VFR into IMC

Personnel information

The pilot held a private pilot licence and a current medical certificate. His total flying experience was about 1,595 hours, of which about 19 were in the accident aircraft. He had flown 11 hours in the previous 30 days and about 8.5 hours on the day of the accident.

The pilot had obtained a NVFR rating in 1981 and a command instrument rating (single engine) in 1986. The instrument rating expired on 31 May 1997. There was no record that the pilot had maintained the recency requirements for these ratings. His logbook showed 305 hours of instrument flight time. However, it was not possible to determine his experience in flying in instrument meteorological conditions.

Meteorological information

The pilot obtained a weather forecast for the flight at about midday on the day of the accident. This included the forecast for the areas between Longreach and Dubbo and the terminal forecast for Coonamble. The forecast was for 3 octas of strato-cumulus cloud at 3,500 ft and 6 octas of alto-stratus cloud at 12,000 ft. Low cloud (base 800 ft) and drizzle were forecast for periods of less than 30 minutes between 1600 and midnight. Fog was not forecast for the period associated with the flight.

A cold front, including a band of middle and low-level cloud and associated rain, cleared the Coonamble area before 2100, leaving the sky mostly clear of cloud. Fog quickly developed in these conditions. An expected south-westerly change did not reach Coonamble until 0330 the following morning. Post-analysis of the synoptic situation indicated that the cloud cleared from the Coonamble area much earlier than expected, but was followed by the development of localised fog.

Aerodrome and approach information

Coonamble aerodrome is 604 ft above sea level. The 1,527 m sealed runway 05/23 was fitted with edge lighting but not approach lighting. A grass strip 12/30 intersected the western side of runway 05/23.

The aerodrome was served by a non-directional beacon (NDB) radio navigation aid located approximately 500 m to the north of the runway 23 threshold. A published instrument approach procedure using the NDB enabled aircraft to descend from 3,500 ft to 1,200 ft above sea level on an inbound track of 200 degrees M. At 1,200 ft an aircraft would have been 596 ft above the aerodrome elevation. The inbound track for the approach was 200 degrees M. If unable to see the runway when the aircraft was over the NDB at 1,200 ft, the procedure required that the pilot maintain a track of 200 degrees M, and climb to 3,500 ft.

Wreckage and impact information

The initial impact occurred about 120 m from the northwestern end of the grass runway while the aircraft was tracking 178 degrees M. Assuming an engine speed of 2,300 RPM, propeller slash marks at the accident site equated to an aircraft groundspeed of about 145 kts. The aircraft was descending at an angle of 5 degrees and was banked 32 degrees left. The landing gear and flaps were retracted. The wreckage trail extended 200 m beyond the initial impact point. The accident was not survivable.

No fault was found with the aircraft or its systems that may have contributed to the accident. At previous periodic inspections, the operational category of the aircraft had been downgraded from IFR to VFR Day. The serviceability status of the flight instruments at the time of the accident could not be established.

FACTUAL INFORMATION

The aircraft had been hired in Victoria by the pilot for an extended private business trip to south-east Queensland.

The aircraft disappeared on a NOSAR (no search and rescue watch) flight from Caloundra to Kooralbyn via Jacobs Well. The aircraft had not been reported missing and there was no evidence that the pilot had made any arrangements for a private SARWATCH. The pilot was not rated for flight in instrument flying conditions.

On 8 January 1996, a body, later identified as that of a passenger in the aircraft, was washed up on a beach near Caloundra and some aircraft wreckage was found on a beach at the south-eastern end of Bribie Island. The pilot's body was found in the same area the following day. Later, a member of the public handed to police additional pieces of wreckage which he had found in the area on 5 January.

Recorded data from the Brisbane Terminal Area radar (TAR) revealed that the aircraft tracked along the Bribie Island coast to a point three kilometres north-north-west of Woorim near the ocean beach. It disappeared from radar at the completion of a 180-degree left turn at 1456 EST. The aircraft was outside controlled airspace at the time and its transponder was not operating. The Bureau of Meteorology weather radar information showed a large rain squall at the southern end of Bribie Island between 1440 and 1520.  Correlation with the TAR-recorded information showed that the aircraft entered the area of the rain squall. Another pilot, who was conducting a scenic flight near the Glass House Mountains, confirmed that the southern end of Bribie Island was obscured by a heavy rain squall at the time of the disappearance.

The aircraft was fitted with an ELT which complied with TSO C91. No reports were received that indicated that the ELT operated during the accident sequence.

The aircraft has not been recovered.

ANALYSIS

Radar plots showed that the aircraft entered a heavy rain squall. The 180-degree turn may have been an attempt by the pilot to regain visual flight, but during the turn, control of the aircraft was probably lost.

SIGNIFICANT FACTORS

1. The pilot did not hold an instrument rating.
2. The aircraft entered a rain squall.

FACTUAL INFORMATION

Sequence of Events

The flight was planned to transport three passengers to Agnes Waters, returning on the same day.

The pilot commenced planning about two weeks before the flight. On the morning of the flight, he submitted a visual flight rules (VFR) flight plan which was received in Brisbane at 0543 EST. The flight plan indicated a planned departure time from Maroochydore of 0630, to cruise at 6,500 ft tracking about 5 NM west of Bundaberg and with a search and rescue time (SARTIME) for Agnes Waters of 1100.

At 0708 the pilot reported to Brisbane Flight Service that he was descending to 3,500 ft due to cloud. This was the last known radio transmission from the pilot.

Witnesses heard the aircraft circling for 5-10 minutes in the Kolan South area (10 NM west of Bundaberg airport) at about 0740. The engine sounded normal, the sound fading and increasing as the aircraft circled. One witness reported hearing a burst of engine power immediately followed by the sound of ground impact. None of the witnesses saw the aircraft before the accident.

The wreckage was found in an open, fallow cane field. The accident was not survivable, and all four occupants were killed by impact forces.

Pilot in Command

The pilot held a valid class 2 medical certificate for a private pilot licence. There was no known medical condition which could have contributed to the accident.

The pilot was adequately rested prior to the accident.

Of his 342 flying hours, the pilot had completed 32 hours on this type of aircraft. He had flown 4 hours (2 hours on type) in the previous 90 days.

Three days before the accident, the pilot had taken part in a club competition with an instructor pilot seated in the right seat. The competition included a climb under simulated instrument meteorological conditions (IMC) from 500 ft to 2,000 ft and some 45-degree angle of bank turns. This exercise was completed to the satisfaction of the instructor pilot. The pilot had logged 7 hours instrument flight time although he did not hold an instrument rating.

The pilot's last biennial flight review was conducted five months before the accident.

