Following an extended flight over water, the helicopter suffered a power loss as it was approaching the coast. The pilot conducted an autorotational descent and landing. The landing on coastal mud flats was heavy, resulting in damage to the skid gear and tail boom. Examination by a Licenced Aircraft Maintenance Engineer (LAME) found that there were blockages of both venturis in the fuel transfer system which prevented the flow of fuel from the two forward tanks to the main fuel tank which supplies the engine. The engine had been running following the forced landing. The fuel supply was obviously not blocked completely, but sufficiently to prevent operations at normal flight power settings. The material blocking the two venturis appeared to consist of tiny specks of fuel tank liner.

The helicopter was being positioned at the North Rankin "A" Platform to transport passengers back to Karratha. When the helicopter arrived on the helideck it was landed into a strong south-westerly wind and positioned into wind with the pilots' eye-line between the two lines painted on the helideck. The pilots elected to shut down the engines when they were told that the passengers were delayed.

They did not reposition the aircraft, so that it was offset from the wind, prior to shutting down the engines, as required by company procedures. Wind tunnel test results for the rig helideck platform show that turbulent airflow over the helideck can be expected under the wind conditions prevailing at the time of the accident. The pilots confirmed that the wind on the helideck was different to the free-stream air flow. They noticed that there was a strong updraft in the vicinity of the leading edge of the helideck.

As a result of a safety audit conducted several months prior to the accident, the company pilots were required to land their helicopters with their eye-line at or very close to the outer of the two lines on the helideck. The helicopter was landed between the two lines with the main rotor disc protruding over the leading edge of the helideck. When the engines were restarted after the passengers were boarded, the blades were seen to rise during the initial couple of revolutions as they came into the view of the cockpit.

At about the same time a noise was heard from the rear of the helicopter and a vibration was felt. The start was discontinued and inspection found that the tail rotor drive shaft had broken at the rear end. Subsequent investigation revealed that the main rotor had struck the drive shaft which had then failed. It is probable that the strong updraft in the vicinity of the leading edge of the helideck caused the advancing main rotor blade to rise and the retreating blade to consequently dip, resulting in the main rotor strike.

The aircraft was cleared by Townsville Sector 1 to track Mackay-Capricorn-Rockhampton at 9000 feet. This clearance was coordinated with, and acknowledged by, Rockhampton Tower. The cleared route tracked through the Shoalwater Bay military training area and a number of restricted areas in this vicinity were active. The error was detected when the aircraft called Rockhampton Tower at 28 miles on the Capricorn-Rockhampton track.

There was significant military air traffic transiting from Townsville to the exercise area and in the area itself. Throughout the morning, there had been frequent changes in the activity state of the various restricted areas (there were 9 notams current at the time of the incident). Consequently, the Sector 1 workload was very high. The display showing the status of the restricted areas at the Sector 1 console had been adjusted to reflect the activity states but was open to misinterpretation as to which areas were active and which were inactive.

The Sector 1 controller interpreted the display as indicating that the restricted areas were inactive and cleared the aircraft via Capricorn. At the time the clearance was coordinated with Rockhampton Tower, the controller involved was distracted and did not clearly hear the cleared route. He assumed that it must have been via reporting point Murph, which would have taken the aircraft to the west of the restricted areas.

The factors considered relevant to the development of this incident were:

1. The workload in Townsville Sector 1 was very high.

2. The Sector 1 display on active restricted areas was not unambiguous.

3. The Sector 1 controller misread the display and cleared the aircraft on the incorrect route.

4. Due to a distraction in Rockhampton Tower, the controller did not hear clearly the cleared route as coordinated by Townsville Sector 1.

5. The Tower Controller did not confirm the cleared route with Sector 1.

VH-RBJ (Cessna 310) was proceeding on an IFR flight from Lismore to Cooranbong at 8,000 ft and had passed Coffs Harbour at 1719 hours with an estimate for Taree at 1752 hours. VH-MML (Beech 1900D) had departed Sydney at 1718 hours on a regular public transport flight to Port Macquarie. It was maintaining flight level (FL) 230 and was estimating Taree at 1751 hours. Sydney Flight Service Sector 4 (SEC 4) was operated by one flight service officer (FSO) who considered the workload moderate.

