AD 2010-10-26

(a) This airworthiness directive (AD) becomes effective June 25, 2010.

(b) This AD supersedes AD 2007-14-02, Amendment 39-15124.

(c) This AD applies to Bombardier, Inc. airplanes, certificated in any category, identified in paragraphs (c)(1), (c)(2), and (c)(3) of this AD.

(1) Model CL-600-1A11 (CL-600), serial numbers 1004 through 1085 inclusive.

(2) Model CL-600-2A12 (CL-601), serial numbers 3001 through 3066 inclusive.

(3) Model CL-600-2B16 (CL-601-3A, CL-601-3R, and CL-604), serial numbers 5001 through 5194 inclusive, and serial numbers 5301 through 5665 inclusive.

(d) Air Transport Association (ATA) of America Code 32: Landing Gear.

(e) The mandatory continuing airworthiness information (MCAI) states:

A specific batch of nose landing gear (NLG) and NLG door selector valves, part number (P/N) 601R75146-1 (Kaiser Fluid Technologies P/N 750006000), may have had their end caps incorrectly lock-wired and/or incorrectly torqued during assembly. This condition can lead to the end cap backing off, with consequent damage to a seal and internal leakage within the valve. Subsequently, if electrical power is transferred or removed from the aircraft before the NLG safety pin is installed, any pressure, including residual pressure, in the No. 3 hydraulic system can result in an uncommanded NLG retraction.

Although there have been no such cases reported on the Challenger models covered by this directive, there have been six cases reported on the CRJ (CL600-2B19) aircraft, one of which resulted in the collapse of the NLG at the departure gate.

This directive mandates a check of the NLG and NLG door selector valves installed on all aircraft in the Applicability section * * *. Depending on the results; replacement, rework and/or additional identification of the valves may be required.

This [MCAI] revision corrects a Service Bulletin number in the Corrective Actions table.

Notes:

1. The check is required whether or not an aircraft has previously been checked in accordance with AD CF-2006-16R1 (now superseded and cancelled by this AD). This is necessary since, following the issuance of AD CF-2006-16R1, it has been determined that the serial number (S/N) range of the affected valves requires expansion from the previous upper limit of S/N 0767 to S/N 2126 and the exact location of each of these additional valves is unknown.

2. Valves that have a S/N with suffix “T” have been manufactured by Tactair Fluid Controls Inc. and do not require any corrective action.

3. Valves manufactured by Kaiser Fluid Technologies, P/N 750006000, with S/N 0001 through 2126, and ink stamp “SB750006000-1”, have already been checked and reworked as necessary and do not require any additional corrective action.

4. The Illustrated Parts Catalog, for each of the models covered in the Applicability section * * *, gives instructions not to install a valve manufactured by Kaiser Fluid Technologies, P/N 750006000, with S/N 0001 through 2126, if the marking “SB750006000-1” is not ink stamped on the valve.

5. CL-600-2B16 (CL-605) aircraft, S/Ns 5701 and subsequent, are not affected by this directive. They were delivered with valves, P/N 750006000, that have either a S/N with suffix “T” or have the ink stamp marking “SB750006000-1”.

(f) You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.

(g) For airplanes having serial numbers (S/Ns) as identified in the service bulletins specified in Table 1 of this AD, as applicable: Within 500 flight hours or 12 months after August 16, 2007 (the effective date AD 2007-14-02), whichever occurs first, inspect to determine the manufacturer part numbers (P/Ns) and serial numbers of the selector valves of the nose landing gear (NLG) and nose gear door. A review of airplane maintenance records is acceptable in lieu of this inspection if the serial numbers of the selector valves can be conclusively determined from that review. For any subject selector valve having Tactair Fluid Controls P/N 750006000 and a S/N from 0001 through 0767 inclusive, before further flight, do related investigative (including a general visual inspection for proper installation of the lock wire of the end cap) and corrective actions; in accordance with the applicable service bulletin identified in Table 1 of this AD. After the effective date of this AD, use only the applicable service bulletin specified in Table 2 of this AD.

Note 1:

Operators should be aware that selector valves having Bombardier P/N 601R75146-1 may be supplied by different manufacturers and have different manufacturer part numbers. Only airplanes having selector valves manufactured by Tactair Fluid Controls, having P/N 750006000, are subject to the investigative and corrective actions specified in paragraph (g) of this AD.

