On 4 July 2002, VH-VBC, a Boeing 737-7Q8 aircraft, was pushed back from Bay 93 at the Domestic-4 apron at Sydney Airport before departure for a flight to Brisbane. At the completion of the pushback, one of the dispatch engineers used the aircraft ground interphone to instruct the pilot in command to park the aircraft brakes. The pilot in command responded with the phrase "Brakes parked, clear to disconnect". The towbar was disconnected, and the crew commenced to taxi the aircraft before the ground interphone had been disconnected. Consequently, the ground engineer who was operating the ground interphone came into close proximity to the right engine as the aircraft began to move forward.

The crew of VBC had operated an earlier flight from Melbourne to Sydney and arrived 21 minutes behind schedule. Consequently, VBC commenced pushback five minutes behind the scheduled departure time for the flight to Brisbane.

Runway 25 was in use at the time and a number of aircraft were using taxiway Golf located adjacent to the Domestic-4 apron. A Saab Aircraft SF-340 aircraft, VH-OLM was taxying inbound for Bay 94A on the Domestic-4 apron. An aero-medical aircraft was following OLM on taxiway Golf, and was taxying to the eastern general aviation parking area, located to the north of the threshold of runway 25.

As VBC commenced the pushback from Bay 93 to towbar disconnect point east, the crew of another B737 located on Bay 91 also requested pushback approval. The air traffic controller did not respond to that request. The controller asked the crew of OLM if they could taxi onto the Domestic-4 apron and then to Bay 94, once VBC had moved forward from towbar disconnect point east. The controller then instructed the crew of VBC to hold clear of the entrance to the Domestic-4 apron so that OLM could enter the apron to allow the aero-medical aircraft to continue taxying towards the eastern general aviation parking area.

The crew of OLM taxied into the Domestic-4 apron, and stopped in the vicinity of towbar disconnect point west, facing VBC, which was at that time located slightly to the east of, and facing west towards towbar disconnect point east.

The controller then instructed the crew of VBC to tow forward to towbar disconnect point east. The crew of VBC advised the controller that the towbar disconnect procedure was complete, and that they could taxi as required. The controller responded by issuing a clearance to the crew of VBC to taxi forward and hold short of taxiway Golf.

The dispatch engineers subsequently reported that their attention had been diverted when OLM taxied into the Domestic-4 apron and onto towbar disconnect point west. The dispatch engineer communicating with the crew recalled that the pilot in command confirmed that the aircraft brakes were parked, but could not recall hearing the pilot in command's instruction "Clear to disconnect". The other dispatch engineer, who was standing at the nose of the aircraft, subsequently reported that he realised the aircraft had begun to move forward when he felt a "bump" on the back of his head as it was contacted by the aircraft radome. He immediately turned, and realising that the other engineer had not noticed that VBC had begun to move, ran aft and dragged the other engineer clear of the vicinity of the right engine. The crew of VBC realised that the disconnect procedure had not been completed and stopped the aircraft. The disconnect procedure was completed and the aircraft recommenced taxying once the dispatch engineers had positioned themselves clear of the aircraft.

The crew of OLM taxied onto Bay 94A once VBC had recommenced taxying and was clear of towbar disconnect point east.

The operator reported that the flight interphone system from VBC was examined following the occurrence, and was found to be serviceable.

The operator's pushback procedures specified that at the completion of the pushback manoeuvre, the dispatch engineer would use the ground interphone to instruct the pilot in command to park the aircraft brakes. The correct response from the pilot in command was "Brakes parked", at which point the dispatch engineer was required to place a chock in front of the aircraft nose wheel and disconnect the pushback tow motor from the aircraft. The dispatch engineers did not place the nose wheel chock in position following the pushback.

The operator's procedures also specified that when the towbar had been disconnected and the steering bypass pin removed from the aircraft, the dispatch engineers were to stand by for the final command from the pilot in command to disconnect the ground interphone unit, using the phrase "Clear to disconnect". When given that command, the dispatch engineers were to disconnect the interphone, close the interphone panel door, and remove the nose wheel chock. They were then required to position themselves clear of the aircraft and in view of the flight crew so that the crew could confirm that the disconnect procedures were complete. The crew, however, commenced to taxi the aircraft without ensuring that the dispatch engineers were clear of the aircraft, and that the disconnect procedures were complete.

