VH-BWC departed from runway 17R and at 500 ft turned right to intercept the 195-degree track to King Island. The pilot elected to maintain an altitude of 700 ft until clear of the downwind leg of the runway 17R circuit and of any possible light aircraft traffic along the coast. Crossing the coast at 700 ft, VH-SGE passed in front of BWC from left to right approximately 200 metres distant and 100 ft higher than VH-BWC. The crew of BWC had not been given traffic advice on SGE and had not heard any inbound call from the aircraft. SGE was joining downwind for runway 17R.

The pilot of SGE said that he was unaware of BWC until he saw the aircraft when it was about 400 ft away. At the time of sighting, he said that he was at 1,000 ft and the other aircraft was about 200 ft lower and appeared to be climbing. Although close, there was no need for avoiding action as it was obvious BWC would pass behind SGE.

Recorded communications showed that the pilot of SGE made a standard inbound call at Carrum and then called again joining downwind. The pilot of BWC reported ready for take-off 25 seconds after SGE's inbound call so was most probably still on ground frequency at the time of that call and therefore did not monitor the call. The aerodrome controller did not pass traffic to BWC on SGE. Timings of calls recorded on tape would suggest there was a potential traffic conflict. The frequency was not busy during the period immediately leading up to the incident. The pilot of SGE did not recall hearing BWC reporting ready and being cleared for take-off.

The aircraft departed Parkes on a VFR flight to Coffs Harbour, tracking via Scone, Mount Seaview and Kempsey. The pilot reported that the weather enroute to Scone had been fine with clear skies and winds from the south at 10 kts, however, active storms were observed developing to the south of the intended track.

Shortly after the aircraft passed over Mount Seaview, the pilot assessed that the weather was unsuitable to continue flight on his planned track. He decided to follow the Macleay River valley to Kempsey, then continue coastal to Coffs Harbour.  However, about 5 NM before Kempsey the weather deteriorated rapidly, forcing the pilot to divert in order to remain in visual meteorological conditions.

An area of high ground, which he had overflown some minutes earlier, was chosen for a landing. The pilot made two precautionary passes over the area and believed that the surface was approximately level. He then approached to land toward the south but discovered upon landing that the surface had a considerable downslope. While attempting to stop the aircraft the wheels locked under braking and skidded on wet ground. The right main landing gear collided with a creek bank, slewing the aircraft at right angles to the landing direction, and resulting in substantial damage.

The pilot reported that after landing on runway 27, he turned off onto the gravel taxiway. As he did so a strong wind gust hit the aircraft from the right rear quarter. The aircraft went over initially onto its left wing and nose where it stayed for a few seconds before being hit by another gust which tipped the aircraft onto its back.

The wind was reported by a local operator to have been from the west-north-west, gusting from 20 to 45 knots.

The student pilot was carrying out his second solo flight, after a dual check. The aircraft was observed to bounce during landing and porpoise along runway 29 L for a short distance before the nose landing gear collapsed. The aircraft slid to a halt on the edge of the runway.

Marks from all wheels were evident from where the aircraft turned off the runway to where it finally came to a stop but the nosewheels left very significant black skid marks indicative of the aircraft going too fast to follow nosewheel steering input. In summary, the skid marks were indicative of an attempt to turn off the runway onto taxiway F at too high a speed. This is consistent with the evidence of the tower controller.

The pilot reported that he was conducting mustering operations with a second person on board. While operating at about 50 ft above ground level and at 15 kts indicated airspeed the pilot realized that the helicopter was moving downwind. He immediately increased power, however the main rotor over-pitched, causing the helicopter to land heavily. The wind was from the south-east at 5 kts.

The pilot decided to sling his helicopter landing trolley a short distance on his own property. He tied two ropes on each side of the trolley so that it would lift evenly from all four corners. The centre point of each rope was then attached to the cargo hook.

With the helicopter in the hover and the trolley airborne about one foot off the ground, one end of the rope on the left side broke where it was tied on to the trolley. The rope recoiled and wrapped around the left skid. As the left side of the trolley dropped to the ground, the right-side rope caught over the heel of the right skid.

The pilot activated the cargo hook release in an attempt to jettison the load but could not free the rope snagged on the heel of the right skid. He managed to land the helicopter precariously partially on the trolley and partially on the ground. Then, after he shut down the engine, and the rotor RPM was decaying, the helicopter settled back on to its tail. As the tail settled on to the ground, the lower end of the vertical stabiliser was damaged, and the tail rotor was destroyed. The main rotors did not strike the ground, but the rope snagged on the heel of the right skid broke the skid off aft of the rear cross tube.

A Major defect Report had been submitted in April 1995 after it was discovered that the nosewheel fork was cracked near the bolt hole, and the nosewheel fork was replaced. The replacement fork was actually a Cessna 150 part, the difference being the size of the axle bolt. The Cessna 150 fork which was fitted had an AN-4 bolt, whereas the correct fork had a larger AN-5 bolt. The pilots reported that after a normal landing the nose gear collapsed. The failure of the bolt at the head appears to be due to fatigue as a result of excessive working loads on the smaller diameter bolt.

