[Federal Register Volume 70, Number 60 (Wednesday, March 30, 2005)]
[Proposed Rules]
[Pages 16182-16185]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-6253]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2005-20756; Directorate Identifier 2004-NM-52-AD]
RIN 2120-AA64


Airworthiness Directives; Bombardier Model DHC-8-102, -03, -106, 
-201, -202, -301, -311, and -315 Airplanes

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

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for certain Bombardier Model DHC-8-102, -103, -106, -201, -202, -301, -
311 and -315 airplanes. This proposed AD would require installation of 
check valves in Numbers 1 and 2 hydraulic systems, removal of the 
filters from the brake shuttle valves, and removal of the internal 
garter spring from the brake shuttle valves. This proposed AD results 
from two instances of brake failure due to the loss of hydraulic fluid 
from both Numbers 1 and 2 hydraulic systems and one incident of brake 
failure due to filter blockage in the shuttle valve. We are proposing 
this AD to prevent the loss of hydraulic power from both hydraulic 
systems which could lead to reduced controllability of the airplane; 
and to prevent brake failure which could result in the loss of 
directional control on the ground and consequent departure from the 
runway during landing.

DATES: We must receive comments on this proposed AD by April 29, 2005.

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed AD.

[[Page 16183]]

     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.
     By 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.
    For service information identified in this proposed AD, contact 
Bombardier, Inc., Bombardier Regional Aircraft Division, 123 Garratt 
Boulevard, Downsview, Ontario M3K 1Y5, Canada.
    You can examine the contents of this AD docket on the Internet at 
http://dms.dot.gov, or in person at the Docket Management Facility, 
U.S. Department of Transportation, 400 Seventh Street SW., room PL-401, 
on the plaza level of the Nassif Building, Washington, DC. This docket 
number is FAA-2005-20756; the directorate identifier for this docket is 
2004-NM-52-AD.

FOR FURTHER INFORMATION CONTACT: Ezra Sasson, Aerospace Engineer, 
Airframe and Propulsion Branch, ANE-171, 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 under ADDRESSES. Include ``Docket No. FAA-2005-20756; 
Directorate Identifier 2004-NM-52-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 submitted 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 our 
docket 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 can review the DOT's complete Privacy Act Statement in the 
Federal Register published on April 11, 2000 (65 FR 19477-78), or you 
can visit http://dms.dot.gov.

Examining the Docket

    You can 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 DMS 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-8-102, -103, -106, -201, -202, -301, -311, 
and -315 airplanes. TCCA advises that there have been two instances 
during which the Numbers 1 and 2 hydraulic systems power was lost due 
to a hydraulic leak downstream of one of the brake shuttle valves. 
Investigation revealed that a minor leak in one of the brake units 
allowed the Number 2 hydraulic system fluid to deplete. In addition, 
the shuttle valve internal garter spring had also failed. This failure 
allowed the Number 1 hydraulic system fluid to also deplete through the 
same brake unit. This condition, if not corrected, could result in loss 
of hydraulic power from both hydraulic systems, which could lead to 
reduced controllability of the airplane.
    An additional incident has been reported of a brake seizure and 
subsequent wheel assembly fire while the airplane was taxiing. An 
investigation revealed that hydraulic pressure remained applied to the 
brake unit even after brake release. It was determined that the 
dislodging of the 10-micron filter in the brake shuttle valve had 
blocked the valve port and prevented hydraulic fluid flow from the 
brake. Brake failure could result in the loss of directional control on 
the ground and consequent departure from the runway during landing.

Relevant Service Information

    Bombardier Inc. has issued Service Bulletin S.B. 8-29-36, Revision 
``B,'' dated January 6, 2003, that describes procedures for installing 
check valves in the Numbers 1 and 2 hydraulic systems by incorporating 
Modsum 8Q101320. Bombardier has also issued S.B. 8-29-37, Revision 
``A,'' dated September 19, 2003, that provides instructions for 
incorporating Modsum 8Q101316 to remove the filter assemblies and 
internal garter spring, and S.B. 8-29-39, dated July 14, 2003, that 
includes instructions for incorporating Modsum 8Q101422 to remove the 
filter assemblies. Accomplishing the actions specified in the service 
information is intended to adequately address the unsafe condition. 
TCCA mandated the service information and issued Canadian airworthiness 
directive CF-2004-02, dated February 9, 2004, to ensure the continued 
airworthiness of these airplanes in Canada.

FAA's Determination and Requirements of the Proposed AD

    These airplane models 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 products of this type design that are certificated for 
operation in the United States.
    Therefore, we are proposing this AD, which would require 
installation of check valves in Numbers 1 and 2 hydraulic systems, 
removal of filters from the brake shuttle valves and removal of the 
internal garter spring from the brake shuttle valves. The proposed AD 
would require you to use the service information described previously 
to perform these actions, except as discussed under ``Differences 
Between the Proposed AD and Canadian Airworthiness Directive.''

