Circumstances:

After departing Hamilton Island, A320 aircraft VH-HYJ tracked via Mackay to Emerald, and then airway route W82 towards Roma at flight level (FL) 370. Boeing 767 VH-OGE departed Brisbane and tracked via Taroom and airway route A464 towards Longreach, also at FL370. The aircraft were being controlled by the Brisbane Sector 5 Procedural Controller. The controller was undergoing a routine periodic performance check by a check controller. Sector 5 airspace covers the greater portion of southern Queensland and extends to 150 nm west of Mount Isa. During the 30 minutes leading up to the occurrence, the Sector 5 controller had been engaged in coordination with Darwin, Townsville, Brisbane Sectors 2 and 3, Adelaide, Alice Springs, and Mount Isa. During that time, he had 12 Regular Public Transport (RPT) jet aircraft which required separation, coordination, and frequency change instructions. Sector 5 airspace has 6 discrete VHF frequencies, which allows continuous VHF communication to be maintained within the Sector. Frequency change points do not coincide with reporting points thus increasing controller workload, particularly when instructions have to be repeated, or communication with aircraft is temporarily lost. For traffic management purposes, each aircraft is assigned a Flight Progress Strip for each position reporting point. The controller had approximately 60 strips on the flight progress console which required surveillance during the period. When it became apparent that there was a potential confliction between VH-OGE and VH-HYJ, the controller offered VH-HYJ FL390 for separation but this was not acceptable to the flight crew. The controller then offered VH-OGE FL390 for separation but this was also unacceptable. The alternative was then to descend VH-HYJ to FL350 but this could not be accomplished until this aircraft had reported sighting and passing a Boeing 737, VH-TAW, which was on the same track, but heading in the opposite direction at FL350. A passing time was calculated, but the aircraft did not sight and pass each other until two minutes later than expected. When the sighting and passing was reported, the controller immediately instructed VH-HYJ to descend to FL350, but it then became apparent that the requisite vertical separation standard (two thousand feet) would not be achieved before VH-HYJ had entered the area of conflict with VH-OGE. The area of conflict is a defined area based on navigation tolerances, within which there can only be one aircraft, unless the prescribed non-lateral separation standard exists. It was determined by reference to a diagram which showed distances from Taroom and Longreach on the airway route A464, and Emerald and Roma on the airway route W82. The aircraft were estimated to be no closer to each other than 30 nm, whilst at the same flight level. The investigation revealed that the incident occurred during a period of extremely high workload. There were no personal or physiological circumstances or conditions that may have contributed to the development of the incident. The traffic was displayed in an efficient manner, however, the ability of the controller to appreciate the potential conflict at an early stage was reduced due to the high workload. The problem was recognised by the check controller and he brought it to the attention of the controller, who did not immediately respond, as his attention was on other tasks. When the potential conflict was recognised, the controller's options became extremely limited, and this resulted in an infringement of the separation standard. To reduce the possibility of a recurrence of this nature, the Civil Aviation Authority has placed an additional controller at the Sector 5 position, to coordinate traffic during identified periods of high workload."

Circumstances:

At 1025 hours Eastern Summer Time on 14 February 1991, Gulfstream Aerospace AC 681 aircraft VH-NYG was entering the downwind leg of the circuit for a landing on runway 30 at Tamworth, New South Wales, when the pilot requested a clearance to land on a cross-runway, runway 18. When the aircraft was about 300 ft above the threshold of runway 18 the pilot advised that he was going to conduct a left orbit. During the orbit, a high rate of descent developed. The aircraft crashed in a wings-level attitude 350 m short of the threshold of runway 18. The aircraft was destroyed by impact forces and the pilot its sole occupant was killed.

