Smoke event, 89 km south-east of Mackay, Queensland, on 9 December 2005, VH-EEQ

At approximately 0530 Eastern Standard Time hours on 9 December 2005, a Fairchild Industries Inc SA227-AC Metroliner, registered VH-EEQ was being operated on a scheduled cargo flight from Rockhampton to Mackay, Qld with a crew of two pilots on board. The crew reported that, during the cruise at flight level (FL) 140, an oily smell was detected emanating from the right nozzle cockpit air vent. Shortly after, and at a position 85 NM north-north-west of Rockhampton, the crew noticed smoke in the cockpit.

Although the crew reported completing the relevant checklist actions, the smoke re-entered the cockpit on two more occasions and the crew diverted to land back at Rockhampton. The third instance of smoke being detected in the cockpit followed shortly after the right engine oil temperature 'approached the top of the green arc' and, in the belief that to do so would prevent more smoke from entering the cockpit, the crew shut down the right engine.

A local engineering examination of the aircraft found that the air cycle machine had failed, releasing lubricating oil mist and smoke into the aircraft's air-conditioning ducts. In addition, that examination revealed that the indicated increased right engine oil temperature was as a result of an indicating system malfunction.

As a result of this incident, a number of safety actions were carried out, or proposed to be carried out, including:

• by the operator, to:
  • amend its operations manual to remove non-type specific instructions that conflict with approved flight manual (AFM) procedures
  • advise its pilots of the Civil Aviation Safety Authority's (CASA) expectations in regard to the application of the word 'recommended' in AFM Emergency Procedures
  • advise its Training Captains to include CASA's expectations for the application of the word 'recommended' in AFM Emergency Procedures in all endorsement training
  • by CASA, which published its interpretation of the term 'recommended' in relation to the required conduct by pilots of aircraft manufacturer's emergency checklist procedures.