VFR into IMC

On 11 October 2005 at about 1815 Eastern Standard Time, a Kawasaki Heavy Industries BK 117 B-2 helicopter, registered VH-BKS, became airborne at Brisbane's Princess Alexandra Hospital on a night Visual Flight Rules (VFR) flight to Maroochydore, Qld. On board the helicopter were the pilot, a paramedic and a crewman. The pilot had earlier departed Hervey Bay on a day VFR medical flight, arriving at the hospital at 1748 that afternoon. The incident flight was to reposition the helicopter at the operator's Maroochydore base location.

At about 1823, the pilot was advised by the Brisbane Approach North controller that the weather at Maroochydore included broken cloud, with a cloud base of 1,000 ft above ground level (AGL). In addition, the pilot reported that he observed a solid layer of cloud beneath and in front of the helicopter along the intended route.

The pilot's decision to continue the flight to Maroochydore committed the pilot to a night VFR flight above more than scattered cloud. The pilot could not assure himself of maintaining Visual Meteorological Conditions (VMC) during the remainder of the flight, with the result that the night VFR flight above more than scattered cloud was not possible.

On arrival at Maroochydore, the cloud base was such that the pilot was restricted to a recovery to land via an instrument approach, in conditions in which he was not qualified to operate, and for which the helicopter was not single-pilot instrument flight rules-equipped.

The report also details extensive safety action undertaken by the operator, the Queensland Department of Emergency Services, Airservices Australia and the Civil Aviation Safety Authority.

History of the flight

The pilot of a Cessna C206 was conducting a charter flight in accordance with the visual flight rules (VFR) from Margaret Bay to Cairns with a passenger and a cargo of live seafood. The flight was reported to have departed Margaret Bay at 1520 EST. At 1719 the Brisbane Daintree sector controller broadcast, on the area frequency, the amended Cairns terminal area forecast and the trend type forecast that indicated visual meteorological conditions (VMC) did not exist. Six minutes later, when the aircraft was estimated to have been northwest of Cooktown, the pilot requested the weather conditions at Mareeba. The controller informed the pilot of the automatic weather observing system information for Mareeba and said that he would attempt to obtain a cloud cover report from an overflying aircraft. The pilot was not informed of that information nor did he subsequently request it. At 1813 he reported at Cape Tribulation, 51 NM north of Cairns, and revised his estimate for Cairns to 1838. That estimate was 10 minutes after last light for Cairns. Shortly after, a pilot on the airstrip at Wonga Beach, about 38 NM north of Cairns, sighted the lights of an aircraft tracking coastal toward Cairns. That observer estimated that the aircraft was flying at an altitude of 100 ft and in visibility reduced to less than 1 NM in heavy rain and approaching darkness.

At 1824, four minutes before last light, the pilot contacted Cairns approach and reported that the aircraft was 33 NM north of Cairns. After the pilot confirmed that his operations were normal the approach controller advised him of the aerodrome terminal information service (ATIS) weather at Cairns. The controller asked the pilot if he was able to remain in sight of the coast and if he was capable of flight in instrument meteorological conditions (IMC). The pilot advised that he had the coast in sight and that he was not capable of flight in IMC. The controller subsequently issued the pilot with a clearance to follow the coast not above 1,000 ft and remain in VMC. Although the pilot had not declared an emergency, the controller recognised the potential danger and declared an uncertainty phase.

Radar data from the time the aircraft was identified north of Cairns showed that the aircraft tracked east of the coast at altitudes varying between 200 and 600 ft. During that time the approach controller provided the pilot with cloud and visibility information reported by pilots conducting instrument approaches to runway 15 at Cairns. He monitored the progress of the flight and provided the pilot with distance and groundspeed information. He also offered the pilot radar headings to establish the aircraft clear of terrain and position the aircraft for an approach to runway 15. The approach controller requested that the aerodrome controller select the approach lighting to maximum illumination. The pilot, in response to a query by the approach controller, advised that he had his landing lights on during the approach.

The Cairns meteorological observation at 1830 recorded a visibility of 2,500 m in rain showers with scattered stratus cloud at 300 ft and broken cumulus at 1,800 ft. A pilot making an instrument approach to Cairns ahead of the C206 reported the main cloud base as 1,100 ft with lower patches of cloud. He reported seeing the approach lights at 4 NM and the runway lights at 1 NM. The aerodrome controller estimated that the visibility at the time the C206 was making its approach was 1,500 m in heavy rain.

