04-24937. Airworthiness Directives; Bombardier Model CL-600-2B16 (CL-604) Series Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to adopt a new airworthiness directive (AD) for certain Bombardier Model CL-600-2B16 (CL-604) series airplanes. This proposed AD would require replacing the side-brace fitting shafts of the main landing gear (MLG) with new, improved side-brace fitting shafts; inspecting for corrosion of the MLG side-brace fitting shafts; and replacing the nut, washer, and cotter pin of the MLG side-brace fitting shafts with new parts; as applicable. This proposed AD is prompted by the discovery of fractures of the MLG side-brace fitting shafts caused by corrosion on the forward side of the side-brace fitting shafts. We are proposing this AD to prevent fracture of the MLG side-brace fitting shafts, which could result in collapse of the MLG.

DATES:

We must receive comments on this proposed AD by December 9, 2004.

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.
• By fax: [phone].
• 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.

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 [phone]; fax [phone].

Plain Language information: Marcia Walters, [e-mail].

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-2004-19563; Directorate Identifier 2003-NM-10-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 [phone]) 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 the FAA that an unsafe condition may exist on certain Bombardier Model CL-600-2B16 (CL-604) series airplanes. TCAA advises that there have been reports of fractures of the side-brace fitting shafts of the main landing gear (MLG). Investigation revealed that the fractures were caused by corrosion on the forward side of the MLG side-brace fitting shafts. Fractures of the side-brace fitting shafts, if not corrected, could result in collapse of the MLG.

Relevant Service Information

Bombardier has issued Alert Service Bulletin (ASB) A604-32-018, Revision 01, dated February 22, 2002. The procedures in that ASB are divided into Parts A, B, and C, each of which applies to different groups of airplanes. Part A of the ASB describes procedures for replacing the side-brace fitting shafts of the left-hand (LH) and right-hand (RH) MLG with new, improved side-brace fitting shafts; and replacing the nut, washer, and cotter pin of the MLG side-brace fitting shafts with new parts. Part B of the ASB describes procedures for inspecting for corrosion of the LH and RH MLG side-brace fitting shafts, replacing the shafts with new, improved shafts if corrosion is found, and replacing the nut, washer, and cotter pin of the MLG side-brace fitting shafts with new parts. Part C of the ASB describes procedures for replacing, with new parts, the nut and washer on the forward side of each MLG side-brace fitting shaft. Accomplishing the applicable actions specified in the ASB is intended to adequately address the unsafe condition. TCCA mandated the ASB and issued Canadian airworthiness directive CF-2002-43, dated September 30, 2002, to ensure the continued airworthiness of these airplanes in Canada.

FAA's Determination and Requirements of the Proposed AD

This airplane model is manufactured in Canada and is 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 AD action is necessary for products of this type design that are certificated for operation in the United States. Therefore, we are proposing this AD, which would require accomplishing the applicable actions specified in the service information described previously, except as discussed under “Difference Among the Proposed AD, ASB, and Canadian Airworthiness Directive.”

Clarification of Inspection Terminology

In this proposed AD, we refer to the inspection for corrosion that is specified in the ASB as a “general visual inspection.” We have included the definition for this type of inspection in a note in the proposed AD.

Difference Among the Proposed AD, ASB, and Canadian Airworthiness Directive

Both the ASB and Canadian Airworthiness Directive specify reporting certain information and returning removed parts to Bombardier. This proposed AD would not require these actions.

Costs of Compliance

This proposed AD would affect about 163 airplanes of U.S. registry. The proposed actions would take up to 16 work hours 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 up to $169,520, or up to $1,040 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.

§ 39.13

[Amended]

2. The FAA amends § 39.13 by adding the following new airworthiness directive (AD):

Bombardier, Inc. (Formerly Canadair): Docket No. FAA-2004-19563; Directorate Identifier 2003-NM-10-AD.

Comments Due Date

(a) The Federal Aviation Administration must receive comments on this AD action by December 9, 2004.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Bombardier, Inc. CL-600-2B16 (CL-604) series airplanes, serial numbers 5301 through 5550 inclusive, certificated in any category.

Unsafe Condition

(d) This AD is prompted by the discovery of fractures of the main landing gear (MLG) side-brace fitting shafts caused by corrosion on the forward side of the side-brace fitting shafts. We are issuing this AD to prevent fracture of the MLG side-brace fitting shafts, which could result in collapse of the MLG.

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.

Service Bulletin Reference

(f) The term “service bulletin,” as used in this AD, means the Accomplishment Instructions of Bombardier Alert Service Bulletin A604-32-018, Revision 01, dated February 22, 2002.

Inspection/Replacement of MLG Side-Brace Fitting Shaft and Hardware

(g) Do the actions specified in paragraph (g)(1), (g)(2), or (g)(3) of this AD, as applicable, at the applicable compliance times specified in those paragraphs.

(1) For airplanes subject to Part A of the service bulletin as specified in paragraph 1.C., “Effectivity,” of the service bulletin: Within 3 months after the effective date of this AD, replace the side-brace fitting shafts of the left-hand (LH) and right-hand (RH) MLG with new, improved side-brace fitting shafts; and replace the nut, washer, and cotter pin of the MLG side-brace fitting shafts with new parts. Do these actions in accordance with Part A of the Accomplishment Instructions of the service bulletin.

(2) For airplanes subject to Part B of the service bulletin as specified in paragraph 1.C., “Effectivity,” of the service bulletin: Within 5 months after the effective date of this AD, perform a general visual inspection for corrosion of the LH and RH MLG side-brace fitting shafts, replace the shafts with new, improved shafts if corrosion is found, and replace the nut, washer, and cotter pin of the MLG side-brace fitting shafts with new parts. Do these actions in accordance with Part B of the Accomplishment Instructions of the service bulletin.

(3) For airplanes subject to Part C of the service bulletin as specified in paragraph 1.C., “Effectivity,” of the service bulletin: Within 5 months after the effective date of this AD, replace, with new parts, the nut, washer, and cotter pin on the forward side of each MLG side-brace fitting shaft. Do these actions in accordance with Part C of the Accomplishment Instructions of the service bulletin.

Note 1:

For the purposes of this AD, a general visual inspection is: “A visual examination of an interior or exterior area, installation, or assembly to detect obvious damage, failure, or irregularity. This level of inspection is made from within touching distance unless otherwise specified. A mirror may be necessary to ensure visual access to all surfaces in the inspection area. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight, or droplight and may require removal or opening of access panels or doors. Stands, ladders, or platforms may be required to gain proximity to the area being checked.”

Actions Done Previously

(h) Actions done before the effective date of this AD in accordance with Bombardier Alert Service Bulletin A604-32-018, dated October 23, 2001, are acceptable for compliance with the corresponding actions required by this AD, provided that the additional actions specified in Part C of the Accomplishment Instructions of Bombardier ASB A604-32-018, Revision 01, dated February 22, 2002, are done, as applicable.

No Reporting Requirement

(i) Although the service bulletin referenced in this AD specifies reporting certain information and returning removed parts to Bombardier, this AD does not require these actions.

Alternative Methods of Compliance

(j) In accordance with 14 CFR 39.19, the Manager, New York ACO, is authorized to approve alternative methods of compliance for this AD.

Note 2:

The subject of this AD is addressed in Canadian airworthiness directive CF-2002-43, dated September 30, 2002.

Issued in Renton, Washington, on November 1, 2004.

Kalene C. Yanamura,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.