AD 2000-01-12

This amendment supersedes an existing airworthiness directive (AD), applicable to certain Bombardier Model CL-600-2B19 (Regional Jet Series 100 and 200) series airplanes, that currently requires repetitive inspections to detect cracks of a certain bulkhead web of the fuselage at certain locations, and repair, if necessary. This amendment revises the repetitive inspection intervals for certain airplanes, and requires modification or repair, as applicable. This amendment is prompted by the development of a modification that will adequately address the identified unsafe condition. The actions specified by this AD are intended to detect and correct fatigue cracking, which could result in uncontrolled depressurization of the airplane and/or reduced structural integrity of the fuselage.

Final rule

2000-01-12 BOMBARDIER, INC. (Formerly Canadair): Amendment 39-11510. Docket 98-NM-192-AD. Supersedes AD 97-14-11, Amendment 39-10082.
Applicability: Model CL-600-2B19 (Regional Jet Series 100) series airplanes, serial numbers 7003 through 7185 inclusive; certificated in any category; except those airplanes on which Canadair Regional Jet Service Bulletin 601R-53-046, Revision `B,' dated December 22, 1997, or Canadair Regional Jet Service Bulletin 601R-53-047, Revision `D,' including Appendix 1 and Appendix 2, dated December 22, 1997, has been accomplished.

NOTE 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (d)(1) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Compliance: Required as indicated, unless accomplished previously.

To detect and correct fatigue cracking in the underfloor pressure bulkhead of the fuselage, which could result in uncontrolled depressurization of the airplane and/or reduced structural integrity of the fuselage, accomplish the following:

Detailed Visual Inspections
(a) Perform a detailed visual inspection to detect cracks at FS409+128 of the bulkhead web drawing number 601R32208-123 of the fuselage, in accordance with Canadair Regional Jet Alert Service Bulletin A601R-53-045, Revision `D,' including Appendix 1, dated December 22, 1997, at the time specified in paragraph (a)(1) or (a)(2) of this AD, as applicable, until accomplishment of paragraph (b) or (c) of this AD, as applicable.

(1) For airplanes that have accomplished a detailed visual inspection in accordance with AD 97-14-11 prior to the effective date of this AD: Perform a subsequent detailed visual inspection prior to the accumulation of 1,000 total flight hours, or within 100 flight hours after the immediately preceding inspection accomplished in accordance with AD 97-14-11, whichever occurs later. Thereafter, repeat the inspection at intervals not to exceed 100 flight hours.

(2) For airplanes that have not accomplished a detailed visual inspection in accordance with AD 97-14-11 prior to the effective date of this AD: Perform a detailed visual inspection within 20 flight hours after the effective date of this AD. Perform a subsequent detailed visual inspection prior to the accumulation of 1,000 total flight hours, or within 100 flight hours after accomplishment of the immediately preceding inspection, whichever occurs later. Thereafter, repeat the inspection at intervals not to exceed 100 flight hours.

NOTE 2: For the purposes of this AD, a detailed visual 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."

NOTE 3: Accomplishment of the inspection required by paragraph (a) of this AD, prior to the effective date
of this AD in accordance with Canadair Regional Jet Alert Service Bulletin A601R-53-045, dated June 25, 1997; Revision `A,' including Appendix 1, dated June 26, 1997; Revision `B,' including Appendix 1, dated June 27, 1997; or Revision `C,' including Appendix 1, dated July 2,1997; is considered acceptable for compliance with the applicable action specified by this AD.

Modification
(b) For any airplane on which no cracking has been detected during any inspection required by paragraph (a) of this AD: Within 9 months after the effective date of this AD, modify FS409+128 of the bulkhead web drawing number 601R32208-123 of the fuselage in accordance with Canadair Regional Jet Service Bulletin 601R-53-047, Revision `D,' including Appendix 1 and Appendix 2, dated December 22, 1997. Accomplishment of this modification terminates the requirements of this AD.

