Aviation safety investigations & reports

Sikorsky Aircraft S-76C, VH-EXU

Investigation number:
Status: Completed
Investigation completed


The pilot in command of a Sikorsky (S-76C) helicopter reported that an aircraft had passed the helicopter at the same level, with 200-300 ft lateral separation, while operating in the vicinity of East Sale aerodrome. The aircraft was subsequently identified as a RAAF HS-748, callsign Hudson 505. At the time of the occurrence, East Sale airspace was uncontrolled, and Mandatory Broadcast Zone (MBZ) procedures were in place on frequency 118.3 MHz.

The S-76C had departed Longford Heliport, located approximately 7 NM south of East Sale. It was proceding to East Sale on climb to 2,500 ft above ground level (AGL) to conduct a practice instrument landing system (ILS) approach for runway 22. Another RAAF HS-748, callsign Hudson 24, was operating in the circuit at East Sale and preparing to conduct an ILS approach for runway 22.

As the S-76C approached East Sale, the crew of Hudson 24 broadcast that they were turning inbound on the ILS, and would be making a full stop landing. At about the same time, the crew of Hudson 505 broadcast that they were departing to the north-east of East Sale and passing 1,700 ft AGL. However, Hudson 505 was actually to the south-west of the aerodrome, and was turning to the left to track back over the East Sale non-directional beacon (NDB) prior to its departure to the north-east.

The S-76C crew, believing that Hudson 505 was north-east of East Sale and clear of their approach, continued inbound to overhead the East Sale NDB. When the S-76C was approximately 3 nm south of the East Sale NDB, maintaining 2,500 AGL, the crew observed Hudson 505 passing in front of the S-76C from left to right, at the same level and in close proximity. At the same time Melbourne Centre called Hudson 505 on frequency 124.0 MHz and advised the crew that unidentified traffic was half a mile to the south-west of the aircraft. The crew of Hudson 505 subsequently reported that they did not see the S-76C.

Safety Action

Local safety action

As a result of the occurrence, the Directorate of Flying Safety - Australian Defence Force, advised that all East Sale and Longford-based crews were briefed on the incident. The briefing drew attention to the following:

  1. terrain shielding exists between Longford and East Sale;
  2. a need for clarity in MBZ broadcasts. Crews should not assume that previously made transmissions were received and thus make the information in each transmission appropriate; and
  3. an enduring requirement for vigilance in lookout, even if an assessment of no conflict exists.

The operator of the S-76C issued instructions to its crews regarding procedures to be followed for instrument training flights at East Sale when the MBZ was active. These included specific procedures for:

  1. departing Longford for the runway 22 ILS approach at East Sale;
  2. departing Longford for the West Sale NDB approach;
  3. departing Longford for the East Sale and West Sale Global Positioning System non-precision approaches; and
  4. crew co-ordination duties between pilot flying and non-flying pilot.
General details
Date: 11 December 2000   Investigation status: Completed  
Time: 1245 hours ESuT    
Location   (show map): East Sale, Aero.    
State: Victoria   Occurrence type: Near collision  
Release date: 12 October 2001   Occurrence category: Incident  
Report status: Final   Highest injury level: None  

Aircraft 1 details

Aircraft 1 details
Aircraft manufacturer Sikorsky Aircraft  
Aircraft model S-76  
Aircraft registration VH-EXU  
Serial number 760432  
Type of operation Business  
Sector Helicopter  
Damage to aircraft Nil  
Departure point Longford, VIC  
Departure time 1240 Hours ESuT  
Destination Longford, VIC  

Aircraft 2 details

Aircraft 2 details
Aircraft manufacturer British Aerospace PLC  
Aircraft model 748  
Aircraft registration HUDSON 505  
Type of operation Military  
Damage to aircraft Nil  
Departure point East Sale, VIC  
Destination Nowra, NSW  
Last update 13 May 2014