AD 2005-23-01

The FAA is adopting a new airworthiness directive (AD) for certain Bombardier Model CL-600-2B19 (Regional Jet Series 100 & 440) airplanes. This AD requires revising the Airworthiness Limitations section of the Instructions for Continued Airworthiness of the Canadair Regional Jet Maintenance Requirements Manual by incorporating new procedures for repetitive detailed and special detailed inspections for cracking of the aft pressure bulkhead. 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 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.

Final rule; request for comments.

2005-23-01 Bombardier, Inc. (Formerly Canadair): Amendment 39-14359. Docket No. FAA-2005-22867; Directorate Identifier 2005-NM-209-AD.

Effective Date

(a) This AD becomes effective November 29, 2005.

Affected ADs

(b) None.

Applicability

(c) 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.

Unsafe Condition

(d) 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.

Compliance

(e) 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 onthe 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 Sec. 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.

Discussion

Transport Canada Civil Aviation (TCCA), which is the airworthiness authority for Canada, notified us that an unsafe condition may exist on certain Bombardier Model CL-600-2B19 (Regional Jet Series 100 & 440) airplanes. TCCA advises that during a complete aircraft fatigue test, cracking of the aft pressure bulkhead was found. Subsequent in-service reports show that fatigue cracking has been found on airplanes with as few as 17,821 total flight cycles. This condition, if not corrected, could result in reduced structural integrity and rapid decompression of the airplane.

Relevant Service Information

Bombardier has issued Canadair Regional Jet Temporary Revision (TR) 2B-2109, dated October 13, 2005, to the Canadair Regional Jet Maintenance Requirements Manual (MRM), Part 2, Appendix B, "Airworthiness Limitations." This TR incorporates repetitive special detailed and detailed inspections for cracking of the aft pressure bulkhead, in accordance with the procedures specified in the applicable task identified in the TR, into the MRM. TCCA mandated airworthiness limitations (AWL) Number 53-61-153 of the TR and issued Canadian airworthiness directive CF-2005-13R1, dated October 6, 2005, to ensure the continued airworthiness of these airplanes in Canada.

FAA's Determination and Requirements of This AD

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. We have examined TCCA's findings, evaluated all pertinent information, and determined that we need to issue an AD for products of this type design that are certificated for operation in the United States.

Therefore, we are issuing this AD to detect andcorrect cracking in the aft pressure bulkhead, which could result in reduced structural integrity and rapid decompression of the airplane. This AD requires revising the AWL section of the Instructions for Continued Airworthiness of the Canadair Regional Jet MRM by incorporating new repetitive detailed and special detailed inspections for cracking of the aft pressure bulkhead. This AD requires incorporating the actions specified in AWL Number 53-61-153 of the TR described previously into the Canadair Regional Jet MRM.

Difference Between the AD and Canadian Airworthiness Directive

The initial compliance times specified in the Canadian airworthiness directive are different than those that are required by this AD. The Canadian airworthiness directive contains a phase-in period based on a previous issue of that airworthiness directive; this AD does not include those compliance times. This difference has been coordinated with TCCA.

FAA's Determination of the Effective DateAn unsafe condition exists that requires the immediate adoption of this AD; therefore, providing notice and opportunity for public comment before the AD is issued is impracticable, and good cause exists to make this AD effective in less than 30 days.

Comments Invited

This AD is a final rule that involves requirements that affect flight safety and was not preceded by notice and an opportunity for public comment; however, we invite you to submit any relevant written data, views, or arguments regarding this AD. Send your comments to an address listed in the ADDRESSES section. Include "Docket No. FAA-2005- 22867; Directorate Identifier 2005-NM-209-AD" at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the AD that might suggest a need to modify it.

We will post all comments we receive, without change, to http://dms.dot.gov , including any personal information you provide. We will also post a report summarizing each substantive verbal contact with FAA personnel concerning this AD. Using the search function of that Web site, anyone can find and read the comments in any of our dockets, including the name of the individual who sent the comment (or signed the comment on behalf of an association, business, labor union, etc.). You may review the DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78), or you may visit http://dms.dot.gov.

Examining the Docket

You may examine the AD docket on the Internet at http://dms.dot.gov , or in person at the Docket Management Facility office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Management Facility office (telephone (800) 647- 5227) is located on the plaza level of the Nassif Building at the DOT street address stated in the ADDRESSES section. Comments will be available in the AD docket shortly after the Docket Management System receives them.

Authority for This Rulemaking

Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, Section 106, describes the authority of the FAA Administrator. Subtitle VII, Aviation Programs, describes in more detail the scope of the Agency's authority.

We are issuing this rulemaking under the authority described in Subtitle VII, Part A, Subpart III, Section 44701, "General requirements." Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.

Regulatory Findings

We have determined that this AD will not have federalism implications under Executive Order 13132. This AD 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.

For the reasons discussed above, I certify that the 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. 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.

We prepared a regulatory evaluation of the estimated costs to comply with this AD and placed it in the AD docket. See the ADDRESSES section for a location to examine the regulatory evaluation.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.Adoption of the Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA amends 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.

Sec. 39.13 [Amended]

2. The Federal Aviation Administration (FAA) amends Sec. 39.13 by adding the following new airworthiness directive (AD):