An incident where a Fairchild SA227 Metro IIIl had to return to Brisbane due to problems with its instrument displays has highlighted the importance of thorough pre-flight checks to ensure the cockpit is correctly configured.
The Australian Transport Safety Bureau says the “navigation incident” occurred on 3 September 2014 at around 02:15 local time. It involved a Toll Priority-operated Metroliner, registered VH-UUO, which was operating a freight service between Brisbane and Bankstown with a single pilot.
After takeoff , at around 200ft above ground level, the pilot noticed that the horizontal situation indicator (HSI) showed that the aircraft was turning right, despite maintaining runway direction. The pilot reported that the attitude indicator (AI) oscillated between showing nose up and nose down altitude.
At around 1,600ft above ground level, he advised air traffic control that the aircraft was experiencing a “minor problem with heading” and would return to Brisbane. Using the copilot’s attitude and horizontal situation indicators, and with no visual cues available, he was able to turn back to Brisbane’s runway 19, landing safely at around 150kg above the type’s maximum landing weight.
The ATSB found that the pilot had configured the cockpit incorrectly prior to taxiing, with the left gyro slaving switch set to ‘free’ instead of ‘slave’ mode. This resulted in the HSI indicating around 50 degrees left of the actual heading before the flight. The AI is thought to have intermittently malfunctioned after take-off, and the pilot became distracted by the two erroneous instruments, although he was able to land safely back at Brisbane.
Since the incident, Toll Priority has developed a simulator exercise to familiarise its pilots with operating the aircraft in the event of limited instrument operations, as well as troubleshooting.
“This incident highlights the importance of completing pre-flight checks and ensuring the cockpit is correctly configured prior to taxiing,” the Bureau adds. “Particularly when operating at night or into instrument meteorological conditions, it is imperative to verify all reference instruments are indicating correctly.”
Source: Cirium Dashboard
