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Proposed Rule

Airworthiness Directives; Bombardier Model CL-600-1A11 (CL-600), CL-600-2A12 (CL-601), and CL-600-2B16 (CL-601-3A, CL-601-3R, and CL-604) Series Airplanes

Document Details

Information about this document as published in the Federal Register.

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AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes to revise an existing airworthiness directive (AD), applicable to certain Bombardier Model CL-600-1A11 (CL-600), CL-600-2A12 (CL-601), and CL-600-2B16 (CL-601-3A, CL-601-3R, and CL-604) series airplanes, that currently requires repetitive inspections to find cracks of a certain bulkhead web of the fuselage at certain locations, and repair if necessary. The actions specified by that AD are intended to prevent cracking in the pressure bulkhead at frame station (FS) 409.00, which could result in uncontrolled depressurization of the airplane and/or reduced structural integrity of the fuselage. This action would provide an optional terminating modification for certain airplanes. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by November 20, 2003.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2001-NM-267-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 (425) 227-1232. Comments may also be sent via the Internet using the following address: 9-anm-nprmcomment@faa.gov. Comments sent via fax or the Internet must contain “Docket No. 2001-NM-267-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 Centreville, 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, 10 Fifth Street, Third Floor, Valley Stream, New York.

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FOR FURTHER INFORMATION CONTACT:

Serge Napoleon, Aerospace Engineer, Airframe and Propulsion Branch, ANE-171, FAA, New York Aircraft Certification Office, 10 Fifth Street, Third Floor, Valley Stream, New York; telephone (516) 256-7512; fax (516) 568-2716.

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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 2001-NM-267-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. 2001-NM-267-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

On November 10, 1997, the FAA issued AD 97-24-02, amendment 39-10209 (62 FR 61436, November 18, 1997), applicable to certain Bombardier Model CL-600-1A11, -2A12, and -2B16 series airplanes, to require repetitive inspections to find cracks of a certain bulkhead web of the fuselage at certain locations, and repair if necessary. That action was prompted by mandatory continuing airworthiness information by a foreign civil airworthiness authority. The requirements of that AD are intended to detect and correct cracking in the pressure bulkhead at frame station (FS) 409.00, which could result in uncontrolled depressurization of the airplane and/or reduced structural integrity of the fuselage.

Actions Since Issuance of Previous Rule

In the preamble to AD 97-24-02, we specified that we considered the requirements “interim action” and that the manufacturer was developing a modification to address the unsafe condition. That AD explained that we may consider further rulemaking if a modification is developed, approved, and available. The manufacturer now has developed such a modification, and we have determined that further rulemaking is indeed necessary; this Start Printed Page 60048proposed AD follows from that determination.

Explanation of Relevant Service Information

Bombardier has issued Service Bulletin 600-0680 (for Model CL-600-1A11 (CL-600) series airplanes), Service Bulletin 601-0503 (for Model CL-600-2A12 (CL-601) and CL-600-2B16 (CL-601-3A/-3R) series airplanes), and Service Bulletin 604-53-006 (for Model CL-600-2B16 (CL-604) series airplanes), all dated November 30, 1999. The service bulletins describe procedures for modification of the pressure bulkhead at FS 409.00. The modification includes an eddy current inspection for cracking of the bulkhead; reinforcement of the pressure bulkhead frame; and a pressure test, leak test, operational test, and functional test of all systems.

Transport Canada Civil Aviation (TCCA), which is the airworthiness authority for Canada, classified these service bulletins as mandatory and issued Canadian airworthiness directive CF-1997-16R2, dated May 31, 2001, in order to ensure the continued airworthiness of these airplanes in Canada.

FAA's Conclusions

These airplane models are manufactured in Canada and are type certificated for operation in the United States under the provisions of § 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 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 revise AD 97-24-02 to continue to require repetitive inspections to find cracks of a certain bulkhead web of the fuselage at certain locations, and repair if necessary. For certain airplanes, this proposed AD also would provide for an optional terminating modification for the repetitive inspections. Consistent with the findings of TCCA, the proposed AD would allow repetitive inspections to continue in lieu of the terminating action. In making this determination, we considered that long-term continued operational safety in this case will be adequately ensured by repetitive inspections to detect cracking before it represents a hazard to the airplane. The actions would be required to be accomplished in accordance with the service bulletins described previously, except as discussed below.

Differences Between Proposed Rule and Service Bulletins/Canadian Airworthiness Directive

The Canadian airworthiness directive specifies reporting crack findings to the manufacturer; however, this proposed AD would not require such action.

The Accomplishment Instructions of the referenced service bulletins describe procedures for completing an Incorporation Notice. However, this proposed AD would not require such action.

In addition, although the service bulletins specify that operators may contact the manufacturer for disposition of certain repair conditions, this proposal would require operators to repair those conditions per a method approved by either the FAA or TCCA (or its delegated agent). 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 approved by either the FAA or TCCA would be acceptable for compliance with this proposed AD.

Explanation of Change Made To Existing Requirements

We have changed all references to a “detailed visual inspection” in the existing AD to a “detailed inspection” in this action.

Cost Impact

There are approximately 237 airplanes of U.S. registry that would be affected by this proposed AD.

The inspections that are required by AD 97-24-02 take approximately 2 work hours per airplane to accomplish, at an average labor rate of $65 per work hour. Based on these figures, the cost impact of the currently required actions is estimated to be $130 per airplane, per inspection cycle.

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.

The optional terminating modification, if done, would take between 125 and 300 work hours per airplane, depending on the airplane configuration, at an average labor rate of $65 per work hour. Required parts would be provided by the manufacturer at no cost to operators. Based on these figures, we estimate the cost of the modification to be between $8,125 and $19,500 per airplane.

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.

