E8-11112. 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).

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: [phone].
• 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 [phone]) 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 [phone]; fax [phone].

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 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.

§ 39.13

[Amended]

2. The Federal Aviation Administration (FAA) amends § 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

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

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 [phone]; fax [phone]; 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.