Unstable approach of a Bombardier DHC8, VH-TQL, Sydney Aerodrome, New South Wales, on 26 December 2008

On 26 December 2008, a Bombardier Inc DHC-8-315 (DHC8), registered VH-TQL, was conducting a regular public transport flight from Moree to Sydney Aerodrome, New South Wales. While on final approach, and after capturing the glideslope for the runway 34 Left (34L) instrument landing system approach, the autopilot commanded the aircraft to descend. This prompted the crew to make a number of configuration changes in an effort to continue the approach. Those changes destabilised the aircraft and diminished its performance, which lead to the activation of the aircraft's stickshaker. Shortly after, a missed approach was commenced by the flight crew.

In this occurrence, the crew continued the approach despite becoming aware of the unstable aircraft state. Positive action to avoid a stickshaker event could have been taken if the crew communicated to each other the inappropriate aircraft configuration as it progressed along the approach.

As a result of this occurrence, the operator has proactively implemented changes to its DHC-8 training syllabus, highlighted to its crews the destabilising effects of changes to an aircraft's configuration during an approach and emphasised to crews the importance of good communication in a multi-crew environment.