The pilot of a Cessna Skylane (C182) was preparing to conduct a private flight with three passengers. The pilot reported that the planned work-related flight was the first following a periodic maintenance inspection. After carrying out a pre-flight inspection, the pilot and passengers boarded the aircraft. The pilot ensured that the passengers' harnesses were secured, and the right front seat occupant was briefed to not touch the controls. The pilot switched on the aircraft's electrical power to use the radios in order to obtain the broadcast aerodrome information and an airways clearance. The pilot estimated that electrical power was drawn from the aircraft's battery for approximately two minutes during which time he made several radio transmissions. When he attempted to start the engine, battery power was depleted, and the electric starter would not turn the propeller.

The pilot reported that he then applied the parking brake and set the engine controls. After again instructing the passengers not to touch the aircraft controls, the pilot alighted and attempted to start the engine by hand swinging the propeller. On the second compression the engine started and accelerated to nearly full power. The aircraft moved forward and accelerated rapidly across the apron. Other than the passengers, no other person was known to have seen the pilot attempting to hand start the aircraft. Personnel working in or around other aircraft parked on the apron were alerted to the occurrence by the sound of an aircraft engine at or near full power.

Witnesses saw the C182 accelerate across the apron pursued by the pilot. They reported that the C182 nearly became airborne before its wingtip struck the windshield of a parked Cessna 402. The C182 continued across the apron and collided with the rear of a parked Metroliner. The rear fuselage of the Metroliner was significantly damaged by successive strikes from the C182's propeller blades. That impact swung the C182 and it continued unchecked, before colliding with a Cessna 206 (C206) that was parked 120 m from where the C182 had started. The pilot chased after the aircraft and although he gained entry to the cabin, he was unable to stop the engine before the collision with the C206.

The collision collapsed the left wing of the C182, preventing normal operation of the left cabin door and the right cabin door was blocked by the C206 fuselage. The pilot forced the left door open to evacuate the passengers. Maintenance personnel who had witnessed the collision came to the assistance of the C182 occupants. During the evacuation sequence, spilled fuel from the ruptured wing tanks had soaked the aircraft occupants and rescuers. One passenger was injured from the force of the collision. All of the occupants and some of the rescuers received minor skin burns from contact with aviation fuel. The other aircraft struck were neither occupied nor had maintenance personnel working on them at the time. The Metroliner, C206 and the C182 were extensively damaged.

The licensed aircraft maintenance engineer who supervised the maintenance inspection of the C182 reported that the 24-volt, lead-acid battery had been removed from the aircraft and inspected. The inspection was performed in accordance with the battery manufacturer's directions and included checking for any discolouration of the electrolyte and topping up. The battery had been placed on a low charge rate for several hours to ensure it was fully charged. Following the occurrence, a test of the battery's capacitance found that, when fully charged, it took six minutes under normal load to discharge. The manufacturer's specification for the battery capacitance equated to an output of 13 amperes for 30 minutes. The battery had been in service for approximately three years.

Post accident inspection of the aircraft controls found the throttle in the fully open position and the throttle friction nut loose. The park brake handle was selected to the on position but not firmly applied. When checked, the park brake functioned normally. The pilot reported that he had not checked the throttle setting and could not account for the setting being anything other than the normal start position. He had applied the park brake but had not chocked the wheels or secured the aircraft with the tail tie-down.

Civil Aviation Regulation (CAR) 231-"Manipulation of propeller", permitted hand starting when assistance from a licenced pilot or appropriately qualified person was not readily available. Although the aircraft was positioned approximately 50 m from the maintenance facility that carried out the inspection, the pilot had not sought assistance from the engineering staff. The maintenance organisation reported that a battery cart was available and the aircraft was fitted with an external power source receptacle.

Additionally, CAR 231 required the person manipulating the propeller to know the correct starting procedures for the aircraft. When attempted, without assistance from another qualified person at the controls, the regulation required that adequate provision was made to prevent the aircraft from moving forward, and that no one was on board the aircraft. The pilot reported that he had been shown the hand starting technique during basic flying training about six years previously. The instructor had demonstrated the technique on a Cessna 150 training aircraft. Although the technique had been demonstrated during that training, the pilot could not recall being briefed on all of the safety precautions associated with hand starting procedures.