When the C206 was almost overhead the airport the pilot reported that he was unable to see the runway lights, so the controller instructed him to make a left orbit for a second landing attempt. The aerodrome controller saw the aircraft descend from 400 ft to approximately 100 ft during the turn and activated the crash alarm because he thought an accident was imminent. He selected omni-directional runway lighting to aid detection. The pilot's second approach was also unsuccessful and again the aircraft was seen to lose altitude while turning left. The approach controller then directed the pilot to take up a northerly heading, away from obstacles and terrain. He intended to position the aircraft for a third approach along the extended runway centre line so that the pilot would be better positioned to use the approach lighting for guidance to the runway. That flight path took the aircraft over the water off Machans Beach. At 1851, on the third attempt to approach and land and while being radar vectored onto a left base leg to runway 15, the aircraft disappeared from radar 2 NM north-north-east of Cairns.

Witnesses at Machans Beach reported seeing the lights of an aircraft flying at low-level offshore. They described seeing the lights rotate in a manner consistent with the aircraft rolling steeply to the left and disappearing from view in rain and mist. One witness reported hearing a faint sound of impact. Airport rescue and firefighting services had been alerted nearly one minute before the aircraft disappeared from radar. Despite the inclement conditions, an air and sea search of the area was conducted by the Cairns based search and rescue helicopter and rescue craft from the airport rescue and firefighting service. At 2050, searchers found the body of the passenger and debris in the water near the reported accident site. The following day some personal items and debris from the aircraft were found. Damage to the recovered aircraft parts suggested that the aircraft had impacted the water heavily and the accident was not survivable.

Air, sea and coastal searches continued over the next few days, including the use of airborne electronic detection equipment, but neither the pilot nor the main aircraft wreckage was found. On 9 November, 3 months after the accident, wreckage was sighted approximately 4 km offshore. Divers recovered parts from the underwater wreckage that were later identified as belonging to the accident aircraft.

Flight planning

The company was contracted to fly cargoes of live seafood, reported to be valued at up to $18,000 per flight, from Margaret Bay to Cairns. On the day of the accident, two company aircraft were scheduled to make the flight. Those flights were normally flown by instrument rated pilots. Regulations allowed cargo flights in single engine aircraft to be conducted in accordance with instrument flight rules (IFR) and at night. That allowed greater planning flexibility when tide levels dictated later departure times from Margaret Bay. Although both aircraft were equipped for flight in accordance with IFR only one had an autopilot. A serviceable autopilot was a requirement for single-pilot IFR. As only one instrument rated pilot was available it was decided that he should fly the auto-pilot equipped aircraft while the accident pilot flew the C206.

Careful planning was necessary to ensure that the aircraft piloted by the non-instrument rated pilot could conduct the flight in accordance with VFR. Flights to Margaret Bay were planned to arrive and depart during periods when tide levels below 1.8 m permitted use of the beach as a landing area. On the day of the accident there were two periods when tide levels were less than 1.8 m, one early to mid morning and the other from 1340 that afternoon. The earlier period was considered impractical. A first light departure from Cairns would not have allowed an arrival at Margaret Bay early enough to complete a normal turnaround on the beach before the advancing tide. The customer also preferred the later arrival time which just made possible a normal turnaround and return flight to Cairns in daylight. The pilot had determined 1500 as the latest time he could safely depart Margaret Bay for an arrival at Cairns before last light.

Boat crewmembers were sometimes transported to Margaret Bay on the flights. Regulations governing the carriage of passengers in single, reciprocating-engine aircraft required the flights to be conducted in accordance with day VFR. On 3 August a passenger was to be flown to Margaret Bay. Additionally, the customer requested that an injured deck hand on the boat be flown to Lockhart River while the transfer of cargo from the boat to the beach was being carried out. The deck hand had severed the tip of a finger the previous day. Although not requiring urgent medical attention he was anxious to get to hospital where it was reported that arrangements had been made to have the severed part of his finger sewn back. Overnight accommodation at Lockhart River had been arranged for the injured deck hand and a reservation made for him on the next day's scheduled flight to Cairns. The aircraft operator advised that the flight was not possible because the additional flying time to Lockhart River and return would not have ensured arrival back at Cairns before last light. Instead, the operator and the customer agreed to limit the volume of cargo in the C206 and fly the passenger direct to Cairns.

