Aviation safety issues and actions

Lack of deviation alert on ATC system

Issue number: AO-2009-004-SI-03
Who it affects: Operations receiving Air Traffic Services via the Australian Defence Air Traffic System
Issue owner: Department of Defence
Transport function: Aviation: Airspace management
Background: Investigation Report AO-2009-004
Issue release date: 05 October 2010
Current issue status: Adequately addressed
Issue status justification:

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

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.

Proactive Action

Action number: AO-2009-004-NSA-059
Action organisation: Australian Government
Date: 05 October 2010
Action status: Closed
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 comment:

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.
Last update 28 February 2014