On 15 June 2006 at approximately 1630 Eastern Standard Time, during a scheduled flight from Hervey Bay, Qld, to Brisbane, Qld, the crew of the Fairchild Industries SA227-AC (Metro III) aircraft, registered VH-SEF, noticed that the cabin temperature was colder than desired. After adjustment to the auto and manual cabin temperature controls, the cabin temperature increased to a higher than expected range and could not be reduced. Shortly after, smoke was seen coming from the right side cockpit air vents. The crew isolated the right bleed air system and diverted the aircraft to Maroochydore, Qld.

After examination of the aircraft's air-conditioning system, the right hot air mixing valve was replaced and the aircraft returned to service without further problem.

During the incident, the crew found that fitment of their emergency oxygen masks was ineffective, requiring them to hold the masks in place with one hand, and that the passenger address system was also ineffective in alerting the passengers to the emergency.

Only one minor injury in the form of sore ears was reported as a result of the incident.

As a result of this incident the Australian Civil Aviation Safety Authority issued an Airworthiness Bulletin to address maintenance aspects of flight crew oxygen masks.