Note 2:

For the purposes of this AD, a general visual inspection is: “A visual examination of an interior or exterior area, installation, or assembly to detect obvious damage, failure, or irregularity. This level of inspection is made from within touching distance unless otherwise specified. A mirror may be necessary to ensure visual access to all surfaces in the inspection area. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight, or droplight and may require removal or opening of access panels or doors. Stands, ladders, or platforms may be required to gain proximity to the area being checked.”

Note 3:

The service bulletins identified in Table 1 of this AD refer to Tactair Fluid Controls Service Bulletin SB750006000-1, Revision A, dated September 6, 2005, as an additional source of guidance for doing the related investigative and corrective actions required by this AD.

(h) Actions accomplished before August 16, 2007, in accordance with Bombardier Service Bulletin 604-32-021, Revision 01, dated February 20, 2006 (for Model CL-600-2B16 (CL-604) airplanes), are considered acceptable for compliance with the corresponding actions specified in paragraph (g) of this AD.

Actions

(i) Unless already done, do the following actions.

(1) Within 250 flight hours or within 6 months after the effective date of this AD, whichever occurs first: Do an inspection of the selector valve of the NLG and the door selector valve of the NLG to determine if P/N 601R75146-1 (Kaiser Fluid Technologies P/N 750006000) is installed, in accordance with the Accomplishment Instructions of the applicable service bulletin specified in Table 3 of this AD. Doing the inspection required by this paragraph terminates the inspection required by paragraph (g) of this AD.

(2) If, during any inspection required by paragraph (i)(1) of this AD, any selector valve having P/N 601R75146-1 (Kaiser Fluid Technologies P/N 750006000) and having a S/N from 0001 through 2126 inclusive without a suffix “T” is found, and the valve is not ink-stamped with the marking “SB750006000-1”: Before further flight, do a general visual inspection for proper installation of the lock wire of the end cap, and replace it with a serviceable selector valve as applicable, in accordance with the Accomplishment Instructions of the applicable service bulletin specified in Table 3 of this AD.

(3) Doing the actions before the effective date of this AD in accordance with the applicable service bulletin specified in Table 4 of this AD is acceptable for compliance with the corresponding actions specified in this AD.

Note 4:

This AD differs from the MCAI and/or service information as follows: No differences.

(j) The following provisions also apply to this AD:

(1) Alternative Methods of Compliance (AMOCs): The Manager, New York Aircraft Certification Office (ACO), ANE-170, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. Send information to ATTN: Program Manager, Continuing Operational Safety, FAA, New York ACO, 1600 Stewart Avenue, Suite 410, Westbury, New York 11590; telephone (516) 228-7300; fax (516) 794-5531. Before using any approved AMOC on any airplane to which the AMOC applies, notify your principal maintenance inspector (PMI) or principal avionics inspector (PAI), as appropriate, or lacking a principal inspector, your local Flight Standards District Office. The AMOC approval letter must specifically reference this AD.

(2) Airworthy Product: For any requirement in this AD to obtain corrective actions from a manufacturer or other source, use these actions if they are FAA-approved. Corrective actions are considered FAA-approved if they are approved by the State of Design Authority (or their delegated agent). You are required to assure the product is airworthy before it is returned to service.

(3) Reporting Requirements: For any reporting requirement in 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 and has assigned OMB Control Number 2120-0056.

(k) Refer to MCAI Canadian Airworthiness Directive CF-2009-21R1, dated May 20, 2009; Bombardier Service Bulletin 600-0721, Revision 03, dated February 23, 2009; Bombardier Service Bulletin 601-0558, Revision 03, dated February 23, 2009; and Bombardier Service Bulletin 604-32-021, Revision 04, dated February 23, 2009; for related information.

(l) You must use the service information contained in Table 5 of this AD to do the actions required by this AD, unless the AD specifies otherwise.

(1) The Director of the Federal Register approved the incorporation by reference of this service information under 5 U.S.C. 552(a) and 1 CFR part 51.

(2) For service information identified in this AD, contact Bombardier, Inc., 400 Côte-Vertu Road West, Dorval, Québec H4S 1Y9, Canada; telephone 514-855-5000; fax 514-855-7401; e-mail thd.crj@aero.bombardier.com; Internet http://www.bombardier.com.

(3) You may review copies of the service information at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington. For information on the availability of this material at the FAA, call 425-227-1221.

(4) You may also review copies of the service information that is incorporated by reference at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.