NOTE 4: Any modification accomplished prior to the effective date of this AD in accordance with Canadair Regional Jet Service Bulletin 601R-53-047, including Appendix 1 and Appendix 2, dated July 18, 1997; Revision `A,' including Appendix 1 and Appendix 2, dated July 31, 1997; Revision `B,' including Appendix 1 and Appendix 2, dated August 22, 1997; or Revision `C,' including Appendix 1 and Appendix 2, dated October 7, 1997; is considered acceptable for compliance with the applicable actions required by this AD.

Repair
(c) For any airplane on which any cracking is detected during any inspection required by paragraph (a) of this AD: Prior to further flight, determine the extent of the cracking as specified in Part A of paragraph 2.B. of the Accomplishment Instructions of Canadair Regional Jet Alert Service Bulletin A601R-53-045, Revision `D,' including Appendix 1, dated December 22, 1997, and accomplish the requirements of paragraph (c)(1) or (c)(2), as applicable.

(1) If the cracking is within the limits specified by Part A of paragraph 2.B. of the Accomplishment Instructions of the alert service bulletin, accomplish the requirements of paragraphs (c)(1)(i) and (c)(1)(ii) of this AD at the time specified in those paragraphs.

(i) Repeat the detailed visual inspection required by paragraph (a) of this AD thereafter at intervals not to exceed 100 flight hours;and

(ii) Within 6 months after the effective date of this AD, or within 3 months after the initial date the crack was detected, whichever occurs later: Repair the affected area in accordance with Canadair Regional Jet Service Bulletin 601R-53-046, Revision `B,' dated December 22, 1997. Accomplishment of this repair terminates the requirements of this AD.

NOTE 5: Any repair accomplished prior to the effective date of this AD in accordance with Canadair Regional Jet Service Bulletin 601R-53-046, dated June 27, 1997, or Revision `A,' dated July 2, 1997, is considered acceptable for compliance with the applicable actions specified by this AD.

(2) If the cracking is outside the limits specified by Part A of the Accomplishment Instructions of the alert service bulletin, prior to further flight, perform a high frequency eddy current (HFEC) inspection to detect cracks of the forward side of the web of fuselage FS409+128 bulkhead web drawing number 601R32208-123, along theupper edge of the horizontal angle part number 601R32208-73, in accordance with Part B of paragraph 2.B. of the Accomplishment Instructions of the alert service bulletin.

(i) If, during any HFEC inspection required by paragraph (c)(2) of this AD, any cracking is detected that is within the limits specified by Part B of paragraph 2.B. of the Accomplishment Instructions of the alert service bulletin, accomplish the requirements of paragraphs (c)(2)(i)(A) and (c)(2)(i)(B) of this AD at the times specified in those paragraphs.

(A) Repeat the HFEC inspection required by paragraph (c)(2) of this AD thereafter at intervals not to exceed 50 flight hours, and repeat the detailed visual inspection required by paragraph (a) of this AD thereafter at interval not to exceed 100 flight hours; and

(B) Within 6 months after the effective date of this AD, or within 3 months after the initial date the crack was detected, whichever occurs later: Repair the affected area in accordance with Canadair Regional Jet Service Bulletin 601R-53-046, Revision `B,' dated December 22, 1997. Accomplishment of this repair terminates the requirements of this AD.

(ii) If, during any HFEC inspection required by paragraph (c)(2) of this AD, any cracking is detected that is outside the limits specified by Part B of paragraph 2.B. of the Accomplishment Instructions of the alert service bulletin, prior to further flight, determine the extent of the cracking as specified in paragraph 1.D. ("Compliance") of Canadair Regional Jet Service Bulletin 601R-53-046, Revision `B,' dated December 22, 1997, and accomplish the requirements of paragraph (c)(2)(ii)(A) or (c)(2)(ii)(B) of this AD, as applicable.

