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Discontinued Investigation

Statement of Reasons

Occurrence investigations commenced from 1 July 2003 are initially categorised as category 4 unless agreed by the ATSB Executive to be above this level at the outset. As detailed in Section 21 (2) of the TSI Act 2003, the Executive Director in empowered to discontinue an investigation at any time. Section 21 (3) of the TSI Act 2003 requires the Executive Director to publish a statement setting out the reasons for discontinuing an investigation (commenced from 1 July 2003) within 28 days of discontinuing the investigation.


Notification reports received from air traffic control and the pilot of a Cessna 404 revealed that the pilot was instructed by air traffic control to maintain 5,000 ft due to crossing traffic at 6,000 ft. He reported that he trimmed the aircraft to maintain 5,000 ft, but it climbed to 5,140 ft. The pilot noticed the aircraft climbing and immediately initiated a descent. Air traffic control reported that as the crossing aircraft passed, the Cessna 404 was observed on radar at 5,400 ft. The crew of the crossing aircraft did not sight the Cessna 404 or receive a TCAS advisory or alert.

The pilots report also advised that, following the occurrence, the Cessna 404s altitude encoder was checked and was found to have an error. The encoder was subsequently repaired.

The ATSB commenced a category 4 investigation to determine if safety was compromised. An assessment of available information indicates that although there was a breakdown of separation standards there was limited safety benefit in continuing the investigation.

Status: Downgraded the occurrence to category 5 and investigation discontinued.

General details
Date: 24 August 2006 Investigation status: Discontinued 
Time: 0833 CST  
Location   (show map):16 NM north of Adelaide Investigation type: Occurrence Investigation 
State: South Australia Occurrence type: Loss of separation 
Release date: 30 August 2006 Occurrence class: Airspace 
Report status: Discontinued Occurrence category: Incident 
 Highest injury level: None 
Aircraft details
Aircraft manufacturer: Cessna Aircraft Company 
Aircraft model: 404 
Aircraft registration: VH-ENT 
Serial number: 404-0818 
Type of operation: Charter 
Damage to aircraft: Nil 
Departure point:Adelaide, SA
Destination:Balcanoona, SA
Crew details
RoleClass of licenceHours on typeHours total
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Last update 18 April 2018