Delayed departure from Margaret Bay

Arrival of the aircraft was signalled to the crew of the fishing boat by circling overhead. When alerted, the crew commenced packing the live seafood into tubs in preparation for air transport to Cairns. Loading and transfer from the boat to the aircraft took longer than normal. Witnesses reported that the pilot appeared to be extremely agitated and was visibly distressed about the delay but he had expressed the belief that more favourable winds at a higher altitude might enable him to make up the lost time. The pilot of another VFR aircraft on the beach at that time reported that he estimated there was inadequate daylight for his return to Cairns with the existing wind conditions and elected to remain overnight. He had suggested the same course of action to the accident pilot but reported that the accident pilot had made up his mind to return to Cairns that day. Logistically, a landing at Cooktown would have taken surface transport over eight hours for the return journey from Cairns. The consequences of that action would have delayed treatment to the injured passenger and risked the loss of the perishable cargo.

Pilot experience

The pilot held a commercial pilot licence and a valid Class 1 medical certificate. He had accumulated 13,157 hours flight experience during 22 years of active employment in general aviation. Most of his flying experience was flight instruction and he held a current Grade 1 Instructor Rating. In 1991 he qualified for a Command Instrument Rating endorsed for non-directional beacon (NDB) approaches only. He had not renewed the rating after its expiry on 30 April 1993. The only recent instrument flight the pilot recorded were practice NDB approaches on a synthetic procedure trainer in preparation for revalidation of his lapsed instrument rating. In the 90 days prior to the accident he had logged 6.6 hours of night flying that included a navigation training flight and a check flight with the Chief Pilot.

During the 12 months preceding the accident the pilot had recorded 515 hours of which 35 hours were charter flying. Nearly all of that charter flying consisted of short local scenic and aerial work flights. Although the pilot had not flown to Margaret Bay for some time, he was familiar with the York Peninsula area. The 72-hour history of the pilot did not reveal any circumstances that would have affected his ability to perform his duties. The family of the pilot reported that he was unusually anxious about undertaking the flight and had expressed concern about the available time frame for the flight. The chief pilot, who was responsible for rostering pilots, described the pilot as reliable and possessing sound judgement. He described the pilot's decision to continue the flight in darkness and poor weather as uncharacteristic.

Aircraft and equipment

It was not possible to determine if there was any aircraft defect that may have contributed to the accident sequence. Examination of the small amount of wreckage that was recovered indicated that the aircraft engine was developing some power at the time of impact. Inspection of the aircraft's maintenance documentation showed that the required maintenance had been certified as completed. Pilots who flew the aircraft before the accident flight reported that it had been serviceable. The aircraft was certified for flight in accordance with the instrument flight rules (IFR). An entry on the duplicate copy of the maintenance release stated that there was no autopilot fitted and that for IFR operation in accordance with Civil Aviation Order (CAO) 20.18 subsection 4.1B (ie, Charter or Airwork), two instrument rated pilots were required. The duplicate copy of the maintenance release also noted that no Emergency Locator Transmitter (ELT) was installed. The aircraft was equipped with a VHF omni-directional radio range (VOR) receiver, incorporating glideslope information that enabled instrument landing system (ILS) approaches to be flown and automatic direction finding (ADF) radio navigation aids. The pilot had borrowed a portable hand-held Global Positioning System (GPS) satellite navigation unit for the flight and had mounted it on top of the instrument panel. The unit also displayed tracking and groundspeed information.

Weather

The forecast obtained by the pilot that morning indicated that VMC could be expected along the planned route but with visibility reduced to 2,000 m in isolated areas of drizzle, showers and smoke. The Cairns terminal area forecast (TAF) issued at 0825 forecast VMC with showers of rain but no further deterioration until 2000; well after the planned arrival at Cairns. At 1328 the Cairns TAF was amended to include an intermittent (INTER) deterioration in conditions below VMC from 1600. An INTER is used to indicate changes expected to occur frequently for periods of less than 30 minutes duration, with conditions fluctuating almost constantly, between the times specified in the forecast. The amended Cairns TAF also included a temporary (TEMPO) deterioration in conditions from 2000. TEMPO is used to indicate changes in prevailing conditions expected to last for a period of less than one hour in each instance. A further amendment to the Cairns TAF was issued at 1531 that forecast a visibility reduced to 9,000 m in showers and patches of low cloud with a base of 800 ft. A TEMPO period from 1800 forecast visibility reduced to 2,000 m in showers with patches of low cloud at 300 ft. This was the forecast broadcast by the controller at 1719, while the aircraft was estimated to be north-west of Cooktown.

Recorded rainfall data indicated that rainfall intensity at Cairns airport for that day was greatest between 1800 and 1900.

