The pilot reported that the aircraft appeared to be slow to respond to aileron control inputs during the previous flight. While carrying out a flight control check prior to departure for the next flight, he noticed that the right aileron did not respond to cockpit control column inputs. The pilot cancelled the flight and advised company maintenance personnel of the apparent problem. Examination revealed that the control rod for the right aileron had fractured, separating the aileron from the aileron control system.

Specialist examination of the control rod confirmed that the fracture originated in the internally threaded tube end fitting at the point where the fitting was pinned to the centre tube section of the rod. The features of the fracture were consistent with the application of excessive stress. There was no evidence of pre-existing cracking or other defects. The spherical bearing in the rod end fitting had seized and there was evidence of sliding contact between the outer edge of the inner race of this bearing and the aileron attachment fitting. This suggested that the rod probably failed as a result of aileron control input loads applied after the rod end bearing had seized.

It could not be determined when the control rod had been fitted to the aircraft. A scheduled 100 hourly maintenance inspection of the aircraft had been completed on the day prior to the incident and no abnormality concerning the aileron control system was noted. The maintenance organisation considered that during routine maintenance activities it was difficult to inspect the complete aileron assembly in the area where the failure occurred. Following advice concerning this incident, the Civil Aviation Safety Authority commenced a review of the maintenance organisation's inspection and certification procedures.

The aircraft was on climb passing through 1200 ft, when the crew observed a fire warning on the right outboard (No. 4) engine. Following completion of the checklist items, the engine was shut down. The aircraft returned to Adelaide and conducted an overweight landing. Engineering inspection of the No 4 engine, found that an "O" ring in the combustion chamber fuel manifold at the No 7 fuel nozzle, had split internally.

The resultant small fuel leak and fire had triggered the fire warning. The detector wire is approximately 3 inches downstream of the failed ring. As the engine was approaching a 5,000-cycle heavy inspection, an engine change was carried out and the aircraft returned to service. The fuel nozzle "O" ring has a finite life of 5,000 cycles. The failed ring had completed 4673 cycles and is the subject of a Defect Report submission to CASA.

While conducting spraying operations, the aircraft hit a single wire earth return (SWER) power line. The power line contacted the propeller and proceeded to wrap about the propeller hub. The power line was pulled taut by the aircraft, the pilot lost control, and the aircraft impacted the ground 1,000 metres beyond the point of wire contact. The lateness of the day combined with low overcast is believed to have contributed to the pilot's inability to detect the wire in his flightpath.

During the impact sequence, the underfloor framework with the attachment points for the seat and seat belt appear to have distorted altering their geometry. This in turn may have allowed sufficient movement of the pilot against the loosened restraints for his head to contact with the instrument panel. As he was wearing a helmet at the time, the sequence resulted in severe concussion and not a more serious head trauma.

The pilot landed the Piper Aerostar with the landing gear in the retracted position. Investigation of the landing gear retraction and extension system, by the operator, failed to identify a problem. The aircraft sustained damage to the propellers, lower fuselage, landing gear doors and lower rudder. Repairs to these areas have been carried out and full retraction tests performed without fault. The aircraft was then returned to service.

During the investigation, the pilot reported that when the landing gear was selected down, it did not extend. The pilot later reported to the company that she did not hear the landing gear warning horn, did not confirm that the landing gear was down prior to the landing and did not complete the pre-landing checklist. The company, in consultation with the Civil Aviation Safety Authority, has instituted a revised check program for its flight crews in response to this accident.

Whilst in cruise at FL250 the aircraft de-pressurised and the oxygen masks deployed. The crew declared a PAN, executed an emergency descent, and performed the Rapid Depressurisation and Emergency Descent drills. During the descent it was determined that the selector switch for the cabin pressure controller was in the DITCH position which had caused all cabin pressure to be lost. The crew re-selected the switch to its normal position and regained control of the pressurisation. The descent was terminated at FL160 and the flight continued to its destination. It was determined that the incident occurred when the co-pilot's shoulder contacted the switch while he was returning to his seat.