Meteorology

Over the period of the flight, the general weather in the area consisted of a very moist, unstable light northerly flow ahead of a trough to the west of the Great Dividing Range. Winds below 5,000 ft were north-westerly at less than 15 kts. In the Maroochydore area at 0600 there was scattered cumuliform cloud with a base around 3,000 ft and broken middle level cloud. ('Scattered' indicates 1-4 octas of cloud cover and 'broken' 5-7 octas.) Further north, the main base lowered and became broken to overcast by Maryborough.

The area forecast (ARFOR) for Area 40 covering the period 0130 to 1800 issued by the Bureau of Meteorology indicated thunderstorms and showers clearing from the coast by 0400 and redeveloping after 1200. The amended Area 40 forecast for the period 0600 to 2100 indicated scattered showers on the coast north of Bundaberg until 0900, isolated showers until 1200 and scattered showers and thunderstorms after 1200.

Terminal area forecasts (TAFs) and amended TAFs issued for Maryborough and Bundaberg were similar. The forecast issued at 0426 indicated a light northerly wind, scattered cumulus cloud and temporary periods after 1300 (up to 60 minutes) of thunderstorm activity. These forecasts were amended at 0725 to reflect intermittent periods (up to 30 minutes) of reduced visibility, showers, rain, and low cloud for the period from 0700 to 1300; and again at 0803 to predict intermittent periods of thunderstorms and rain between 0800 and 1300.

A pilot who arrived at Bundaberg at about 0710 from Archerfield stated that conditions were visual until about 20 NM south of Bundaberg when he encountered heavy rain. Maryborough had some cloud, but the circuit area was visual. He made a distance measuring equipment (DME) arrival to Bundaberg down to 840 ft before landing. He stated that there were lower patches of cloud with rain, and he estimated the cloud base on departure 25 minutes later to be about 900 ft.

A second pilot departed Bundaberg soon after 0700. He said the cloud base was about 400 ft, broken and in layers. There was no rain, and visibility was about 10 NM.

A third pilot who also departed soon after 0700 reported scattered cloud at about 300 ft in layers and that the coastal route to the south-east appeared to be good. To the north-west through north to the north-east, visibility was restricted in falling rain. He said the cloud extended to Flight Level (FL) 170.

A pilot who arrived at 0905 said that the cloud was unbroken from FL160 to 600 ft from 30 NM south of Bundaberg. There were build-ups with heavy rain to the north and south of Bundaberg.

Witnesses on the ground in the South Kolan area reported hearing a thunderstorm at the time of the accident. They reported low cloud and light rain.

Communications

A transmission from the pilot at 0708 was the last recorded transmission from the aircraft. The Bundaberg aviation data tape did not record any transmissions from the accident aircraft.

An analysis of the appropriate radar tapes did not indicate any trace of the aircraft.

Wreckage and Impact

The aircraft had impacted the ground in a steep nose-down attitude, right wing low, while rotating to the right. The aircraft disintegrated on impact, with the majority of the wreckage coming to rest about 23 m forward of the initial impact site.

The right wingtip had struck the ground first about 4 m before the main impact, followed by the right mainwheel.

After the main impact, the aircraft broke up, with sections of wreckage found up to 60 m from the main impact point. Fuel was spread over a wide area to the right of the wreckage centreline; consequently, the wreckage did not burn.

Both wings displayed typical evidence of in-flight overstress in a positive 'g' direction, indicating a possible attempt to recover the aircraft to level flight before impact. All control surfaces were present and control cables and push rods were still attached although severely disrupted.

The engine was subjected to an on-site examination and later to a partial tear down. No pre-accident fault could be found with the engine. The lack of pre-impact damage is supported by witness evidence of hearing the sound of an aircraft's engine.

Other components were examined in an attempt to determine aircraft configuration, attitude, and serviceability. The attitude indicator gyro and the vacuum pump both showed signs of operation before impact, but the degree of damage made obtaining any useful information from any of the other recovered components impossible. A further difficulty was encountered in finding small components due to their wide distribution and a combination of soft soil and torrential rain.

The aircraft was fitted with a Trimble global positioning system (GPS) mounted on the instrument panel with tape but not connected to the aircraft. The pilot had prepared the GPS the day before the accident and had asked for help from another pilot to program it. One pilot claimed that it was not an easy GPS to use and that he had difficulty turning it on. No information was recovered from the GPS.

Emergency Locator Transmitter

The aircraft was equipped with a fixed Dorne and Margolin 6.1 emergency locator transmitter (ELT) which complied with TSO C91. The ELT was severely damaged in the accident and failed to operate.

Weight and Balance

The aircraft's weight was estimated at 1,270 kg at take-off, which is within weight limits. Load distribution could not be determined.

Aircraft Documentation

The current maintenance release was not found at the accident site. However, previous maintenance releases and aircraft logbooks indicated that all relevant engine and airframe airworthiness directives were incorporated and that the aircraft should have been serviceable for the flight.

ANALYSIS

The pilot probably held ARFORs and TAFs issued at 0130 and 0426 which indicated little concern for the period of the flight to Agnes Waters and return. The ARFOR indicated only scattered showers for the period and the TAF predicted scattered cumulus cloud. Consequently, the pilot probably had few concerns about proceeding VFR on his planned track.

A TAF issued for Bundaberg at 0725 indicated intermittent periods from 0700 to 1300 of reduced visibility, showers, rain, and cloud at 900 ft. The pilot was probably not aware of this forecast.

The aircraft seemed to be serviceable at the time of impact. The engine was operating, and the airframe was intact. No evidence was found to suggest any flight control circuit failures. Damage to the attitude indicator gyro and the vacuum pump indicated that both of these components were operating at impact. Consequently, the aircraft flight instruments were probably operating normally.

The pilot was considered to be cautious and conscientious in his approach to flight preparation and in-flight procedures. He commenced planning the trip two weeks before departure by discussing the route with instructor pilots and preparing a chart. He had sought help in preparing the GPS and participated in a club competition three days before the accident. On the day of the flight, the pilot had submitted a flight plan.

About 30 minutes before the accident the pilot had descended to avoid cloud. This indicates that his intention was to continue with the planned flight and to remain visual. However, at some point near Bundaberg the aircraft entered cloud. This may have been inadvertent, or the pilot, relying on the forecast which he held, may have decided to fly through what he thought was a small area of cloud.

Witnesses reported the aircraft circling for up to 10 minutes and during this manoeuvring, the pilot probably entered a thunderstorm. A combination of low instrument hours, no instrument rating and turbulence in the cloud could lead to pilot disorientation and loss of control.

