What happened
On 3 September 2014, at about 0215 Eastern Standard Time (EST),[1] a Fairchild SA227 aircraft, registered VH-UUO, took off from Brisbane Airport, Queensland for a freight charter flight to Bankstown Airport, New South Wales, with one pilot on board. Following the take-off, when at about 200 ft above ground level, the pilot observed the horizontal situation indicator (HSI) indicating a right turn although the aircraft was still maintaining runway direction. The pilot reported that the attitude indicator (AI) displayed alternately a nose up and nose down attitude.
When at about 1,600 ft above ground level, the pilot advised air traffic control of a ‘minor problem with heading’ and was directed to conduct a right turn onto an easterly heading to avoid noise sensitive areas. The pilot turned the aircraft to the right, towards the Pacific Ocean, while referring to the HSI on the co-pilot’s instrument panel, which was providing more accurate heading information. The pilot was aware that the captain’s AI and HSI instruments were providing erroneous indications, but became disoriented by continuing to scan those instruments. The pilot looked out of the window in an attempt to gain a visual reference but could see only blackness.
The pilot continued a shallow right turn until the lights of runway 19 became visible. The aircraft landed back at Brisbane, on runway 19 about 150 kg above the aircraft’s maximum landing weight.
What the ATSB found
The ATSB found that the cockpit was not configured correctly prior to taxi, nor was the incorrect heading reference detected or corrected during the taxi or line up. The left gyro slaving switch was selected to ‘free’ instead of ‘slave’ mode, resulting in the captain’s HSI indicating about 50° left of actual heading throughout the flight.
The AI probably intermittently malfunctioned after take-off, and the pilot became distracted by the two erroneous instrument indications. These, combined with the dark night and flight over water without visual reference, contributed to the pilot’s difficulty in maintaining orientation and achieving the planned departure track. The pilot therefore elected to return to land at Brisbane.
What has been done as a result
The aircraft operator developed a simulator exercise based on the incident, to ensure all company pilots demonstrated limited instrument panel skills – without reference to attitude indicator or direction indicator, and troubleshooting skills.
Safety message
This incident highlights the importance of completing pre-flight checks and ensuring the cockpit is correctly configured prior to taxiing. Particularly when operating at night or into instrument meteorological conditions, it is imperative to verify all reference instruments are indicating correctly. This incident also highlights the importance of communication, especially as emergencies arise. If a pilot is having difficulty controlling an aircraft and maintaining instrument or visual reference, then alerting air traffic control enables them to provide the necessary and appropriate assistance.
[1] Eastern Standard Time (EST) was Coordinated Universal Time (UTC) + 10 hours.