Findings

1. The pilot was medically fit correctly licensed and qualified to undertake the flight.

2. Meteorological conditions and sun angle at the time of the accident were not significant.

3. The fuel planning figure given by the endorsing pilot was incorrect.

4. Neither the company nor the pilot established the correct fuel usage rate for the aircraft.

5. The engines' fuel flow indications were incorrect.

6. The fuel quantity gauge indications may have been erroneous.

7. The 'fuel level low' warning system was probably not functional.

8. The aircraft was not loaded with sufficient fuel to complete the flight.

9. Both engines failed due to fuel exhaustion.

10. The pilot probably did not realise that the fuel was exhausted.

11. The initial impact with the ground was not survivable.

Recommendations:

Early in the investigation the Civil Aviation Authority was advised of certain apparent operational irregularities. Consequently, no new recommendations arising from the investigation were considered necessary.

Circumstances:

The Air Tractor, VH-OMC, and an Ayres SR2 aircraft were operating in company. The spraying operation had been completed, and both aircraft were loaded with water in order to flush the hoppers and spray equipment during the return flight to St George. After departing the strip, the aircraft deposited the water onto a disused field and then headed for St George, flying at approximately 50 feet above ground level and about 30 metres apart. The pilot of the Ayres S2R saw VH-OMC, which was on his left, suddenly pull up into a climb. He then lost the aircraft from view but moments later saw a cloud of dust rising where it had impacted. Ground witnesses saw both aircraft flying level, approximately line abreast, when the Air Tractor suddenly pulled up steeply, as if to make a turning manoeuvre at the end of a spray run. However, at the top of the pull up the aircraft became inverted and fell to the ground. An inspection of the wreckage revealed no mechanical defects which might have contributed to the accident. The engine was operating at impact.

Significant Factors:

The factors relating to the development of this accident could not be determined.

Circumstances:

The Boeing 737 (B737) had been cleared from Cowes direct to Launceston via the 320 radial of Launceston VOR and to leave flight level 330 (33 000 ft) descending initially to 7000 ft before receiving further descent clearance to 6000 ft. The Fokker F28 (F28) had departed Launceston runway 32, followed by a left turn to intercept the 314 radial of the VOR with an altitude restriction of 5000 ft. At about 16 nm from Launceston, the B737 reported at 6000 ft, inbound on the 320 VOR radial in visual flight conditions. The Launceston Aerodrome Controller (ADC) advised the B737 to expect further descent shortly and to track to enter the circuit on a right downwind leg for runway 32. The F28 had become airborne about 2 min earlier with an amended clearance to intercept the 314 radial outbound instead of the normal 325 radial as specified in the Launceston Standard Instrument Departure procedure. At 13 nm from Launceston, the B737 was cleared by the ADC to continue descent to 5000 ft. The pilot undergoing command training in the B737 unintentionally veered slightly right of the 320 inbound radial towards the F28 tracking on the 314 outbound radial. The F28 was about 9 nm from Launceston on the 314 radial, breaking through broken cloud tops at about 4200 ft, when the aircrew first sighted the B737. The F28 veered slightly left to increase separation from the B737. Readout of the Digital Flight Data Recordings from both aircraft indicated that at 9.5 nm from Launceston, the B737 and the F28 had passed with a horizontal separation of 0.7 nm (i.e. 1.3 km) without vertical separation when both aircraft were at approximately 5000 ft. There were two qualified air traffic controllers performing ADC functions at Launceston at the time of the incident. One officer was a current controller monitoring familiarisation of the second experienced officer who had recently returned from leave. The monitoring ADC had sighted the B737 at approximately 20 nm from Launceston and verified that it was inbound on the 320 radial. He also visually assessed that the F28 was tracking outbound on the 314 radial in accordance with instructions. The monitoring ADC then discontinued visual surveillance of the B737 and the F28 for a short time. He became occupied with surveillance of two other aircraft departing towards the NE to ensure that the sequence planned by the training ADC would ensure separation from the approaching B737. By this time, neither ADC was maintaining surveillance of the B737 or the F28. Neither sighted the B737 again until shortly after both aircraft had passed and the crews had exchanged comments on their proximity. The controllers then noticed that the B737 had unexpectedly veered slightly right of the 320 radial.

Significant Factors:

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

1. The use of visual separation standards may have been inappropriate at the time of application due to cloud and aircraft positions.

