Document ID: chunk:federal_register_of_legislation:F2006L03843:body:0:p2
Version: federal_register_of_legislation:F2006L03843
Segment Type: other
Provision Reference: 
Character Range: 3434–5910

Note 3:  If the aircraft has had winglets for only part of its life, revise the hours and flights in the Retirement Schedule proportionally.  For example, consider a late-production 414A that had winglets fitted at 2000 hours and 2500 flights.  When the winglets were fitted, it had already used 2000/13700 (15%) of the spar's hours.  That leaves 85% of 6900 hours.  So, retire the spar at 2000 + (0.85 × 6900) = 7865 hours.  Do a similar calculation for the flights.

             Note 4:  If there is no record of time for a flight, assume this:
             Model                  Flight time
             425                    1.50 hours
             401/402 (Except 402C)  0.50 hours
             402C                   0.45 hours
             411/411A               0.50 hours
             Others                 0.80 hours

Compliance:  This Amendment becomes effective on 21 December 2006.
Background:  This Airworthiness Directive retires structure from service, before dangerous fatigue cracks are likely, if aircraft are not on Cessna's SID program.

             Amendment 8:

                  * Reduced lives for most 'C' models (testing did not confirm prediction);

        * Added the 414 and 414A;

        * Added winglets for the 414A and early 421C; and

        * Replaced 'Average Cruise Weight' by 'Average Ramp Weight'.

   Amendment 9 gave operators more time to plan for Amendment 8's changes.

   Amendment 10 exempted strapped and inspected spars from Requirement 1.

   Amendment 11 increased the life for the stronger spars in later 414A aircraft.

   Amendment 12:

        * Reworded Requirement 2 to clarify that it applies to aircraft with strapped spars; and

        * Added the Aeronautical Engineers Australia life extension program for the 402.

   Amendment 13:

        * Aligned the life of the wing attachment fittings with the main spar lower cap; and

        * Limited lives by flights as well as hours.

   Amendment 14:

        * Exempts aircraft on Cessna's SID program (another way of managing fatigue);

        * Changes Note 1 to a recommendation in Requirement 1;

        * Deletes Note 2 (the SID is what it foreshadowed);

        * No longer exempts Cessna 402s on Aeronautical Engineers Australia's life extension program from Requirement 2 (the program is no longer active); and

        * Improves the style.

David Villiers
Delegate of the Civil Aviation Safety Authority

9 November 2006