Document ID: chunk:federal_register_of_legislation:F2006L02225:body:0:p2
Version: federal_register_of_legislation:F2006L02225
Segment Type: other
Provision Reference: 
Character Range: 3084–4527

used in accordance with the applicable CMM:
             Part           Number
             Upper Bearing  P/N CRS85-167-11
             Damper Ring    P/N CRS85-167-31, CRS85-167-33
             Seal Carrier   P/N CRS85-167-21

             Note 2:  Transport Canada AD CF-2006-14 dated14 June 2006 refers.
Compliance:     1. Within 3000 flight hours after the effective date of this directive, unless already accomplished.

                2. Within 30 days after the effective date of this directive, unless already accomplished.

                3. As of the effective date of this AD.
             This Airworthiness Directive becomes effective on 3 August 2006.

Background:  Over the past 10 years there have been six cases reported in which the MLG shock strut piston has over-extended, allowing the torque links to go over-centre and rest on the piston.  This resulted in a loss of shock absorption on touchdown and, in one case, also resulted in failure of the shock strut cylinder housing.  Although it has not occurred in any of the reported cases, failure of the shock strut cylinder housing could also possibly result in a subsequent loss of directional control.

             Investigation has determined that over-extension of the shock strut resulted from damage to the upper bearing and seal carrier, caused by a loss of internal damping.

James Coyne
Delegate of the Civil Aviation Safety Authority

21 June 2006