The Australian Transport Safety Bureau did not conduct an on-scene investigation of this occurrence. The report presented below was prepared principally from information supplied to the Bureau.
REPORTED INFORMATION
At 1151 Eastern Standard Time, on 11 October 2004, while in cruise at FL230, the pilots of a DHC-8-315 aircraft, registered VH-SBV, operating a scheduled flight from Horn Island to Cairns, Queensland, noticed the presence of smoke in the flight deck, which was followed by a loud bang emanating from a panel behind the pilot in command's (PIC) seat.
At the same time, a number of warning lights illuminated, including the primary and auxiliary inverter annunciations. The PIC's electronic horizontal situation indicator, attitude director, altimeter and vertical speed indicator instruments lost electrical power, so control of the aircraft was handed over to the copilot.
Because of the presence of smoke, the pilots donned their oxygen masks, commenced an emergency descent and conducted `Oxygen' and `Fire and Smoke' drills. By the time those drills had been completed, the smoke had dissipated enough to allow the removal of the oxygen masks, and the aircraft was levelled at 10,000 feet.
Inspection of the panel behind the PIC's seat identified a problem with the primary inverter. After completing the appropriate emergency procedures listed in the Quick Reference Handbook (QRH), the primary inverter was isolated and the auxiliary inverter selected, however, the PIC's instruments did not resume operation.
As the smoke had dissipated rapidly from the flight deck and the primary inverter had been isolated, the crew elected to continue to Cairns where a normal approach and landing was carried out.
A subsequent examination by the operator's ground engineers confirmed that the primary inverter had failed creating a power spike that resulted in a number of circuit breakers (CB) tripping, including the auxiliary inverter CB. The tripping of the auxiliary inverter CB prevented the restoration of electrical power to the PIC's instruments.
After resetting the auxiliary inverter CB and functionally testing the system, the aircraft was flown to Brisbane, under the provisions of the minimum equipment list, where the primary inverter was replaced, and the aircraft was returned to service.