The officer had several flight progress strips (FPS) in his flight progress board (FPB) including one on a Beech 99 that was overflying Taree at 7,000 ft with an estimate there of 1745 hours. When the FSO assessed the traffic situation he gave great consideration to this aircraft but finally decided that it would not effect the other two and elected to pass 'no traffic' to VH-RBJ and VH-MML. He was aware of the possible conflict between these two aircraft but thought he would wait for an update on the position of VH-MML before making any decisions on the matter.

He subsequently lost an awareness of the traffic situation and convinced himself that all conflicts in his area of responsibility had been advised to the pilots. The FPS on VH-RBJ was still in the Coffs Harbour Bay of the FPB but should have been transferred to the next most southerly bay in the geographical layout. At approximately 1740 hours the crew of VH-MML contacted SEC 4 and received the advice of no traffic.

At 1751 hours they then asked SEC 4 if there was any traffic at Taree and the FSO immediately reassessed the situation and realised that the conflict existed. As he was about to inform the pilots of the confliction the pilot of VH-RBJ reported that VH-MML had passed through his level within 2 NM. Both pilots stated that they did not see each other prior to passing. No traffic on each other was passed to either crew prior to the occurrence.

Significant Factors

1. The FSO forgot that the conflict between VH-MML and VH-RBJ still existed after deciding to delay the traffic alert decision until an update position on VH-MML had been received.

2. The FSO did not transfer the FPS on VH-RBJ to the correct position on the FPB.

3. The closing speed of the aircraft made an unalerted see and avoid action unlikely.

VH-ITQ was approaching Mudgee at 6000 feet tracking 203 degrees from Tamworth. Flight Service (FS) advised that VH-UJX was conducting Airwork at Mudgee up to 6000 feet and would be departing for Tamworth in about six minutes. The pilot of ITQ was unable to contact UJX on either FS or the common traffic advisory frequency (CTAF). UJX was subsequently sighted in close proximity, proceeding in the opposite direction to ITQ and entering cloud. At that time UJX was about 100 feet higher than ITQ. Monitoring of the FS tape showed that at the time ITQ changed to CTAF to contact UJX, UJX had left CTAF to call FS. UJX gave a departure call to FS indicating the aircraft was maintaining 6000 feet.

FS then gave UJX traffic on ITQ and UJX then corrected part of the departure call saying they were on climb to 7000 feet which was the flight planned altitude for UJX. In a discussion about the incident, the pilot in command of UJX said that the aircraft was equipped with only one VHF radio set which meant that it was not possible to monitor both FS and CTAF at the same time. Had this been possible then this incident could have been avoided. The aircraft was about to have a second VHF set fitted. He also said that they had departed the CTAF before requesting traffic which was an error on their part, and which would not normally be done.

It is worth noting that the same incident could still have occurred even if UJX had not departed the CTAF without first getting traffic from FS. This is because UJX was airworking in the CTAF up to 6000 feet (the cruising altitude of ITQ) and could just have easily been in almost the same position at the same time and missed making contact with the overflying aircraft due to simultaneous frequency changes. This would be particularly true if ITQ did not change to CTAF until close to the CTAF boundary.

Significant Factors

The following factors were considered relevant to the development of the occurrence:

1. The two aircraft missed communicating with each other because they were not on the same frequency at the time ITQ called UJX.

2. UJX was fitted with only one VHF radio set and therefore could not monitor both the CTAF and FS frequencies at the same time.

3. The present design of the airspace system contributes to this type of occurrence.

4. UJX departed the CTAF before getting traffic information.

The pilot reported that both engines operated normally as he commenced the take-off roll on runway 10. He said that at about three quarters of the way down the runway, as he raised the nose, the aircraft immediately veered to the left from what he recognised as a partial loss of power from the left engine.

The landing gear was retracted but the aircraft climb performance was insufficient to prevent a collision with the top of a sand dune beyond the end of the runway. The aircraft continued over the dune and came to rest on the beach beyond.

A subsequent visual inspection of the aircraft determined the left propeller blades were in fine pitch and the right propeller blades were in the feathered position. The reason for the reported loss of power from the left engine was not determined. However, only about 3 litres of oil remained in the right engine, with no obvious signs of oil leakage.

The pilot was landing the aircraft on a strip beside a paddock of barley. The right wing tip became entangled in the barley causing the aircraft to ground loop.

The aircraft was crewed by a captain from another company base who was inexperienced on the route and a first officer who was very experienced on the route. The first officer told the captain he would take complete responsibility for clearances, tracking etc and give any support required by the captain. The aircraft was told to call Melbourne Control approaching 10,000 feet (the lower limit of controlled airspace) on the climb for further clearance. Preceding traffic on this track meant that the aircraft would be subject to a step climb. The aircraft called Melbourne passing 10,800 feet on climb to flight level (F160). The aircraft was already in controlled airspace without a clearance and was instructed to maintain F130 due to the preceding traffic having just left F140.