VFR considerations

The Aeronautical Information Publication stated that day VFR flights must not depart from an aerodrome unless the Estimated Time of Arrival (ETA) for the destination or alternate is at least 10 minutes before last light, after allowing for any required holding. Calculations based on aircraft performance and forecast winds gave a planned time interval of 3 hours 15 minutes. That meant that a departure from Margaret Bay at 1520 would result in an ETA for Cairns of 1835, seven minutes after last light. The amended Cairns TAF with the INTER requirement, broadcast by the controller at 1719, would have necessitated an arrival at Cairns no later than 1748 in order to meet the requirements for VFR flight. Pilots of VFR aircraft faced with similar circumstances were taught, as part of their training, to make an in-flight diversion to another destination while weather and daylight permitted. Weather conditions at Cooktown that afternoon were reported to be VMC.

Operational control

Operational control was defined as the exercise of authority over the initiation, continuation, termination or diversion of a flight, in the interest of the safety of an aircraft.

Prior to January 1992 the then Civil Aviation Authority through its specialist air traffic services personnel provided a comprehensive operational control service. Pilots of VFR flights proceeding more than 50 NM were required to submit flight plan information that was checked by controllers to ensure compliance with regulations and operational requirements. Operations controllers with access to current weather and NOTAM information monitored all flights to ensure that pilots were aware of significant changes to weather and other operational factors that may affect the safety of the flight. That information was transmitted through the aeronautical communications network to a pilot and, when considered necessary, an appropriate response sought. In extreme cases, pilots could be directed to land or be diverted to ensure the safety of the flight.

Following a review of that service, changes to Australian regulations were made to more closely align with international regulations. Those changes resulted in the withdrawal of the operational control service and greater responsibility for the safe conduct of a flight to the pilot in command. In effect that meant that operational control was exercised by a pilot complying with regulations, standard operating procedures as published in company Operations Manuals and by displaying sound airmanship.

The Civil Aviation Safety Authority (CASA), in its program of regulatory reform, intends to require air transport (incorporating what is currently termed charter) operators to establish and maintain a method of supervision of operations. If accepted, the changes would require operators to state in their Operations Manual the means by which operational control is to be exercised. It is envisioned that such regulation would cover at least a description of responsibilities concerning the initiation, continuation, termination or diversion of each flight and include specific information to pilots on suitable alternate aerodromes and the means of updating weather and NOTAM information.

Decision-making

In the manual "Aeronautical Decision Making for Commercial Pilots" developed for the United States Federal Aviation Administration (FAA), the point is made that charter pilots often have to balance commercial considerations against safety and compliance with regulations. In doing so they can be subjected to pressures from management, clients and passengers more attuned to non-safety related issues such as economy and expediency. Those people may assume that the pilot will resist these pressures if there is any "real" danger and respond appropriately to avoid disaster. Conversely, pilots can be persuaded, even to the detriment of safety, by the knowledge that a decision contrary to the wishes of the customer or management may incur economic penalties that could adversely affect commercial viability and hence their employment. Pilots who regularly fly in such environments become used to recognising those conflicting demands and practicing their decision-making skills.

The importance of good pilot decision-making skills was recognised by the Civil Aviation Safety Authority. In 1996 decision-making as a topic was included in the Human Performance and Limitations section of the Day VFR Syllabus (Aeroplanes) of the Aeronautical Knowledge requirements for pilots. The requirements included a knowledge of the basic concepts of decision making including the influence of employer pressure, the desire to get the task done, workload management, work overload and currency. That knowledge requirement was not made retrospective. Transport Canada introduced a similar requirement for commercial pilots engaged in multi-crew operations to complete a "once only" pilot decision-making course. Following an accident in 1998 involving a high-performance single-engine turbine aircraft, the Canadian Transportation Safety Board recommended that the requirement be extended to all pilots engaged in commercial operations.

Risk management

Identifying hazards and developing contingency plans to avoid or mitigate their effect is a risk management strategy used by safety-conscious individuals or organisations to reduce risk. The transport of perishable cargo from a remote beach landing site presented additional hazards to that of normal charter operations. The company had addressed the hazards associated with landing and taking off from beaches by determining tide heights that permitted adequate runway width and by additional beach take-off and landing training for pilots. Flights made under the IFR were not as likely to be delayed or diverted and reduced the risk of losing valuable cargoes because of the perishable nature of the live seafood. However, use of VFR aircraft and pilots increased the possibility of weather or daylight affecting an assured arrival.

