E6-13713. Airworthiness Directives; Bombardier Model CL-600-1A11 (CL-600), CL-600-2A12 (CL-601), and CL-600-2B16 (CL-601-3A and CL-601-3R) Airplanes

AGENCY:

Federal Aviation Administration (FAA), Department of Transportation (DOT).

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to adopt a new airworthiness directive (AD) for all Bombardier Model CL-600-1A11 (CL-600), CL-600-2A12 (CL-601), and CL-600-2B16 (CL-601-3A and CL-601-3R) airplanes. This proposed AD would require implementing a corrosion prevention and control program (CPCP) either by accomplishing specific tasks or by revising the maintenance inspection program to include a CPCP. This proposed AD results from the determination that, as airplanes age, they are more likely to exhibit indications of corrosion. We are proposing this AD to prevent structural failure of the airplane due to corrosion.

DATES:

We must receive comments on this proposed AD by September 20, 2006.

ADDRESSES:

Use one of the following addresses to submit comments on this proposed AD.

• DOT Docket Web site: Go to http://dms.dot.gov and follow the instructions for sending your comments electronically.
• Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your comments electronically.
• Mail: Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, room PL-401, Washington, DC 20590.
• Fax: [phone].
• Hand Delivery: Room PL-401 on the plaza level of the Nassif Building, 400 Seventh Street SW., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

Contact Bombardier, Inc., Canadair, Aerospace Group, P.O. Box 6087, Station Centreville, Montreal, Quebec H3C 3G9, Canada, for service information identified in this proposed AD.

FOR FURTHER INFORMATION CONTACT:

Richard Beckwith, Aerospace Engineer, Airframe and Propulsion Branch, ANE-171, FAA, New York Aircraft Certification Office, 1600 Stewart Avenue, suite 410, Westbury, New York 11590; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to submit any relevant written data, views, or arguments regarding this proposed AD. Send your comments to an address listed in the ADDRESSES section. Include the docket number “FAA-2006-25645; Directorate Identifier 2005-NM-201-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the proposed AD. We will consider all comments received by the closing date and may amend the proposed AD in light of those comments.

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 proposed 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 [phone]) 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.

Discussion

Transport Canada Civil Aviation (TCCA), which is the airworthiness authority for Canada, notified us that an unsafe condition may exist on all Bombardier Model CL-600-1A11 (CL-600), CL-600-2A12 (CL-601), and CL-600-2B16 (CL-601-3A and CL-601-3R) airplanes. TCCA advises that, as airplanes age, they are more likely to exhibit indications of corrosion. Operators must implement a corrosion prevention and control program (CPCP) that identifies specific areas to be inspected to minimize and control deterioration of the airplane from corrosion. This condition, if not corrected, could result in structural failure of the airplane.

Relevant Service Information

Bombardier has issued Challenger 600 Time Limits/Maintenance Checks (CPCP) Supplement, PSP 605 (CPCP), dated July 28, 2004 (for Model CL-600-1A11 (CL-600) airplanes); Challenger 601 Time Limits/Maintenance Checks (CPCP) Supplement, PSP 601-5 (CPCP), dated July 28, 2004 (for Model CL-600-2A12 (CL-601) airplanes); and Challenger 601 Time Limits/Maintenance Checks (CPCP) Supplement, PSP 601A-5 (CPCP), dated July 28, 2004 (for Model CL-600-2B16 (CL-601-3A and CL-601-3R) airplanes). In this proposed AD, we refer to these publications as “the Manual.”

Paragraph 6 “Corrosion Levels” of the Manual defines three levels of corrosion:

• Level 1 corrosion:

1. Occurs between repetitive inspections and can be reworked within certain limits; or

2. Exceeds allowable limits and is attributed to an event not typical of the usage of the other airplanes in the operator's fleet; or

3. Exceeds allowable limits as a result of accumulated blend-out of light corrosion found in previous inspections such that the structural item must be reinforced or replaced.

• Level 2 corrosion occurs between repetitive inspections and requires a single rework that exceeds allowable limits, necessitating a repair or partial or complete replacement of a structural significant element.
• Level 3 corrosion is found during initial or repetitive inspections and is determined to be a potentially urgent unsafe condition necessitating expeditious action.

Paragraph 9 “List of Tasks” of the Manual contains the CPCP task numbers, description of the inspections for corrosion, repetitive intervals, and necessary re-protection actions.

TCCA mandated the Manual and issued Canadian airworthiness directive CF-2005-06, dated March 10, 2005, to ensure the continued airworthiness of these airplanes in Canada.

FAA's Determination and Requirements of the Proposed AD

These airplane models are manufactured in Canada and are 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 airplanes of this type design that are certificated for operation in the United States.

Therefore, we are proposing this AD, which would require implementing a CPCP either by accomplishing specific tasks or by revising the maintenance inspection program to include a CPCP. The proposed AD would require you to use the Manual described previously to perform these actions. The proposed AD also would require you to report findings of Level 3 corrosion to the airplane manufacturer.

