The design of the horizontal stabiliser bungs did not consider aspects that would ensure the identification of an installed bung, or the safe operation of the aircraft if the bungs were not removed prior to flight.
To be advised.
The Australian Transport Safety Bureau recommends that Regional Express Pty Ltd further reviews the horizontal stabiliser bungs design and pre-flight procedures to ensure that installed bungs are readily identifiable and will not adversely affect the continued safe operation of the aircraft if not removed prior to flight.