AD 97-24-02 R1

This amendment revises 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 amendment provides an optional terminating modification for certain airplanes. This action is intended to address the identified unsafe condition.

Final rule.

97-24-02 R1 Bombardier, Inc. (Formerly Canadair): Amendment 39- 13417. 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.

Incorporation by Reference

(f) Unless otherwise specified in this AD, the actions shall be done in accordance with Canadair Challenger Service Bulletin 600- 0679, dated September 12, 1997, Canadair Challenger Service Bulletin 601-0501, dated September 12, 1997, or Canadair Challenger Service Bulletin 604-53-007, dated September 30, 1997; and Bombardier Service Bulletin 601-0503, dated November 30, 1999, Bombardier Service Bulletin 600-0680, dated November 30, 1999, or Bombardier Service Bulletin 604-53-006, dated November 30, 1999; as applicable.

(1) The incorporation by reference of Bombardier Service Bulletin 601-0503, dated November 30, 1999; Bombardier Service Bulletin 600-0680, dated November 30, 1999; and Bombardier Service Bulletin 604-53-006, dated November 30, 1999; is approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51.

(2) The incorporation by reference of Canadair Challenger Service Bulletin 600-0679, dated September 12, 1997; Canadair Challenger Service Bulletin 601-0501, dated September 12, 1997; and Canadair Challenger Service Bulletin 604-53-007, dated September 30, 1997; was approved previously by the Director of the Federal Register as of December 3, 1997 (62 FR 61436, November 18, 1997).

(3) Copies may be obtained from Bombardier, Inc., Canadair, Aerospace Group, P.O. Box 6087, Station Centre-ville, Montreal, Quebec H3C 3G9, Canada. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, New York Aircraft Certification Office, 1600 Stewart Avenue, Westbury, New York; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

Note 2: The subject of this AD is addressed in Canadian airworthiness directive CF-1997-16R2, dated May 31, 2001.

Effective Date

(g) This amendment becomes effective on February 13, 2004.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by revising AD 97-24-02, amendment 39-10209 (62 FR 61436, November 18, 1997), which is applicable to certain Bombardier Model CL-600-1A11, -2A12, and -2B16 series airplanes, was published in the Federal Register on October 21, 2003 (68 FR 60047). The action proposed to continue to require repetitive inspections to find cracks of a certain bulkhead web of the fuselage at certain locations, and repair if necessary. The action also provides an optional terminating modification for certain airplanes.

Comments

Interested persons have been afforded an opportunity to participate in the making of this amendment. No comments were submitted in response to the proposal or the FAA's determination of the cost to the public.

Conclusion

The FAA has determined that air safety and the public interest require the adoption of the rule as proposed.

Cost Impact

There are about 237 airplanes of U.S. registry that will be affected by this AD.

The inspections that are required by AD 97-24-02 take about 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 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 adopted herein will 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 final rule does not have federalism implications under Executive Order 13132.

For the reasons discussed above, I certify that this action (1) is not a "significant regulatory action" under Executive Order 12866; (2) is not a "significant rule" under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) will not have a significanteconomic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. A final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it may be obtained from the Rules Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.

Adoption of the Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends 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 removing amendment 39-10209 (62 FR 61436, November 18, 1997), and by adding a new airworthinessdirective (AD), amendment 39-13417, to read as follows: