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Factual Information

Summary

On 23 July 2000 at 2326 EST, the pilot of a Bell 206L-3 Longranger helicopter was called by the Rockhampton Ambulance Service Communications (CAPCOM) and requested to transport Queensland Ambulance Service (QAS) personnel to a patient located on "Yarandoo", a property approximately 90 NM northwest of Rockhampton. CAPCOM records revealed that the helicopter departed Rockhampton at 2340. The flight was conducted under the night visual flight rules (NVFR).

After arrival at the property, a decision was made to transport the patient (a child) and his mother to the Rockhampton Hospital. On board for the return flight to Rockhampton were the pilot in command, a crewman-paramedic, an intensive-care paramedic, the child and the child's mother. Throughout the flight, the pilot was in radio communication with CAPCOM.

At 0114 hours Eastern Standard Time (EST), the pilot reported departure from Yarandoo and at 0126, passed an estimate for Rockhampton "10 minutes past the hour". At 0132, the pilot reported that "because of a fairly high fuel burn rate", he was going to divert from his present position direct to Marlborough and that he estimated Marlborough in about 10 minutes. He asked that CAPCOM arrange road transport to Rockhampton for the patient, his mother and the intensive-care paramedic. In response, CAPCOM directed a Marlborough-based ambulance vehicle to deploy to the Marlborough state school sports field to meet the helicopter.

Fog had formed at Marlborough before the helicopter arrived. At 0141, the pilot called the officer in charge of the Marlborough-based ambulance vehicle, now deployed to the school sports field, and asked him to switch on all of the vehicle's external flashing lights. The ambulance officer replied that the vehicle's lights were on and that visibility on the ground was "about the length of a football field".

The helicopter arrived overhead the sports field at 0144. The pilot could see the vehicle when the helicopter was directly overhead, but the fog was sufficiently thick to deny the pilot any slant visibility of ground objects. The pilot then switched the "Nightsun" searchlight on, and made two further attempts to initiate an approach to the sports field, without success. At 0154, the pilot asked the ambulance officer to reposition the ambulance vehicle to the northern intersection of the Bruce Highway and Perkins Road, which was illuminated by overhead orange lights. The pilot said that he could see the cross-pattern of lights and that he would use the cross as an approach reference. At 0159, the pilot informed the ambulance officer that he would aim his approach to the centre of the cross-pattern, and asked the ambulance officer to check the road going west from the intersection for aerial cables that could become a hazard during the final approach. A witness reported that throughout that time, the helicopter's "Nightsun" searchlight remained illuminated.

At 0201, the ambulance officer informed the pilot that visibility was about 5 m. The pilot replied, but the reply could not be understood. At 0203 and again one minute later, the ambulance officer called the pilot but received no reply. Around that time, he heard a sound consistent with a ground impact.

At 0206, a Marlborough resident arrived at the intersection and told the ambulance officer that he believed the helicopter had crashed. State Emergency Service volunteers, the Queensland Police Service officer at Marlborough, the ambulance officer and several residents immediately began to search for the accident site. About one hour later, two residents searching in fog with 20 m visibility located the accident site. The helicopter had been destroyed and all occupants had received fatal injuries.

Wreckage examination

On-site examination of the wreckage revealed that the helicopter had struck the ground in a steep nose-down attitude while in a left bank. After striking the ground, the helicopter had rolled forward and come to rest inverted. The entire forward section of the fuselage back to the rear cabin bulkhead was destroyed in the impact sequence.

During the impact sequence the tail boom, with the tail rotor and tail rotor gearbox still attached, failed and bent downwards relative to the fuselage. The main rotor gearbox and engine had separated from the deck attachment and transmission mounting points but both remained with the wreckage. The main engine-to-transmission drive-shaft coupling had been pulled out at the transmission end. There was no evidence of torque twisting or bending along the shaft. The outer coupling and inner male drive gears showed little evidence of damage. No significant torque twisting was evident at the separation points. The type and degree of damage to the tail rotor blades indicated that their energy state at impact was low. The twist grip throttle control mounted on the pilot's collective pitch lever, was badly bent and had been overwound in the impact sequence, preventing determination of its pre-impact position. Damage to the engine, the main and tail rotor assemblies and drive systems was consistent with the engine delivering little or no power at impact.

The caution/warning panel was removed for laboratory examination. Four warning lights, ROTOR LOW RPM, TRANS CHIP, BATTERY RLY and TRANS OIL TEMP were missing from the panel and were not recovered from the wreckage. Inspection of the filaments of the recovered warning lights indicated that the FUEL LOW and LITTER DOOR OPEN lights were illuminated at impact, the GEN FAIL, L/FUEL PUMP and R/FUEL PUMP lights filament status were inconclusive, and all other light filaments indicated that they were not illuminated at impact.