2. Vertical and lateral separation standards were replaced by visual separation standards without confirmation that the aircraft had safely passed.

3. Neither aircraft had been alerted of the proximity of the other. This incident was not the subject of an on-scene investigation.

Circumstances:

The aircraft was engaged in glider towing operations. After a normal glider release at 3 300 ft, the tug aircraft was seen to enter a left descending turn at about 45 degrees angle of bank. At about 2 000 ft, the direction of turn rapidly reversed and the right wing was observed to have collapsed in the vicinity of the wing strut's attachment points. The rate of turn and rate of descent increased rapidly before the aircraft impacted the ground in a high-speed spiral. Examination revealed that the right wing of VH-SUT had failed at the rear spar inboard of the lift strut attachment point between rib numbers 8 and 9. The failure had commenced at a weathered compression shake area. There was no evidence that the aircraft had been used in aerobatic flight or had been subjected to excessive flight loads immediately prior to the failure. The aircraft was in a steady left, descending turn when the wing collapsed. VH SUT had suffered minor damage to both wings in an overturn accident in late 1987. As a result, the wings were subjected to inspections in accordance with Airworthiness Directive AD/CHA/23 which required inspection of the wing spars for compression failures. No spar damage was found. Shortly after this accident, another Bellanca Scout wing became available for examination, and a number of compression failures were found. The aircraft logbook indicated that the wing had previously sustained minor damage. A study of foreign accident reports and articles in aircraft magazines also indicated that what was often perceived as minor, superficial wing damage from a main landing gear collapse, overturn, or wind gust on the ground, could cause extensive internal damage to the wing spars. It was evident that compliance with AD/CHA/23 would not guarantee that all existing compression shakes would be found.

Significant Factors:

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

1. Forces applied during a previous accident probably initiated a compression failure in the timber of the rear spar.

2. Maintenance inspections in accordance with Airworthiness Directive AD/CHA/23 did not detect the failure because the AD did not require the area of the failure to be inspected.

Recommendations:

The Bureau made a recommendation to the Civil Aviation Authority in the early stages of the investigation that Airworthiness Directive AD/CHA/23 should be revised to incorporate an inspection of the the whole spar. The Civil Aviation Authority issued an Airworthiness Advisory Circular article on 21 March 1991 and Amendment 1 to AD/CHA/23 on 16 May 1991.

Circumstances:

The flight was scheduled as a Supplemental Airline (SAL) flight number 421S, but due to the unavailability of a SAL qualified pilot, the flight was rescheduled as a charter flight. Both passengers were booked on airline flights out of Brisbane, one of which was scheduled to depart at 0905. When the pilot and passengers walked out to the aircraft it was raining, and the passengers put their umbrellas and a brief case in the right wing locker. The pilot then closed the locker door before boarding the aircraft. The pilot transmitted a taxiing call to Brisbane Flight Service at 0801 local time. Seven minutes later, he reported lining up on runway 11 and requested an airways clearance. After the aircraft became airborne, witnesses saw it make a left turn and proceed downwind, close to the runway, at about 150 feet above ground level. The landing gear was down, and there was a heavy rain shower in progress at the time at the aerodrome. When the aircraft was abeam the downwind end of the runway, it was seen making a steeply banked turn to the left. As the turn progressed through south, the bank angle became steeper and was estimated by witnesses to be approximately 90 degrees. The aircraft then became inverted and descended into trees. A piece of cleaning rag, found later on the runway, was identified as having been in the left wing locker when the aircraft returned from the previous flight. The rag had apparently fallen from the wing locker after the aircraft became airborne. It could not be determined if the door was incorrectly secured before flight or if it came open of its own accord as the aircraft became airborne. However, it does appear that the pilot noticed the open door soon after take-off and was returning to land and fasten the door when the accident occurred. The resultant delay would have caused the aircraft to arrive in Brisbane late and could explain the pilot's apparent haste to land. Witnesses near the accident site said it was raining very heavily at the time of the accident. This could have caused the pilot to temporarily lose sight of the runway. The aircraft had passed through the extended runway centreline by approximately 200 metres, when the aircraft stalled and struck the trees. There were no mechanical defects found which may have contributed to the development of the accident.

