAA-2008-0864; Directorate Identifier 2008-NM-120-AD; Amendment 
39-15644.

Effective Date

    (a) This AD becomes effective September 2, 2008.

Affected ADs

    (b) This AD supersedes AD 2007-12-03.

Applicability

    (c) This AD applies to Bombardier Model DHC-8-400, DHC-8-401, 
and DHC-8-402 airplanes, certificated in any category; serial 
numbers 4001 and 4003 and subsequent.

Unsafe Condition

    (d) This AD results from low No. 2 hydraulic pressure in-flight, 
which caused the power transfer unit to overspeed, and the fluid 
flow within the No. 1 hydraulic system to increase. We are issuing 
this AD to prevent 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

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

Requirements of AD 2007-12-03

Airplane Flight Manual (AFM) Revision

    (f) Within 14 days after July 10, 2007 (the effective date of AD 
2007-12-03), 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.

[[Page 47821]]



                                        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.

New Requirements of This AD

AFM Revision

    (g) Within 14 days after the effective date of this AD, 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 (f) 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.
----------------------------------------------------------------------------------------------------------------

Alternative Methods of Compliance (AMOCs)

    (h) The Manager, New York Aircraft Certification Office, 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: Fabio Buttitta, Aerospace Engineer, Systems and 
Flight Test Branch, ANE-172, FAA, New York Aircraft Certification 
Office, 1600 Stewart Avenue, Suite 410, Westbury, New York 11590; 
telephone (516) 228-7303; fax (516) 794-5531. Before using any 
approved AMOC on any airplane to which the AMOC applies, notify your 
appropriate principal inspector (PI) in the FAA Flight Standards 
District Office (FSDO), or lacking a PI, your local FSDO.

Related Information

    (i) Canadian airworthiness directive CF-2006-08, dated April 26, 
2006, also addresses the subject of this AD.

Material Incorporated by Reference

    (j) You must use the applicable temporary amendment identified 
in Table 3 of this AD to perform the actions that are required by 
this AD, unless the AD specifies otherwise. (Only the last pages of 
the temporary amendments identified in Table 4 of this AD contain 
the issue date, no other pages of those documents are dated.)

                                 Table 3--All Material Incorporated by Reference
----------------------------------------------------------------------------------------------------------------
                                                                             To Bombardier Dash 8 Q400 airplane
 Bombardier temporary amendment--       Issue--             Dated--                   flight manual--
----------------------------------------------------------------------------------------------------------------
13...............................                 1  July 14, 2005.......  Model 400 PSM 1-84-1A.
13...............................                 1  July 14, 2005.......  Model 401 PSM 1-84-1A.
13...............................                 1  July 14, 2005.......  Model 402 PSM 1-84-1A.
13...............................                 3  June 9, 2008........  Model 400 PSM 1-84-1A.
13...............................                 3  June 9, 2008........  Model 401 PSM 1-84-1A.
13...............................                 3  June 9, 2008........  Model 402 PSM 1-84-1A.
----------------------------------------------------------------------------------------------------------------

    (1) The Director of the Federal Register approved the 
incorporation by reference of the temporary amendments identified in 
Table 4 of this AD in accordance with 5 U.S.C. 552(a) and 1 CFR part 
51.

                                 Table 4--New Material Incorporated by Reference
----------------------------------------------------------------------------------------------------------------
                                                                             To Bombardier Dash 8 Q400 airplane
 Bombardier temporary amendment--       Issue--             Dated--                   flight manual--
----------------------------------------------------------------------------------------------------------------
13...............................                 3  June 9, 2008........  Model 400 PSM 1-84-1A.
13...............................                 3  June 9, 2008........  Model 401 PSM 1-84-1A.

[[Page 47822]]


13...............................                 3  June 9, 2008........  Model 402 PSM 1-84-1A.
----------------------------------------------------------------------------------------------------------------

    (2) On July 10, 2007 (72 FR 30968, June 5, 2007), the Director 
of the Federal Register approved the incorporation by reference of 
the temporary amendments identified in Table 5 of this AD.

                         Table 5--Previously Approved Material Incorporated by Reference
----------------------------------------------------------------------------------------------------------------
                                                                             To Bombardier Dash 8 Q400 airplane
 Bombardier temporary amendment--       Issue--             Dated--                   flight manual--
----------------------------------------------------------------------------------------------------------------
13...............................                 1  July 14, 2005.......  Model 400 PSM 1-84-1A.
13...............................                 1  July 14, 2005.......  Model 401 PSM 1-84-1A.
13...............................                 1  July 14, 2005.......  Model 402 PSM 1-84-1A.
----------------------------------------------------------------------------------------------------------------

    (3) Contact Bombardier, Inc., Bombardier Regional Aircraft 
Division, 123 Garratt Boulevard, Downsview, Ontario M3K 1Y5, Canada, 
for a copy of this service information. You may review copies at the 
FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington; or 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/cfr/ibr-locations.html.

    Issued in Renton, Washington, on July 31, 2008.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E8-18683 Filed 8-14-08; 8:45 am]

BILLING CODE 4910-13-P
