05-20065. 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 certain 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 measuring to detect migration of the lower gimbal pin and inspecting for other discrepancies of the horizontal stabilizer trim actuator (HSTA). This proposed AD also would require replacing or modifying the HSTA, as applicable. This proposed AD results from reports of failure of the lower gimbal pin of the HSTA. We are proposing this AD to prevent migration of the lower gimbal pin of the HSTA, which could result in loss of the horizontal stabilizer and consequent loss of control of the airplane.

DATES:

We must receive comments on this proposed AD by November 7, 2005.

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 Centre-ville, Montreal, Quebec H3C 3G9, Canada, for service information identified in this proposed AD.

FOR FURTHER INFORMATION CONTACT:

Daniel Parrillo, Aerospace Engineer, Systems and Flight Test Branch, ANE-172, 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-2005-22627; Directorate Identifier 2005-NM-156-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 certain 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 there have been two failures of the lower gimbal pin of the horizontal stabilizer trim actuator (HSTA). In both cases, the broken pin was found during routine maintenance, and the broken pin had not migrated to the extent that operation of the HSTA was impaired. This condition, if not corrected, could result in loss of the horizontal stabilizer and consequent loss of control of the airplane.

Relevant Service Information

Bombardier has issued these service bulletins, both dated January 31, 2005:

• Bombardier Service Bulletin 600-0720 (for Model CL-600-1A11 (CL-600) airplanes).
• Bombardier Service Bulletin 601-0555 (for Bombardier Model CL-600-2A12 (CL-601), and CL-600-2B16 (CL-601-3A and CL-601-3R) airplanes).

These service bulletins describe procedures for a one-time “special check” of the HSTA (which the service bulletins also refer to as the “pitch trim actuator”) for migration of the lower gimbal pin, by measuring the clearance between the yoke and the lower side of the gimbal pin head, and for other discrepancies. Discrepancies are defined in a certain chapter of the airplane maintenance manual (which is referenced in the service bulletins), and include, but are not limited to, improper engagement of the lower gimbal pin retainers, loose or missing fasteners for the pin retainers, or other damage. If the gimbal pin has migrated or any discrepancy is found, the service bulletin specifies replacing the HSTA with a new or serviceable, modified HSTA, and reporting the findings to the manufacturer. If the gimbal pin has not migrated and no discrepancy is found, the service bulletin specifies modifying the HSTA by installing the gimbal pin kit (which involves installing additional pin retainer brackets and re-identifying the HSTA) or replacing the HSTA with a new or serviceable, modified HSTA.

Accomplishing the actions specified in the service information is intended to adequately address the unsafe condition. TCCA mandated the service information and issued Canadian airworthiness directive CF-2005-20, dated June 23, 2005, to ensure the continued airworthiness of these airplanes in Canada.

The Bombardier service bulletins refer to Goodrich Service Bulletin 21207-00X-27-05, dated January 31, 2005, as an additional source of service information for doing the modification of the HSTA.

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 accomplishing the actions specified in the service information described previously. The proposed AD would also require sending the inspection results to the manufacturer if the gimbal pin is found migrated. These inspection reports will help to determine the extent of migrated gimbal pins within the affected fleet. (While TCCA has received reports of broken lower gimbal pins, there have been no reports of migrated pins.) However, if migrated pins are found during the inspections that would be required by this proposed AD, this may indicate that further action is warranted.

Clarification of Inspection Terminology

The Canadian airworthiness directive and Bombardier service bulletins specify performing a “special check” of the HSTA for migration of the lower gimbal pin, by measuring the clearance between the yoke and the lower side of the gimbal pin head. The Bombardier service bulletins also specify to look for damage during this special check. For clarification, in this proposed AD, we refer to this check as a measurement (of the clearance between the yoke and the lower side of the gimbal pin head on the HSTA) to detect migration of the lower gimbal pin of the HSTA, and a detailed inspection for other discrepancies of the HSTA. We have included a note defining “detailed inspection.”

Costs of Compliance

This proposed AD would affect about 269 airplanes of U.S. registry. The proposed measurement/inspection and modification would take about 5 work hours per airplane, at an average labor rate of $65 per work hour. Required parts would cost about $462 per airplane. Based on these figures, the estimated cost of the proposed AD for U.S. operators is $211,703, or $787 per airplane.