Significant Factors:

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

1. The left wing locker door was open in flight for reasons which could not be determined.

2. The pilot was making a close low level circuit and misjudged the turn onto final approach.

3. The pilot used excessive bank during the turn onto final approach and the aircraft stalled.

CIRCUMSTANCES:

"The aircraft was conducting a night DEPARTURE from Runway 36 at Wondai, Queensland. After an apparently normal take-off, it struck the ground 600 metres beyond the end of the runway in a shallow, wings level descent and at high speed. The aircraft was destroyed by impact forces and fire, and five of the six occupants on board were killed.

3. FINDINGS

3.1 The pilot was medically fit, correctly licenced and qualified to undertake the flight.

3.2 There were no significant meteorological conditions existing at the time of the accident, but the night was dark with no moon and no visible horizon.

3.3 There was evidence of influences which could have resulted in the pilot experiencing the effects of fatigue and/or stress at the time of the accident.

3.4 The pilot received no formal ""human factors"" education during his instrument flying training.

3.5 The aircraft became airborne after a take-off roll of about 900 metres and probably reached a height of about 70 feet (21 metres) above the level of the runway before commencing a shallow descent.

3.6 The pilot transmitted an airborne call very soon after lift-off.

3.7 The aircraft speed at impact was approximately 183 knots.

3.8 The aircraft was in controlled flight, wings level and in a shallow descent at impact.

3.9 The aircraft landing gear and flaps were in the retracted position at impact.

3.10 No evidence was found that the aircraft was not capable of normal operation at the time of the accident.

4. FACTORS

The circumstances leading to the development of this accident could not be established conclusively. However, the evidence supports the following as probable factors

4.1 The pilot might not have been aware of the human factors aspects associated with dark night take-offs.

4.2 The pilot could have been influenced by stress and/or fatigue.

4.3 The aircraft was taking off towards dark textureless terrain and no visible horizon.

4.4 By transmitting his airborne call very soon after lift-off, the pilot was not devoting his full attention to flying the aircraft.

4.5 The pilot became disorientated and placed the aircraft in a shallow descent as it accelerated after take-off.

5. SAFETY ACTION

A search of the Bureau's records revealed a number of accidents with circumstances generally similar to this accident. With some exceptions, a pattern emerged in which total pilot experience was moderate to high but hours on type were comparatively low. Pilot age was typically 40-60 years.

The Bureau is undertaking a detailed analysis of these accidents with the aim, among others, of producing a profile of the ""at risk"" pilot. The results of the study will be published in the BASI Journal. Some other aspects of this accident have also been identified as areas which warrant further research. These include

5.1 Instrument rating tests and their effectiveness, particularly in such areas as the transition from visual to instrument flight and test effectiveness when conducted in aircraft of significantly lower performance than that normally flown by the pilot.

5.2 The training methods used in night take-off/no visible horizon situations their effectiveness."

RECCOMENDATIONS:

6.1 It is expected that at least one safety enhancement recommendation will be made as a result of this investigation.

Circumstances:

Witnesses reported seeing the aircraft take off toward the south-west and climb to a height of between 100 and 150 feet above the ground. It then turned right and flew past the witnesses with the wheels about one metre above ground level. As the aircraft crossed the strip, it entered a 15 degree climb to a height of about 150 feet before rolling inverted and diving through trees into the ground. On-site examination showed that the aircraft passed through the treetops at an angle of 80 degrees nose down. The right wing then struck another tree and was torn off. The aircraft attitude at ground impact was about 40 degrees nose down. No evidence was found of any pre-existing defects in the aircraft. Each aircraft seat was fitted with two seat belt systems - an aerobatic harness and a lap/sash type harness. The pilot was wearing the aerobatic harness at impact, but his lap/sash harness was not secured. The rear seat aerobatic harness was firmly fastened on the seat cushion, but the lap sash belt was not secured. This harness consisted of a short lap belt and a one-piece lap/shoulder strap. Tests showed that, if the lap/shoulder strap had been looped over the rear control column, it could have caused a control restriction at about 3/4 right and 3/4 forward control column travel. However, there was no evidence that the strap had fouled the control column in this instance. On a number of occasions during the past few years, the pilot had complained of heart disturbances. He underwent tests but the results were normal. In the week prior to the accident the pilot had reported feeling faint and almost blacking out during flight. He was reported to have planned to consult a medical practitioner on this matter on the Tuesday following the accident. The postmortem examination on the pilot found evidence of a chronic inflammatory disorder of the heart muscle known as myocarditis. This condition can cause disturbances of heart rhythm. However, specialist assessment of the available medical and postmortem information concluded that physical incapacitation of the pilot was a most unlikely factor in the accident. The cause of the accident was not positively determined.

