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.