CONCLUSIONS

Findings

1. The pilot in command held a valid pilot licence.
2. The pilot in command did not hold an instrument rating.
3. There was no evidence found to indicate that the performance of the pilot in command was adversely affected by any physical or medical condition.
4. There was no evidence found to indicate that the aircraft was other than airworthy for the flight.
5. The weather forecasts obtained by the pilot indicated that the weather was suitable for the flight as planned.
6. The pilot submitted a VFR flight plan for the Maroochydore to Agnes Waters route.
7. While en route, the weather deteriorated, necessitating a descent by the aircraft.
8. Amended forecasts issued while the aircraft was in flight were probably not received by the pilot.
9. The aircraft entered cloud.
10. The accident was not survivable.

Significant Factors

1. Weather conditions encountered south of Bundaberg were considerably worse than the forecast held by the pilot.
2. The pilot allowed the aircraft to enter cloud.
3. The pilot in command lost control of the aircraft and was not able to recover control before ground impact.

1. FACTUAL INFORMATION

1.1 History of the flight

The pilot had planned to fly his own aircraft to Brisbane to attend an important business meeting. On the day of the flight a weather forecast was obtained by the pilot before his early morning departure from Longreach. The Area 40 forecast described a moist air mass which had engulfed south-eastern Queensland resulting in low stratus cloud, rain and fog over the eastern Darling Downs. A clearing change from the south-west was expected during the afternoon.

The aircraft was fitted with a GPS (Global Positioning System) which was unserviceable. Subsequently, the pilot borrowed a portable unit as an aid to navigation for this flight. He had planned to fly direct to Archerfield, the general aviation aerodrome for Brisbane. No flight plan was lodged with air traffic services for the VFR (visual flight rules) flight nor was there a need to do so.

In the Injune area the pilot noticed extensive cloud ahead along his chosen route and he decided to divert to Roma. During the subsequent descent the aircraft entered cloud at 9,000 ft and broke out at 7,000 ft. Following the landing the pilot was met by a local operator, who was a LAME (licenced aircraft maintenance engineer) and a pilot. The operator had extensive knowledge of operations in south-east Queensland. He was aware of the poor weather further east which he later confirmed by obtaining an actual weather observation from another pilot stationed at Toowoomba airport.  Over coffee he advised the pilot to delay his departure until the next day as an early morning start would still enable him to meet his business commitment. However, the pilot seemed inclined to continue with his original plan. He explained the importance of his business meeting in Brisbane, scheduled at 0900 the next day.

The pilot delayed his departure until 1240 leaving the local operator with the impression that he intended to follow the Warrego Highway to Brisbane. At about 1405, the aircraft, which was partially obscured by cloud, was sighted by a LAME as it flew to the south of Toowoomba airport. The aircraft was next observed by several witnesses, some of whom were pilots, as it flew over Toowoomba City at 150-200 ft AGL (above ground level), under a cloud base of 400-500 ft. It appeared to be at cruise speed and the sound of the engine supported this observation. The aircraft was flying due east and was seen to enter a fog bank in the vicinity of the Toowoomba Grammar School and then bank slightly to the left as it disappeared from view.

Next, the aircraft broke minor branches off the top of a 15 m high tree located on the crest of the Toowoomba Range which was enveloped in thick fog. The aircraft was in a shallow descent when it struck the lower trunk of a large tree and crashed through the roof of a house 325 m beyond and below the ridgeline. The aircraft exploded on impact partially demolishing the house and setting it on fire. The pilot received fatal injuries. The two occupants of the house escaped through windows. Both were injured with one person requiring hospitalisation.

1.2 Personnel information

1.2.1 Pilot in Command

The pilot was aged 51 years and had commenced flying training in 1979.  In 1983 he obtained a restricted private pilot licence which he upgraded to an unrestricted licence in 1990.  Over the 15 year period he accumulated 285 hours flying experience, 30 of which were on the Cessna 210 aircraft type. His medical status for the licence was valid until 16 June 1996. His last medical examination report was annotated with the requirement to wear spectacles whilst flying.

During his stopover at Roma, he confided to the local operator that he still was uncomfortable flying his aircraft and that he was not fully knowledgeable about its operation. The local operator observed that the pilot looked fatigued. The pilot admitted that he had retired to bed at 0230 that morning and had arisen at 0530 to prepare for the flight to Archerfield. He also said that he felt fatigued especially after his experience of descending through cloud which had unnerved him. He said that he had little instrument flying experience and did not have an instrument rating.

1.2.2 Previous 72 hours history

The pilot owned a hotel and was involved in running the business. On the night before the flight, he had had a maximum of three hours sleep. His previous recent history could not be established. The postmortem examination report indicated the presence of Paracetamol, a pain killer available without prescription.

1.3 Aircraft information

The aircraft was placed on the Australian Register on 8 January 1979. The present owner obtained the aircraft on 2 March 1995. The maintenance release was destroyed in the fire. A cursory inspection of the maintenance release by the LAME during its stopover at Roma indicated that the aircraft was due for a periodic maintenance inspection in 16 flight hours. Examination of the known flying activity of the aircraft reduced this period to 10 hours. There were no known outstanding maintenance defects.

1.4 Meteorological information

1.4.1 Introduction

The flight was to be operated under VFR from the departure aerodrome. The pilot was required to obtain the area forecasts (ARFORs) covering his route and the appropriate terminal area forecasts (TAFs). The pilot obtained ARFORs 40 and 41, but it is not known whether he obtained a TAF for his destination, Archerfield. ARFOR 40 covers a large area of south-east Queensland, including the eastern Darling Downs and the Brisbane area.

1.4.2 Area 40 forecast

The forecast valid from 0300 to 1800, gave an overview of scattered rain and showers clearing slowly from western parts after 0900. Forecast cloud consisted of broken stratus, base 700 ft, tops 3,000 ft, rain and showers. Also present was scattered cumulus, strato-cumulus, base 4,000 ft, tops 8,000 ft inland and alto-cumulus above 12,000 ft. The predicted visibility was 3,000 m in rain and showers.

The Archerfield TAF current from 0600 to 1800, forecast one OKTA (one-eighth cloud cover) stratus at 1,000 ft and 4 OKTA strato-cumulus at 2,500 ft with a deterioration to 5 OKTA stratus at 1,000 ft with visibility reduced to 4,000 m in rain. The Toowoomba TAF was similar with the cloud base 800 ft.

1.4.3 Weather conditions at Toowoomba

Actual weather observations by local pilots and other witnesses in the Toowoomba area indicated a cloud base sloping down to the east. The general cloud base at Toowoomba aerodrome was about 800 ft as forecast. It sloped to 400-500 ft over the city. A large fog bank enveloped the range area on the eastern boundary of the city until 1500 when the fog lifted to form low stratus. The Bureau of Meteorology observation at 1500 in the city reported complete cloud cover, rain with dry and wet bulb temperatures of 14 degrees Celsius.

