On radar handoff from Sydney, both aircraft were at Flight Level (FL) 250 and on the Point Lookout-Casino track. The Brisbane Sector 2 controller indicated to Sydney that this arrangement was acceptable. The lead aircraft, VH-NYC had a groundspeed of 290 kt and VH-EWJ 440 kt. The controller was conscious of this and when he gave a 25 degree heading change right to VH-EWJ, he assessed that separation standards would not be infringed. However, it quickly became apparent that this would not be so.

VH-EWJ was then instructed to descend to FL 240. The minimum distance between the aircraft reduced to 3 NM. This occurred when there was 500 ft vertical separation between the aircraft. Workload on Sector 2 at the time was high with both northbound and southbound traffic. There were also some technical problems with the Sector 2 control console and periodic interruptions occurred as technicians rectified the faults. The controller had held a Sector 2 rating for 2 months, having previously been a controller in Darwin for some 18 years.

The factors considered relevant to the development of this occurrence are:

1. The controller was relatively inexperienced in the position.

2. The sector workload was high.

3. There were probable distractions caused by technicians adjusting the console.

4. The controller was late in vectoring the overtaking aircraft.

The pilot had planned to land the aircraft in a paddock on his father's property. During the attempted landing, the nose landing gear broke off and the aircraft overturned. Investigation revealed that the landing was attempted in a paddock covered in dense grass ranging from 500 to 700 millimetres in length. The density of the grass caused the nose gear to break off. The pilot said that he was "misinformed on strip conditions and unable to identify grass length" from the air.

Significant Factors

• The surface condition of the landing area selected by the pilot was unsuitable for use as a landing area.
• The pilot was unaware of the surface condition prior to attempting to land.

VH-UCI was operating on a training exercise involving asymmetric flight and had been cleared for a touch-and-go landing on runway 29. The aircraft touched down before the slight rise in the runway and the pilot was unable to see all the runway ahead until reaching the top of the rise. At this time, while travelling at about 95 knots, another aircraft was sighted crossing the runway, in front, from right to left. The take-off was continued and the aircraft cleared each other by about 250 metres. The other aircraft, VH-TFE, had been cleared to taxi but instructed to hold short of runway 29. The pilot acknowledged this instruction but thought he had been cleared to cross the active runway.

The aircraft took off and departed Darwin with engine bleed air off, utilizing the auxiliary power unit (APU) for air-conditioning. The APU was not shut down immediately after take-off to allow it a longer cooling period. As the aircraft reached flight level 330, the purser noticed a vibration near the rear entry door and advised the flight crew. The first officer investigated the problem, and as he returned to the cockpit the APU fire warning light illuminated, and the fire bell sounded. Fire procedures were carried out, the extinguisher bottle discharged, and the fire warning ceased. The purser also reported that the vibration then ceased. The flight continued to Alice Springs and landed without further incident. Subsequent investigation of the APU revealed evidence of burning near the thermocouple and the APU was replaced.

During the climb, at about 5,000ft, the crew became aware that the aircraft cabin was not pressurising. Alternate selections were tried without success. The captain then decided to proceed to the destination at FL130 after briefing the cabin crew to be alert for any passenger distress and to administer oxygen from portable bottles if necessary. In accordance with safety requirements, the captain and first officer both donned oxygen masks for the flight above 10,000ft.

After reaching cruise level, several passengers and one member of the cabin crew reported headaches and light headedness. The captain descended the aircraft to FL120, and later to 10,000ft when fuel reserves permitted. The flight continued and landed without further incident. None of the affected passengers required medical attention. The aircraft had suffered a pressurisation system failure three days earlier on a flight from Canberra to Sydney.

After rectification at Sydney, it flew without incident until this flight. Investigation revealed that the Cabin Outflow Valve and the Equipment Cooling Auto Flow Control Valve were out of adjustment. The Panel Pressurisation Control Mode Selector Switch was also faulty with an intermittent continuity failure. The pilots did not contravene any regulation or company procedure by continuing the flight unpressurised. However, no consideration had been given to any medical problems that any of the passengers may have had, or that could affect their well-being at higher cabin altitudes.

Safety Action

As a result of the incident, the company has issued instructions that an aircraft that fails to pressurise after take-off and does not respond to early corrective action should return to the departure port or divert to the closest suitable airport.

The pilot had calculated he would arrive at his destination five minutes before last light. Ten minutes before last light he realised the light was fading, so decided to land at a property airstrip he could see below. During the landing roll the left wing of the aircraft struck the star pickets of a barbed wire fence. The aircraft yawed to the left and the right main gear collapsed. The pilot had not seen the fence until it was struck by the left wing.

VH-ELZ departed Brisbane for Toowoomba and was given an initial heading of 270 degrees. Two minutes later, VH-SGQ departed, also for Toowoomba, and was given a departure heading of 240 degrees. At about the same time, Approach instructed VH-ELZ to turn on to 240 degrees. The aircraft came within 3 miles of one another without vertical separation existing. Approach was occupied by a trainee under the supervision of a training officer at the time of the occurrence.

The trainee had recently transferred from another centre where Tower did not depart aircraft less than three minutes apart. This was to ensure that five miles separation existed when the aircraft contacted Approach. In this instance, the trainee was surprised when VH-SGQ departed less than three minutes after VH-ELZ. The training officer said that he misjudged the level of expertise of the trainee. This probably affected how closely he monitored the trainee, allowing the loss of separation to develop.

The following factors contributed to the development of this occurrence:

1. The Approach position was occupied by a trainee controller under the supervision of a training officer.

2. The trainee expected the second aircraft to be further separated from the first than was the case.

3. The training officer misjudged the level of expertise of the trainee.

Both aircraft were inbound to Sydney on different but converging routes, cruising at the same level. The Sydney Flow Controller requested that VH-TJL be positioned 15NM behind VH-TJD to facilitate their arrival. The controller responsible for the aircraft instructed VH-TJD to turn right (to place it on the same track as VH-TJL) and to descend. As VH-TJD converged on the track flown by VH-TJL the required lateral separation of 5NM was lost before the required vertical separation was achieved.

The helicopter was being used for feral animal culling with the pilot and a shooter on board. Weather conditions at the time were hot, and the helicopter was operating close to its maximum all up weight. While flying downwind the helicopter began to sink and the pilot overpitched the main rotor system while attempting to recover. The resultant loss of rotor RPM caused the helicopter to descend rapidly and strike a tree. Both occupants escaped with minor injuries, but the helicopter was destroyed.

On arrival in the circuit area at Wedderburn, the pilot was unable to extend the landing gear by the normal method. The failure of the gear to extend was accompanied by a very loud high-pitched noise in the headset and speaker systems. His attempts to lower the landing gear by the manual emergency system were also unsuccessful.

As a result, the pilot elected to return to Bankstown. However, on arrival in the circuit, he was unable to communicate by radio to the Tower or other aircraft. Air traffic control staff recognised the pilot was experiencing difficulties with the landing gear and called out the emergency services. When the services were in place the aerodrome was closed and the pilot advised by signal light that he was cleared to land.

The aircraft subsequently landed on runway 11 with the landing gear retracted. An investigation revealed a fault in the alternator field circuit which prevented the battery from being charged. The landing gear failed to extend by the normal means due to low battery voltage. The pilot was unable to lower the gear by the manual system because he could not gain access to the emergency gear extension handle due to an incorrectly fitted piece of interior trim. It was not determined how the trim came to be incorrectly fitted.