A Boeing 737-476 (737) was en route from Melbourne to Coolangatta tracking northeast at flight level (FL) 310. A Cessna Aircraft Company C500 (Citation) was tracking southwest from Coolangatta to Essendon at the same level. The aircraft were on reciprocal tracks and the air traffic controller did not provide any assurance of separation between the two aircraft. The rate of closure of the aircraft was later calculated to be in excess of 800 kts. When the distance between the two aircraft was approximately 22 NM, the controller instructed the crews of both aircraft to alter heading and flight level. The controller's intervention ensured that a separation standard was established and maintained. The radar system's short-term conflict alert (STCA) activated. While the horizontal radar separation standard of 5 NM was never infringed, vertical separation, which assured separation for aircraft on reciprocal tracks, was not established until 25 seconds prior to the aircraft passing.

The 737 was being operated as a regular public transport flight and was flight planned at FL350. That aircraft departed Melbourne at 09:37 Eastern Standard Time and tracked via air route H66. That air route passed through the Benalla sector controller's area of responsibility. The Benalla sector controller was located in the Melbourne Air Traffic Control Centre. The crew of the 737 had requested FL290 on first contact with the Benalla sector controller, which was approved. At 09:52:51, the crew requested climb to FL310. The controller assigned FL310 at 09:55:59 and the recorded radar data indicated the aircraft reached that level at 09:57:43.

The Citation was operating a private flight at FL310 and departed Coolangatta at 08:16. Flight level 310 was a non-standard level for the track flown. Cruising levels were published in the Manual of Air Traffic Services (MATS) and the Aeronautical Information Publication (AIP). MATS also stated that aircraft operating at other than a level conforming to the table of cruising levels for the particular direction of flight or notifying intention to cruise at such a level, shall be advised accordingly and the pilot's intention sought. Non-standard levels were regularly used by air traffic control for maximum utilisation of available airspace.

The Citation pilot had flight planned to track via Parkes and TAREX, which was a non-standard route. The AIP stated that prior air traffic control approval was required for RNAV [area navigation] tracking on routes other than those published in AIP. An aircraft tracking from Coolangatta to Essendon would normally have tracked via air route Q94 and would have remained clear of the Benalla sector airspace. The pilot of the Citation had not received prior air traffic control approval to plan and conduct the flight via a non-standard route.

At 09:41:22, the crew of the 737 established radio contact with the Benalla sector controller. The controller was managing the combined airspace sectors of Eildon Weir and Benalla. The 737 crew was on climb FL200 and was recleared to the requested level of FL290. The controller was expecting the crew of the 737 on frequency and had earlier anticipated that the aircraft may be a problem at the planned flight level. However, at FL290 it would be separated from other aircraft.

Due to confusion caused by an anomaly with another aircraft, the Benalla controller was required to complete a significant period of coordination with another sector controller. The Benalla controller was discussing that problem at the console with the team leader when the crew of the 737 again made radio contact at 09:52:51. They reported maintaining FL290 and requested climb to FL310. The controller acknowledged the request and annotated the flight track with that request. The controller continued his discussion with the team leader and did not immediately coordinate the higher level request with the adjacent Parkes Sector.

At 09:53:37, the controller designated and accepted jurisdiction on the radar display of the Citation's flight track. That was before the pilot of the Citation established radio contact at 09:54:18 and reported maintaining FL310. The controller acknowledged that transmission and then transferred jurisdiction of two other aircraft to the Parkes sector controller.

At 09:55:56, about three minutes after receiving the 737 crew's change of level request, the controller coordinated the 737 with a request for FL310 with the Parkes sector controller. The Parkes sector controller concurred with the higher level and the Benalla controller cleared the 737 crew to climb. The controller did not recognise the potential conflict between the 737 and the Citation and continued his discussion with the team leader.

At 09:59:55, the controller activated the "individual quick look" function for the flight plan tracks of both aircraft. Almost simultaneously, the controller commenced action to ensure a separation standard was maintained between the two aircraft. The controller instructed the crew of the 737 to expedite descent to FL290 and instructed the pilot of the Citation to turn right 30 degrees. At 10:00:15, he further instructed the crew of the 737 to turn right 20 degrees. He also broadcast essential traffic information to the 737 crew about the position of the Citation. During that transmission, the short term conflict alert on the controller's radar display activated at 10:00:28 highlighting the close proximity of both aircraft. The traffic alerting and collision avoidance system (TCAS) of the 737 also activated, providing a traffic advisory warning to its crew. At 10:00:34, the controller told the pilot of the Citation to climb to FL320. At 10:00:57, a 2,000 ft vertical separation standard was established between the two aircraft when they were approximately 9 NM apart.

