[Federal Register Volume 69, Number 230 (Wednesday, December 1, 2004)]
[Proposed Rules]
[Pages 69842-69844]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-26493]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2004-19754; Directorate Identifier 2004-NM-181-AD]
RIN 2120-AA64


Airworthiness Directives; Bombardier Model CL-600-2C10 (Regional 
Jet Series 700 & 701) Series Airplanes, and Model CL-600-2D24 (Regional 
Jet Series 900) Series Airplanes

AGENCY: Federal Aviation Administration (FAA), 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 CL-600-2C10 (Regional Jet Series 700 & 
701) series airplanes, and Model CL-600-2D24 (Regional Jet Series 900) 
series airplanes. This proposed AD would require revising the 
Airworthiness Limitations section of the Instructions of Continued 
Airworthiness by incorporating new repetitive inspections and an 
optional terminating action for the repetitive inspections, and would 
require repairing any crack. This proposed AD is prompted by reports of 
hydraulic pressure loss in either the number 1 or number 2 hydraulic 
systems due to breakage or leakage of hydraulic lines in the aft 
equipment bay and reports of cracks on the aft pressure bulkhead web 
around these feed-through holes. We are proposing this AD to prevent 
loss of hydraulic pressure, which could result in reduced 
controllability of the airplane and to detect and correct cracks on the 
aft pressure bulkhead web, which could result in reduced structural 
integrity of the aft pressure bulkhead.

DATES: We must receive comments on this proposed AD by January 3, 2005.

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed AD.
    <bullet> DOT Docket Web site: Go to http://dms.dot.gov and follow 
the instructions for sending your comments electronically.
    <bullet> Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your 
comments electronically.
    <bullet> Mail: Docket Management Facility, U.S. Department of 
Transportation, 400 Seventh Street, SW., Nassif Building, room PL-401, 
Washington, DC 20590.
    <bullet<ls-thn-eq> By fax: (202) 493-2251.
    <bullet> 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., Canadair, Aerospace Group, P.O. Box 6087, Station 
Centre-ville, Montreal, Quebec H3C 3G9, 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-2004-19754; the directorate identifier for this 
docket is 2004-NM-181-AD.

FOR FURTHER INFORMATION CONTACT:
    Technical information: Serge Napoleon, 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) 228-7312; fax (516) 794-5531.
    Plain language information: Marcia Walters, <a href="/cdn-cgi/l/email-protection#83eee2f1e0eae2adf4e2eff7e6f1f0c3e5e2e2ade4ecf5"><span class="__cf_email__" data-cfemail="375a5645545e561940565b435245447751565619505841">[email protected]</span></a>.

SUPPLEMENTARY INFORMATION:

Docket Management System (DMS)

    The FAA has implemented new procedures for maintaining AD dockets 
electronically. As of May 17, 2004, new AD actions are posted on DMS 
and assigned a docket number. We track each action and assign a 
corresponding directorate identifier. The DMS AD docket number is in 
the form ``Docket No. FAA-2004-99999.'' The Transport Airplane 
Directorate identifier is in the form ``Directorate Identifier 2004-NM-
999-AD.'' Each DMS AD docket also lists the directorate identifier 
(``Old Docket Number'') as a cross-reference for searching purposes.

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-2004-19754; 
Directorate Identifier 2004-NM-181-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.
    We are reviewing the writing style we currently use in regulatory 
documents. We are interested in your comments on whether the style of 
this document is clear, and your suggestions to improve the clarity of 
our communications that affect you. You can get more information about 
plain language at http://www.faa.gov/language and http://www.plainlanguage.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 CL-600-2C10 (Regional Jet Series 700 & 701) 
series airplanes, and Model CL-600-2D24 (Regional Jet Series 900) 
series airplanes. TCCA advises that there have been a number of 
reported cases of

[[Page 69843]]

hydraulic pressure loss in either the number 1 or number 2 hydraulic 
systems due to breakage or leakage of hydraulic lines in the aft 
equipment bay. In some cases, hydraulic lines and connector jam nuts 
were found loose at the aft pressure bulkhead web. Loosening of the jam 
nuts also resulted in elongation of the affected feed-through holes on 
the aft pressure bulkhead web at fuselage station 1098.2, stringers 8 
and 9, left- and right-hand sides. In addition, cracks were found on 
the aft pressure bulkhead web around these feed-through holes. Loss of 
hydraulic pressure, if not corrected, could result in reduced 
controllability of the airplane. Cracks on the aft pressure bulkhead 
web, if not detected and corrected, could result in reduced structural 
integrity of the aft pressure bulkhead.

Relevant Service Information

    Bombardier has issued CRJ 700/900 Series Temporary Revision (TR) 
MRM2-129, dated June 1, 2004. The TR describes procedures for new 
repetitive inspections of the aft pressure bulkhead and pylon pressure 
pan in the vicinity of the hydraulic fittings, and the hydraulic tube 
adapters. The TR also describes an optional terminating action for the 
repetitive inspections. 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-2004-14, dated July 20, 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 
Sec.  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 revising 
the Airworthiness Limitations section of the Instructions of Continued 
Airworthiness by incorporating new repetitive inspections and an 
optional terminating action for the repetitive inspections, and would 
require repairing any crack.

