VH-HYC was under the control of Melbourne Sector one on track from Oodnadatta to Woomera cruising at Flight Level (FL) 380. The pilot requested a climb to FL390. The aircraft was cleared to FL390, but the coordination of level change was not passed onto Adelaide Control which was the next controlling authority.

The sector controller advised that there was more than 15 minutes to the adjoining airspace boundary when the aircraft requested a climb which meant he did not have to coordinate with Adelaide Control prior to approving the level change. He believes that he cocked the VH-HYC flight strip as a reminder to coordinate with Adelaide after approving the level change. It is possible that while processing two other flight strips, he may have inadvertently knocked the strip for VH-HYC back into its normal position thereby removing his memory cue for the need to coordinate with Adelaide.

Air Traffic Services (ATS) management personnel have subsequently formalised a procedure for marking flight strips which should facilitate scanning techniques and help guard against items being overlooked.

Significant Factors

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

1. The controller probably inadvertently lost his reminder cue to coordinate the aircraft's change of level with Adelaide ATS.

The aircraft had been engaged on a target towing exercise involving live firing of ground-to-air missiles in a military restricted area north of Adelaide.

The target had been deployed at the full 5240 metre extension of the cable. The aircraft and target carried out 10 tracking runs before one missile was fired at the target, without hitting either the target or the cable. After this firing the Army firing point advised the aircraft to recover the target and depart the area.

The operator commenced reeling in the target as the pilot banked the aircraft 30 degrees to the left and began a climb. With 4920 metres of cable still deployed the cable tension indication fell to zero indicating that the cable had broken. The cable cutter was activated to ensure that no cable was trailing behind the aircraft, and the aircraft was returned to Edinburgh.

The 4920 metres of cable landed along the main street of a fishing village creating some disruption to electrical services, but without causing any other damage or injuries.

The cable probably failed when the armour wrap covering a splice became jammed in the reel unit, over stressing the cable. The reel unit was serviceable, and the cable had been subjected to 14 flights with no abnormal loads or stresses. The normal life of a cable is 20 flights.

The pilot reported that during cruise, the engine had a tendency to overspeed when the power lever was retarded but was operating normally at high power. He elected to proceed to the destination with high power set. When power reduction was required for landing a precautionary engine shut down was carried out and a single engine landing was made.

Investigation revealed that the concentric control shafts at the fuel control unit were binding and causing mutual interference. The shafts were lubricated and the overspeed defect disappeared. The aircraft had been washed recently. Failure to reapply lubrication after the wash probably contributed to the defect.

Significant factors

• The FCU concentric control shafts were not lubricated after the aircraft was washed.

Circumstances

VH-TJR [Boeing 737] had departed Melbourne for Canberra at 1529 hours and was on a 10NM final for runway 35 at Canberra airport. The crew had been cleared to make the approach by Air Traffic Control [ATC].

VH-TCO [Cessna 150] was performing circuit training with a student pilot at the controls being supervised by an instructor. The aircraft was instructed by ATC to make a right orbit when on downwind leg and as the trainee was completing the manoeuvre ATC instructed the crew to sight and follow a B737 on an 8NM final. They looked to their left and saw a twin engined jet passenger aircraft that looked like a B737 and acknowledged the ATC instruction as they turned their aircraft onto base leg. The aircraft they saw was an Airbus Industries A320 which was carrying out an approach to runway 35 ahead of VH-TJR.

As VH-TCO was proceeding on its base leg the instructor realised that the aircraft they saw was not at the 8NM final position that was indicated by the Aerodrome Controller [ADC]. He then looked to his right and saw a second twin engined jet passenger aircraft, VH-TJR and calculated that his present track and altitude would take his aircraft above and behind that aircraft. At this point the ADC again issued traffic information to VH-TCO as he observed the two aircraft closing on one another.

As the relative tracks of the two aircraft closed the captain of VH-TJR looked to his left and saw VH-TCO in a position that appeared to be on a collision course and immediately took evasive action by turning his aircraft to the right. After diverging about 0.5NM, the aircraft then re-joined final approach and made an uneventful landing.

The crew in VH-TCO did not take evasive action, as the instructor watched the B737 pass clear, in front and below his aircraft. He had maintained visual contact with VH-TJR continuously from the time he had first seen it. The aircraft came within 300 metres and 300ft of each other.

Significant Factors

1. The crew of VH-TCO initially sighted the wrong aircraft and selected a flight path based on this incorrect sighting.

2. The crew of VH-TCO realised their error while on base leg and elected to continue with that track having correctly sighted the B737.

3. Separation between the aircraft reduced to the point where the crew of VH-TJR considered that evasive action was necessary to maintain adequate clearance from VH-TCO.

The pilot was on the last leg of his first trip to Cairns. He was cleared by Cairns Approach to descend to 3000 ft, not below the DME (Distance Measuring Equipment) steps. Subsequently the Approach Controller observed, on the radar, that the aircraft had descended to 6000 ft at 27 DME. The minimum altitude when conducting a DME Arrival at this distance is 6500 ft. The aircraft was instructed to climb to 6500 ft and the flight continued normally to Cairns.