The first officer reported that he called prior to 10,000 feet but got no response. He then found that he had selected an incorrect frequency on the VHF radio. He selected the correct frequency and made contact but during this time the aircraft had entered the lower limit of controlled airspace. The first officer realised that he should have told the captain to level at 10,000 feet until they got a clearance but he had anticipated they would have the clearance prior to reaching 10,000 feet and accordingly he had not briefed the captain to maintain 10,000 feet until they got a clearance. The preceding traffic was a Dash 8 which was climbing faster than their aircraft. There was no breakdown of separation.

Significant Factors

The following factors contributed to the development of the incident:

1. The captain was inexperienced on the route.

2. The first officer was experienced on the route and briefed the captain that he would take responsibility for clearances, tracking etc.

3. The first officer did not advise the captain as the aircraft approached controlled airspace.

4. The first officer inadvertently selected an incorrect radio frequency. By the time he had corrected this error the aircraft had penetrated controlled airspace.

Envoy 606 (Falcon 900) was arriving at Canberra from Sydney and was assigned 7,000 ft on descent on the Wollongong - Canberra track. The pilot had been given a requirement to reach 7,000 ft by 20 DME Canberra due to conflicting traffic and reported at 7,000 ft when 25 NM from Canberra. VH-IEL (Cessna 172) had departed Goulburn for Canberra on a VFR training flight with the student performing all the functions and the instructor engaged in an examining role. The aircraft was outside controlled airspace at 6,500 ft and was tracking via Lake Bathurst.

The control area (CTA) step passes through the north eastern corner of Lake Bathurst and is 30 NM from Canberra. However, the reporting point is an island in the centre of the lake, and this is 28 NM from Canberra. The student was approaching Lake Bathurst and prepared to contact Canberra Approach to request an airways clearance but for some reason delayed the call until at the CTA boundary.

The instructor was allowing the student to conduct his own operation as a test was in progress and although mindful of the requirement to remain outside controlled airspace until obtaining a clearance, he elected to let the situation continue up to the last instant. The instructor was about to instruct the student to make an orbit when the student made contact with air traffic control (ATC). At the time of the call by VH-IEL, ATC observed the aircraft to be 28 NM and Envoy 606 25 NM and therefore considered that a breakdown in separation had occurred.

By the time altitudes were checked and VH-IEL positively identified, the aircraft were 5 NM apart and a radar separation standard existed. The tracking tolerances were 4 NM for VFR flight and 1.2 NM for the radar at that distance. The required separation standard was 5 NM by radar or 1,000 ft vertically. To remain in controlled airspace the pilot of Envoy 606 would need to be 9,000 ft at 30 NM. The descent profile of Envoy 606 was steeper than normal due to the requirement to reach 7,000 ft by 20 NM.

Significant Factors

1. The student pilot allowed his aircraft to proceed to the CTA boundary before initiating an airways clearance request to ATC.

2. The instructor on VH-IEL allowed his aircraft to penetrate CTA prior to obtaining an airways clearance.

The aircraft was being ferried from Bankstown to Perth, a journey expected to extend over several days. During the first sector, the pilots became aware of non VMC weather at Wagga and decided to divert to Cootamundra. It was reported that at about the time this decision was taken, they noticed the left fuel tank was not feeding and that fuel was being drawn from the right tank only. Assuming a fuel system malfunction, and a reduced endurance of about 15 minutes, the pilot-in-command decided to carry out a precautionary landing.

A section of gravel road was chosen for a landing site, as nearby paddocks were unsuitable. Although the touchdown was normal, the aircraft began to veer to the right on the heavily cambered road surface. When the pilot was unable to regain directional control, full power was applied for a go round. The aircraft became airborne, still diverging to the right, and collided with a boundary fence before nosing over into an adjacent paddock. The Skyfox CA 22 aircraft has two fuel tanks, one in each wing, which feed into a common collector tank via a two position, on/off fuel selector. Each tank is vented via a port in each fuel cap.

Asymmetric fuel flow from the tanks is known to occur occasionally and one tank is exhausted first, upon which the remaining tank feeds normally. The manufacturer is expected to soon issue an amendment to the Flight manual by which pilots will be warned by a cautionary note of this phenomenon.