Document ID: chunk:federal_register_of_legislation:F2006B06087:body:0:p2
Version: federal_register_of_legislation:F2006B06087
Segment Type: other
Provision Reference: 
Character Range: 2863–5069

105 CIVIL AVIATION SAFETY AUTHORITY
 SCHEDULE OF AIRWORTHINESS DIRECTIVES

            For Requirement 2 - Before 30 October 2000.

            For Requirement 3 - Within the next 200 hours time in service after the effective date of this Directive or at the next inspection for issue of a Maintenance Release, whichever occurs earlier.

            This Airworthiness Directive becomes effective on 16 October 2000.

            Background:  Intermittent tripping of the windshield heater circuit has been experienced during prolonged operation of the windshield heating system in the LIGHT mode on aircraft having the enlarged heated area windshield. The power supply circuit breakers of the LH and RH windshield ice and rain protection system are prone to trip (open) and de- energise the system during flight in very cold outside air temperature (OAT) conditions, if LIGHT position is selected.

            If the LIGHT position is selected (which heats the complete windscreen), the electrical load of the LH and RH windshields can become too high at cruise altitudes. This is due to the cold OAT which decreases the electrical resistance of the windshield heater elements. Tripping of the circuit breaker renders the complete windshield heating powerless, which could lead to icing of the windscreen.

            This Directive supersedes AD/PC-12/23 which required amendment of the AFM/POH Limitations Section with a Temporary Revision and the installation of a placard on the DE-ICING panel, prohibiting the operation of the windshield heating system in the LIGHT mode.

            This Directive requires replacement of the existing POH/AFM Temporary Revision and verification/installation of a placard adjacent to the windshield heating switch, prohibiting operation of the windshield heating system in the LIGHT mode.
            Furthermore the Directive requires modification of the windshield de-ice system, which removes the restriction on the operation of the windshield heating system in the LIGHT mode.

 Eugene Paul Holzapfel
 Delegate of the Civil Aviation Safety Authority 12 October 2000

 The above AD is notified in the Commonwealth of Australia Gazette on 16 October 2000.