A visiting pilot was being trained on the motorised glider over a number of days. During this flight the pilot and his instructor intended conducting several circuits. On the climb out after the second touch and go, the engine stopped at 250 to 300 ft above ground level. The instructor took over and elected to land on a cross runway that was situated behind the aircraft, as the terrain off the end of the strip in use was not suitable for a landing. This decision required that he conduct a 180 degree turn to the left, followed by an 80 degree turn to the right, to align with the runway. The second turn was conducted at a low height, and required all the pilot's concentration. He then realised that the aircraft was lined up on the paddock next to the aerodrome. During the landing roll the aircraft struck a ditch and the landing gear was torn off.

The pilot reported that the engine stopped because the aircraft had run out of fuel. He had logged the fuel state but did not check the log prior to this flight. He had forgotten about flying conducted about two days earlier, during which the engine was used extensively. The clear plastic tube fuel gauge was reported to be inaccurate as it often became blocked at the bottom of the tank.

A portable emergency locator transmitter was carried behind the seats but it was not turned on.

FACTUAL INFORMATION

Two BA146s were inbound to Brisbane from the north. Both aircraft were being processed for landing on runway 01. There were thunderstorms in the area north of Brisbane and the crew of the leading BA146 requested approval to divert east and west of the aircraft's cleared track to avoid weather. These diversions were approved by the sector controller, who advised the crew to divert a specific number of miles left or right of track.

A new air route structure had been implemented the previous week and this had introduced significant changes to the handling of traffic. Controllers were consolidating their understanding of the routes and the processing of traffic. The sector controller was suitably rated and traffic numbers were low. Traffic complexity had increased as a result of the route changes and the weather. In previous years, prior to the start of the summer storm activity, the Airservices' Northern District office had issued a temporary local instruction reminding controllers of the impact of aircraft diversions on safety and co-ordination. The local instruction had not been issued for the current season.

The diversions caused the lead BA146 to eventually be displaced approximately 9 NM east of, and parallel to, the second BA146. To maintain separation between the two BA146s, the Flow controller co-ordinated with the sector controller for the eastern BA146 to track via Maleny for an approach to runway 14. The amended track and runway was issued to the crew of that aircraft. The crew advised the controller that further diversions would be required.

The crews of both BA146s were assigned descent and were being separated using radar. The crew of the eastern BA146 transmitted to the sector controller that they were diverting 10 NM right of track due to weather. The sector controller acknowledged the transmission with "Roger". This was approved terminology but the Manual of Air Traffic Services stated that it should not be used in reply to a question requiring a direct answer in the affirmative or negative. The crew of an aircraft requiring diversion from a cleared route, in controlled airspace, are to obtain air traffic control approval prior to changing track. The crew of the BA146 did not request approval for the diversion. The sector controller did not reply to the crew that the change in the aircraft's tracking was approved or disapproved.

The crew of the BA146 assumed the diversion was approved. They tracked the aircraft to the west towards the other BA146. The sector controller became concerned at the diminishing horizontal separation, between the two aircraft, and instructed the western BA146 to turn right onto a heading of 180 degrees due to traffic to the east. The controller instructed the crew of the diverting BA146 to turn right onto a heading of 270 degrees to enable the aircraft to pass behind the other BA146. The controller issued instructions to the crews of both aircraft in an attempt to establish vertical separation of 1,000 ft before horizontal separation reduced to less than the required standard of 5 NM. The sector controller did not issue traffic information to the crews of either aircraft when the horizontal and vertical separation standards were infringed. The Manual of Air Traffic Services states that when a separation standard does not exist, a controller shall issue traffic information to the aircraft concerned when, in his opinion, their proximity warrants it.

Analysis of the radar data showed that the horizontal separation had reduced to 4 NM when the vertical separation was 700 ft. There was a breakdown of separation.

ANALYSIS

Previous approvals by the sector controller for the crew to divert around weather were quite specific. On the last occasion the sector controller acknowledged the transmission but did not provide a positive instruction to the crew. The terminology used by the controller was ambiguous. The crew of the diverting BA146 assumed that the acknowledgement by the sector controller was an approval to divert off track. The crew were distracted by the need to avoid the weather and did not query the controller before diverting off track.

The sector controller did not use suitable separation assurance techniques to ensure that separation was maintained between the aircraft. The use of these techniques was essential for aircraft that were diverting around weather, due to the potential for random tracking and an increase in cockpit workload.

The non-issue of the local instruction may have removed a prompt to the sector controller of the need to apply separation assurance techniques.

The controller was aware that the separation between the two BA146s was reducing and endeavoured to rectify the situation. The provision of traffic information may have enabled one of the crews to sight the other BA146 and to assist in maintaining separation.

SIGNIFICANT FACTORS

1. The Northern district office did not issue the temporary local instruction regarding traffic management aspects during inclement weather.

2. The sector controller did not use appropriate separation assurance techniques.

3. The crew of the BA146 assumed that their intended diversion off track was approved.

4. The sector controller did not issue traffic information to either crew when the vertical and horizontal separation reduced to below the standard.

SAFETY ACTION

Local safety action Airservices Australia Northern District Office management has noted that controllers need to be aware of the impact of diversions and will re-issue the temporary local instruction each October.