The controller had held a full performance rating within the group for a period just less than four years. He was completing the third day of a 5-day roster cycle. Although the controller was working a combined sector, the workload was considered light to moderate.

The British Aerospace BAe 146-200A (BAe 146) was being operated on a regular public transport service from Brisbane, Qld to Canberra, ACT. Approximately 5 minutes after take-off the flight crew detected that smoke was present on the flight deck. They donned their oxygen masks in accordance with the emergency checklists that dealt with smoke, fumes or fire and made a PAN transmission to air traffic control, requesting a return to the airport. The approach controller issued radar vectors to facilitate the prompt return of the aircraft to Brisbane and placed the airport's emergency services on standby. During the descent, the pilot in command briefed the cabin crew, alerting them to the possibility of a cabin evacuation.

At the time of the incident, the BAe 146 Quick Reference Handbook (QRH) contained an emergency checklist procedure titled Smoke, Fumes or Fire on Flight Deck or in Cabin - Any Source. That checklist inferred that if the source of the smoke was identified, the crew should then conduct an appropriate procedure from a choice of further checklists contained within the QRH. The crew's selection of an appropriate checklist was dependent on whether the source of smoke was either from the electrical system, from the air conditioning system, or from the cabin equipment/furnishings.

Initially believing that the electrical system was the source of the smoke, the crew commenced the emergency checklist for Electrical Smoke, Fumes or Fire of Unknown Origin. That checklist had the potential to take in excess of 8 minutes to complete because it involved the troubleshooting of the aircraft's electrical system to determine the source of the smoke. As the aircraft was close to landing and the crew's priority was to land as soon as possible, that checklist was not completed. Since the incident, the aircraft manufacturer issued a revision to the QRH that simplified and combined the checklists described above. The new checklist was not generated in response to this particular incident.

The aircraft landed 20 minutes after take-off without further incident. Rescue and fire fighting services (RFFS) were in attendance as the crew stopped the aircraft on the taxiway. The RFFS personnel inspected the aircraft's electronics bay in an attempt to trace the source of the smoke, but nothing abnormal was observed. The aircraft was then taxied to the airport terminal and the passengers were disembarked. The co-pilot suffered eye irritation as a result of the smoke, but the passengers and the other members of the crew reported no symptoms.

Maintenance personnel inspected the aircraft and established that the smoke and fumes in the cockpit were due to contaminated bleed air from the number 1 engine. During normal operation, bleed air from that engine, along with bleed air from the number 2 engine, was fed to air conditioning pack one. Pack one supplied conditioned air to the flight deck and augmented the passenger cabin supply. Bleed air from the number 3 and number 4 engines was fed to pack two, which in normal operation supplied air to the cabin only.

The engineers addressed the defect in accordance with the Civil Aviation Safety Authority (CASA) airworthiness directive AD/BAe146/86 and the British Aerospace Systems Information Service Bulletin (ISB) 21-150. That ISB required certain actions to be performed whenever a cabin air quality problem was identified, which was suspected of being associated with oil contamination of the air supply from the air conditioning packs. The bleed air supply from the number 1 engine was isolated, and the defect was deferred in accordance with the aircraft's approved Minimum Equipment List. The aircraft resumed service, and no further smoke or fumes were evident during subsequent flights.

The defective engine was removed from the aircraft 5 days later and was returned to the engine manufacturer for overhaul. The overhaul procedure revealed that the engine's number 2 forward and aft carbon seals had heavy carbon build-up and were leaking oil. The manufacturer's report stated that the engine's number 4 carbon seal also showed evidence of oil leakage. Previous incidents of air system contamination on this type of aircraft had indicated that the fumes were a consequence of failures of the engine oil seals.

It has been noted in previous incidents, both in Australia and overseas, that there was a reluctance of the crews to use oxygen masks when air contamination was detected on the flight deck. Those incidents indicated that operating crews were not aware of their potential impairment and the consequent effect on their decision-making ability. The safety implications of that impairment was reflected in the decision by CASA to adopt a United Kingdom Air Accidents Investigation Branch (AAIB) recommendation requiring flight crew to use oxygen masks selected to 100 percent when there was a suspicion of flight deck or cabin air contamination.