1.5 Other information

1.5.1 A Safety Study of VFR Flight into Adverse Weather issued by the Transport Safety Board (TSB) of Canada published on 14 November 1990 found that:

• TSB data demonstrated a considerably higher accident rate for pilots with less than 400 flight hours.
• Business flying pilots were older than average (older than 40 years) and few held an instrument rating.
• They showed a tendency to fly in conditions which surpassed their personal ability or that of their aircraft.
• Visual restrictions in older pilots (50 years plus) lead to an increase in vertigo occurrences.
• Low time pilots had a strong tendency for poor in-flight decision making and often chose to fly into adverse weather.
• Occurrences showed inadequate planning, entering into flight operations beyond the pilot's ability and adopting improper procedures.
• Business pilots often made a conscious decision to continue flight despite the adverse weather conditions being encountered. Pressure to complete the flight was evident often from the pilot himself and this pressure took on a sufficiently high priority to jeopardise safety.

1.5.2 The Bureau's records show that on 1 May 1995 the pilot had been involved in conducting a VFR flight in IMC (instrument meteorology conditions) at Townsville. During descent to Townsville the pilot found himself in cloud and the services of the Townsville Approach Radar controller were required to vector the aircraft to a known clear area.

1.5.3 The visual flight rules state that the flight must be conducted in VMC (visual meteorological conditions). For flight outside controlled airspace and below 3,000 ft AMSL (above mean sea level), or 1,000 ft AGL (above ground level) whichever is the higher, the visibility must be 5,000 m or greater and the aircraft must remain clear of cloud.

2. ANALYSIS

2.1 Introduction

The investigation established that the aircraft was capable of normal operation at the time of impact. There was evidence to indicate that the performance of the pilot was affected by fatigue which may have adversely influenced his ability to carry out his task. Most of the aspects identified in the Canadian study of flight into adverse weather were present in this accident.

2.2 Examination of the aircraft

Information from witnesses who saw and heard the aircraft in the Toowoomba area said the engine sounded normal.

Metallurgical examination of the exhaust manifold confirmed the engine was operating at the time of impact. Inspection of the aircraft wreckage and documentation did not reveal any significant discrepancies which could have contributed to the accident. The immediate explosion on impact and the intensity of the fire which followed indicated that the fuel tanks contained a substantial amount of fuel when the aircraft crashed.

2.3 The weather

Witnesses were unanimous in describing thick fog over the Toowoomba Range which did not lift until about an hour after the crash. This was a clear indication that VMC did not exist at the time of the accident.

2.4 Conduct of the flight

It is clear from the pilot's comments that he was inexperienced and underconfident in operating his aircraft. Prior to the accident he admitted feeling fatigued and a witness remarked that he looked fatigued. While the pilot may have admitted feeling fatigued, one of the most dangerous aspects of performance degradation with sleep loss, is that a person is unlikely to be aware of the manner and extent of their deteriorating performance (Hawkins, 1987). Fatigue can result in a number of significant decreases in performance such as poor self-monitoring, increased susceptibility to distraction, lowered arousal and increased reaction time.

The pilot felt compelled to continue his flight to attend an important business meeting. He could have landed his aircraft at either Oakey or Toowoomba aerodromes and hired a vehicle to drive the remaining distance to Brisbane for his business meeting, which was not scheduled until 0900 the next day. One important aspect of acute fatigue is that the ability to make clear decisions is markedly reduced. Despite his previous encounter with cloud, the pilot continued the flight in non-VMC weather conditions.

2.5 The final flight path

The distance flown from entry into the fog bank to impact was approximately 850 m which would have been covered in about 10 to 12 seconds flying at a slow cruise. Considering the proximity of the terrain which the pilot must have been aware of, his anxiety and disorientation in the fog would have been significant. The aircraft's attitude at impact was nearly wings level and in a slight descent. This would suggest that the pilot maintained sufficient control to keep the aircraft nearly level from the time it entered fog to the point of impact. It is possible that the slight descent profile in the aircraft's attitude was a pilot control input in an attempt to regain visual contact with the ground.

3. CONCLUSIONS

3.1 Findings

1. The aircraft was serviceable and carried sufficient fuel for the intended flight.
2. The Area 40 Forecast indicated that a VFR flight to destination was unlikely to succeed.
3. Cloud in the Toowoomba Range area was at ground level.
4. The pilot did not have an instrument rating.
5. He was relatively inexperienced in total hours and on the aircraft type.
6. He was suffering from fatigue.
7. He seemed compelled to continue the flight to destination.
8. He had an important business meeting to attend in Brisbane the next morning.
9. He was flying under a low overcast when the aircraft entered fog.

3.2 Significant Factors

1. The pilot was suffering from fatigue.
2. The weather en route was not suitable for VFR flight.
3. The pilot had an important meeting to attend the following morning.
4. The pilot operated his aircraft in IMC. He was not rated for nor experienced in IMC operations.

The purpose of the flight, which had departed from Moorabbin earlier in the week, was to enable the pilot to achieve the required hours for the issue of a commercial pilot licence.

On the day of the accident the pilot had submitted a visual flight rules (VFR) flight plan before departing from Ayers Rock at about 1000 CST, accompanied by one passenger.  The aircraft tracked via Nullabor to Ceduna, where a stop was made for fuel and lunch, then departed at about 1625 for Adelaide.

At 1754, in the vicinity of Cowell, the pilot contacted Adelaide Flight Service Unit requesting clearance to climb from 3,000 ft to 6,000 ft above mean sea level (AMSL). The Flight Service Officer (FSO) queried the request as 6,000 ft was non-hemispherical, and an IFR altitude, although no instrument flight rules (IFR) flight plan was held for the aircraft. After further discussions with the pilot, the FSO established that the flight was operating under VFR, and the pilot amended the requested altitude to 5,500 ft.

The pilot was instructed to contact Adelaide Approach, and, as the aircraft approached 50 km from Adelaide, it was cleared to descend to 1,000 ft. The pilot advised commencing descent immediately. Several minutes later the aircraft was observed on radar, about 46 km north-west of Adelaide over St Vincent Gulf, passing through 2,600 ft on descent.  The radar return then disappeared and attempted radio contact with the aircraft was unsuccessful. A distress phase was initiated.

An IFR aircraft, departing Adelaide to the north, was diverted to the area in an effort to locate the missing aircraft. The pilot reported that the cloud base was 1,000 ft with patches to 600 ft.  It was dark, and rain showers were in the area. The Bureau of Meteorology advised that isolated thunderstorms were also in the area.

