On 14 December 2010, the crew of an Aero Commander 500-S aircraft, registered VH-KAV, departed Norfolk Island for Brisbane, Queensland.
When about 180 NM (333 km) east of Brisbane, the crew noticed intense fumes in the cockpit followed by smoke emanating from the avionics panel. The pilot in command (PIC) shutdown the aircraft's electrical system and discharged the portable fire extinguisher. The smoke dissipated immediately after.
About 30 minutes later, the crew noticed that the hydraulic pressure had declined, and the unsafe landing gear light was illuminated. The crew reinstated the electrical system and attempted to restore the auxiliary hydraulic pump, but it did not respond.
In preparation for their arrival into Brisbane, the crew conducted an emergency landing gear extension. The aircraft landed and vacated the runway. While taxiing to the parking area, smoke was observed emanating from the left engine. The PIC immediately shut down the aircraft and the crew egressed. It was determined that fluid from the hydraulic reservoir in the left engine was leaking onto the aircraft's brakes causing smoke.
A subsequent examination of the automatic direction finder (ADF) receiver found a burnt resistor and that a circuit board in close proximity had been damaged. A capacitor was found to have short circuited, which caused the resistor to burn.