An Airbus Industries A330 (A330) aircraft was en-route from Melbourne, Vic. to Denpasar, Indonesia. The Yarowee sector air traffic controller had issued the crew of the A330 with a clearance to climb to flight level (FL) 340. The A330 was on a crossing flight path with a Boeing 737 (737) that was en-route from Adelaide, SA to Melbourne, Vic. at FL310. The 737 was under the control of the adjacent Canty sector controller. Both the Yarowee and Canty sector controllers had recognised that there was a potential confliction between the two aircraft. The controllers discussed the potential confliction at 1119 EST and estimated that the aircraft would pass close to the boundary between the two sectors. The Yarowee controller accepted the responsibility for separation. That controller reported a reasonably low traffic level, which allowed him the opportunity to monitor the separation between the two aircraft. To ensure that the minimum horizontal separation standard distance of 5 NM was maintained, the Yarowee controller advised the Canty controller that the A330 would travel to the left of the proposed track and pass to the west of the 737.

Subsequent to that decision, the Canty controller reassessed the separation between the two aircraft and concluded that the potential confliction would occur inside the Canty sector. At 1121 the Canty controller instructed the Yarowee sector controller to assign the A330 crew FL300 on climb. Maintaining that altitude would ensure that the vertical separation minimum of 1,000 ft would not be infringed. The Yarowee controller entered FL300 into The Australian Advanced Air Traffic System (TAAATS) as the amended cleared flight level (CFL) for the A330. That entry changed the colour of the CFL in the label of the A330 that was displayed to the Yarowee controller on his air situation display. According to TAAATS procedures, the different colour provided a memory prompt to the Yarowee controller indicating that he had not received a correct amended CFL read back by the crew of the A330. Normally, once a controller had assigned a CFL to a crew and received a correct read back of that CFL, the controller would cancel the prompt and the CFL in the aircraft label would return to its regular colour.

There was a distraction at a neighbouring console just after the Yarowee controller had entered FL300 into TAAATS but before he had assigned the crew of the A330 the amended CFL. When the attention of the Yarowee controller returned to the Yarowee air situation display, the cleared flight level for the A330 was highlighted to prompt him to confirm that FL300 had been issued to the A330 crew. The controller believed he had already issued the crew of the A330 the amended CFL and that he had received a correct read back of the amended CFL from the crew prior to the distraction. The Yarowee controller cancelled the prompt. Analysis of the voice recording confirmed that the crew of the A330 had not been issued FL300.

The Yarowee controller incorrectly believed the A330 crew had been assigned FL300 and consequently that a vertical separation standard of 1,000 ft had been established between the A330 and the 737. At 1127, the controller approved the A330 crew to track direct to Woomera. That action placed the two aircraft on crossing flight paths with no prescribed lateral separation.

At 1131, as the A330 approached the Yarowee sector boundary, the Yarowee controller transferred jurisdiction of the A330 to the Canty controller. The Canty controller accepted jurisdiction of the A330 at FL295 and waited for the A330 to call on the Canty frequency.

At 1132, the Canty controller received a TAAATS Cleared Level Adherence Monitor (CLAM) alarm when the A330 passed FL303 on climb to FL340. A short time later, when the A330 and the 737 were 12.5 NM apart, both the Canty and the Yarowee controllers received a Short-Term Conflict Alert (STCA) alarm from TAAATS. This alarm indicated to the controllers that the two aircraft were in potential conflict. Vertical separation reduced to 900 ft while horizontal separation reduced to 7.5 NM. That horizontal distance exceeded the minimum separation standard. There was no infringement of separation standards.

At the time of the CLAM and STCA alarms, the crew of the A330 was still on the Yarowee sector frequency. The Yarowee controller reported observing the A330 pass FL303 and resumed jurisdiction over the A330. That controller then queried the A330 crew about their assigned flight level. He did not pass traffic information to the crew of the A330 about the 737 because he did not believe there would be an infringement of separation standards. Nonetheless, he subsequently issued a turn instruction to the A330 crew to ensure that separation was maintained. The A330 crew acknowledged traffic following that controller's query regarding their CFL.

The Canty controller was unable to contact the crew of the A330. The controller was aware that the A330 had climbed through what the controller believed was the assigned level of FL300 and issued turn instructions to the 737 crew to ensure that separation was not infringed. The Canty controller did not inform the 737 crew of the reason the vector was issued, however, the 737 crew subsequently acknowledged sighting the A330.

The Canty sector was combined with a low-level sector at the time of the incident and the controller reported that there was a medium traffic level at the time of the occurrence.

The Yarowee controller had recently returned from leave. He had completed the three required familiarisation shifts, had a two-day break, and completed one unsupervised shift during the day prior to the incident shift.