FR Doc E7-6267

[Federal Register: April 4, 2007 (Volume 72, Number 64)]
[Proposed Rules]
[Page 16289-16291]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr04ap07-23]

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

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-27755; Directorate Identifier 2006-NM-289-AD]
RIN 2120-AA64

Airworthiness Directives; Bombardier Model DHC-8-400 Series
Airplanes

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

ACTION: Notice of proposed rulemaking (NPRM).

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

SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD)
for certain Bombardier Model DHC-8-400 series airplanes. This proposed
AD would require revising the Limitations section of the airplane
flight manual 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 proposed AD results from reports
of fluid loss in the No. 2 hydraulic system, causing the power transfer
unit to overspeed, increasing the fluid flow within the No. 1 hydraulic
system. We are proposing 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: We must receive comments on this proposed AD by May 4, 2007.

ADDRESSES: Use one of the following addresses to submit comments on
this proposed AD.
DOT Docket Web site: Go to http://dms.dot.gov and follow

the instructions for sending your comments electronically.
Government-wide rulemaking Web site: Go to http://www.regulations.gov
and follow the instructions for sending your

comments electronically.
Mail: Docket Management Facility, U.S. Department of
Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401,
Washington, DC 20590.
Fax: (202) 493-2251.
Hand Delivery: Room PL-401 on the plaza level of the
Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
Contact Bombardier, Inc., Bombardier Regional Aircraft Division,
123 Garratt Boulevard, Downsview, Ontario M3K 1Y5, Canada, for service
information identified in this proposed AD.

FOR FURTHER INFORMATION CONTACT: Ezra Sasson, 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) 228-7320; fax (516) 794-5531.

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to submit any relevant written data, views, or
arguments regarding this proposed AD. Send your comments to an address
listed in the ADDRESSES section. Include the docket number ``FAA-2007-
27755; Directorate Identifier 2006-NM-289-AD'' at the beginning of your
comments. We specifically invite comments on the overall regulatory,
economic, environmental, and energy aspects of the proposed AD. We will
consider all comments received by the closing date and may amend the
proposed AD in light of those comments.
We will post all comments we receive, without change, to http://dms.dot.gov
, including any personal information you provide. We will

also post a report summarizing each substantive verbal contact with FAA
personnel concerning this proposed AD. Using the search function of
that web site, anyone can find and read the comments in any of our
dockets, including the name of the individual who sent the comment (or
signed the comment on behalf of an association, business, labor union,
etc.). You may review the DOT's complete Privacy Act Statement in the
Federal Register published on April 11, 2000 (65 FR 19477-78), or you
may visit http://dms.dot.gov.

Examining the Docket

You may examine the AD docket on the Internet at http://dms.dot.gov
, or in person at the Docket Management Facility office

between 9 a.m. and 5 p.m., Monday through Friday, except Federal
holidays. The Docket Management Facility office (telephone (800) 647-
5227) is located on the plaza level of the Nassif Building at the DOT
street address stated in the ADDRESSES section. Comments will be
available in the AD docket shortly after the Docket Management System
receives them.

Discussion

Transport Canada Civil Aviation (TCCA), which is the airworthiness
authority for Canada, notified us that an unsafe condition may exist on
certain Bombardier Model DHC-8-400 series airplanes. TCCA advises that
it has received several reports of fluid loss in the No. 2 hydraulic
system, causing the power transfer unit (PTU) to overspeed. This
resulted 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. This caution light indicated that the hydraulic fluid
temperature had exceeded 225 degrees Fahrenheit. Had the temperature of
the hydraulic fluid continued to increase to 275 degrees Fahrenheit,
the No. 1 system hydraulic firewall shutoff would have closed, leaving
only the standby power unit (SPU) available. The SPU is not capable of
meeting the increased flow demands of the PTU and other No. 1 hydraulic
system services. Therefore, the No. 1 hydraulic system would have also
been lost, leaving only the No. 3 hydraulic system available.
Inoperative systems would include flaps, brakes and emergency brakes,
nose wheel steering, and all primary flight controls other than
elevator control and degraded aileron control.
This condition, if not corrected, could result in the potential
loss of several functions essential for safe flight and landing of the
airplane.

