AD 2010-20-19

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

Do the following actions.

(1) Within 1,000 flight hours after the effective date of this AD or before the first scheduled ADG functional test after the effective date of this AD, whichever occurs first, inspect to determine the part number of the installed ADG. A review of the airplane maintenance records is acceptable in lieu of this inspection if the part number can be conclusively determined from that review.

(i) If a Hamilton Sundstrand ADG having part number 1711405 is installed, the strut thickness is within specification and no further action is required by this AD.

(ii) If a Hamilton Sundstrand ADG having a part number in the 761339 series is installed, within 1,000 flight hours after the effective date of this AD or before the first scheduled ADG functional test after the effective date of this AD, whichever occurs first, inspect to determine the serial number of the ADG. A review of the airplane maintenance records is acceptable in lieu of this inspection if the serial number can be conclusively determined from that review.

(A) If the serial number of the ADG is 2000 or higher, the strut wall thickness is within specification and no further action is required by this AD.

(B) If the serial number of the ADG is in the range 0101 through 1999 and symbol “24-3” is marked in the serial number block of the identification plate, the strut wall thickness is within specification, no further action is required by this AD.

(C) If the serial number of the ADG is in the range 0101 through 1999 and the symbol “24-3” is not marked in the serial block of the identification plate, within 1,000 flight hours after the effective date of this AD or before the first scheduled ADG functional test after the effective date of this AD, whichever occurs first, inspect to determine the serial number of the strut and generator housing assembly. A review of the airplane maintenance records is acceptable in lieu of this inspection if the serial number can be conclusively determined from that review.

(1) If the serial number of the strut and generator housing assembly is in the range 0001 through 2503, do a fluorescent penetrant inspection in accordance with paragraph (g)(2) of this AD at the times specified in paragraph (g)(2) of this AD.

(2) If the serial number of the strut and generator housing assembly is 2504 or higher, the strut wall thickness is within specification and no further action is required by this AD.

(3) If the serial number of the strut and generator housing assembly is not inspected or it is not possible to determine the serial number, do a fluorescent penetrant inspection in accordance with paragraph (g)(2) of this AD at the times specified in paragraph (g)(2) of this AD.

(2) For ADGs having a strut and generator assembly identified in paragraph (g)(1)(ii)(C)(1) or (g)(1)(ii)(C)(3) of this AD: Within 1,000 flight hours after the effective date of this AD or before the first scheduled ADG functional test after the effective date of this AD, whichever occurs first, do a fluorescent penetrant inspection for cracking of the ADG strut, and if any crack is found, before further flight, replace the ADG with a serviceable ADG, in accordance with the Accomplishment Instructions of Bombardier Alert Service Bulletin A601R-24-120, Revision C, dated April 20, 2009 (for Model CL-600-2B19 airplanes); or Bombardier Alert Service Bulletin A670BA-24-020, Revision C, dated April 20, 2009 (for Model CL-600-2C10, CL-600-2D15, and CL-600-2D24 airplanes).

(3) Fluorescent penetrant inspections accomplished before the effective date of this AD in accordance with any applicable service bulletin specified in Table 1 of this AD are considered acceptable for compliance with the corresponding fluorescent penetrant inspection specified in this AD.

Note 1: Additional guidance on the ADGs specified in paragraphs (g)(1)(ii)(C)(1)and (g)(1)(ii)(C)(3) of this AD and the repetitive fluorescent penetrant inspections specified as part of the periodic ADG functional check procedure may be found in the applicable tasks identified in Table 2 of this AD. These tasks can be found in Part 2—Airworthiness Limitations, Appendix A—Certification Maintenance Requirements (CMR), of the Bombardier CL-600-2C10, CL-600-2D15, and CL-600-2D24 Maintenance Requirements Manual; and the Canadair CRJ Series Regional Jet Aircraft Maintenance Manual (AMM); as applicable.

Note 2: Additional guidance on the ADGs specified in paragraph (g)(1)(ii)(C)(1), and the fluorescent penetrant inspection necessary following each future unscheduled in-flight ADG deployment can be found in the tasks specified in Table 3 of this AD.

Note 3: In Hamilton Sundstrand Service Bulletin ERPS10AG-24-3, the fluorescent penetrant inspection is referred to as a “Penetrant Check.”.

Note 4: This AD differs from the MCAI and/or service information as follows: No differences.