The VFR pilot of the other aircraft engaged in the transport of live seafood from Margaret Bay to Cairns had identified risks associated with his operation and taken precautions to avoid them. He had fitted a marine high frequency channel to his aircraft's radio to permit direct communication with the fishing boat crew. That enabled him to advise them of his arrival so that they could prepare for the transfer of cargo and avoid delay. He also forewarned the crew of his latest time of departure of 1445 and his alternative arrangements for an overnight stay should the deadline not be met. Importantly, when the boat crew failed to meet the deadline he implemented his contingency plan and flew to a nearby island where he remained overnight, returning the next day as arranged, to collect the cargo and fly it to Cairns. That was the course of action he had suggested to the pilot of the C206 on the beach at Margaret Bay.

The Civil Aviation Safety Authority, in a discussion paper issued in May 2000, proposed changes for certification of commercial air transport operators (incorporating charter) that included an obligation for those operators to introduce an accident prevention and flight safety program incorporating risk management processes and hazard identification.

The helicopter company's operations, based at Cairns Airport, Queensland, included passenger charter flights between The Pier, at Cairns Harbour (4 km SE Cairns Airport) and Green Island (22 km NE Cairns Airport).

At about 1035 eastern standard time the pilot departed The Pier for Green Island in a Bell 206 helicopter with six passengers on board. Because of the likelihood of mechanical turbulence in the lee of the high terrain south of Trinity Inlet, he initially tracked via the Cairns Harbour shipping channel. When he reached the end of the shipping channel, he was unable to see the island because of rain so he descended from his cruise altitude of 500 ft to about 300 ft and was then able to see the island about 9 km ahead. The helicopter arrived at Green Island at about 1045.

At 1130, the pilot departed Green Island for The Pier with six passengers on board. There was light drizzle falling at the time but he assessed that conditions in the area were suitable for flight utilising external visual reference. The pilot again elected to track via the shipping channel. Clearance to enter the Cairns Control Zone was not immediately available because of other traffic, so the pilot conducted a number of orbits in the helicopter until he was issued with a clearance at about 1139 to track to The Pier via the shipping channel, not above 500 ft. The controllers advised the pilot that, within 7-9 km from The Pier, the cloud base was 800-1,000 ft, with some showers, and visibility less than 10 km.

As the pilot continued tracking along the shipping channel, using the channel beacons as track markers, he noticed that the weather conditions ahead were deteriorating. A short time later, he descended the helicopter to about 150 ft to keep the water surface in sight, and reduced speed. At about 1143, the controller cautioned the pilot that a parasail was operating in the Cairns Harbour area. A short time later, the pilot received a request for his arrival time from the company's office at The Pier. He responded that he expected to arrive in 5 minutes.

The pilot later reported that by that time the weather conditions had deteriorated further, he was flying at 50 ft or less above the water in light to moderate rain and could no longer see any channel beacons. He selected the windscreen demister on as condensation had begun to form on the inside surface. He also armed the inflatable floats that were fitted to the skid-type landing gear.

At about 1146, the pilot asked the controller for directions to The Pier. The tower controller advised that The Pier was on a bearing of 205 degrees M, at a range of 1.5 NM (3 km). At about that time, in-flight visibility rapidly deteriorated to an extent where external visual cues were not available. The pilot, noticing that the altimeter was indicating 100 feet, placed the helicopter in a gentle descent in an attempt to keep the surface of the water in sight. The helicopter contacted the water a short time later and rolled inverted. The pilot and five passengers quickly escaped from the fuselage to the surface of the water. One passenger was trapped in the cabin for a number of minutes and did not survive the accident.

The helicopter was certified for flight under the Visual Flight Rules and was equipped with a satellite navigation system receiver. Inflatable floats were attached to the skid type landing gear. These could be inflated by the pilot in the event of a water landing. The helicopter was not fitted with a radio altimeter.

The Cairns area was under the influence of south-easterly stream weather. The Bureau of Meteorology issued an amended aerodrome forecast for Cairns at 0808 for the 24-hour period from 1000. The forecast was for an easterly wind at 15 kt, visibility of 9,000 m, and light rain. Some cloud patches were expected with a base of 800 ft, a broken layer at 1,800 ft, and overcast at 10,000 ft. Periods of up to 1 hour of heavy rain, scattered cloud at 800 ft, and broken cloud at 1,500 ft were expected over the forecast period.

Controllers on duty in the tower indicated that the weather conditions had been fluctuating significantly and rapidly throughout the morning. There were periods when conditions met the criteria for VFR flight. This contrasted with intervals of low cloud and very heavy rain, amongst the worst conditions they had seen at Cairns. Radar images and rainfall rates suggested that visibility in the area of the accident could have been reduced to a few hundred metres or less. Personnel who were at The Pier at the time of the accident described the rainfall as torrential, with visibility as low as one car length.