Differences Between the Proposed AD and Canadian Airworthiness 
Directive

    Although the Canadian airworthiness directive recommends, for 
airplanes that removed the filters from the brake shuttle valve, 
removal of the internal garter spring at the next overhaul of each 
brake shuttle valve, we have determined that a specific compliance time 
is needed. In developing appropriate compliance times for this proposed 
AD, we considered not only the manufacturer's recommendation, but also 
the degree of urgency associated with addressing the subject

[[Page 16184]]

unsafe condition, and the average utilization of the affected fleet. 
Considering these factors, we find that after removing the filters, a 
compliance time of 40,000 flight hours for the removal of the internal 
garter spring is warranted. We have coordinated this issue with TCCA.

Costs of Compliance

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

                                                                     Estimated Costs
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                                                                                                                     Number of
                                                                            Average                    Cost per        U.S.-
                          Action                            Work hours    labor rate       Parts       airplane     registered      Average fleet cost
                                                                           per hour                                  airplanes
--------------------------------------------------------------------------------------------------------------------------------------------------------
Installation of check valves in Numbers 1 and 2 hydraulic             3           $65     $279-$405     $444-$600           179         $79,476-$107,400
 systems.................................................
Removal of filters and internal garter springs from brake             3            65     252-1,360     447-1,555           179           80,013-278,345
 shuttle valves..........................................
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Authority for This Rulemaking

    The FAA's authority to issue rules regarding aviation safety is 
found in Title 49 of the United States Code. 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.
    This rulemaking is promulgated 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 
proposed AD.

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. 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 FAA amends Sec.  39.13 by adding the following new 
airworthiness directive (AD):

Bombardier, Inc. (Formerly de Havilland, Inc.): Docket No. FAA-2005-
20756; Directorate Identifier 2004-NM-52-AD.

Comments Due Date

    (a) The Federal Aviation Administration must receive comments on 
this AD action by April 29, 2005.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Bombardier Model DHC-8-102, -103, -106, -
201, -202, -301, -311, and -315, certificated in any category; 
serial numbers 003 through 593 inclusive.

Unsafe Condition

    (d) This AD results from two instances of brake failure due to 
the loss of hydraulic fluid from both Numbers 1 and 2 hydraulic 
systems and one incident of brake failure due to filter blockage in 
the shuttle valve. We are proposing this AD to prevent the loss of 
hydraulic power from both hydraulic systems which could lead to 
reduced controllability of the airplane; and to prevent brake 
failure which could result in the loss of directional control on the 
ground and consequent departure from the runway during landing.

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.

Installation of Check Valves in Numbers 1 and 2 Hydraulic Systems

    (f) Within 12 months after the effective date of this AD, 
install check valves in the Numbers 1 and 2 hydraulic return systems 
by incorporating Modsum 8Q101320 in accordance with the 
Accomplishment Instructions of Bombardier Service Bulletin S.B. 8-
29-36, Revision `B,' dated January 6, 2003.

Removal of Filters and Internal Garter Spring From the Brake Shuttle 
Valves

    (g) Within 12 months after the effective date of this AD, modify 
the brake shuttle valves, part number (P/N) 5084-1, by doing the 
actions in either paragraph (g)(1) or (g)(2) of this AD. The 
installation specified in paragraph (f) of this AD must be done 
prior to doing any actions in accordance with Bombardier Service 
Bulletin S.B. 8-29-37, Revision `A,' dated September 19, 2003 
(Modsum 8Q101316) that are specified in paragraphs (g)(1) and (g)(2) 
of this AD.
    (1) Remove the filter assemblies by incorporating Modsum 
8Q101422 in accordance with the Accomplishment Instructions of 
Bombardier Service Bulletin S.B. 8-29-39, dated July 14, 2003; and 
within 40,000 flight hours after removing the filter assemblies, 
remove the internal garter spring by incorporating Modsum 8Q101316 
in accordance with the Accomplishment Instructions of Bombardier 
Service Bulletin S.B. 8-29-37, Revision `A,' dated September 19, 
2003.
    (2) Remove the filter assemblies and internal garter spring by 
incorporating Modsum 8Q101316 in accordance with the Accomplishment 
Instructions of Bombardier Service Bulletin S.B. 8-29-37, Revision 
`A,' dated September 19, 2003.

    Note 1: You can mix shuttle valves that have incorporated either 
Modsum 8Q101316 or 8Q101422 on the same airplane.

Actions Accomplished According to Previous Issues of Service Bulletins

    (h) Installations accomplished before the effective date of this 
AD according to Bombardier Service Bulletin S.B. 8-29-36,

[[Page 16185]]

dated December 6, 2002, and Revision `A,' dated December 12, 2002, 
are considered acceptable for compliance with the corresponding 
installation specified in paragraph (f) of this AD.
    (i) Removals of the filters and internal garter springs 
accomplished before the effective date of this AD according to 
Bombardier Service Bulletin S.B. 8-29-37, dated July 15, 2003, are 
considered acceptable for compliance with the corresponding removals 
specified in paragraph (g) of this AD.

Alternative Methods of Compliance (AMOCs)

    (j) 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.

Related Information

    (k) Canadian airworthiness directive CF-2004-02, dated February 
9, 2004, also addresses the subject of this AD.

    Issued in Renton, Washington, on March 22, 2005.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 05-6253 Filed 3-29-05; 8:45 am]
BILLING CODE 4910-13-P