COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Aircraft - General
AD/GENERAL/43 Power Supply Connections to Hourmeters 6/70
Applicability: All aircraft fitted with hourmeters.
Requirement: 1. Inspect the hourmeter installation to ascertain that it is NOT connected to a Class 1 circuit.
2. If the hour meter is connected to a Class 1 circuit, separate graded protection must be fitted, or the system must be removed from the Class 1 circuit and connected through a separate protective device.
Note: Hourmeters utilizing the power supply through the landing gear up lock switch (i.e. Beech Aircraft) should have fitted, at the up lock switch connection, a fuse or circuit breaker of such a value that it will open the circuit before the landing gear control and indication circuit breaker trips.
Compliance: Within 100 hours time in service after 30 June 1970.