A weather radar system operated by the Bureau of Meteorology was located at Saddle Mountain, approximately 11 km north-west of Cairns Airport. The weather radar data recorded at 1150 showed an area of moderate rainfall centred over Cairns Harbour, adjacent to Cairns City. It extended about 5.4 km north-south and about 3.6 km east-west.

The weather information the controller passed to the pilot was based on his visual assessment of the weather in Cairns Harbour as he saw it from the control tower. When the controller issued the caution to the pilot regarding the parasail, the radar indicated altitude of the helicopter was 100 ft.

The Bureau of Meteorology advised that conditions of minimum visibility at Cairns Airport occurred during the period between about 1155 and 1210. The recorded rainfall of 5.8 mm between 1150 and 1210 at Cairns Airport was similar to that which would be encountered in thunderstorms. Although there was an automatic weather station at Green Island it was not equipped to measure rainfall.

Examination of recorded Air Traffic Services radar data provided information on the track, altitude, and groundspeed of the helicopter for a portion of the flight. The data indicated that the helicopter was initially tracking via the Cairns Harbour shipping channel at about 100 kts and an altitude of 200 ft above mean sea level. At about 7 km from The Pier, the speed gradually decreased to 55-60 kts and then to below 40 kts. The last recorded speed was 31 kts. The recorded altitude during the final 2 minutes of the recording was 100 ft, apart from one value of 200 ft. The last recorded position of the helicopter was 2.4 km north-east of The Pier at about 1148.

Examination of the wreckage confirmed that the helicopter struck the water in a slight left skid-low, nose-low attitude, and at low forward and vertical speeds. All seats and safety harnesses retained their integrity. There was evidence of flexing of the roof frame on the right forward side of the cabin, immediately behind the pilot's seat resulting from induced stresses following main rotor blade contact with the water.

The postmortem examination report stated that the non-surviving passenger had received a minor head injury that may have had sufficient effect to prevent her from releasing her safety harness. The examination established that the passenger died as a result of drowning. The flexing of the cabin roof occurred above the seating position of the passenger who was trapped in the helicopter. It is possible that the roof flexed sufficiently to cause the head injury to that passenger.

Company ground staff who worked at Green Island conducted a safety briefing (in Japanese) for the passengers. Those staff had completed proficiency testing in emergency procedures applicable to Bell 206 helicopters. The operation of the life jackets, seat belts, and emergency exit procedures was demonstrated. The information was summarised on safety information cards (in English and Japanese) in the helicopter. Each passenger wore a life jacket contained in a belt-mounted bag.

The pilot said that, after the cabin filled with water, he was able to easily egress from the helicopter. When he surfaced, he saw 2 or 3 passengers on the opposite (left) side of the upturned fuselage. He dived and attempted to open the passenger door on the right side of the helicopter but was unable to do so. When he next surfaced, there were 5 passengers on the surface. He made a number of further attempts to open the right side door but could not. Two passengers had made a few dives from the opposite side of the helicopter and they brought the injured passenger to the surface.

The pilot reported that, during an earlier positioning flight to The Pier, the airspeed indicator (ASI) was not functioning normally in that it did not indicate above 40 kts. He thought that the fault was probably due to water in the pitot-static system and expected it to clear during the flight to Green Island. However, the fault remained. After landing at Green Island, the pilot sucked then blew into the pitot head in an attempt to remove any blockage that might be in the system. Because there were no maintenance facilities on the island, there was no means of assessing the serviceability of the instrument before the subsequent flight. The ASI did not function during the accident flight. The pilot said that he relied on the ground speed display on the GPS for speed information during the flight. He did not consider that this had any meaningful affect on his cockpit workload during the flight.

The opinion of other experienced helicopter pilots spoken to during the investigation was that the absence of an ASI would have increased the pilot's workload, particularly in view of the weather conditions. The erroneous indication on the ASI and the need to refer to the GPS display would have disrupted the pilot's normal instrument scan pattern. Further, the GPS displayed ground speed, not "airspeed", so the speed information the pilot was receiving was not appropriate to some flight regimes. Civil Aviation Order Part 20, Section 18 specifies that, for VFR charter operations, a helicopter must be equipped with a serviceable ASI prior to take-off.

The company advised that periods of poor weather usually generated higher demand for helicopter flights because rough seas and/or rain discouraged some tourists from returning to Cairns by boat. The pilot indicated that the company expected the pilots to "give it a go" in the case of bad weather. The company indicated that pilots were expected to "have a good look before turning back" during operations away from the departure area, but that there was no pressure placed on pilots to complete flights in unsuitable weather conditions.