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-2005-22627; Directorate Identifier 2005-NM-156-AD.

Comments Due Date

(a) The FAA must receive comments on this AD action by November 7, 2005.

Affected ADs

(b) None.

Applicability

(c) This AD applies to the Bombardier airplanes identified in Table 1 of this AD, certificated in any category.

Table 1.—Applicability

Bombardier airplane models	Serial Nos.
CL-600-1A11 (CL-600)	1004 through 1085 inclusive.
CL-600-2A12 (CL-601)	3001 through 3066 inclusive.
CL-600-2B16 (CL-601-3A and CL-601-3R)	5001 through 5194 inclusive.

Unsafe Condition

(d) This AD results from reports of failure of the lower gimbal pin of the horizontal stabilizer trim actuator (HSTA). We are issuing this AD to prevent migration of the lower gimbal pin of the HSTA, which could result in loss of the horizontal stabilizer and consequent loss of control 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.

Service Bulletin Reference

(f) The term “service bulletin,” as used in this AD, means the Accomplishment Instructions of the service bulletins identified in paragraphs (f)(1) and (f)(2) of this AD, as applicable.

(1) For Model CL-600-1A11 (CL-600) airplanes: Bombardier Service Bulletin 600-0720, dated January 31, 2005.

(2) For Bombardier Model CL-600-2A12 (CL-601), and CL-600-2B16 (CL-601-3A and CL-601-3R) airplanes: Bombardier Service Bulletin 601-0555, dated January 31, 2005.

Note 1:

The Bombardier service bulletins identified in paragraphs (f)(1) and (f)(2) of this AD refer to Goodrich Service Bulletin 21207-00X-27-05, dated January 31, 2005, as an additional source of service information for doing the modification of the HSTA.

Measurement and Modification or Replacement

(g) Within 600 flight hours or 16 months after the effective date of this AD, whichever is first: Measure the clearance between the yoke and the lower side of the gimbal pin head on the HSTA to detect migration of the lower gimbal pin of the HSTA, and do a detailed inspection to detect discrepancies of the HSTA, in accordance with the service bulletin.

(1) If the lower gimbal pin has not migrated and no discrepancy is found: Modify the HSTA by installing the gimbal pin kit, or replace the existing HSTA with a new or serviceable, modified HSTA, in accordance with the service bulletin.

(2) If the lower gimbal pin has migrated or any discrepancy is found: Before further flight, replace the HSTA with a new or serviceable, modified HSTA, in accordance with the service bulletin.

Note 2:

For the purposes of this AD, a detailed inspection is: “An intensive examination of a specific item, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at an intensity deemed appropriate. Inspection aids such as mirror, magnifying lenses, etc., may be necessary. Surface cleaning and elaborate procedures may be required.”

Reporting

(h) If any gimbal pin is found migrated: Submit a report of the findings (migrated pins only) of the measurement and inspections required by paragraph (g) of this AD to Bombardier, Attention Dept. Customer Support Program Office (CSPO), fax (514) 855'8798. Submit the report at the applicable time specified in paragraph (h)(1) or (h)(2) of this AD. The report must include the airplane serial number, the HSTA part number and serial number, the results of the inspection, and the action taken. Submitting the Service Bulletin Feedback Form of the applicable service bulletin is an acceptable means of complying with this requirement. Under the provisions of the Paperwork Reduction Act of 1980 (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 has assigned OMB Control Number 2120-0056.

(1) If the measurement was done after the effective date of this AD: Submit the report within 30 days after the inspection.

(2) If the measurement was done prior to the effective date of this AD: Submit the report within 30 days after the effective date of this AD.

Parts Installation

(i) As of the effective date of this AD, no person may install an HSTA on any airplane unless the actions required by paragraph (g) of this AD are accomplished on it.

Alternative Methods of Compliance (AMOCs)

(j)(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 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

(k) Canadian airworthiness directive CF-2005-20, dated June 23, 2005, also addresses the subject of this AD.

Issued in Renton, Washington, on September 28, 2005.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.