Differences Among the Proposed AD, the Manual, and the Canadian Airworthiness Directive

Although the Manual and Canadian airworthiness directive CF-2005-06 specify that all corrosion findings be reported to the airplane manufacturer, this proposed AD would only require reporting of Level 3 corrosion.

The Canadian airworthiness directive CF-2005-06 specifies to incorporate the CPCP within one year and then to accomplish CPCP tasks at the next corresponding maintenance review board (MRB) task or the next CPCP task interval. However, this proposed AD specifies accomplishing CPCP tasks at the next CPCP task interval specified in the applicable Manual or within 12 months, whichever occurs later. In developing an appropriate compliance time for this proposed, we considered the urgency associated with the subject unsafe condition, the availability of required parts, and the practical aspect of accomplishing the required actions within a period of time that corresponds to the normal scheduled maintenance for most affected operators.

Clarification of Compliance Times in the Manual

The compliance times in the Manual are not clearly identified. In this proposed AD, we clarify that the times in the “Interval” column of the Manual are in flight hours unless there is an “M” adjacent to the number. If there is an “M” adjacent to the number, the time is in months. If there are two different numbers for a task, the number with a “T” adjacent to it is the threshold and the number with an “R” adjacent to it is the repetitive interval.

Costs of Compliance

This proposed AD would affect about 204 airplanes of U.S. registry. There are between 72 and 74 specific inspections, depending on the applicable Manual. The inspections would take about 74 work hours per airplane, per inspection cycle, at an average labor rate of $80 per work hour. Based on these figures, the estimated cost of the proposed AD for U.S. operators is $1,207,680, or $5,920 per airplane, per inspection cycle.

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 proposed AD would not have federalism implications under Executive Order 13132. This proposed AD 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.

For the reasons discussed above, I certify that the 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. 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 proposed 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
• Safety

The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 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. The Federal Aviation Administration (FAA) amends § 39.13 by adding the following new airworthiness directive (AD):

Bombardier, Inc. (Formerly Canadair): Docket No. FAA-2006-25645; Directorate Identifier 2005-NM-201-AD.

Comments Due Date

(a) The FAA must receive comments on this AD action by September 20, 2006.

Affected ADs

(b) None.

Applicability

(c) This AD applies to all Bombardier Model CL-600-1A11 (CL-600), CL-600-2A12 (CL-601), and CL-600-2B16 (CL-601-3A and CL-601-3R) airplanes, certificated in any category.

Unsafe Condition

(d) This AD results from the determination that, as airplanes age, they are more likely to exhibit indications of corrosion. We are issuing this AD to prevent structural failure of the airplane due to corrosion.

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.

Manual References

(f) The term “the Manual,” as used in this AD, means the documents specified in paragraphs (f)(1), (f)(2), and (f)(3) of this AD, as applicable. Although the Manual specifies to submit certain information to the manufacturer, this AD requires reporting only Level 3 corrosion.

(1) For Model CL-600-1A11 (CL-600) airplanes: Challenger 600 Time Limits/Maintenance Checks (CPCP) Supplement, PSP 605 (CPCP), dated July 28, 2004;

(2) For Model CL-600-2A12 (CL-601) airplanes: Challenger 601 Time Limits/Maintenance Checks (CPCP) Supplement, PSP 601-5 (CPCP), dated July 28, 2004; and

(3) For Model CL-600-2B16 (CL-601-3A and CL-601-3R) airplanes: Challenger 601 Time Limits/Maintenance Checks (CPCP) Supplement, PSP 601A-5 (CPCP), dated July 28, 2004.

Initial Inspections

(g) At the later of the times specified in paragraphs (g)(1) and (g)(2) of this AD: Perform each of the CPCP tasks, including re-protection actions, as applicable, specified in Paragraph 9 “List of Tasks” of the applicable Manual in accordance with the procedures specified in the applicable Manual.

(1) Within 12 months after the effective date of this AD.

(2) At the next CPCP task interval specified in the “Interval” column in the applicable table in Paragraph 9 “List of Tasks” of the applicable Manual. The times in the “Interval” column are in flight hours unless there is an “M” adjacent to the number. If there is an “M” adjacent to the number, the time is in months. If there are two different numbers for a task, the number with a “T” adjacent to it is the threshold and the number with an “R” adjacent to it is the repetitive interval.

Repetitive Inspections

(h) After accomplishment of each initial CPCP task required by paragraph (g) of this AD, except as provided by paragraph (i) of this AD: Repeat each of the CPCP tasks, and re-protection actions, as applicable, specified in Paragraph 9 “List of Tasks” of the applicable Manual at intervals not to exceed the compliance time specified in the “Interval” column in the applicable table in Paragraph 9 “List of Tasks” of the applicable Manual. The times in the “Interval” column are in flight hours unless there is an “M” adjacent to the number. If there is an “M” adjacent to the number, the time is in months. If there are two different numbers for a task, the number with a “T” adjacent to it is the threshold and the number with an “R” adjacent to it is the repetitive interval.