The pilot was programmed to conduct a number of other flights later in the day. However, he stated that the schedule had no bearing on his decision to depart Green Island. The pilot reported that the usual routes from Green Island to Cairns were via the shipping channel, or coastal via False Cape. Wind from the south or south-east at about 15 knots or greater caused mechanical turbulence in the lee of the high terrain on the southern side of Trinity Inlet. Under such conditions he usually avoided the False Cape/coastal route because of passenger comfort considerations. The accident flight was one such instance.

The pilot said that when he departed Green Island, the weather conditions easily met the VFR criteria. His technique in conditions of deteriorating visibility was to descend, maintain a visual reference outside the cockpit and to reduce speed. He applied this technique on the accident flight. Although visibility was poor, he continued, in part because of his experience in operating in similar conditions, but also because the advice from the controller indicated that the weather would improve as he neared Cairns. However, the pilot emphasised that he had turned back on a number of previous occasions because of unsuitable weather conditions.

The pilot stated that, even though he held a night VFR rating it was not current. In addition, he disliked instrument flight and had undertaken minimal instrument flying since achieving the rating in 1992. In any event, the helicopter was not certified for IFR flight. Against this background, he did not consider turning at low level to fly back towards better conditions as a safe option.

The pilot reported that the visibility conditions during the return flight from Green Island were the worst that he had experienced. The sea surface became flat and featureless and blended completely with the precipitation. By that time, it was too late to turn around. He reflected that he might have been better placed by tracking coastal because vegetation and other land features would have provided a higher level of visual contrast against the rain/cloud and may have enabled him to safely continue the flight. Alternatively, he would have been able to land the helicopter and await passage of the weather.

The aerodrome controller activated the Cairns Airport Emergency Plan at 1147 after the helicopter disappeared from radar and the pilot did not respond to radio calls. The police, ambulance, Queensland Emergency Service (QES) helicopter, and Cairns Aviation Rescue and Fire Fighting (ARFF) unit responded. The ARFF response involved dispatching a vehicle towing a trailer mounted rescue boat to Marlin Marina boat ramp, near The Pier. The vehicle arrived at the boat ramp at 1204 and the boat reached the crash scene at 1209. By that time, a tourist vessel and a seaplane were in attendance and the QES helicopter was overhead. All persons involved in the accident were placed aboard the tourist vessel and taken to the Marlin Marina boat ramp. The ARFF later commented that had a launching facility been available at the Barron River adjacent to the airport, they would have arrived on the scene much quicker.

On 8 June 1998, at 0855 EST, the pilot of a Boeing 737 air transport aircraft reported receiving an emergency locator transmitter (ELT) signal about 25 NM west of Melbourne. The pilots of several other aircraft also reported hearing the emergency beacon signal on 121.5 MHZ. At 0949 the Australian search and rescue centre received the distress signal via a satellite and had a possible location in the Mount Macedon area. At 1012, VH-SAR, a dedicated search aircraft, departed Moorabbin tasked with locating the beacon using a homing device. The pilot of SAR reported that the cloud tops over Mount Macedon were about 4,500 ft. By about 1245, Cessna 210, UNH, was assessed to be the missing aircraft. UNH had been conducting a no search and rescue (NOSAR), visual flight rules (VFR) flight from Bendigo to Moorabbin. At 1302 a ground party discovered the wreckage of UNH on the north western slope of the Mount Macedon feature at a ground elevation of about 2,840 ft above mean sea level (AMSL). The aircraft had cut a 100 metre swath through tall trees in the direction of 060 degrees magnetic. Both wings and the tail plane were torn off before the fuselage impacted sloping ground.

Melbourne radar recorded only one minute 35 seconds of UNH's flight path. UNH had maintained a steady track of about 160 degrees magnetic at 122 kts groundspeed from Kyneton before turning east in the Woodend area. Shortly thereafter the aircraft turned onto an east north easterly heading before disappearing off radar. Briefly during the recorded easterly turn, the radar recorded a groundspeed of 153 kts. The groundspeed then decreased to 77 kts just before the aircraft disappeared off the radar screen. The forecast wind at the time was 180 deg (true) at 20 kts at 2,000 ft AMSL, and 170/20 kts at 5,000 ft. There was no altitude recorded for UNH on the radar tape.

