COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Bombardier (Canadair) CL-600 (Challenger) Series Aeroplanes
AIRWORTHINESS DIRECTIVE
For the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/CL-600/35 and issues the following AD under subregulation 39.1 (1) of CAR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.
AD/CL-600/35
Amdt 1
Main Landing Gear Main Fitting 3/2001
Applicability: Model CL-600-2B19 “Regional Jet” aircraft, serial numbers 7003 through 7999.
Requirement: 1. Perform an eddy current inspection of the main landing gear main fittings in accordance with Part B of the Accomplishment Instructions of Bombardier Alert Service Bulletin (ASB) A601R-32-079. Replace any cracked main landing gear main fitting before further flight.
2. Service both the left and right main landing gear shock struts in accordance with the applicable Part C or D of the Accomplishment Instructions of Bombardier ASB A601R-32-079, Revision C.
3. Inspect both the left and right main landing gear shock struts for nitrogen pressure, visible chrome dimension and oil leakage in accordance with Part E of the Accomplishment Instructions of Bombardier ASB A610R-32-079, Revision C.
If the shock strut nitrogen pressure and visible chrome dimensions are outside the limits and/or oil leakage is found, before further flight, service the affected main landing gear shock strut in accordance with the applicable Part C or D of the Accomplishment Instructions of ASB A601R-32-079 Revision C.
Note: Transport Canada AD CF-1999-32R1 refers.
Compliance: 1. Initially upon accumulating a total of 1,500 flight cycles since new, or within 150 flight cycles after 22 March 2001, whichever occurs later. Thereafter at intervals not to exceed 500 flight cycles.
The eddy current inspection interval of 500 flight cycles may be increased to 1,000 flight cycles provided that:
- following the shock strut servicing required by Requirement 2 of this Directive, the next four consecutive shock strut inspections accomplished in accordance with Requirement 3 of this Directive yield inspection parameters within the limits; and,
COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
b. no cracks are found on the affected main landing gear main fittings during the five consecutive eddy current inspections accomplished in accordance with Requirement 1 of this Directive and concurrent with the shock strut inspections of paragraph (a) above.
2. Upon accumulating a total of 1,500 flight cycles since new, or within 500 flight cycles after 22 March 2001, whichever occurs later.
3. Initially within the next 500 flight cycles after completing the servicing specified in Requirement 2 of this Directive, and thereafter at intervals not to exceed 500 flight cycles.
This amendment becomes effective on 22 March 2001.
Background: There have been three reported cases of premature failure of the main landing gear main fitting. The reports indicated that a circumferential crack was found on the fitting at the radius between the fitting cylinder area and the upper attachment lug for the shock strut.
Amendment 1 is issued is response to a revision of the related Transport Canada AD which adds servicing of the main landing gear shock struts, and repetitive inspection of the shock strut for nitrogen pressure and visible chrome dimensions. Further investigation revealed that, under certain conditions, a mis-serviced shock strut could lead to premature failure of the fitting. This amendment also allows the eddy current inspection interval to be increased under certain conditions.
The original issue of this Airworthiness Directive became effective on 24 February 2000.
David Alan Villiers
Delegate of the Civil Aviation Safety Authority 9 February 2001
The above AD is notified in the Commonwealth of Australia Gazette on 21 February 2001.