AD 2005-23-01 Airworthiness Directives; Bombardier Model CL-600-2B19 (Regional Jet Series 100 & 440) Airplanes

This AD applies to Bombardier Model CL-600-2B19 (Regional Jet Series 100 & 440) airplanes, certificated in any category, having serial numbers 7003 through 8025 inclusive, 8030 and 8034. Note 1: This AD requires revisions to certain operator maintenance documents to include new inspections. Compliance with these inspections is required by 14 CFR 91.403(c). For airplanes that have been previously modified, altered, or repaired in the areas addressed by these inspections, the operator may not be able to accomplish the inspections described in the revisions. In this situation, to comply with 14 CFR 91.403(c), the operator must request approval for an alternative method of compliance according to paragraph (h) of this AD. The request should include a description of changes to the required inspections that will ensure the continued damage tolerance of the affected structure. The FAA has provided guidance for this determination in Advisory Circular (AC) 25-1529.

You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done. Revision to the Airworthiness Limitations (AWL) Section (f) Within 30 days after the effective date of this AD: Revise the Airworthiness Limitations section of the Instructions for Continued Airworthiness of the Canadair Regional Jet Maintenance Requirements Manual (MRM), Part 2, Appendix B, “Structural Airworthiness Limitations” by incorporating the information specified in AWL Number 53-61-153 of the Canadair Regional Jet Temporary Revision (TR) 2B-2109, dated October 13, 2005, into the AWL section. Perform the applicable detailed and special detailed inspections for cracking of the aft pressure bulkhead, as specified in the TR, at the applicable compliance time specified in Table 1 of this AD. Repeat the detailed inspection thereafter at intervals not to exceed 1,085 flight cycles, and repeat the special detailed inspection thereafter at intervals not to exceed 4,360 flight cycles, in accordance with the procedures specified in Structural Airworthiness Limitations, AWL Number 53-61-153, as introduced by the MRM. Table 1.—Compliance Times for Initial Inspections As of the effective date of this AD: If the total flight cycles accumulated on the airplane are— Inspect before the airplane accumulates— 8,000 or fewer 12,000 total flight cycles. More than 8,000 but fewer than 12,000 15,000 total flight cycles or within 4,000 flight cycles after the effective date of this AD, whichever is first. 12,000 or more but fewer than 15,000 17,000 total flight cycles or within 3,000 flight cycles after the effective date of this AD, whichever is first. 15,000 or more but fewer than 17,000 18,500 total flight cycles or within 2,000 flight cycles after the effective date of this AD, whichever is first. 17,000 or more but fewer than 18,500 19,500 total flight cycles or within 1,500 flight cycles after the effective date of this AD, whichever is first. 18,500 or more but fewer than 19,500 20,000 total flight cycles or within 1,000 flight cycles after the effective date of this AD, whichever is first. 19,500 or more 500 flight cycles after the effective date of this AD. (g) When the information in AWL Number 53-61-153 of the Canadair Regional Jet TR 2B-2109, dated October 13, 2005, is included in the general revisions of the MRM, the general revisions may be inserted into the AWL section of the Instructions for Continued Airworthiness, and this information may be removed from the MRM. Alternative Methods of Compliance (AMOCs) (h)(1) The Manager, New York Aircraft Certification Office, FAA, has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19. (2) Before using any AMOC approved in accordance with § 39.19 on any airplane to which the AMOC applies, notify the appropriate principal inspector in the FAA Flight Standards Certificate Holding District Office. Related Information (i) Canadian airworthiness directive CF-2005-13R1, dated October 6, 2005, also addresses the subject of this AD. Material Incorporated by Reference (j) You must use Canadair Regional Jet Temporary Revision 2B-2109, dated October 13, 2005, to the Canadair Regional Jet Maintenance Requirements Manual, Part 2, Appendix B, “Airworthiness Limitations,” to perform the actions that are required by this AD, unless the AD specifies otherwise. The Director of the Federal Register approved the incorporation by reference of this document in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Contact Bombardier, Inc., Canadair, Aerospace Group, P.O. Box 6087, Station Centre-ville, Montreal, Quebec H3C 3G9, Canada, for a copy of this service information. You may review copies at the Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street SW., room PL-401, Nassif Building, Washington, DC; on the Internet at http://dms.dot.gov ; or at the National Archives and Records Administration (NARA). For information on the availability of this material at the NARA, call (202) 741-6030, or go to http://www.archives.gov/federal_ register/code_of_federal_ regulations/ibr_locations.html . Issued in Renton, Washington, on October 31, 2005. Ali Bahrami, Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 05-22309 Filed 11-10-05; 8:45 am] BILLING CODE 4910-13-P

This AD results from a fatigue test which revealed cracking of the aft pressure bulkhead; subsequent in-service reports show that fatigue cracking has been found on certain other airplanes. We are issuing this AD to detect and correct cracking in the aft pressure bulkhead, which could result in reduced structural integrity and rapid decompression of the airplane.