04-5947. Airworthiness Directives; Bombardier Model CL-600-2B19 (Regional Jet Series 100 & 440) Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Bombardier Model CL-600-2B19 (Regional Jet Series 100 & 440) airplanes. This proposal would require repetitive detailed and eddy current inspections on the main fittings of the main landing gears (MLG) to detect discrepancies, and related investigative/corrective actions if necessary. This proposal also would require servicing the shock strut of the MLGs; inspecting the shock strut of the MLGs for nitrogen pressure, visible chrome dimension, and oil leakage; and servicing any discrepant strut. This action is necessary to detect and correct premature cracking of the main fittings of the MLGs, which could result in failure of the fittings and consequent collapse of the MLGs during landing. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by April 17, 2004.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2003-NM-149-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9 a.m. and 3 p.m., Monday through Friday, except Federal holidays. Comments may be submitted via fax to [phone]. Comments may also be sent via the Internet using the following address: [e-mail]. Comments sent via fax or the Internet must contain “Docket No. 2003-NM-149-AD” in the subject line and need not be submitted in triplicate. Comments sent via the Internet as attached electronic files must be formatted in Microsoft Word 97 or 2000 or ASCII text.

The service information referenced in the proposed rule may be obtained from Bombardier, Inc., Canadair, Aerospace Group, P.O. Box 6087, Station Centre-ville, Montreal, Quebec H3C 3G9, Canada. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, New York Aircraft Certification Office, 1600 Stewart Avenue, suite 410, Westbury, New York.

FOR FURTHER INFORMATION CONTACT:

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].

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to participate in the making of the proposed rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this action may be changed in light of the comments received.

Submit comments using the following format:

• Organize comments issue-by-issue. For example, discuss a request to change the compliance time and a request to change the service bulletin reference as two separate issues.
• For each issue, state what specific change to the proposed AD is being requested.
• Include justification (e.g., reasons or data) for each request.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report summarizing each FAA-public contact concerned with the substance of this proposal will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this action must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 2003-NM-149-AD.” The postcard will be date stamped and returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this NPRM by submitting a request to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2003-NM-149-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

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-600-2B19 (Regional Jet Series 100 & 440) airplanes. TCCA advises that the results of a stress analysis revealed that certain main fittings of the main landing gears (MLG) are susceptible to premature cracking, starting in the radius of the upper lug. This condition, if not corrected, could result in failure of the main fittings of the MLGs and consequent collapse of the MLGs during landing.

Explanation of Relevant Service Information

Bombardier has issued Alert Service Bulletin A601R-32-088, including Appendices A, B, and C, dated February 20, 2003, which describes, among other actions, the following procedures:

• Performing repetitive detailed inspections on the main fittings of the MLGs to detect discrepancies (e.g., linear paint cracks or lack of paint (paint peeling), any other paint damage, adhesion, paint bulging, or corrosion), and related investigative/corrective actions if necessary. The related investigative actions include either an eddy current or fluorescent penetrant inspection of the main fittings of the MLGs for discrepancies. The corrective action includes replacing the MLGs or main fittings of the MLGs with new parts and repainting, repairing, and/or reworking any paint damage; as applicable.
• Performing repetitive eddy current inspections on the main fittings of the MLGs to detect cracks, and replacement of the main fittings of the MLGs with new or serviceable fittings if necessary.
• Servicing the shock strut of the MLGs.
• Inspecting the shock strut of the MLGs for nitrogen pressure, visible chrome dimension, and oil leakage, and servicing the affected shock strut of the MLGs if necessary.

Accomplishment of the actions specified in the service bulletin is intended to adequately address the identified unsafe condition. TCCA classified this service bulletin as mandatory and issued Canadian airworthiness directive CF-2003-09, effective June 6, 2003, to ensure the continued airworthiness of these airplanes in Canada.

FAA's Conclusions

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. The FAA has examined the findings of TCCA, reviewed all available information, and determined that AD action is necessary for products of this type design that are certificated for operation in the United States.

Explanation of Requirements of Proposed Rule

Since an unsafe condition has been identified that is likely to exist or develop on other airplanes of the same type design registered in the United States, the proposed AD would require accomplishment of the actions specified in the service bulletin described previously, except as discussed below.

Difference Between Proposed Rule and Canadian Airworthiness Directive/Service Bulletin

Operators should note that, although the Accomplishment Instructions of the referenced service bulletin describe procedures for submitting a comment sheet related to service bulletin quality and a sheet recording compliance to the airplane manufacturer bulletin, this proposed AD would not require those actions. The FAA does not need this information from operators.

Cost Impact

The FAA estimates that 288 airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately 4 work hours per airplane to accomplish the proposed actions, and that the average labor rate is $65 per work hour. Based on these figures, the cost impact of the proposed AD on U.S. operators is estimated to be $74,880, or $260 per airplane.

The cost impact figure discussed above is based on assumptions that no operator has yet accomplished any of the proposed requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted. The cost impact figures discussed in AD rulemaking actions represent only the time necessary to perform the specific actions actually required by the AD. These figures typically do not include incidental costs, such as the time required to gain access and close up, planning time, or time necessitated by other administrative actions. Manufacturer warranty remedies may be available for certain labor costs associated with this proposed AD. As a result, the costs attributable to the proposed AD may be less than stated above.

Regulatory Impact

The regulations proposed herein 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. Therefore, it is determined that this proposal would not have federalism implications under Executive Order 13132.