The FUEL LOW light should illuminate when 50 - 75 lb of useable fuel remains. The ENG OUT warning light should illuminate when the RPM of the gas producer reduces to 55% +/-3%.

The engine was removed from the wreckage and later set up in an engine test cell. In the test, the engine started immediately and accelerated to idle speed normally. After normal heat-soaking, the engine was accelerated normally to 35% torque. The test run was carried out using all the accessories that were fitted to the engine in service before the accident. The test indicated that there was no technical fault in the engine that would have prevented it from producing power before impact.

Damage to all other helicopter systems was consistent with impact damage. The wreckage examination did not reveal any pre-impact technical fault that could have contributed to the accident. The maintenance records for the helicopter showed compliance with all applicable airworthiness directives, and all required maintenance had been carried out.

Fuel system examination

The entire fuel system, including both main and auxiliary fuel cells, remained intact. All fuel lines were clear of obstructions and were intact, apart from one fracture between a bulkhead and the engine; that fracture was assessed as impact damage. There was no evidence of fuel spillage or any fuel smell in the wreckage. The main fuel line to the airframe filter and from the filter to the engine contained very little fuel. The airframe filter contained a small quantity of clean fuel in the bottom of the bowl. The filter was clean with no visible contaminants present.

The main fuel cell was opened for examination and to determine the quantity of fuel remaining. A total of 22.5 L of fuel was drained from the three fuel tanks, revealing a maximum useable fuel load of 17.5 L. There was some green/brown sedimentary growth at the bottom of the main fuel cell and some small clumps of the growth on the cell walls. The growth was confined to the rear fuel tank. There was no evidence of the growth in the fuel lines, filters or remainder of the fuel system. The "finger filter" on the fuel control unit was removed for inspection, and found to be free of any contamination.

A sample of the fuel was taken from the rear tank and sent for specialist analysis, which confirmed that the fuel conformed to the density specifications and was free of water and contaminants.

Pilot

The pilot held a Commercial Pilot Licence (Helicopter) and a Commercial Pilot Licence (Aeroplane) with a Night Visual Flight Rules Rating. He had 3,928 flying hours of which 3,185 were on helicopters, including almost 50 hours on the Bell 206L-3 (Longranger). He was a former military pilot whose military flying experience included 968 hours on Bell 206 (Kiowa) and 2,059 hours on Bell 47 (Sioux) helicopters. As a military pilot, he had held a command instrument rating, but his rating was no longer valid.

The pilot was employed as a relief pilot, working tours of full-time duty with the operator as the need arose. He had completed previous tours of duty in September and October 1997, February 1998, April 1998, October 1998, February 1999 and September 1999, totalling 43 flights. Between tours of duty, he did not fly. Nine days before the accident, while preparing for his current tour of duty, he underwent a flight review with the operator's chief pilot. The flight review included day and night emergency procedures. On the day following the flight review, he flew a short NVFR flight, and on the following day, he flew a short day flight. For the next five days until 0700 on the day of the accident, he had been off duty.

The pilot was not a permanent resident of Rockhampton, having taken up temporary residence there during his tours of duty. He had been living in a house near the operator's hangar since his arrival in Rockhampton on 14 July. He had completed flights on 15, 16, and 17 July and had then been off duty until 23 July when he assumed duty at 0700. During that day he remained on standby at the house of which he was the sole occupant. He was reported to have spent the day quietly and to have retired to bed early in the evening.

The pilot assumed the standby duty from the operator's senior pilot at 0700 on 23 July. The senior pilot reported that he informed the pilot, amongst other things, that the helicopter was fully serviceable and that it had 500 lb of fuel on board. The senior pilot reported that he then offered to brief the pilot on any aspect of aircraft systems, but the pilot replied that he had covered the operation of the Global Positioning System and the "Shadin" electronic fuel management system in discussions with the chief pilot, and that he was satisfied with his understanding. The senior pilot also showed the pilot the weather forecast covering the previous night and warned the pilot to expect fog during his shift.

The pilot had undergone an annual medical examination on 8 June 2000, and was assessed as medically fit to Class 1 standard, with a requirement to wear prescription spectacles for vision correction. However, he had been required to provide a blood lipid analysis for his 1997 medical renewal. There was no evidence that this analysis was completed at the required time, but the pilot's designated aviation medical examiner (DAME) had written a letter to the Civil Aviation Safety Authority (CASA) dated 19 May 1997, stating that the pilot's lipids had been analysed in 1995 and were found to be normal, but provided no figures to substantiate the finding.

