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.
The ATSB recognises that Airservices have done work to review this safety issue and compare their processes with other agencies. The ATSB also notes that no changes have been made to Airservices’ existing guidance. Regardless of the number of ATS-attributable occurrences involving the use of block level clearances, the issue of limited formal guidance for pilots and controllers remains. The Manual of Air Traffic Services states that controllers are to cancel block level clearances if other aircraft request a clearance to operate at levels within the block, but it does not define the proximity parameters of the other aircraft. In addition, there are no formal procedures or guidance to state other conditions under which block level clearances should not be provided, such as when experiencing high workloads, and there are also no time restrictions specified for the use of block levels.
The Australian Transport Safety Bureau recommends that Airservices Australia takes safety action to address the limited formal guidance to controllers and pilots regarding the conditions in which it was safe and appropriate to use block levels.
Airservices notes that the ATSB considers we have not yet demonstrated that we have satisfactorily addressed this issue and the associated recommendation. Prior to receiving the ATSB final report, Airservices had decided to undertake a review to assess the adequacy of the existing guidance material and procedures within Manual of Air Traffic Services (MATS) and National ATS Procedures Manual (NAPM) in respect of block level clearances. The review is anticipated to be completed by the end of November 2013. Airservices will advise the ATSB of the outcome of this review and any intended actions.
The ATSB recognises that Airservices have done work to review this safety issue and compare their processes with other agencies. The ATSB also notes that no changes have been made to Airservices’ existing guidance. Regardless of the number of ATS-attributable occurrences involving the use of block level clearances, the issue of limited formal guidance for pilots and controllers remains. The Manual of Air Traffic Services states that controllers are to cancel block level clearances if other aircraft request a clearance to operate at levels within the block, but it does not define the proximity parameters of the other aircraft. In addition, there are no formal procedures or guidance to state other conditions under which block level clearances should not be provided, such as when experiencing high workloads, and there are also no time restrictions specified for the use of block levels.