Significant Factors:

The following factor was considered relevant to the development of the accident:

The pilot was conducting an aerobatic manoeuvre at an unnecessarily low height.

Circumstances:

The aircraft was observed to land about halfway along a 490 metre long north-south grass strip. It became airborne again and appeared to climb slowly before veering left and disappearing from view behind trees. The aircraft failed to reappear and was located a short time later having crashed inverted adjacent to a road. The investigation revealed that, after liftoff from the strip, the aircraft had struck and severed power lines 82 metres beyond the end of the strip and eight metres above ground level. It continued to fly for a further 450-500 metres before striking the upper branches of 17-metre-high trees in a nose down attitude at a bank angle of approximately 90 degrees. Ground impact was 24 metres beyond the trees. The purpose of the flight was practice for a forthcoming commercial pilot's licence flight test for the pilot-under-instruction. His task was to locate and then conduct an airborne inspection of the strip and decide whether or not it was suitable for landing. The strip was regularly used for this purpose by the training organisation. It was assessed as a difficult strip because of its approaches and comparative short length. Pilots under training were, therefore, expected to decide against landing. A decision to attempt a landing would be countered by the instructor. The instructor (pilot-in-command) was familiar with the strip and was aware of the training organisation's policy that students were not to attempt to land on the strip. No fault was found with the aircraft, including the engine and flight controls, which might have contributed to the accident. The aircraft configuration at impact was landing gear up and flaps set at 20 degrees. (This is the flap setting listed in the Pilot's Operating Handbook for a balked landing.) The carburettor heat control was in the off position. Information from the Bureau of Meteorology indicated that the local wet and dry bulb temperatures at the time of the accident were 15 and 19 degrees Celsius, respectively. These figures indicate the probability of carburettor icing was moderate at cruise power and high at descent power. If icing was present, and the intention was to fly an approach to the strip and then conduct an overshoot, the performance of the engine could have been affected to the extent that a landing was unavoidable. Carburettor icing could also have affected the aircraft's climb performance after becoming airborne again from the strip. The evidence indicates that the wires had been cleanly severed by the propeller and had not contacted any other part of the aircraft. The effect of the collision with the wires on the aircraft's performance is difficult to quantify, but it is noteworthy that the aircraft flew for a further 450-500 metres after hitting the wires. It was not determined how far from the end of the strip the aircraft became airborne again. The angle from ground level at the end of the strip to the power line was 5 degrees. The Pilot's Operating Handbook indicates that in a maximum rate of climb configuration (full power, flaps up), the aircraft's climb angle is about 5 degrees. If the aircraft became airborne near the end of the strip, it might not have had the capability to climb above the level of the wires, particularly if the flap setting at this time was 20 degrees. Two kilometres beyond the end of the strip is a ridge line which rises 200 metres above the elevation of the strip. The accident site was in a valley which ran to the east of this ridge line, the position of the wreckage being some 200 metres left of the strip centreline but at substantially the same elevation as the strip. It is possible that the aircraft was deliberately flown along the valley to avoid the high ground and in an attempt to increase performance. The attitude of the aircraft when it struck the trees was indicative of the pilot having lost control.

