
[Federal Register: May 19, 2008 (Volume 73, Number 97)]
[Proposed Rules]               
[Page 28754-28756]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr19my08-11]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2008-0555; Directorate Identifier 2008-NM-074-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), Department of 
Transportation (DOT).

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to revise an existing airworthiness directive 
(AD) that applies to certain Bombardier Model CL-600-2C10 (Regional Jet 
series 700 & 701) series airplanes and Model CL-600-2D24 (Regional Jet 
series 900) series airplanes. The existing AD currently requires 
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 
repairing any crack. This proposed AD would clarify the applicability 
of the existing AD. This proposed AD results from reports of hydraulic 
pressure loss in either the number 1 or number 2 hydraulic system 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 June 18, 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-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., Canadair, Aerospace Group, P.O. Box 6087, Station Centre-ville, 
Montreal, Quebec H3C 3G9, 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 proposed 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: Pong Lee, 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) 228-7324; 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-2008-0555; 
Directorate Identifier 2008-NM-074-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy

[[Page 28755]]

aspects of this proposed AD. We will consider all comments received by 
the closing date and may amend this proposed 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 proposed AD.

Discussion

    On June 10, 2005, we issued AD 2005-13-02, amendment 39-14138 (70 
FR 35987, June 22, 2005), 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. That AD requires 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 
repairing any crack. That AD resulted from reports of hydraulic 
pressure loss in either the number 1 or number 2 hydraulic system 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 issued that 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.

Actions Since Existing AD Was Issued

    Since we issued AD 2005-13-02, we have determined that is it 
necessary to clarify the affected airplanes in paragraph (c), 
``Applicability,'' of that AD. Paragraph (c) excludes ``airplanes on 
which Modification Summaries 670T00494 or 670T11944; and Modification 
Summary 670T11508 or Bombardier Service Bulletin 670BA-29-008, dated 
March 12, 2004, or Revision A, dated May 5, 2004; has been incorporated 
in production.'' In the case of AD 2005-13-02, Bombardier Service 
Bulletin 670BA-29-008 affects only airplanes in service, not airplanes 
``in production.'' Therefore, for clarification purposes, we have 
revised paragraph (c) of the existing AD by removing the phrase ``in 
production.''

U.S. Type Certification of Airplanes

    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.
    This proposed AD would revise AD 2005-13-02 and would retain the 
requirements of the existing AD. This proposed AD would clarify the 
applicability of the existing AD.

Costs of Compliance

    This proposed AD would affect about 116 airplanes of U.S. registry. 
The actions that are required by AD 2005-13-02 and retained in this 
proposed AD take about 1 work hour per airplane, at an average labor 
rate of $80 per work hour. Based on these figures, the estimated cost 
of the currently required actions is $9,280, or $80 per airplane.

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 
removing amendment 39-14138 (70 FR 35987, June 22, 2005) and adding the 
following new airworthiness directive (AD):

Bombardier, Inc. (Formerly Canadair): Docket No. FAA-2008-0555; 
Directorate Identifier 2008-NM-074-AD.

Comments Due Date

    (a) The FAA must receive comments on this AD action by June 18, 
2008.

Affected ADs

    (b) This AD revises AD 2005-13-02.

Applicability

    (c) This AD applies to the airplanes listed in Table 1 of this 
AD, certificated in any category, excluding those airplanes on which 
Modification Summaries 670T00494 or 670T11944; and Modification 
Summary 670T11508 or Bombardier Service Bulletin 670BA-29-008, dated 
March 12, 2004, or Revision A, dated May 5, 2004; has been 
incorporated.

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

[[Page 28756]]


(2) CL-600-2D24 (Regional Jet Series 900)        15001 through 15990 inclusive.
 series airplanes.
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Unsafe Condition

    (d) This AD resulted from reports of hydraulic pressure loss in 
either the number 1 or number 2 hydraulic system 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.

Restatement of Requirements of AD 2005-13-02

Revision of Airworthiness Limitations Section

    (f) Within 30 days after July 27, 2005 (the effective date of AD 
2005-13-02), 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 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, the general revisions may be inserted into the Airworthiness 
Limitations section of the Instructions of Continued Airworthiness 
and 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) At the applicable time specified in paragraph (h)(2)(i) or 
(h)(2)(ii) 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.
    (i) If the repair required by paragraph (h)(1) of this AD is 
done after the effective date of this AD: Revise the Airworthiness 
Limitations section within 12 months after the repair.
    (ii) If the repair required by paragraph (h)(1) of this AD was 
accomplished before July 27, 2005: Revise the Airworthiness 
Limitations section within 12 months after the repair or 30 days 
after July 27, 2005, whichever occurs later.

Alternative Methods of Compliance (AMOCs)

    (i)(1) The Manager, New York ACO, FAA, ATTN: Pong Lee, Aerospace 
Engineer, Airframe and Propulsion Branch, ANE-171, FAA, New York 
ACO, 1600 Stewart Avenue, suite 410, Westbury, New York 11590; 
telephone (516) 228-7324; fax (516) 794-5531; has the authority to 
approve AMOCs for this AD, if requested using the procedures found 
in 14 CFR 39.19.
    (2) To request a different method of compliance or a different 
compliance time for this AD, follow the procedures in 14 CFR 39.19. 
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

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

    Issued in Renton, Washington, on May 8, 2008.
Michael J. Kaszycki,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
 [FR Doc. E8-11112 Filed 5-16-08; 8:45 am]

BILLING CODE 4910-13-P