For the reasons discussed above, I certify that this 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) if promulgated, 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. A copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Safety

The Proposed Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend part 39 of the Federal Aviation Regulations (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. Section 39.13 is amended by adding the following new airworthiness directive:

Bombardier, Inc. (Formerly Canadair): Docket 2003-NM-149-AD.

Applicability: Model CL-600-2B19 (Regional Jet Series 100 & 440) airplanes, equipped with main fittings, part numbers (P/N) 601R85001-81 and 601R85001-82 (Messier Dowty Incorporated P/N 17064-105 and 17064-106), of the main landing gears (MLG); certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To detect and correct premature cracking of the main fittings of the MLGs, which could result in failure of the fittings and consequent collapse of the MLGs during landing, accomplish the following:

Note 1:

Where this AD differs from the referenced service bulletin, the AD prevails.

Detailed Inspection of Main Fittings of the MLGs

(a) Before the accumulation of 2,500 total flight cycles on the MLGs, or within 250 flight cycles after the effective date of this AD, whichever occurs later, do a detailed inspection on the main fittings of the MLGs to detect discrepancies (i.e., linear paint cracks or lack of paint (paint peeling), any other paint damage, adhesion, paint bulging, or corrosion), in accordance with Part A of the Accomplishment Instructions of Bombardier Alert Service Bulletin (ASB) A601R-32-088, dated February 20, 2003. Repeat the inspection thereafter at intervals not to exceed 100 flight cycles.

Note 2:

For the purposes of this AD, a detailed inspection is defined as: “An intensive visual examination of a specific structural area, system, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at intensity deemed appropriate by the inspector. Inspection aids such as mirror, magnifying lenses, etc., may be used. Surface cleaning and elaborate access procedures may be required.”

Related Investigative/Corrective Actions

(b) If any discrepancy is detected during any inspection required by paragraph (a) of this AD, before further flight, do the related investigative/corrective actions in accordance with Part B or F of the Accomplishment Instructions of Bombardier ASB A601R-32-088, including Appendices A and C, dated February 20, 2003. If an eddy current inspection (a related investigative action specified in Part B) is used to confirm the detailed inspection findings, the next eddy current required by paragraph (c) of this AD must be conducted within 500 flight cycles after the eddy current inspection specified in this paragraph, and thereafter at intervals not to exceed 500 flight cycles.

Eddy Current Inspection of Main Fittings of the MLGs

(c) At the time specified in paragraph (a) of this AD, do an eddy current inspection on the main fittings of the MLGs to detect cracks in accordance with Part B of the Accomplishment Instructions of Bombardier ASB A601R-32-088, including Appendix A, dated February 20, 2003. Repeat the eddy current inspection thereafter at intervals not to exceed 500 flight cycles. If any crack is found, before further flight, replace the affected main fittings of the MLGs with new or serviceable fittings in accordance with paragraph E.(5) of Part B of the Accomplishment Instructions of service bulletin.

Servicing of Shock Struts and Serving If Necessary

(d) Before the accumulation of 2,500 total flight cycles on the MLGs, or within 500 flight cycles after the effective date of this AD, whichever occurs later, service the shock strut of the MLGs in accordance with Part C or D, as applicable, of the Accomplishment Instructions of Bombardier ASB A601R-32-088, including Appendix B, dated February 20, 2003.

Shock Strut Inspection

(e) Within 500 flight cycles after completing the servicing required by paragraph (d) of this AD, inspect the shock strut of the MLGs for nitrogen pressure, visible chrome dimension, and oil leakage in accordance with Part E of the Accomplishment Instructions of Bombardier ASB A601R-32-088, including Appendix B, dated February 20, 2003. Repeat the inspection thereafter at intervals not to exceed 500 flight cycles. If the nitrogen pressure and visible chrome dimensions are found outside the limits (the service bulletin refers to the airplane maintenance manual as the source of defined limits) and/or oil leakage is found, before further flight, service the affected shock strut of the MLGs in accordance with Part C or D, as applicable, of the Accomplishment Instructions of the service bulletin.

Reporting

(f) Submit a report of all findings (both positive and negative) after each inspection and servicing required by this AD to Bombardier Aerospace, In-Service Engineering, attention Jean Gauthier, fax [phone], e-mail [e-mail], at the applicable time specified in paragraph (f)(1) or (f)(2) of this AD. Under the provisions of the Paperwork Reduction Act of 1980 (44 U.S.C. 3501 et seq.), the Office of Management and Budget (OMB) has approved the information collection requirements contained in this AD and has assigned OMB Control Number 2120-0056.

(1) If any inspection or servicing is done after the effective date of this AD: Submit the report within 30 days after the applicable inspection or servicing.

(2) If any inspection or servicing was accomplished before the effective date of this AD: Submit the report within 30 days after the effective date of this AD.

(g) Although the Accomplishment Instructions of the service bulletin referenced in this AD specifies to submit a comment sheet related to service bulletin quality and a sheet recording compliance to the airplane manufacturer bulletin, this AD does not include such a requirement

Alternative Methods of Compliance

(h) In accordance with 14 CFR 39.19, the Manager, New York Aircraft Certification Office, FAA, is authorized to approve alternative methods of compliance for this AD.

Note 3:

The subject of this AD is addressed in Canadian airworthiness directive CF-2003-09, dated April 23, 2003.

Issued in Renton, Washington, on March 5, 2004.

Ali Bahrami,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.