Factors

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

1. Atmospheric conditions were conducive to the formation of carburettor ice.

2. For reasons which could not be established, the aircraft struck and severed power lines.

3. The pilot lost control of the aircraft.

At approximately 1740 hours on 11 May 1990 Cessna 500 Astec Eagle aircraft registered VH-ANQ crashed into the eastern slopes of Mt Emerald, Queensland.

VH-ANQ was engaged in operating a charter flight with one crew member and ten passengers. All occupants received fatal injuries as a result of the impact, and the aircraft was destroyed.

History of the flight

Cessna 500 VH-ANQ was operating the Proserpine to Mareeba leg of a charter flight. The aircraft departed Proserpine at 1635 hours on 11 May 1990. It was being operated by Air North Queensland Pty Ltd, a Cairns based charter company.

The charter flight had been organised to transport members of five local government authorities from the Cairns/Atherton Tablelands area to a Local Government Association Conference at Airlie Beach, Queensland. The aircraft departed Cairns on the morning of 10 May 1990 and proceeded to Mareeba, to emplane further passengers, before continuing to the destination, Proserpine. The pilot and passengers remained at the conference facility overnight.

The pilot had submitted a flight plan, prior to departure from Cairns, for both the outbound flight to Proserpine and the return flight to Cairns. Late the following morning he submitted a further flight plan, by telephone, for the return flight to Cairns. The flight plan details, with the exception of the fuel endurance which had been increased to 177 minutes ex Proserpine, were the same as the previously submitted plan. The plan indicated that the flight would follow Instrument Flight Rules (IFR) and depart Proserpine at 1630 hours with a planned cruising altitude of Flight Level 330 (approximately 33,000 feet). The aircraft was planned to track via overhead Townsville then direct to Mareeba with a flight time interval of 68 minutes.

Departure from Proserpine was reported as 1635 hours and the aircraft was cleared to climb to Flight Level 330. The estimated arrival time at Mareeba was 1743 hours. The flight apparently continued normally and at 1726 hours the aircraft was cleared to descend to Flight Level 170 and instructed to call Cairns Approach. (Cairns Approach controls the airspace down to 6,000 feet above mean sea level above Mareeba Airport which has an elevation of 1,560 feet).

On first contact with Cairns Approach, the pilot advised that the aircraft was tracking for Mareeba via the 163 radial at 41 miles (76 kilometres) DME (Distance Measuring Equipment) from Biboohra. (There are no radio navigational aids at Mareeba, the nearest aids for tracking and instrument approach purposes are at Biboohra, about 16 kilometres north of Mareeba). The aircraft was advised to maintain Flight Level 170 but a short time later was cleared to descend to Flight Level 120. The pilot stated that he would not be dosing down the engines at Mareeba and that his estimated departure time was 1750 hours.

At 1735 hours VH-ANQ was cleared to descend to 10,000 feet and one minute later the pilot advised that the aircraft was "approaching over Mareeba and visual". Cairns Approach advised VH-ANQ that there would be a short delay at 10,000 feet and following a request from the pilot gave approval for the aircraft to circle over Mareeba.

At 1740:22 hours, one minute and 14 seconds after the last transmission from VH-ANQ, Cairns Approach instructed the aircraft to descend to 7,000 feet. This transmission, and other subsequent transmissions to the aircraft, went unanswered.

The Civil Aviation Authority commenced Search and Rescue procedures. An aircraft operating in the area reported hearing the signal from an Emergency Locator Transmitter at about 1820 hours. However, the aircraft was unable to determine the exact location of the transmitter because of the adverse weather in the area.

The wreckage of VH-ANQ was ultimately located on the eastern slopes of Mt Emerald, 15 kilometres south of Mareeba Airport, by searching helicopters at 0240 hours on 12 May 1990.

This accident was unusual in that the last report by the pilot indicated that the aircraft was at 10,000 feet and on a track that was 55 kilometres to the east of the accident site. There was no substantiated, and very little circumstantial evidence to suggest what caused the aircraft to descend 6,400 feet and to be displaced a considerable distance to the west of track. As a result, the causal factors associated with this accident remain undetermined.