Lack of deviation alert on ATC system
Date issue released
Safety Issue Description

The absence of an altitude deviation alert within the Australian Defence Air Traffic System increases the risk of undetected altitude variation and contributed to the significant loss of altitude.

Issue number
AO-2009-004-SI-03
Transport Function
Airspace
Issue Owner
Department of Defence
Mode of Transport
Aviation
Issue Status Justification

expected that the introduction of a common system will probably include functionality similar to the existing TAAATS CLAM.

Proactive action
Action number
AO-2009-004-NSA-059
Organisation
Australian Government
Action date
Action Status
Closed
Action description

In May 2010, the Australian Government announced that the replacement Air Traffic Services (ATS) system for the Australian Defence Air Traffic System and the Australian Advanced Air Traffic System (TAAATS) would be via a joint acquisition project that would result in a common ATS system throughout Australia. It could be expected that the system would included common alert functions, such as the existing cleared level adherence monitoring (CLAM) alert in TAAATS.

ATSB Response

The ATSB is satisfied that, on the basis that the replacement common ATS services system will retain some form of CLAM-like alert, the action taken by the Australian Government will, once in place, adequately address this safety issue.