An air and sea search found pieces of floating wreckage and other debris. Later searching discovered the wreckage on the seabed in the vicinity of the point where the aircraft was last seen on radar.

Underwater photography showed that the aircraft had sustained extensive damage, indicating a high-speed impact with the water.  All extremities of the aircraft could be accounted for.  The instrument panel was recovered from the wreckage for further analysis which revealed that all instruments had been serviceable, and that vacuum pressure was available for the gyro instruments.  During inspection of the attitude indicator, witness marks indicated that the aircraft was probably in a wings level, 60 degree nose down attitude at impact.

No evidence has been found to suggest that the aircraft was other than serviceable prior to impact.

The recorded radar data was examined in detail and showed the aircraft descending to, then levelling at about 1,000 ft before commencing a steepening left turn with a very high rate of descent.  The radar return was lost at about 300 ft.  The radar data does not take the current QNH into consideration and indicated altitudes may not coincide with AMSL altitudes.

Approaching Adelaide, the pilot probably commenced an early descent in order to remain beneath the cloud base. The left turn observed on radar is consistent with an attempt by the pilot to regain visual reference following inadvertent entry to cloud.

The pilot may have been suffering from fatigue, having been on duty since early that morning and having flown for more than 6 hours, particularly as the latter part of the flight was in marginal VFR weather conditions.

Significant factors

1. It is likely that the pilot inadvertently entered instrument meteorological conditions.
2. While attempting to regain visual reference, control of the aircraft was lost at a height insufficient to effect recovery.

FACTUAL INFORMATION

Circumstances

The pilot of the Piper Aztec submitted flight plan details by telephone to Cairns Tower for a visual flight rules (VFR) charter flight from Cairns to Palm Island via Innisfail. The plan indicated an initial track of 153 degrees M at an altitude of 5,000 ft.

The aircraft departed Cairns at 0946 hours EST and the pilot advised Cairns Approach that he was tracking on the

153 omni radial from Cairns. At 0954.35 he reported maintaining 5,000 ft. At 0956.02 a regular public transport (RPT) aircraft inbound to Cairns from the south reported approaching 7,000 ft and was subsequently cleared to descend to 6,000 ft. At 0956.59, after the potential confliction with the Aztec was resolved, the RPT aircraft was cleared to descend to 4,100 ft. At this time the Aztec was 23 NM from Cairns at 4,600 ft and about 2 NM right of track. A short time later the approach controller noticed that the radar returns from the Aztec had ceased.

Terrain in the area is known to cause shielding and the loss of radar returns. The controller assumed that shielding had caused the Aztec to disappear from radar so he instructed the pilot of the Aztec to call the area flight service frequency, as there was no further requirement to remain on the approach frequency. No reply to this transmission was received and this was also thought to be due to terrain shielding. A short time later other aircraft in the area reported the operation of an emergency beacon. A distress phase was initiated, and the wreckage of the Aztec was subsequently located on the western side of a blind valley north-west of Bellenden Ker Centre Peak at about 4,200 ft above mean sea level (AMSL) by a search helicopter.

Examination of the recorded radar data indicated that the aircraft gradually drifted right of track during the climb to 5,000 ft. At top of climb, some 15 NM south of Cairns Airport, it was about 0.75 NM right of track. At around this point, the track deviated further right by about 12 degrees. This track remained relatively constant until the aircraft was about 24 NM from Cairns where it again turned right. The aircraft maintained 5,000 ft to about 19 NM from Cairns after which it descended to 4,800 ft and remained between 4,800 and 4,700 ft until about 23 NM from Cairns. From this position it commenced further descent which continued for about 1 minute until the radar return ceased at a recorded altitude of 4,200 ft. During the descent the computed groundspeed of the aircraft decreased from 137 kt to 105 kt.

Examination at the accident site indicated that the aircraft struck the rainforest canopy at 4,200 ft AMSL with a descent angle of about 8 degrees and banked about 22 degrees to the right. The aircraft track at impact was about 196 degrees M.

Wreckage Examination

Examination of the aircraft wreckage did not reveal any abnormality which might have contributed to the accident.

Other than a complete set of Instrument Approach and Landing Charts, no other maps or charts were found in the wreckage. 

The Pilot

The pilot held a commercial pilot licence and was endorsed to fly PA-23 aircraft. Although his instrument rating had expired, he had conducted some instrument flying practice during the day prior to the accident.

The pilot had only limited flying experience in the Cairns area. This experience consisted of a short check flight at Cairns on 27 February 1994, a flight from Palm Island to Cairns on 17 March 1994, and two check flights at Cairns on 17 and 18 March 1994. The accident flight was the first recorded occasion of the pilot flying from Cairns to another destination.

The aircraft operator indicated that the pilot had not been given any specific briefing on the Cairns area as he considered that a pilot with 4,500 flying hours experience would not require such a briefing.

The post-mortem examination revealed some coronary artery occlusion which was considered to be too minor to have adversely affected the performance of the pilot.

Weather

The weather forecast for the area indicated a fresh to strong south-easterly airflow over the area with isolated showers over the coast and ranges. Broken stratus cloud was forecast from 1,000 to 3,000 ft in precipitation, along with scattered cumulus from 2,000 to 10,000 ft. Rain showers with 4 km visibility and occasional moderate turbulence below 7,000 ft near the ranges were also forecast.

The weather recorded on the Cairns Automatic Terminal Information Service (ATIS) at 0849 was wind 160 degrees M at 10-15 kts, temperature 25 degrees C, two oktas of cloud at 2,500 ft with lower patches and three oktas at 3,500 ft. There were showers in the area. Cairns Tower controllers stated that the top 500 ft of Mt Bellenden Ker appeared to be covered by cloud around the time of the accident.

Operating requirements

Aeronautical Information Publication (AIP) Australia RAC - 50a para 43.5.1 addresses flight under the VFR. The requirements include, inter alia:

1. the pilot in command of a VFR flight in controlled airspace must navigate by visual reference to the ground or water; and
2. when operating at or below 2000 ft above the ground or water, the pilot in command must be able to navigate by continuous visual reference to the ground or water or by the use of approved radio navigation apparatus as specified in CAO 20.8.

Under the VFR, AIP RAC - 33 requires that for the track being flown by the accident aircraft, the appropriate altitude would have been odd thousands of feet plus 500 ft for example 5,500 ft or 7,500 ft.

RAC CTL - 1 para 14.1 states, inter alia that a pilot must not deviate from track or change level without obtaining ATC approval when in controlled airspace.

