Document ID: chunk:federal_register_of_legislation:F2005L02062:body:0:p2
Version: federal_register_of_legislation:F2005L02062
Segment Type: other
Provision Reference: 
Character Range: 9100–15883

replacing the impulse coupling assembly.
                3. If a snap-ring impulse coupling assembly is replaced with a riveted impulse coupling assembly, strike out the "A" on the magneto data plate.
             Note 3:  FAA AD 2005-12-06 Amdt 39-14122 refers.
Compliance:  For Requirement 1 -
                  a. Magnetos that have not previously been inspected - Initially as specified in Table 2 and thereafter as specified in Table 3.
                 Table 2
             Type of Impulse Coupling Assembly                                                                                                                                                                                                                                                                                                                                                                    Impulse Coupling Time in Service (TIS) as of the Effective Date of this Directive      Inspect
    Riveted  100 or more hours time since new or overhaul (TSN) or TSN is unknown.                                                                                                                                                                                                                                                                                                                                Within 10 hours TIS after the effective date of the original issue of this Directive.

             Fewer than 100 hours TSN.                                                                                                                                                                                                                                                                                                                                                                            Before accumulating 100 hours TSN.
                 Snap-ring                                                                                                                                                                                                                                                                                                                                                                                        450 or more hours TSN.                                                                 Within 50 hours TIS after the effective date of the original issue of this Directive.
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         Before accumulating 500 hours TSN.

                                                                                                                                                                                                                                                                                                                                                                                                                  Fewer than 450 hours TSN.
             Note 4:  Previous inspections may have been accomplished in accordance with AD/ELECT/68 (FAA AD 96-12-07).
                  b. Magnetos that have previously been inspected - Repeat the inspections as specified in Table 3.

             Table 3
             Type of Impulse Coupling Assembly                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                Inspect
    Riveted  Within 100 hours time since the last inspection.
                 Snap-ring                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    Within 500 hours time since the last inspection.
             For Requirement 2 - Before further flight after the Requirement 1 inspection.
             For Requirement 3 - Before further flight after the snap-ring impulse coupling assembly is replaced.
             This Amendment becomes effective on 1 September 2005.
Background:  This Directive supersedes AD/ELECT/68 which will be cancelled.  AD/ELECT/68 required repetitive inspections of riveted and snap-ring impulse coupling assemblies and, if necessary, their replacement when they were worn beyond limits.
             This Directive requires a reduced inspection interval for magnetos with riveted impulse coupling assemblies installed on certain Lycoming engine models.  The Directive does not lower the inspection interval for magnetos with snap-ring impulse coupling assemblies.  The Directive also limits the applicability to certain Lycoming engine models.  These actions result from data provided by the manufacturer to the United States Federal Aviation Administration that showed a need to reduce the inspection intervals for riveted-impulse coupling assemblies used on certain Lycoming engine models.
             Note 5:  Teledyne Continental Ignitions Systems Service Bulletin SB643B dated 6 April 2005 provides the manufacturer recommended periods for inspection/overhaul for TCM magnetos installed on engine types that are not specifically referenced in this Amendment.  Inspection periods specified in this Amendment supersede those in SB643B.
             The original issue of this Directive was issued to aid in the prevention of failure of the magneto impulse coupling assembly and possible engine failure.
             This Amendment continues the requirements of the original issue but corrects Table 1 by limiting the listing to magnetos