The crew of VH-KDJ taxied the aircraft for departure from runway 18. Calls were made on both the area and Mandatory Traffic Advisory Frequency (MTAF). From this it was ascertained there were two other aircraft operating in the area. Initially both were to use runway 18, but one of these advised he would land on 36 instead. This did not cause any problems for the crew of VH-KDJ, and they were still able to use runway 18.

Engine power was applied for take-off and as the roll started, they transmitted a call that they were rolling. The pilot of the aircraft using runway 36 called them and said there was another aircraft, of which they were not aware, taking off in the opposite direction. The take off in VH-KDJ was rejected at low speed and the two aircraft did not get close.

The conflicting aircraft on runway 36 was a Jabiru which was being flown on circuits. It was subsequently learned that the radio on the Jabiru was defective. A carrier wave could be heard when the pilot tried to transmit a message, but the pilot's voice could not be heard.

Significant Factor

The following factor was considered relevant to the development of the accident:

1. The VHF radio on the Jabiru was unserviceable.

The crew of VH-FNB flew the aircraft into the circuit area intending to land on runway 06. They then sighted another aircraft on final for runway 24. Calls were made to the other aircraft on the area frequency and the Mandatory Traffic Advisory Frequency (MTAF). No reply was received.

The crew of VH-FNB changed their approach to land on runway 24. The other aircraft made a touch and go landing on runway 24 and then made a radio call. A call from the crew of VH-FNB advised that they were on final approach for runway 24. Radio contact was established with VH-MUF, the other aircraft, and the pilot of VH-MUF advised he had previously had the volume on his radio turned down.

Significant Factor

The following factor was considered relevant to the development of the incident:

1. The pilot of VH-MUF was operating with the radio volume turned down.

VH-JJT was on departure from Ayers Rock climbing through 4000 feet and intercepting the outbound track for Alice Springs when the crew spotted a Cessna in their 2 o'clock position about 800 metres distant. The Cessna was at the same altitude and apparently on descent into Ayers Rock. No avoiding action was necessary but prior to the sighting the crew of JJT were not aware of the presence of the Cessna. They also believe the Cessna was unaware of their presence.

At the time of the occurrence there was a tour group of aircraft at Ayers Rock and the MTAF frequency was being used by tour organisers to arrange aircraft parking and for other non operational purposes. This meant that the frequency was extremely busy. There were a number of other aircraft in the area at the time and the crew of JJT reviewed the traffic situation before take-off but they did not have information on the Cessna that they conflicted with.

Either the Cessna did not make an advisory call or the crew of JJT missed any call that may have been made. It is also possible that any call from the Cessna was over-transmitted by another source.

Significant Factors

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

1. The crew of JJT were not aware of the presence of the Cessna.

2. The MTAF frequency was extremely busy.

3. Either the crew of JJT missed any advisory call made by the Cessna pilot or no call was made.

Overhead Kinglake at 5,500 ft on approach into Melbourne the crew received a terrain proximity alarm and applied emergency climb power, climbing to 7,000 ft.

This is one of a large number of spurious warnings occurring to the world fleet of Boeing 747-400 aircraft. In broad terms, the problem is in the logic of the ground proximity warning system (GPWS) which allows a warning to be registered when the landing gear is retracted, and the number 1 radio altimeter registers an altitude of 2,500 ft (i.e. 2,500 ft above terrain).

The aircraft manufacturer has devised a modification to the antenna and the number 1 radio altimeter that has since been incorporated into the operator's fleet and these spurious warnings no longer occur.

On entering downwind for runway 06 the crew of VH-FKA saw an aircraft on the taxiway. The aircraft was then observed to enter the runway, backtrack and take off on runway 06.

No communications could be established with the departing aircraft on either the area frequency or the Mandatory Traffic Advisory Frequency (MTAF). There was no loss of separation.

With the assistance of company personnel on the ground the crew of VH-FKA were able to establish the registration of the departing aircraft was VH-PMT.

Significant factors

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

1. The pilot of VH-PMT did not follow the radio communication procedures for operation in an MTAF. The reason for this was not determined.

When the pilot attempted to add power to correct an undershoot on short final for landing, he discovered that the throttle had jammed. As he manoeuvred the aircraft to avoid a fence, it stalled from about 10 feet. The aircraft landed heavily and the landing gear collapsed.