Relevant Service Information

Bombardier has issued the following airplane flight manual (AFM)
temporary amendments:

[[Page 16290]]

Table.--AFM Temporary Amendments
----------------------------------------------------------------------------------------------------------------
Bombardier
For model-- temporary Issue-- Dated-- To Bombardier Dash 8 Q400
amendment-- airplane flight manual--
----------------------------------------------------------------------------------------------------------------
-400 airplanes.................. 13 1 July 14, 2005..... PSM 1-84-1A
-401 airplanes.................. 13 1 July 14, 2005..... PSM 1-84-1A
-402 airplanes.................. 13 1 July 14, 2005..... PSM 1-84-1A
----------------------------------------------------------------------------------------------------------------

The temporary amendments describe 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. TCCA mandated the service
information and issued Canadian airworthiness directive CF-2006-08,
dated April 26, 2006, to ensure the continued airworthiness of these
airplanes in Canada.

FAA's Determination and Requirements of the Proposed AD

These airplanes are manufactured in Canada and are type
certificated for operation in the United States under the provisions of
section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and
the applicable bilateral airworthiness agreement. Pursuant to this
bilateral airworthiness agreement, TCCA has kept the FAA informed of
the situation described above. We have examined TCCA's findings,
evaluated all pertinent information, and determined that we need to
issue an AD for airplanes of this type design that are certificated for
operation in the United States. Therefore, we are proposing this AD,
which would require revising the Limitations section of the 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.

Interim Action

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

Costs of Compliance

The following table provides the estimated costs for U.S. operators
to comply with this proposed AD.

Estimated Costs
----------------------------------------------------------------------------------------------------------------
Number of
Average Cost per U.S.-
Action Work hours labor rate Parts airplane registered Fleet cost
per hour airplanes
----------------------------------------------------------------------------------------------------------------
AFM revision................ 1 $80 $0 $80 21 $1,680
----------------------------------------------------------------------------------------------------------------

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 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 that the 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. 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, 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 Federal Aviation Administration (FAA) amends Sec. 39.13 by
adding the following new airworthiness directive (AD):

Bombardier, Inc. (Formerly de Havilland, Inc.): Docket No. FAA-2007-
27755; Directorate Identifier 2006-NM-289-AD.

Comments Due Date

(a) The FAA must receive comments on this AD action by May 4,
2007.

Affected ADs

(b) None.

Applicability

[[Page 16291]]

airplanes, certificated in any category; serial numbers 4001 and
4003 and subsequent.

Unsafe Condition

(d) This AD results from reports of fluid loss in the No. 2
hydraulic system, causing the power transfer unit to overspeed,
increasing the fluid flow within the No. 1 hydraulic system. 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.

Airplane Flight Manual (AFM) Revision

(f) Within 14 days after the effective date of this AD, 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
Temporary To Bombardier Dash 8 Q400
For Model-- Amendment-- Issue-- Dated-- Airplane Flight Manual--

----------------------------------------------------------------------------------------------------------------
-400 airplanes.................. 13 1 July 14, 2005..... PSM 1-84-1A.
-401 airplanes.................. 13 1 July 14, 2005..... PSM 1-84-1A.
-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.

Alternative Methods of Compliance (AMOCs)

(g)(1) The Manager, New York Aircraft Certification Office, FAA,
has the authority to approve AMOCs for this AD, if requested in
accordance with the procedures found in 14 CFR 39.19.
(2) Before using any AMOC approved in accordance with Sec.
39.19 on any airplane to which the AMOC applies, notify the
appropriate principal inspector in the FAA Flight Standards
Certificate Holding District Office.

Related Information

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

Issued in Renton, Washington, on March 26, 2007.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. E7-6267 Filed 4-3-07; 8:45 am]

BILLING CODE 4910-13-P