On this and one other aircraft in the operator's fleet the selection to DITCH is achieved by pushing in and rotating the switch in an anticlockwise direction. All other aircraft in the fleet are fitted with a selector where the selection of DITCH is achieved by pulling out the selector switch and then rotating in an anticlockwise direction. The operator removed the pressure control panel and returned it to the vendor for a check of the switch depression and spring tension settings. Pending the results of these tests the operator is examining the replacement of the push actuated switches with the pull actuated switches. An Operational Notice has been issued to all pilots reminding them of the position and operation of the selector, alerting them to take particular care when getting in and out of the right pilot's seat in flight.

The airship was tasked to fly at night over the city of Melbourne to broadcast a live link to a TV variety show. The pilot telephoned the Bureau of Meteorology aviation forecasters twice before 1830 for a briefing on weather conditions. He was advised by the forecasters that conditions would be windy. The area forecast issued at 1415 indicated that winds at 2,000 ft would be from the north at 35kt.

Moderate turbulence was forecast at all levels with occasional severe turbulence in the lee of the ranges, situated to the north of Melbourne. At 1626 the Bureau issued an amended forecast for Essendon with winds from 350 degrees at 18 kt gusting to 35 kt with moderate turbulence below 5,000 ft. The airship departed Essendon at 2105 and was cleared to operate in the Albert Park Lake area at 1,000 ft. At 2125 the air traffic controller in the Essendon tower noticed that the airship was operating below 1,000 ft.

At the same time the controller and police began to receive telephone calls from the public reporting that the airship was flying very low and erratically. The pilot advised ATC that he was operating at a lower level due to winds, otherwise operations were normal and no emergency conditions existed. When ATC observed a radar altitude of 400 ft AMSL an altitude alert was issued to the pilot. Concerned members of the public alerted the police and emergency services, both of which followed the airship during its return to Essendon.

After arrival at Essendon the airship landed and was secured without further incident. Video recordings of the flight taken both on board and from the ground showed the airship pitching, rolling and yawing while being buffeted by the wind. The extent of the disruption to normal flight could not be accurately assessed because some of the images had been increased in speed when broadcast by television news outlets.

The pilot reported that he was taxiing for departure on runway 07. As he turned the aircraft to line up, the left main gear leg fractured. The left wingtip and the left horizontal stabiliser contacted the ground. Subsequent examination of the fracture showed a fatigue failure emanating from a small impression or dent on the leading edge of the leg. The leg appeared to have been cracked for some considerable time, and eventually failed longitudinally in a straight line. The aircraft had been operating for some years on rough runways, and had been engaged in parachuting operations continually. This type of operation generates an unusually high number of cycles (take-offs and landings) and would contribute to a fatigue failure of this nature.

While climbing through FL 210 on route from Broom to Perth, the aircraft's No 1 engine experienced a sudden failure. The crew shut the engine down and diverted the aircraft to Newman where it landed safely. The engine examination revealed extensive secondary damage to the High-Pressure Turbine (HPT) section caused by failure in the HPT Stage 2 area. All Stage 2 blades had failed.

The blade fracture surfaces contained small area of fatigue at the trailing edges. The fatigue area was not large enough the cause failure of the blades. It is suspected that the Stage 2 nozzle honeycomb abradable material partially separated from the nozzle, initiating a one per revolution vibration that resulted in fatigue propagating through majority of the Stage 2 blades. The engine failure was probably caused by a section of the honeycomb separating and causing blades failure.

FACTUAL INFORMATION

The crew of a Bell 212 helicopter, operating under instrument flight rules (IFR), contacted the controller and requested a clearance from Kooringal to the Royal Brisbane Hospital at 2,000 ft. The Bell 212 was required to transit airspace under the jurisdiction of the approach south controller. As the radar advisory service frequency was assigned to the approach north position, that controller coordinated a clearance for the Bell 212 with approach south.