(i) After accomplishment of each initial CPCP task required by paragraph (g) of this AD, the FAA may approve the incorporation into the operator's approved maintenance/inspection program of either the CPCP specified in the applicable Manual and this AD, or an equivalent program that is approved by the FAA. In all cases, the initial CPCP task for each airplane area must be completed at the compliance time specified in paragraph (g) of this AD. For the purposes of this paragraph, the FAA is defined as the cognizant Flight Standards District Office.

(1) Any operator complying with paragraph (i) of this AD may use an alternative recordkeeping method to that otherwise required by section 91.417 (“Maintenance records”) or section 121.380 (“Maintenance recording requirements”) of the Federal Aviation Regulations (14 CFR 91.417 or 14 CFR 121.380, respectively) for the actions required by this AD, provided that the recordkeeping method is approved by the FAA and is included in a revision to the FAA-approved maintenance/inspection program. For the purposes of this paragraph, the FAA is defined as the cognizant Flight Standards District Office.

(2) After the initial accomplishment of the tasks required by paragraph (g) of this AD, any extension of the repetitive intervals specified in the applicable Manual must be approved by the FAA. For the purposes of this paragraph, the FAA is defined as the Manager, New York Aircraft Certification Office (ACO), FAA.

Corrective Actions

(j) If any corrosion is found during accomplishment of any action required by paragraph (g) or (h) of this AD: Before further flight, rework, repair, or replace, as applicable, all subject parts, in accordance with Paragraph 7 “Application of the CPCP Check” of the applicable Manual.

Reporting Requirements and Repetitive Actions for Remainder of Affected Fleet

(k) If any Level 3 corrosion, as defined in the Introduction of the applicable Manual, is found during accomplishment of any action required by this AD: Do paragraphs (k)(1), (k)(2), and (k)(3) of this AD. Under the provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.), the Office of Management and Budget (OMB) has approved the information collection requirements contained in this AD, and assigned OMB Control Number 2120-0056.

(1) Within 3 days after the finding of Level 3 corrosion, report findings to Bombardier in accordance with paragraph 7.J. of the applicable Manual.

(2) Within 10 days after the finding of Level 3 corrosion, either submit a plan to the FAA to identify a schedule for accomplishing the applicable CPCP task on the remainder of the airplanes in the operator's fleet that are subject to this AD, or provide data substantiating that the Level 3 corrosion that was found is an isolated case. The FAA may impose a schedule other than proposed in the plan upon finding that a change to the schedule is needed to ensure that any other Level 3 corrosion is detected in a timely manner. For the purposes of this paragraph, the FAA is defined as the cognizant Principal Maintenance Inspector (PMI) for operators that are assigned a PMI (e.g., part 121, 125, and 135 operators), and the cognizant Flight Standards District Office for other operators (e.g., part 91 operators).

(3) Within the time schedule approved in accordance with paragraph (k)(2) of this AD, accomplish the applicable task on the remainder of the airplanes in the operator's fleet that are subject to this AD.

Limiting Future Corrosion Findings

(l) If corrosion findings that exceed Level 1 are found in any area during any repeat of any CPCP task after the initial accomplishment required by paragraph (g) of this AD: Within 60 days after such finding, implement a means approved by the FAA to reduce future findings of corrosion in that area to Level 1 or better. For the purposes of this paragraph, the FAA is defined as the cognizant PMI for operators that are assigned a PMI (e.g., part 121, 125, and 135 operators), and the cognizant Flight Standards District Office for other operators (e.g., part 91 operators).

Scheduling Corrosion Tasks for Transferred Airplanes

(m) Before any airplane subject to this AD is transferred and placed into service by an operator: Establish a schedule for accomplishing the CPCP tasks required by this AD in accordance with paragraph (m)(1) or (m)(2) of this AD, as applicable.

(1) For airplanes on which the CPCP tasks required by this AD have been accomplished previously at the schedule established by this AD: Perform the first CPCP task in each area in accordance with the previous operator's schedule, or in accordance with the new operator's schedule, whichever results in an earlier accomplishment of that CPCP task. After the initial accomplishment of each CPCP task in each area as required by this paragraph, repeat each CPCP task in accordance with the new operator's schedule.

(2) For airplanes on which the CPCP tasks required by this AD have not been accomplished previously, or have not been accomplished at the schedule established by this AD: The new operator must perform each initial CPCP task in each area before further flight or in accordance with a schedule approved by the FAA. For the purposes of this paragraph, the FAA is defined as the cognizant PMI for operators that are assigned a PMI (e.g., part 121, 125, and 135 operators), and the cognizant Flight Standards District Office for other operators (e.g., part 91 operators).

Alternative Methods of Compliance (AMOCs)

(n)(1) The Manager, New York ACO, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19.

(2) Before using any AMOC approved in accordance with 14 CFR 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

(o) Canadian airworthiness directive CF-2005-06, dated March 10, 2005, also addresses the subject of this AD.

Issued in Renton, Washington, on August 11, 2006.

Kalene C. Yanamura,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.