Subsequently it was found that the throttle inner cable had broken and jammed in the outer cable.

Significant Factors

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

1. The throttle cable broke in flight.

2. The pilot was unable to increase power to correct an undershoot.

3. The pilot stalled the aircraft while trying to avoid a fence.

VH-KTF [Beech76] was proceeding on an instrument flight rules [IFR] training flight from Goulburn to Canberra and was being radar vectored by Canberra Approach control [APP] for a right downwind leg for runway 35. The pilot was maintaining 6,000 feet being the last assigned altitude.

VH-CZP [Boeing 737] was proceeding on a regular public transport flight from Melbourne to Canberra and was being radar vectored by APP for a left base to runway 35. The pilot was also assigned 6,000 feet by Air Traffic Control [ATC].

APP was being performed by a trainee controller who had completed four weeks of a proposed twelve week training period. This controller was supervised by a suitably qualified training officer.

At 1406 hours VH-KTF was given a left turn onto a heading of 320 degrees with the intention by ATC of using this turn to provide 5NM separation with VH-CZP who was to be given a left turn onto the localiser ahead of VH-KTF.

As VH-CZP was approaching the centre line the training officer realised that the trainee was leaving the issuing of the turn instruction a little late and decided to instruct the trainee to turn VH-CZP immediately. At 1408 hours the trainee issued the turn instruction using the callsign CZF. The captain of VH-CZP then queried this instruction and with this further delay the ATC training officer decided to take over and issued instructions to both VH-CZP and VH-KTF which placed the two aircraft on diverging headings. During these manoeuvres the horizontal distance between the aircraft reduced to 2.5NM with no vertical differential.

The weather conditions were such that both crews were in cloud throughout the occurrence and no pilot saw another aircraft.

The required separation standard was either 5NM horizontally or 1,000 feet vertically.

Significant Factors

1. The trainee approach controller allowed VH-CZP to get too close to the localiser before implementing a turn onto final.

2. The trainee approach controller used the wrong callsign when issuing VH-CZP with a turn instruction.

3. The training officer allowed the traffic situation to develop to a point where he was unable to guarantee separation once the trainee made an error.

The flying instructor advised that at 300 feet, after taking off to the north from the eastern grass at Moorabbin, he first heard an odd noise and then felt a violent vibration through the airframe. He also noticed that rotor RPM had begun to diminish. Immediately he lowered the collective, closed the throttle, and carried out an autorotation into an area just outside the airfield boundary. The engine continued to idle from the moment of closing the throttle.

Engineers found that the aft bearing on the lower pulley assembly had disintegrated internally, and the forward bearing was rough. (This pulley assembly is part of the drive train which transmits engine power to the main gearbox via eight rubber belts.)

The bearing (part number 269A5050-78) which failed was lifed at 1800 hours. It failed at 741 hours total time in service and 246 hours since it was last inspected/greased. There was no evidence of lack of grease or overheating of the bearings.

Significant Factor

The following factor was considered relevant to the development of the incident:

1. The lower pulley aft bearing failed in flight.

VH-MFS was inbound to Darwin and cleared to maintain 1,500 feet by Darwin Approach Control, then subsequently instructed to call Darwin Tower.

When the pilot contacted the tower, he was advised of traffic, VH-BYK, a Cessna 210 on downwind for runway 36. This aircraft was sighted about two kilometres in front and 100-200 feet below. VH-MFS passed directly over VH-BYK.

The pilot of VH-MFS was advised by the RAAF controller that an error of judgement on their part had resulted in the confliction.

Safety Action

Deficiencies identified during this and other investigations involving procedures by Darwin RAAF controllers are the subject of further analysis in conjunction with the Directorate of Flying Safety - Air Force.

The pilot of the Fokker F-50 VH-FNA reported that when he was lined up on Runway 24 at Ballina and about to commence take-off, a Piper Arrow suddenly appeared overhead the airfield, crossing the intended take-off path. Its undercarriage was extending and the aircraft appeared to be joining the circuit for landing. A taxiing call had been made by the pilot of VH-FNA, and contact had been made with another transiting aircraft on the Mandatory Traffic Advisory Frequency. No calls were heard from the arriving aircraft by the crew of VH-FNA or by the transiting aircraft.

The unannounced aircraft was observed turning base for Runway 24 when VH-FNA departed.