Approach south initially instructed the approach north controller to track the Bell 212 via overhead Brisbane aerodrome and for it to transfer to the aerodrome control frequency. Approach north advised approach south that the Bell 212 was an aeromedical evacuation flight and consequently approach south agreed for the helicopter to track direct to the Royal Brisbane Hospital. Approach south advised approach north that an arriving Boeing 747 (B747), also operating under IFR, was being sequenced for runway 01 and would be manoeuvred clear of the Bell 212 if necessary. There was no further coordination between approach north and approach south with respect to the two aircraft.

The direct track from Kooringal to the hospital passed approximately 2 NM south of the threshold to runway 01. Approach north advised the aerodrome controller of the details of the Bell 212 in accordance with Local Operating Instructions. The aerodrome controller was not asked to provide separation between the Bell 212 and the B747. As the Bell 212 was about to cross the runway 01 extended centreline, approach north observed, on the radar display, the B747 turning onto a 5 NM final, about 6 NM from the Bell 212. Approach north instructed the crew of the Bell 212 to report sighting the B747 but did not receive a reply. Approach north then asked the aerodrome controller to separate the Bell 212 and the B747. As this coordination was being conducted, the crew of the Bell 212 advised approach north that they could see a heavy jet in their 12 o'clock position and requested approval to turn left and pass behind that aircraft.

Approach north approved the request. There was no infringement of separation standards. The approach south controller was undertaking his ninth consecutive shift without a rostered day free of duty. He advised that he felt slightly fatigued and, although he did not believe at the time that it unduly affected his performance, it was possible that fatigue may have had some effect. Traffic levels were moderate and approach south was aware of the potential conflict between arriving aircraft and the transiting Bell 212. However, based on his initial requirement for the Bell 212 to be handed over to the aerodrome controller, he had a mindset that separation would be provided by the aerodrome controller. Approach north did not initially request assistance from the aerodrome controller to separate the two aircraft because the approach south controller had indicated that he would manoeuvre the B747 clear of the Bell 212 if necessary.

The aerodrome controller was not asked to provide separation between the Bell 212 and B747 until very late, by which time the Bell 212 crew had sighted the B747 and had assumed responsibility to maintain their own separation from that aircraft. The investigation revealed that clear, concise and precise coordination was not conducted between the two approach controllers. In particular, standard procedures were not followed with respect to the assignment and acceptance of responsibility for the provision of separation between the Bell 212 and the B747. The investigation did not determine why standard coordination procedures were not followed.

ANALYSIS

As the approach south controller was feeling slightly fatigued, he may not have been well placed to assess the effects of fatigue on his own performance. As such, although he did not believe that fatigue unduly affected his performance, it is possible that fatigue was a factor in this incident. As a result of the the coordination conducted between approach north and approach south shortly after the Bell 212 departed Kooringal, there was no apparent reason for approach north to conduct further coordination with approach south. However, had approach north provided a relay of radar identification or formal radar hand-off to approach south, it may have acted as a prompt for approach south as to the developing conflict and may have lead to approach south taking more positive control of the situation.

The use of non-standard and incomplete coordination procedures lead to a lack of understanding from all the controllers involved in the incident as to the assignment of responsibility for separation between the two aircraft. Separation between the Bell 212 and the B747 was achieved through conflict resolution, rather than through traffic planning and conflict avoidance to assure separation. As a result, the Bell 212 crew sighted and accepted responsibility for their own separation from the B747 as the two aircraft approached the minimum horizontal radar separation standard required.

SIGNIFICANT FACTORS

1. The use of non-standard coordination procedures lead to misunderstanding between the two approach controllers as to who was responsible for the provision of separation between the aircraft.

2. The approach south controller did not accept the Bell 212 on his radio frequency.

3. No controller took positive control of the situation. Consequently, separation assurance techniques between the aircraft were not applied.

4. The crew of the Bell 212 sighted the B747 prior to infringement of the required separation standard.