A Rockwell Aero Commander 500-S, VH-KAV, was being ferried from New Zealand to Australia. After a night stop following the first sector of the ferry, the aircraft departed Kerikeri, at the Northern tip of New Zealand's Northern Island for Norfolk Island (Australia). This would be a 480 nm (889 km) leg, with roughly 99% of the flight over the Tasman Sea.
VH-KAV in 2008, © Lachian Brendan
The last sector of the ferry flight would be another 790 nm (1463 km) track over the Tasman sea. After pre-flighting and refueling the aircraft they set of for this last sector for a flight under IFR rules.
Approximately 2 1/2 hours the crew entered instrument meteorological conditions, including heavy rain, ATC cleared them any altitude between 6000 and 8000 feet. After approximately an hour they cleared the bad weather, and all appeared well.
That was until they observed intense fumes in the cockpit and a short while later smoke started emanating from between the ADF and Transponder in the avionics panel between the pilots. The Commander shut down the aircraft's electrical system and discharged the portable fire extinguisher.
The smoke cleared and a cockpit storm window was opened for ventilation. Neither of the 2 pilots suffered any effects from the smoke.
With the electrical systems shut down the crew contacted ATC via satellite telephone, advised them of the situation, and ascertained that a visual approach to Brisbane was available. Due to the situation, the crew prepared for a ditching should the smoke reappear. Lifejackets were donned, EPIRBs were placed in an accessible place and other survival equipment was raddied. About half an hour after the smoke event the crew noticed that the hydraulic pressure was dropping and followed by a gear unsafe indication. In an attempt to correct the gear unsafe they decided to repower the electrical system, to power the Auxiliary Hydraulic pump. Did not work, the auxiliary pump would not pressurize the hydraulics. Communication with ATC via de Sattelite telephone was difficult, so the crew opted to restore power to one of the aircraft's radios and informed ATC of the evolving situation. The rest of the flight was uneventful and 35 nm (65 km) from Brisbane they received their approach clearance for a visual approach to runway 14. Prior to descending from 6000 feet, the crew performed the alternate gear down procedure as per the emergency checklist and all gears were locked down and indicated accordingly.
The approach and landing, with emergency services on standby, were without any issues. After vacating the runway and taxing to the ramp the fire service, who were trailing the aircraft, reported smoke started emanating from the left engine area. The aircraft was stopped and the applicable checklist was performed, concluded by the crew evacuating from the aircraft.
An investigation on the taxiway revealed that hydraulic oil from the left engine hydraulic reservoir was leaking onto the hot brakes, causing the smoke, luckily no fire! After that was established the aircraft was towed to the ramp for an investigation into the smoke in the flight deck during the flight,
The aircraft's route of the flight from Norfolk island to Brisbane (from public domain)
The cause of both smoke events was investigated and corrected prior to the aircraft resuming service;
Smoke on the flight deck The cause of the smoke on the flight deck was traced to a short circuit in a capacitor and a burned resistor in the ADF receiver. The damaged parts were replaced, the unit was tested, and returned to service
Smoke caused by a hydraulic leak The hydraulic pressure line connected to the accumulator was found to have some pinhole corrosion, which caused the hydraulic leak. The line was replaced, no further leaks were observed
This incident demonstrates the benefits of being appropriately prepared for long, overwater, flights. The crew was able to establish initial contact with ATC through the use of an alternative means of communication: a satellite phone. The phone was also used throughout the flight to obtain updates on the weather conditions. The crew also ensured that the appropriate survival equipment was on board, such as life jackets and EPIRBs in the event a ditching was required.
More details about this incident can be found by clicking here.