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List of Subjects in 14 CFR Part 39

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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:

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PART 39—AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

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Authority: 49 U.S.C. 106(g), 40113, 44701.

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[Amended]

2. Section 39.13 is amended by removing amendment 39-10209 (62 FR 61436, November 18, 1997), and by adding a new airworthiness directive (AD), to read as follows:

Bombardier, Inc. (Formerly Canadair): Docket 2001-NM-267-AD. Revises AD 97-24-02, Amendment 39-10209.

Applicability: Model CL-600-1A11 (CL-600) series airplanes, serial numbers 1004 through 1085 inclusive; Model CL-600-2A12 (CL-601) series airplanes, serial numbers 3001 through 3066 inclusive; Model CL-600-2B16 (CL-601-3A/-3R) series airplanes, serial numbers 5001 through 5194 inclusive; and Model CL-600-2B16 (CL-604) series airplanes, serial numbers 5301 through 5352 inclusive; certificated in any category.

Compliance: Required as indicated, unless accomplished previously. To prevent cracking in the pressure bulkhead at frame station (FS) 409.00, which could result in uncontrolled depressurization of the airplane and/or reduced structural integrity of the fuselage, accomplish the following:

Restatement of Requirements of AD 97-24-02: Detailed Inspections/Repair

(a) For Model CL-600-1A11 (CL-600) airplanes: Prior to the accumulation of 1,900 total landings, or within 100 landings after December 3, 1997 (the effective date of AD 97-24-02, amendment 39-10209), whichever occurs later, perform a detailed inspection to detect cracks at FS 409.00 of the bulkhead web (part number (P/N) 600-32014-71/-95/-105), in accordance with Canadair Challenger Service Bulletin 600-0679, dated September 12, 1997.

Note 1:

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.”

(1) If no crack is detected, repeat the detailed inspection thereafter at intervals not to exceed 600 landings.

(2) If any crack is detected and if all three of the conditions specified in paragraphs (a)(2)(i), (a)(2)(ii), and (a)(2)(iii) of this AD are met, within 600 landings or 12 months after the crack is detected, whichever occurs first, repair the crack in accordance with a method approved by the Manager, New York Aircraft Certification Office (ACO), FAA. Until the repair is accomplished, repeat the detailed inspection at intervals not to exceed 100 landings.

(i) No more than one crack exists at each corner radius, as specified in the service bulletin; and

(ii) No crack extends under the angles having P/N 600-32014-13 and P/N 600-32014-15 on the aft side of the bulkhead web; and

(iii) No crack exists in angles having P/N 600-32014-13 and P/N 600-32014-15 on the aft side of the bulkhead web.

(3) If any crack other than that identified in paragraph (a)(2) of this AD is detected, prior to further flight, repair it in accordance with a method approved by the Manager, New York ACO.

(b) For Model CL-600-2A12 (CL-601), CL-600-2B16 (CL-601-3A/-3R), and CL-600-2B16 (CL-604) series airplanes: Prior to the accumulation of 1,100 total landings, or within 100 landings after December 3, 1997, whichever occurs later, perform a detailed inspection to detect cracks at FS 409.00 of the bulkhead web (P/N 600-32014-105/-137), in accordance with Canadair Challenger Service Bulletin 601-0501, dated September 12, 1997 (for Model CL-600-2A12 (CL-601) and CL-600-2B16 (CL-601-3A/-3R) series airplanes); or Canadair Challenger Service Bulletin 604-53-007, dated September 30, 1997 (for Model CL-600-2B16 (CL-604) series airplanes); as applicable.

(1) If no crack is detected, repeat the detailed inspection thereafter at intervals not to exceed 600 landings.

(2) If any crack is detected and if all three of the conditions specified in paragraphs (b)(2)(i), (b)(2)(ii), and (b)(2)(iii) of this AD are met, within 600 landings or 12 months after the crack is detected, whichever occurs first, repair the crack in accordance with a method approved by the Manager, New York ACO. Until the repair is accomplished, repeat the detailed inspection at intervals not to exceed 100 landings.

(i) No more than one crack exists at each corner radius, as specified in the service bulletin; and

(ii) No crack extends under the angles having P/N 600-32014-113 and P/N 600-32014-115 on the aft side of the bulkhead web; and

(iii) No crack exists in angles having P/N 600-32014-113 and P/N 600-32014-115 on the aft side of the bulkhead web.

(3) If any crack other than that identified in paragraph (b)(2) of this AD is detected, prior to further flight, repair it in accordance with a method approved by the Manager, New York ACO.

New Requirements of This AD: Optional Terminating Modification

(c) For airplanes on which no crack has been found during accomplishment of any inspection required by AD 97-24-02; or on which the pressure bulkhead was not previously repaired: Modification of the pressure bulkhead at FS 409.00 (including inspection, installation of reinforcing material, and tests) by accomplishing all the actions specified in paragraphs 2.A. through 2.D. of the Accomplishment Instructions of Bombardier Service Bulletin 601-0503 (for Model CL-601 and CL-601-3A/-3R series airplanes), Service Bulletin 600-0680 (for Model CL-600 series airplanes), or Service Bulletin 604-53-006 (for Model CL-604 series airplanes); all dated November 30, 1999, per the applicable service bulletin, terminates the repetitive inspections required by this AD.

Repair

(d) If any crack is found during any inspection specified in paragraph (c) of this AD: Before further flight, repair in accordance with a method approved by the Manager, New York ACO; or Transport Canada Civil Aviation or its delegated agent.

Alternative Methods of Compliance

(e) 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-1997-16R2, dated May 31, 2001.

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Issued in Renton, Washington, on October 10, 2003.

Ali Bahrami,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

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[FR Doc. 03-26469 Filed 10-20-03; 8:45 am]

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