The Approach Controller's duties included a requirement to maintain general radar surveillance of his area of responsibility insofar as the performance of other functions permitted. As part of this monitoring function, the controller was required to advise the pilot of a radar identified aircraft when that aircraft was observed to deviate beyond the normal navigational tolerance from the intended track. This tolerance is defined in the Manual of Air Traffic Services (MATS) as plus or minus 2 NM when an aircraft is 2,001 to 5,000 ft AGL and is navigating by visual tracking and position fixing.

MATS indicates that assigned cruising levels shall whenever practicable be in accordance with the level selected by the pilot and assigned levels shall normally conform to the appropriate table of cruising levels. Levels not conforming to these tables may be assigned when air traffic or other circumstances require. Prior to assigning an aircraft a non-standard level the controller shall consider workload and coordination implications along with the effect on aircraft already operating at standard levels.

Air Traffic Control

After the pilot had reported maintaining 5,000 ft he did not request a clearance to descend or alter heading.

A significant proportion of air traffic in the Cairns area operates in the VFR category. These flights often operate in an environment involving inclement weather and high terrain. The Cairns air traffic controllers reported that, particularly during the wet season (December-March), local weather conditions are frequently such that aircraft operating VFR are required to deviate from track to remain clear of cloud or avoid high terrain.  In this environment the controllers become accustomed to aircraft operating adjacent to high terrain or deviating off track and it is not unusual for radar and radio contact with VFR aircraft to be lost because of terrain shielding.

The final 30 seconds of VH-BOC's descent were observed by a supervising controller who was randomly monitoring a radar screen in the control tower. On seeing the radar return from VH-BOC disappear he immediately returned to the Approach Control Centre to check the status of the aircraft, which by this time was no longer in radio contact.

Flight Planning

The pilot was not asked by the briefing officer or the air traffic controller why he chose to fly at 5,000 ft. No explanation was found as to why the pilot chose to fly the route at 5000 ft. There was no requirement for air traffic control to query the cruise altitude nominated by the pilot even though the controllers were aware that 5000 ft was not normally used by VFR traffic in the area. Aircraft operating in the VFR category in the Cairns area normally cruise below 2,000 ft or above 6,500 ft due to the prevalence of cloud on the ranges.

ANALYSIS

The recorded radar data showed a distinct change in aircraft track at about 16 NM from Cairns shortly after top of climb.  The forecast winds were fairly constant from 2,000 ft to 7,000 ft so the track change seems unlikely to have been due to wind. It is possible that the pilot deliberately altered heading towards the blind valley west of Bellenden Ker Centre Peak in an attempt to avoid the deteriorating weather conditions along the intended track.

The descent pattern flown by the aircraft could also indicate that the pilot was manoeuvring the aircraft to remain clear of cloud. Having limited familiarity with the area and apparently no topographical maps on board the aircraft the pilot was not well placed to safely navigate the aircraft. The final descent and right turn made by the aircraft were possibly an attempt to remain clear of cloud.

Once VH-BOC had passed the inbound regular public transport traffic, when traffic separation considerations were no longer a factor, ongoing surveillance of the aircraft reverted to becoming part of the controller's normal monitoring function. A number of considerations influenced the controller's subsequent monitoring of the aircraft. There was other traffic, including IFR traffic, under the controller's jurisdiction which required his attention. The aircraft remained within 2 NM of the Cairns-Innisfail track until about one minute 30 seconds before radar contact was lost. The aircraft was not significantly beyond 2 NM right of track until 30 seconds or so before radar contact was lost. Because of the terrain and weather conditions generally prevailing in the Cairns area, controllers can in effect, become desensitised to track and altitude deviations by aircraft operating in the VFR category.

Had the pilot reported to ATC that he was deviating to the right of track and/or descending or that he was experiencing difficulties with weather conditions, he would have alerted the controllers and been provided with navigation assistance.

CONCLUSION

Significant factors

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

1. The pilot was not familiar with the area.
2. The pilot apparently did not have with him in the aircraft any relevant topographical maps or charts covering the route being flown.
3. The pilot did not advise air traffic control that he was deviating from track and/or descending nor that he was encountering weather difficulties.

The pilot had been authorised to carry out a night-VFR flight in the Maitland training area on 19 March. That evening VH-RNN was observed to depart Maitland and later in the evening the pilot was seen in his car in the airport carpark. The following morning witnesses observed an unidentified aircraft flying in a northerly direction below low cloud on the eastern side of the F3 freeway, approximately 105 km south of Maitland. The aircraft was subsequently observed to bank steeply to the left and appeared to descend before disappearing from view. The wreckage of VH-RNN was subsequently found on 30 March, near the F3 freeway, about 800 m south of the earlier sighting of the unidentified aircraft.

Toxicological analysis of the pilot revealed the presence of the drug Dextropropoxyphene at levels which may have caused him to experience sleepiness, hallucinations, delusions and confusion during the flight.

The pilot's intentions could not be established. The aircraft was observed manoeuvring in conditions of low cloud and reduced visibility and it is likely that the pilot was attempting to turn back to an area of more favourable conditions. The pilot's ability to remain safely clear of terrain may have been adversely affected by the effects of the drug Dextropropoxyphene.

Significant Factors

1. The aircraft was operating at a low height in conditions of low cloud and reduced visibility.
2. The pilot's ability to safely control the aircraft may have been adversely affected by an analgesic drug.

SYNOPSIS

The aircraft was engaged on a freight courier service and had departed Bankstown at 0630 EST on 9 March 1994 and proceeded to Tamworth, Armidale, Glen Innes and Inverell. The pilot rested at Inverell for approximately seven hours before departing at about 1640 on the return flight to Bankstown via Glen Innes, Armidale and Tamworth. The flight was planned to be conducted in accordance with the Instrument Flight Rules (IFR) and departed Armidale for Tamworth at 1723. At about 1734 the aircraft impacted a mountain 8.2 NM north-east of Tamworth at 2,685 ft above mean sea level (AMSL), after being cleared to make a visual approach by Tamworth Tower. A short time after the accident, the pilot of a search aircraft observed that the top of the mountain was obscured by cloud.

1. FACTUAL INFORMATION

1.1   History of the flight

VH-SWP was operating on a standard company flight plan for the route Bankstown-Tamworth-Armidale-Glen Innes-Inverell and return, and the flight plan indicated the flight would be conducted in accordance with IFR procedures. The classification of the flight was shown as non-scheduled commercial air transport although the aircraft was operating to a company schedule, and departure and flight times for each route segment were indicated on the flight plan.

The aircraft departed Bankstown at about 0640 and proceeded as planned to Inverell where the pilot rested until his departure that afternoon for the return journey. The schedule required an Armidale departure at 1721. At 1723 the pilot reported to Sydney Flight Service that he was departing Armidale for Tamworth. The planned time for the flight was 17 minutes.