(A) If the cracking is within the limits specified by paragraph 1.D. ("Compliance") of the service bulletin, prior to further flight, repair in accordance with the service bulletin. Accomplishment of this repair terminates the requirements of this AD.

(B) If the cracking is outside the limits specified by paragraph 1.D. ("Compliance") of the service bulletin, prior to further flight, repair in accordance with a method approved by the Manager, New York Aircraft Certification Office (ACO).

Alternative Methods of Compliance
(d) (1) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, New York ACO. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, New York ACO.

(2) Alternative methods of compliance, approved previously in accordance with AD 97-14-11, amendment 39-10082, are approved as alternative methods of compliance for this AD.

NOTE 6: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the New York ACO. Special Flight Permits

(e) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished.

Incorporation by Reference
(f) Except as provided by paragraph (c)(2)(ii)(B) of this AD, the actions shall be done in accordance with Canadair Regional Jet Alert Service Bulletin A601R-53-045, Revision `D,' including Appendix 1, dated December 22, 1997; Canadair Regional Jet Service Bulletin 601R-53-047, Revision `D,' including Appendix 1 and Appendix 2, dated December 22, 1997; and Canadair Regional Jet Service Bulletin 601R-53-046, Revision `B,' dated December 22, 1997; as applicable. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. 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, Engine and Propeller Directorate, New York Aircraft Certification Office, 10 Fifth Street, Third Floor, Valley Stream, New York; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

NOTE 7: The subject of this AD is addressed in Canadian airworthiness directive CF-97-11R2, dated December 22, 1997.

(g) This amendment becomes effective on February 17, 2000.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by superseding AD 97-14-11, amendment 39-10082 (62 FR 38206, July 17, 1997), which is applicable to certain Bombardier Model CL-600-2B19 (Regional Jet Series 100 and 200) series airplanes, was published in the Federal Register on November 9, 1999 (64 FR 61039). The action proposed to continue to require repetitive inspections to detect cracks of a certain bulkhead web of the fuselage at certain locations, and repair, if necessary. The action also proposed to revise the repetitive inspection intervals for certain airplanes, and require modification or repair, as applicable.

Comments
Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the single comment received.

The commenter supports the proposed rule.

Change to Service Bulletin Citation
The FAA has revised paragraphs (a) and (b) and NOTE 4 of the final rule to correctly specify that Appendix 2 is included in Canadair Regional Jet Service Bulletin 601R-53-047. This appendix was incorrectly associated with Canadair Regional Jet Alert Service Bulletin A601R-53-045 in the proposed rule.

Conclusion
After careful review of the available data, including the comment noted above, the FAA has determined that air safety and the public interest require the adoption of the rule with the change described previously. The FAA has determined that this change will neither increase the economic burden on any operator nor increase the scope of the AD.

Cost Impact
There are approximately 77 airplanes of U.S. registry that will be affected by this AD.

The inspection that is currently required by AD 97-14-11 takes approximately 2 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the currently required inspection on U.S. operators is estimated to be $9,960, or $120 per airplane, per inspection cycle.

The repair that is required by this AD will take approximately 300 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Required parts will cost approximately $1,828. Based on these figures, the cost impact of the repair on U.S. operators is estimated to be $19,828 per airplane.

The modification that is required by this AD will take approximately 212 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Required parts will cost approximately $935. Based on these figures, the cost impact of the modification on U.S. operators is estimated to be $13,655 per airplane.

The cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the requirements of this AD, and that no operator would accomplish those actions in the future if this AD were not adopted. However, the FAA has been advised thatthe manufacturer has committed previously to its customers that it will bear the labor costs associated with the repair and modification associated with accomplishing the actions required by this AD. Additionally, the manufacturer has indicated that warranty remedies may be available to defer the cost of the replacement parts also associated with accomplishing the actions required by this AD.

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 significant economic 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 39-10082(62 FR 38206, July 17, 1997), and by adding a new airworthiness directive (AD), amendment 39-11510, to read as follows: