Document ID: chunk:federal_register_of_legislation:F2014L00496:body:0:p2
Version: federal_register_of_legislation:F2014L00496
Segment Type: other
Provision Reference: 
Character Range: 3019–6005

exact location of each of these additional valves is unknown.
                Note 2:  Valves that have an S/N with suffix "T" have been manufactured by Tactair Fluid Controls Inc. and do not require any corrective action.
                Note 3:  Valves manufactured by Kaiser Fluid Technologies, part number (P/N) 750006000, with S/N from 0001 to 2126 inclusive, and ink stamp "SB750006000-1", have already been checked and reworked as necessary and do not require any additional corrective action.
                Note 4:  A valve manufactured by Kaiser Fluid Technologies, with P/N 750006000, and S/N from 0001 to 2126 inclusive, must not be installed unless the marking "SB750006000-1" is ink stamped on the valve. The Illustrated Parts Catalogue for the relevant model gives this instruction.
                Note 5:  CL-600-2B16 (CL-605) aircraft, with S/N of 5701 or higher, are not affected by this AD. They were delivered with valves, P/N 750006000, that either have an S/N with suffix "T" or have the ink stamp marking "SB750006000-1".
                Note 6:  Transport Canada AD CF-2009-21R1 dated 26 May 2009 refers. That AD superseded TC AD CF-2006-16R1, which was referred to in CASA AD/CL-600/86, and corrected an error in TC AD CF-2009-21 dated 6 May 2009.
Compliance:     The action set out in the requirement section must be taken by the earlier of the following:
                  (a)   within 250 flight hours after 30 July 2009;
                  (b)   the end of 30 January 2010.
                This AD becomes effective on 9 May 2014.
Background:     A specific batch of NLG and NLG door selector valves, P/N 601R75146-1 (Kaiser Fluid Technologies P/N 750006000), may have had their end caps incorrectly lock‑wired 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 AD, there have been 6 cases reported on the CRJ (CL600-2B19) aircraft, 1 of which resulted in the collapse of the NLG at the departure gate.
                AD/CL-600/111 became effective on 30 July 2009. It mandated a check of the NLG and NLG door selector valves installed on all aircraft in the applicability section above. Depending on the results, replacement, rework and additional identification of the valves may be required.
                This AD is issued to correct a typographical error in the table in the requirement section of AD/CL-600/111. The applicable service bulletin reference for the Model CL-600-2A12 (CL-601) has been corrected. There are no changes to the technical requirements or the compliance