A few minutes before the accident a qualified pilot, on the ground 6.5 km S of Kyneton, witnessed an aircraft meeting the description of UNH. This aircraft was flying SE at about 500 ft above ground level (AGL) just below the cloud. The weather to the north of Kyneton was clear sunshine. The cloud line was from Kyneton to the northern edge of Woodend. The Mount Macedon feature was obscured by cloud. The aircraft maintained a steady track towards Gisborne. He reported that the aircraft's engine sounded normal. He lost sight of the aircraft as it neared Woodend. At 0829 two other people heard an aircraft flying very low over their house near Woodend but they did not see it. They described the weather conditions as heavy fog to below the tops of tall trees. Another qualified pilot witnessed the weather from the ground in the Woodend area at about the time of the accident. He described the cloud as low stratus in the form of fog. He also said that Mount Macedon was not visible due to cloud coverage.

The ground level at Kyneton was about 1700 ft AMSL and at Woodend about 1900 ft, compared to about 2,840 ft at the accident site.

The Bureau of Meteorology described the weather conditions as: "Rain showers and drizzle accompanied by patchy low cloud, generally widespread on and south of the Great Dividing Range mainly east of 144 deg E, while conditions to the north were quite clear due to the drying out of the airstream". There was no cloud and excellent visibility at Bendigo and visual meteorological conditions (VMC) prevailed at Moorabbin. At Melbourne airport, 30 minutes after the accident, there were three OKTAS of cloud at 300 ft AGL, seven OKTAS at 800 ft, plus drizzle.

The 37-year-old pilot held a private pilot's licence, issued in August 1982. He was qualified to fly the Cessna 210, UNH, which he owned. He held a valid class two medical certificate with a restriction of needing vision correction to meet the near vision standard. No evidence was found that the pilot was suffering from any medical condition which could have contributed to the accident. Vision correction spectacles were found at the accident site and a taxi driver, who drove the pilot to Bendigo airport on the morning of the accident, stated that the pilot was wearing spectacles. The pilot had logged total flight time of 340 hours, comprised of 120 hours dual and 220 hours as pilot-in-command by day. He had never qualified for an instrument rating. He had logged only eight hours of simulated instrument flight time but was reported to have gained more simulated instrument flight rules (IFR) experience by practising with a safety pilot in accordance with the provisions of Civil Aviation Regulation 153. He was reported to have accrued 1.5 hours simulated IFR flight time as recently as 30 May 1998 between Mildura and Leigh Creek. His last biennial flight review was conducted on 28 May 1998. From 29 May 1998 until 8 June 1998, the pilot had logged 17 hours as pilot-in-command of UNH. He had shared the flying with another private pilot from Moorabbin to the Northern Territory to Bendigo. He was on the last leg of the return flight from the Northern Territory to Moorabbin when the accident occurred.

Late on the afternoon of 7 June 1998, the pilot, his companion pilot and two passengers had arrived at Bendigo in UNH. They refuelled the aircraft with 243 litres of AVGAS. Their intention was to continue the flight to Moorabbin that day but as there was some doubt about reaching Moorabbin before last light, the pilot elected to remain overnight at Bendigo and to continue the flight on 8 June 1998, weather permitting. For reasons unrelated to the accident, the companion pilot and one of the passengers elected to be driven by road to Melbourne on the night of 7 August 1998.

At 0644 on the morning of 8 June 1998, the pilot telephoned an Airservices Australia briefing officer and was given weather details for the proposed flight from Bendigo to Moorabbin. He did not submit a flight plan or a search and rescue time (SARTIME) to the briefing office for the flight. A flight log sheet, found in the aircraft after the accident, confirmed that the pilot had planned the flight from Bendigo to Moorabbin via Kyneton, Mount Cottrell and Point Ormond. On the recent flight legs from Victoria to the Northern Territory and return the pilot had nominated SARTIMEs to Airservices Australia.

For the trip to the Northern Territory and return to Victoria, the pilot had used his portable Garmin 195 global positioning system (GPS) to assist with navigation. He was reported to have been quite competent with its use. Another pilot, who had flown UNH in the past, using a similar portable GPS, reported experiencing erratic GPS tracking in the Mount Macedon area. However, on 30 June 1998 Airservices conducted flight test trials in the Mount Macedon area using a Gulfstream Commander 1000 test aircraft fitted with five GPS receivers. One GPS was a handheld Garmin GPS 90 with an external antenna, comparable to the GPS used in UNH. No fault was found with GPS tracking in the Mount Macedon area at the time of the trials.

The aircraft was examined at the accident site before being retrieved to Moorabbin airport where it was subjected to detailed examination. Evidence was found at the accident site that there was fuel on board the aircraft at impact. Damage sustained by the engine crankshaft confirmed that the engine was producing power at impact. No fault was found with the airframe or engine which may have contributed to the accident. Damage sustained by instruments and avionics was consistent with impact forces.