A Virgin Australia Avions de Transport Regional ATR-72-212A, registration VH-VPJ performing flight VA-1188 from Port Macquarie,NS to Sydney,NS (Australia), was enroute at FL180 about 40nm north of Williamtown,NS (Australia) when the crew reported smoke in the cockpit and diverted to Williamtown for a safe landing about 15 minutes later. The ATSB rated the occurrence an incident and opened an investigation. On Feb 24th 2017 The Aviation Herald learned that the smoke was emanating from the instrument panel of the aircraft. The crew diverted the aircraft and initiated an evacuation of the aircraft. Three occupants were treated by paramedics, two of them were taken to hospitals for possible smoke inhalation. On Jul 27th 2017 the ATSB released their final report concluding the probable causes of the serious incident were: - The C603 capacitor within the number one static inverter failed leading to failure of the static inverter and associated smoke. - Difficulties in communication caused by oxygen mask use led to misunderstandings between the flight crew and cabin crew and increased flight crew workload. - The Cabin Preparation cards were inaccessible to a seated cabin crewmember. The ATSB reported the flight was enroute at FL180 when the crew received indication of the #1 static inverter failure as well as messages indicating the loss of systems being supplied from the inverter. The aircraft systems automatically transferred the power supply to the #2 static inverter, the messages concerning loss of depending systems disappeared. 8 seconds later a master warning activated and an electrical smoke warning appeared. The crew donned their oxygen masks and worked the electrical smoke memory items followed by the electrical smoke checklist. The odour became stronger and faint whispy smoke appeared in the cockpit. The checklist instructed to select the avionics vent exhaust to overboard, the smoke dissipated and the smoke warning ceased. The crew decided to divert to Williamtown. The flight crew advised cabin crew after some problems to get understood by cabin crew due to the muffled sounds from the flgiht crew oxygen mask, that they were diverting to Williamtown and cabin crew should initiate the evacuation as soon as the fast seat belt signs extinguished. After safe landing the flight crew stopped the aircraft, shut the engine down and extinguished the fasten seat belts, the evacuation was initiated by cabin crew. At the same time the flight crew noticed that the odour intensified again prompting the flight crew to vacate the flight deck immediately after the last passenger. The ATSB analysed: The C603 capacitor within the number one static inverter failed in a manner consistent with other C60x series capacitor failures. Failure of the capacitor resulted in failure of the static inverter and smoke being emitted into the cockpit. Difficulties in communication with the flight deck led the SCC to initially believe the flight crew were managing an unspecified ‘leak’. Therefore, the SCC began preparing for a possible depressurisation. However, as the required actions were similar to those required for the smoke event in progress, the misunderstanding did not impact on the management of the cabin during the incident. The Cabin Preparation cards were inaccessible during the period that procedures directed the SCC to use them. However, as the SCC was able to complete the required actions without reference to the cards this did not impact on their ability to prepare the cabin for landing and the precautionary disembarkation.