Although the flight-planned altitude for this sector was 6,000 ft, the pilot was unable to climb immediately because a slower aircraft, which had departed Armidale for Tamworth two minutes earlier, was climbing to that altitude. In addition, there was opposite direction traffic at 7,000 ft. The next most suitable altitude was 8,000 ft, but separation from the other two aircraft, which were also IFR, had to be established by the pilot before further climb was possible. The published IFR lowest safe altitude for the route was 5,400 ft.

The pilot subsequently elected to remain at 4,500 ft in visual meteorological conditions (VMC) and at 1727 requested an airways clearance from Tamworth Tower.  A clearance was issued by ATC to the pilot to track direct to Tamworth at 4,500 ft visually. At about 1732 the pilot requested a descent clearance. He was cleared to make a visual approach with a clearance limit of 5 NM by distance measuring equipment (DME) from Tamworth and was requested to report at 8 DME from Tamworth. The pilot acknowledged the instructions and reported leaving 4,500 ft on descent. Transmissions from ATC to the pilot less than two minutes later were not answered. The aircraft was not being monitored on radar by ATC, nor was this a requirement.

At about 1740, reports were received by the police and ATC of an explosion and possible aircraft accident near the mountain range 8 NM north-east of Tamworth Airport. The aircraft wreckage was discovered at about 2115 by searchers on the mountain range.

Soon after the aircraft was reported missing, a search aircraft pilot, who had extensive local flying experience, reported to ATC that the top of the range (where the accident occurred) was obscured by cloud, and that there was very low cloud in the valley nearby.

1.2    Damage and impact information

The aircraft was on the Armidale to Tamworth track 8.2 NM from Tamworth when it impacted trees at approximately 2,685 ft AMSL. It was descending at an angle of approximately 3.5 degrees and was banked about 17.5 degrees to the left at impact. The aircraft maintained a straight path after initial impact but had rolled to a bank angle of 25 degrees left by the time the left wing struck a second tree 35 m further on. It then impacted the ground left wing low and inverted, before bouncing into a rock face 200 m from initial impact. The main fuselage wreckage caught fire, and the cabin area was destroyed.

1.3    The pilot

The pilot was 24 years old and was correctly qualified and endorsed to perform the flight. He had flown on the two days prior to the accident following three days off duty. He had not flown this route before. He completed a flight check on 28 October 1994 and his performance was assessed as satisfactory. The flight check report stated that the requirement to be aware of terrain at all times was reviewed with the pilot.

The pilot was not known to be suffering from any ailment and appeared to be in good spirits on the day of the accident.

1.4    The aircraft

1.4.1    Aircraft history

The Swearingen SA226-AT aircraft was manufactured in 1975. The Australian certificate of airworthiness was issued on 15 May 1986. The last periodic inspection was completed on 11 January 1994.

1.4.2    Weight and balance

The aircraft weight and balance (centre of gravity) were within limits for the flight.

1.4.3   Aircraft serviceability

There were no known unserviceabilities other than the windscreen wipers. When the aircraft arrived at Tamworth in the morning it was raining, and the aircraft was cleared to land on runway 30 right. During the approach the pilot made a comment to the aerodrome controller (ADC) to the effect that it was difficult to see out of the aircraft without the windscreen wipers working. Why the windscreen wipers were not working, or when they became unserviceable, could not be determined. Effective use of the windscreen wipers would not have been possible at the speed at which the aircraft was flying immediately prior to the accident.

1.5    Wreckage examination

1.5.1    Structure

All aircraft extremities and control surfaces were accounted for at the accident site. The damage sustained was consistent with the application of excessive loads during the accident sequence and subsequent fire. There was no evidence found of in-flight fire. As far as could be determined there was no pre-impact abnormality with the structure and all damage was a result of impact forces.

1.5.2    Flight controls

All control systems were examined although only portions of control surfaces were recovered. Where found, the hinges, push-pull rods and cables were correctly assembled and secured. Witness marks indicated that at the time of wing impact with the trees, the aileron was in a neutral position, aileron trim was neutral, and flaps were in the up position.

1.5.3    Landing gear

All major components of the landing gear system had been torn from the aircraft, and it was not possible to determine if the individual legs were up or down. However, the hydraulic actuators which remained attached to the right wing were in a position consistent with the right gear being in the retracted position 

1.5.4    Other systems

Due to the extent of destruction of the aircraft, the functional status of its systems, including the fuel, electrical, and pitot-static systems, could not be determined. 

1.5.5    Crashworthiness

The amount and nature of aircraft destruction indicated that the aircraft approached the accident site at high speed. The cockpit area was destroyed. Examination of the pilot's seat and harness indicated that although the shoulder harness had not been fastened at the time of impact, the impact dynamics were such that the accident was non-survivable.

1.6   Meteorological information

A low-pressure system was situated near Albury NSW with a central pressure of 1,010 hectopascals (hPa). A weak trough extended from the low into Queensland. A high-pressure system with a central pressure of 1,028 hPa was centred in the Tasman Sea. The resulting airstream was a very moist northerly to north-easterly flow with extensive low cloud over the north-eastern regions of New South Wales.

The information being broadcast on the Tamworth Automatic Terminal Information Service (ATIS) at the time of the accident indicated that the weather at Tamworth airport included a light and variable wind, two octas of cloud at 1,000 ft, with visibility reducing to 3,000 m in rain.

The pilot of a search aircraft which was in the area about 20 minutes after contact was lost with VH-SWP said that the general cloud base was about 2,200 ft with lower patches. He said he had climbed above the cloud and found the tops at 2,800 ft, with some higher patches to about 3,100 ft. The higher patches were obscuring the terrain. There was a higher layer of cloud with a base at about 3,800 ft. He could not see towards Armidale as it seemed as though the two layers converged. From the accident area he could see Tamworth easily and visibility in that direction was good. When the same pilot later ascertained where the accident occurred, he confirmed that the area of the accident site had been covered by wispy cloud when he flew over it shortly after the accident.

1.7   Additional information

1.7.1   Recorded radar data

The aircraft was under radar coverage from Armidale to a point approximately 2.5 NM from the accident location. The recorded radar data showed that the aircraft departed Armidale (runway 05) and turned left to intercept the Armidale-Tamworth track. The aircraft climbed initially to 5,000 ft but then descended to 4,500 ft and maintained this altitude until about 1731 when it climbed to 4,900 ft. (Its position at that time coincided with Mt Gulligal which is 4,070 ft AMSL.) The radar data showed the aircraft leaving 4,500 ft at 1732:40, which was the time the pilot received descent clearance. The last recorded altitude was 3,900 ft when radar contact was lost at about 10 NM from Tamworth. The computed aircraft ground speed at that position was 260 kts.