The pilot advised that he was not expecting to be given a DME Arrival and had not checked the procedure prior to the flight. However, he checked the procedure when cleared by Cairns and had his wife hold the approach plate for him. About that time his son became ill, and his wife dropped the plate. By the time he had recovered the situation the aircraft had been allowed to descend below the profile. The aircraft was in cloud at the time and the pilot reported that it was turbulent.

The Dash 8 aircraft was tracking to the south after departure from Lockhart River. The aircraft had transmitted a taxiing call prior to departure. The call was acknowledged by the Flight Service operator, but no traffic was given to the aircraft. As the aircraft was climbing through 4,500 ft the crew monitored a Lockhart River position report from a northbound aircraft, VH-PSQ. VH-PSQ was cruising at 4,000 ft. Both aircraft were in cloud and did not sight each other.

The Flight Service operator reported that he had not recognised that the aircraft were conflicting traffic and as a result had neglected to pass the required information to each aircraft. At the time the operator had a high workload with other aircraft on his frequency, which was further increased by an aircraft that was out of communications.

To facilitate arrival at Cairns, the aircraft had been instructed to maintain an indicated airspeed of 340 kts during descent and was given a DME Arrival to 3,000 ft. A DME (Distance Measuring Equipment) Arrival is an approach that places upon the pilot the responsibility for monitoring the descent of the aircraft. On this type of approach, the pilot is required to descend the aircraft so that it is above the published distance/altitude steps. The instructions were acknowledged by the pilot. Subsequently, when the pilot reported that the aircraft was in visual conditions, the Cairns approach controller noticed, on his radar screen, that the aircraft had descended below the DME step (i.e. the minimum altitude allowed) at 16 DME.

Analysis of the aircraft flight recorder data and the recorded Cairns radar information indicated that the aircraft had descended below the 6,400 ft DME step at 22 DME to 6,000 ft. It was levelled at that altitude before commencing a further descent, subsequently descending below the 5,500 ft step at 18 DME and remaining below the minimum allowed altitude until 13 DME.

The flight crew reported that, except for a very short period at 18 DME, the aircraft was operated clear of cloud.

During the approach the aircraft was being operated with the flight management computer programmed to maintain the aircraft above the DME Arrival steps. The flight management system can be operated in several modes, according to the requirements of the pilot. As the aircraft approached cloud, during the descent, the pilot changed the operating mode selection to slow the aircraft in case turbulence was encountered. In doing this he cancelled the programmed DME Arrival descent profile. After passing through the cloud the previous mode was reselected but, as the DME Arrival profile was not reprogrammed, the aircraft continued a normal descent to the assigned altitude of 3,000 ft.

Safety Action

As a result of this and several other occurrences involving DME arrivals, the Bureau of Air Safety Investigation made a Recommendation (R930274) to the Civil Aviation Authority under Occurrence Report 9301953. This recommendation stated in part:

The Bureau of Air Safety Investigation recommends that the Civil Aviation Authority:

Examine the need for instrument rated pilots to demonstrate proficiency in the DME Arrival procedure.

The Civil Aviation Authority replied in part:

'The majority of recent reports have occurred at Cairns since the commissioning of the Cairns terminal area radar. This was indicative of a localised problem and subsequent discussion with domestic airlines has confirmed this. The airlines have introduced a training program to overcome any deficiencies in this area.

Within the Authority agreement has been reached to make DME Arrivals a mandatory flight training and flight checking requirement. This will be reflected in forthcoming amendments to the Syllabus of Training and the Flight Test Report Form.'

The pilot reported that during cruise he noticed fuel flow fluctuations on both digital and analog fuel flow indicators. This was followed by power fluctuations which progressively worsened.

The pilot had decided to carry out a precautionary landing into a clear area he had located, when the engine failed completely. A power off landing was carried out into a small clearing in mountainous terrain approximately 4,000 ft AMSL.

Relevant Factors

• Fuel starvation led to an engine power loss.
• The cause of the fuel starvation was not determined.

The pilot advised that, while carrying out a practice forced landing at the conclusion of a local scenic flight, he allowed the aircraft to become too slow and too low. As a consequence the aircraft touched down and nosed over approximately 40 metres short of the runway threshold. The aircraft's left wing and propeller were substantially damaged as a result of the ground contact.

The pilot confirmed that there was no mechanical fault with the aircraft's engine or flight controls that would have contributed to the accident.

At 800 ft after take-off the left engine suffered a complete power failure. After securing the engine the pilot carried out a successful asymmetric landing.

The engine was disassembled, and the rear main bearing was found to have rotated in the case. This caused a loss of oil flow with subsequent overheating and metal contamination of the engine. The camshaft seized and failed causing loss of drive to the accessory drive train and total loss of power.

The cause of the rear main bearing failure was not found.