Document ID: chunk:federal_register_of_legislation:F2005L02831:body:0:p2
Version: federal_register_of_legislation:F2005L02831
Segment Type: other
Provision Reference: 
Character Range: 2779–5110

SB 21714R2 or later Transport Canada approved revisions.

                  (b) If no crack is found, the engine can be put back into service.

             Note 2:  (Applies to Requirement 2 and 3 inspections: Visual & Internal) Compliance using inspection methods contained in any of the previous versions of P&WC SB 21714 prior to the effective date of the directive satisfy the requirements of SB 21714, Revision 2, mandated by this directive.

                4. Propeller shafts listed in Table 4 of Transport Canada AD CF-2005-29 must be removed and destroyed/discarded.

             Note 3:  Transport Canada AD CF-2005-29 refers.
Compliance:     1. Within five days after the effective date of this directive.

                2. Within five days after the effective date of this directive, and repeated every week afterwards until the propeller shafts are removed from service.

                    (a)(i) Before further flight.

                    (a)(ii) Following rectification of the oil leak.

                    (a)(iii) Before further flight.

                3. Within 250 hours air time, or not more than 3 months after the effective date of this directive, whichever occurs first.

                  (a) Before further flight.

                4. No later than 31 December 2007.  No extensions or alternate means of compliance are permitted.
             This Airworthiness Directive becomes effective on 27 October 2005.
Background:  There have been two reported instances of propeller shafts being found with through going cracks at the no. 19 bearing area.  The root cause was positively identified as "Hydrogen Embrittlement" caused by the improper nickel-plating repair process performed at two different overhaul facilities.  These two exceptional events are related to the excessive period of time that the propeller shaft spent in the nickel-plating tank.

             Both events were discovered following a persistent external oil leak in the propeller shaft area, as the crack had migrated past the seal runner.

   Transport Canada has issued Service Difficulty Alert AL-2005-05 in March 2005 to provide information about this issue and explain the planned corrective actions to rectify this problem.

James Coyne
Delegate of the Civil Aviation Safety Authority

16 September 2005