Differences Between the Proposed AD and Canadian Airworthiness 
Directive

    Canadian airworthiness directive CF-2004-14 specifies that you may 
contact the manufacturer for instructions on how to repair certain 
conditions, but this proposed AD would require you to repair those 
conditions using a method that we or TCAA (or its delegated agent) 
approve. In light of the type of repair that would be required to 
address the unsafe condition, and consistent with existing bilateral 
airworthiness agreements, we have determined that, for this proposed 
AD, a repair we or TCAA approve would be acceptable for compliance with 
this proposed AD.

Costs of Compliance

    This proposed AD would affect about 116 airplanes of U.S. registry. 
The proposed actions would take about 1 work hour per airplane, at an 
average labor rate of $65 per work hour. Based on these figures, the 
estimated cost of the proposed AD for U.S. operators is $7,540, or $65 
per airplane.

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 Canadair): Docket No. FAA-2004-19754; 
Directorate Identifier 2004-NM-181-AD.

Comments Due Date

    (a) The Federal Aviation Administration must receive comments on 
this AD action by January 3, 2005.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to the airplanes listed in Table 1 of this 
AD, certificated in any category.

                         Table 1.--Applicability
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             Bombardier model                        Serial Nos.
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(1) CL-600-2C10 (Regional Jet Series 700 &  10003 through 10999
 701) series airplanes.                      inclusive.
(2) CL-600-2D24 (Regional Jet Series 900)   15001 through 15990
 series airplanes.                           inclusive.
------------------------------------------------------------------------

Unsafe Condition

    (d) This AD was prompted by reports of hydraulic pressure loss 
in either the number 1 or number 2 hydraulic systems due to breakage 
or leakage of hydraulic lines in the aft equipment bay and reports 
of cracks on the aft pressure bulkhead web around these feed-through 
holes. We are issuing this AD to prevent loss of hydraulic pressure, 
which could result in reduced controllability of the airplane and to 
detect and correct cracks on the aft pressure bulkhead web, which 
could result in reduced structural integrity of the aft pressure 
bulkhead.

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.

Revision of Airworthiness Limitations Section

    (f) Within 30 days after the effective date of this AD, revise 
the Airworthiness Limitations section of the Instructions of 
Continued Airworthiness by inserting a copy of the new repetitive 
inspections and an optional terminating action of Bombardier CRJ 
700/900 Series Temporary Revision (TR) MRM2-129, dated June 1, 2004, 
into Section 1.4, Part 2 (Airworthiness Limitations), of Bombardier 
Regional Jet Model CL-600-2C10 and CL-600-2D24 Maintenance 
Requirements Manual, CSP B-053. Thereafter, except as provided in 
paragraph (h)(2) or (i) of this AD, no alternative

[[Page 69844]]

structural inspection intervals may be approved for this aft 
pressure bulkhead and pylon pressure pan in the vicinity of the 
hydraulic fittings and the hydraulic tube adapters.
    (g) When the information in TR MRM2-129, dated June 1, 2004, is 
included in the general revisions of the Maintenance Requirement 
Manual, this TR may be removed.

Corrective Action

    (h) If any crack is found during any inspection done in 
accordance with Bombardier CRJ 700/900 Series TR MRM2-129, dated 
June 1, 2004, or the same inspection specified in the general 
revisions of the Maintenance Requirement Manual, do the actions 
specified in paragraphs (h)(1) and (h)(2) of this AD.
    (1) Before further flight, repair the crack in accordance with a 
method approved by either the Manager, New York Aircraft 
Certification Office (ACO), FAA; or Transport Canada Civil Aviation 
(TCCA) (or its delegated agent).
    (2) Within 30 days after repairing any crack in accordance with 
paragraph (h)(1) of this AD, revise the Airworthiness Limitations 
section of the Instructions of Continued Airworthiness by inserting 
a copy of the inspection requirements for the repair required by 
paragraph (h)(1) of this AD into Section 1.4, Part 2 (Airworthiness 
Limitations) of Bombardier Regional Jet Model CL-600-2C10 and CL-
600-2D24 Maintenance Requirements Manual, CSP B-053. Thereafter, 
except as provided in paragraph (i) of this AD, no alternative 
structural inspection intervals may be approved for this aft 
pressure bulkhead and pylon pressure pan in the vicinity of the 
hydraulic fittings, and the hydraulic tube adapters.

Alternative Methods of Compliance (AMOCs)

    (i) The Manager, New York ACO, 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

    (j) Canadian airworthiness directive CF-2004-14, dated July 20, 
2004, also addresses the subject of this AD.

    Issued in Renton, Washington, on November 17, 2004.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 04-26493 Filed 11-30-04; 8:45 am]
BILLING CODE 4910-13-P


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