1.7.2   Air-ground communications

Automatic voice recordings of air-ground and air-air communications indicated that satisfactory two-way communications existed in the period leading up to the accident.

2. ANALYSIS

Other traffic on the Armidale-Tamworth route delayed the pilot of VH-SWP from climbing to his planned altitude of 6,000 ft. As a result, he apparently elected to remain at 4,500 ft and conduct the flight in VMC. When the pilot called Tamworth Tower, he reported being visual at 4,500 ft, and was given a clearance to track direct to Tamworth in visual conditions at 4,500 ft before being cleared for a visual approach. The accident site was observed to be covered by cloud shortly after the accident. It is possible, therefore, that the pilot inadvertently entered cloud and failed to remain in visual contact with the ground.

3. CONCLUSIONS

3.1    Findings

1. The pilot was correctly endorsed and qualified to undertake the flight, and the flight was operating in accordance with the scheduled departure time from Armidale.
2. The flight was planned to be conducted under the instrument flight rules but because of other traffic it was not expedient to climb to an appropriate altitude.
3. The flight was conducted at 4,500 ft, apparently under the visual flight rules.
4. The pilot reported that he could remain visual and was cleared by ATC to make a visual approach.
5. The aircraft was not being monitored on radar by ATC, nor was this a requirement.
6. The last recorded radar data showed the aircraft descending through 3,900 ft, 2.5 NM from the accident site.
7. There was low cloud and rain in the area at the time of the accident.
8. The pilot allowed the aircraft to descend into terrain for reasons which could not be determined.
9. No evidence was found of any physiological impairment of the pilot or of aircraft defects which may have contributed to the accident.

3.2   Significant factors

1. The pilot was making a visual approach in weather conditions unsuitable for such an approach.
2. The pilot had not flown this route before.
3. The aircraft was flown below the lowest safe altitude in conditions of poor visibility.

The flight had progressed from Melbourne to Gunnedah, apparently without incident. After refuelling at Gunnedah, the aircraft departed for Noosa. No flight plan was submitted, nor were any documents indicating an intended route recovered from the accident site. The aircraft was subsequently observed passing over the parachuting centre at Toogoolawah. Weather in that area was poor, with a low cloud base. Parachuting operations had been suspended due to the cloud.

The aircraft apparently tracked north of Kilcoy and eventually around the northern edge of a range before tracking east. The weather on ranges closer to the coast was probably sufficiently poor to deter the pilot from tracking to the coast. Witnesses saw the aircraft in a valley between Conondale and Kenilworth, to the west of Maroochydore airport. Cloud covered all the ranges around the valley. The aircraft was last observed by one witness to be tracking towards Kilcoy. This information was consistent with the position of and direction to the accident site.

Searchers found wreckage of the aircraft at the top of a ridge line east of the main range to the west of Conondale. The aircraft had collided with the upper portion of a tree while in a left bank. Further breakup of the aircraft continued along a direction of 230 degrees, down the side of the ridge and across a small gully. No evidence of any mechanical defect or abnormality was found. From the available evidence, the aircraft was probably either in cloud or at the base of the cloud at the time of the accident. No evidence was found to indicate that the aircraft was equipped with instrumentation appropriate for flight in instrument meteorological conditions.

Significant Factor

1. The pilot continued flight into weather conditions in which he was unable to maintain the visual reference necessary to ensure adequate terrain clearance.

After completing a TB-20 aircraft type endorsement at Nowra the pilot hired the aircraft for a return flight to Forbes via Bankstown.  During the afternoon of Friday 1 October, he completed the Nowra to Bankstown sector but had to postpone the flight to Forbes due to en route weather conditions which precluded flight under visual flight rules (VFR).

On Sunday 3 October the pilot obtained area weather forecasts, and an aerodrome forecast for Forbes which indicated that the weather at Forbes was fine but the en route weather was not suitable for VFR flight. The pilot was also advised that two helicopters bound for Bathurst had turned back to Bankstown due to poor visibility.  Despite the forecasts and reports of adverse en route weather the pilot decided to attempt the flight to verify the accuracy of the forecasts which had predicted an improvement after 0900 hours.  The pilot did not submit details of his proposed flight to the CAA, nor did he request a SAR watch or leave a flight note.

VH-JTI subsequently departed Bankstown at 0830 EST and after the pilot changed from the tower frequency there was no further radio contact with the aircraft.  At about 0900 bushwalkers in the Kowmung River valley saw a single engine light aircraft flying in a southerly direction in the valley. The aircraft, which was not identified, was observed turning west to enter the Christies Creek Gorge.  The unbroken cloud base obscured the tops of the ridges and the aircraft, which appeared to be operating normally, was flying about midway between the valley floor and the cloud base.

JTI was reported missing during the evening of Sunday 3 October after it failed to arrive at Forbes.  An intensive air search was commenced the following day.  The bushwalkers did not report sighting an aircraft in the valley because a Sydney daily newspaper they had read incorrectly identified the date on which the aircraft was reported missing.

The wreckage was located on the eastern side of the Boyd Range on Sunday 24 October by a bushwalker who was about 2 kms from the site on the opposite side of the valley. The accident site was at an elevation of 2,500 ft on steeply sloping terrain which was moderately timbered with trees 18 to 25 m in height. The occupants survived the impact forces but suffered burns from a fuel fed fire which started when the aircraft began to break up during the collision with trees. Several days later they perished from the combined effects of their burns and exposure after they had walked about 2 km down to Wheengee Whungee Creek.

Examination of the wreckage found the landing gear and the wing flaps retracted.  Propeller inspection indicated that the engine was operating at a low power setting at ground impact.  No defects which may have influenced the circumstances of the accident were identified.

A removable emergency locater transmitter was attached to the floor of the luggage compartment at the rear of the cabin. The transmitter assembly had a self-contained aerial and was therefore capable of operating remotely from the aircraft. The transmitter was destroyed by intense fire which gutted the cabin area and there were no reports of any transmissions being received from the transmitter.

CONCLUSION

Significant Factors

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

1. Forecast and observed weather conditions over the Blue Mountains and Great Dividing Range in the general area of the proposed route were unsuitable for flight in accordance with visual flight rules.
2. The pilot continued flight over mountainous terrain in weather conditions which were unsuitable for flight under visual flight rules.
3. The pilot was inexperienced, both generally and on the accident aircraft type.
4. The aircraft was not configured for the optimum manoeuvring speed in the prevailing conditions.