The air traffic services provider had limited formal guidance to controllers and pilots regarding the conditions in which it was safe and appropriate to use block levels.
Response to safety issue
Airservices Australia (Airservices) reported that there were existing procedures relating to the use of block level clearances in certain areas. In addition, they advised that further standardisation and guidance would be considered, with the ATSB to be advised of any intended action.
ATSB comment/action in response
The ATSB is not satisfied that Airservices has adequately addressed the identified safety issue. No evidence was provided to the ATSB of the existing procedures relative to certain areas and there remains limited formal guidance to controllers and pilots for the safe and appropriate conditions for the use of block levels. In addition, given Airservices has advised that further standardisation and guidance would be considered, the ATSB issues the following recommendation.