Post mortem histology indicated that the pilot had severe calcific artherosclerosis (otherwise called coronary artery disease) with a maximum narrowing, although difficult to assess, estimated to be at least 50%. The post mortem also found a "localised area of scarring and myofibre hypertrophy, consistent with ischaemia". The histology indicated coronary vessel disease (narrowing of the arteries causing a degree of blockage) of long standing. The changes were indicative of long-term effects (progressing over many years) of nutrient starvation to focal areas of the heart muscle, caused by significant narrowing of the critical coronary vessels responsible for supplying oxygenated blood to those areas.

The pilot had previously rejected flights that he considered involved unjustified risk. These decisions had given the operator's chief pilot confidence in the pilot's judgement, and were key factors in the operator's decision to employ him.

Weather

The Bureau of Meteorology issued an amended area forecast for Area 44 at 1852 on 23 July. The amended forecast covered the period from 230900 Universal Co-ordinated Time (UTC) (231900 EST) to 232300 UTC (240900 EST) and included isolated smoke areas with scattered fog patches along the coast and ranges from 1400 UTC (midnight EST) to 2200 UTC (240800 EST). The Bureau issued a second amended forecast for Area 44 at 2147. That forecast covered the period from 231130 UTC (232130 EST) to 232300 UTC (240900 EST) and included isolated smoke areas and isolated fog patches, tending scattered along the coast and ranges from 1500 UTC (240100 EST) to 2130 UTC (240730 EST). (Area 44 is bounded approximately by the coastal areas from just south of Rockhampton to just north of Townsville, inland to Emerald in the south, thence north-west along a line approximately parallel to the coast and about 250 km inland.)

By the time the helicopter arrived at Marlborough, extensive areas of fog had formed. The ambulance officer at Marlborough estimated the horizontal visibility in the fog from "the length of a football field" at the school sports ground initially, down to 5 m at the intersection of the Bruce Highway and Perkins Road by the time of the accident.

The Bureau of Meteorology reported that the temperature profiles obtained on the day before and on the day after the accident, plus a pilot report at 2100 UTC (0700 EST), indicated that the top of some fog patches could have been up to 2,000 ft above mean seal level (AMSL). The altitude of the top of the fog over Marlborough at the time of the accident was not determined but observation of fog patches in the area on the day after the accident indicated that the top of the fog was about 300 ft above ground level (AGL). Above the top of the fog, there was little or no cloud. [Marlborough is 80 m (approximately 260 ft) AMSL.]

Whether the pilot was aware of the amended area forecasts could not be established.

Fuel management

In addition to the standard fuel management system, the helicopter had been fitted with a "Shadin" electronic fuel management system. The system provided information to the pilot, such as flight time remaining, fuel used and fuel remaining in addition to fuel flow. According to its manufacturer, the system had an accuracy of +/- 2% or better. The pilot received information through a two-window instrument and a flashing warning light placarded CAUTION - ABOUT TO USE RESERVE FUEL. The warning light was programmable to illuminate at a given flight-time remaining, and had been programmed to illuminate when the usable fuel remaining was sufficient to sustain 45 minutes of flight at the prevailing fuel flow.

The operator's procedure was to leave the helicopter on standby with 500 lb of fuel, approximately two-thirds of a full fuel load, in the tanks. When the operator received a task, the pilot would calculate the required fuel load and the maximum fuel load the aircraft could carry given the configuration and payload for the task.

Section B2 of the company Operations Manual, para. 904, "Fuel Management" stated that "Fuel consumption planning is to be based on a minimum of 250 pounds per hour [lb/h] [Long Ranger] and 180 pounds per hour [lb/h] [Jet Ranger] regardless of weight, altitude and temperature. This figure may be adjusted in flight after completion of a fuel flow check to confirm actual consumption." For planning purposes, the operator used a fuel consumption of 250 lb/h when flying for range below 5,000 ft with the "Nightsun" fitted, and 230 lb/h when flying for endurance.

The helicopter's last flight before the day of the accident took place on 22 July; two days previously. After that flight, the helicopter was refuelled to 500 lb in accordance with the operator's normal procedure. The operator confirmed that the most recent fuel delivery to the operator also took place 2 days before the accident, after the last 500 lb refuelling. The operator's underground fuel tanks plus six jerrycans kept in the hangar, were full indicating that no additional fuel above the standby load of 500 lb had been added to the helicopter's tanks before its departure on the accident task.

The helicopter departed Rockhampton at about 2340 EST and the pilot reported on final approach for Yarandoo at 0039, approximately 1 hour after departure. During the flight the helicopter would have consumed approximately 250 lb of fuel. The pilot reported departure from Yarandoo bound for Rockhampton at 0114, updated his estimate for Rockhampton at 0126, and reported his decision to divert to Marlborough at 0132. The helicopter arrived overhead Marlborough at 0144, after a 30 minute sector and subsequently calculated to have consumed approximately a further 125 lb of fuel. Thus about 375 lb of fuel would have been consumed after departure from Rockhampton, leaving approximately 125 lb of fuel remaining on arrival at Marlborough.

By the time the pilot reported his intention to divert to Marlborough, the helicopter had flown for 78 minutes, representing a fuel consumption of about 325 lb. At that time, approximately 175 lb of fuel would have remained, representing 42 minutes of flight time available. It is likely that the flashing light in the "Shadin" fuel management system, which was set to illuminate when 45 minutes of fuel remained, had illuminated some minutes earlier, and that the pilot had used the intervening period to decide to divert, to determine his new destination, and in consultation with the paramedics, to determine the further ambulance services required for the patient.

The flight to Yarandoo and return to Rockhampton would have required about 120 minutes of flight time, consuming 500 lb of fuel. The company's operating procedures specified a fuel reserve of 30 minutes for night operations, so the task required a minimum fuel load of 625 lb. Configured for the task, the helicopter could have been loaded with up to 675 lb of fuel to depart Rockhampton at maximum gross weight.

Queensland Ambulance Service (QAS) tasking

Chapter 31 of the Queensland Ambulance Service Operations Manual "Aeromedical Operations" detailed all procedures for the operation of aeromedical services and the persons or agencies responsible for each step.

Paragraph 3150 of that chapter "Activation Process" detailed each step between receipt of a request for QAS assistance and completion of a flight followed by local area transfer of a patient to a medical facility. The District Communications Centre (DCC) (in this case CAPCOM) normally received the request and, generally in consultation with the clinical co-ordinator (a designated medical officer who determines the medical resource requirements for the task), would activate the aircraft and crew. On this occasion, a medical consultation was not obtained. However in retrospect, medical officers stated that they agreed with the decision to task the helicopter. Sub-para. (d) of para. 3150 stated:

"The District Communications Centre will then consult the pilot or service provider to establish the feasibility of the flight, i.e. weather, aircraft suitability, etc."

The decision to fly is made by the pilot. In discussion, DCC staff emphasised that they never questioned a pilot's decision not to fly. Further, it was normal practice in Rockhampton that when considering an aero-medical operation, DCC staff did not inform a pilot of the details of a task, thus avoiding any undue pressure on the pilot to fly. On this occasion, normal procedure was followed and the pilot accepted the task.

Classification of operations

At the time of the accident, CASA classified aircraft operations in accordance with the type of flight being conducted. Operators that carry fare-paying passengers (regular public transport and charter) are required to meet higher regulatory standards and receive a higher level of surveillance from CASA than other types of operators. Emergency Medical Service Operations, and Search-and-Rescue operations are classed as "aerial work" operations.

CASA has undertaken a project on Classification of Operations Policy. Civil Aviation Safety Regulation (CASR) 133, entitled "Air transport and aerial work operations (rotorcraft)" has been included within the project. Among other matters, the project is considering:

  1. aircraft certification requirements and crew (including supernumery crew) training requirements for aerial work operations;
  2. introducing performance requirements for helicopters in line with similar requirements for aeroplanes;
  3. introducing rules specific to certain types of aerial work operations;
  4. re-introducing minimum fuel requirements; and
  5. the issue of "persons directly involved" (including patients whose travel has been requested by a medical officer and an escort, usually a member of the patient's immediate family) travelling on aerial work flights.

CASR 133 is expected to be available from October 2002.

Sleep inertia

Sleep inertia refers to a feeling of disorientation, mental dullness or sluggishness that occurs after awakening from a period of sleep. In broad terms, sleep inertia may affect mood, memory, attention, concentration, cognitive processing, performance accuracy and reaction time. It is a recognised state of transition from sleep to wakefulness.

A variety of factors can influence the effect of sleep inertia on performance. When awakening from sleep normally, the effect of sleep inertia is believed to last for less than 5 minutes. When abruptly awoken, the effects have been identified as typically lasting up to 30 minutes, with some research indicating that performance can be impaired for over 1 hour.

 
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