History of the flight

At about 1703 EST, aircraft operating north of Gladstone reported receiving an emergency locator transmitter (ELT) signal. Shortly afterwards, a satellite detected the signal, and at 1755 the Australian Search and Rescue organisation (AusSAR) established that the signal was originating from an area near Hixson Cay, on the edge of the Great Barrier Reef, about 150 NM northeast of Rockhampton. At 1900, a fixed-wing aircraft tasked by AusSAR departed Rockhampton to locate the source of the ELT transmission.

At 1953, the captain of a fishing vessel reported that he was communicating with the crew of a yacht who reported that the yacht was sinking. At 2006, the crew of the aircraft tasked by AusSAR reported locating the yacht and its two occupants. The crew also reported that the yacht's life raft had drifted away and that retrieval of the crew by the fishing vessel was unlikely due to the proximity of the reef. Nineteen minutes later, AusSAR received further reports from the crew of the aircraft that the yacht was in danger of sinking.

At 2055, AusSAR requested the availability of a Rockhampton-based rescue helicopter (Rescue 407) to assist in the rescue of the two people stranded on the yacht. The helicopter was only equipped for flight under the visual flight rules (VFR). The duty pilot advised AusSAR that he would not be able to recover the yacht's crew at night, but after confirming the weather details and planning the mission, he agreed to drop a life raft to them. He subsequently called in the duty crewman, who was employed as a paramedic and was a volunteer crewman with the helicopter rescue service.

AusSAR also sought the assistance of an instrument flight rules (IFR) capable helicopter, a Bell 412 (Rescue 500) from Brisbane. Rescue 500 departed Brisbane at 2115 and arrived at Heron Island at 0015.

The Rescue 407 crew refuelled the helicopter to full tanks and loaded several Jerry cans of fuel into the locker located behind the helicopter's cabin. The pilot reported that to hold fuel reserves for the required alternate airfield at Gladstone he had planned to land the helicopter at Hixson Cay to refuel from the Jerry cans. Hixson Cay was about 4 minutes flying time from the stranded yacht's location. Rescue 407 departed Rockhampton at about 2145, arriving on scene at about 2250. The fixed-wing aircraft that had been in the search area since 1945, departed for Rockhampton at about 2157.

The Rescue 407 crew reported that during the transit to the search area at 7,000 ft, they conducted the operator's standard over-water passenger briefing and the intentions for descending to locate the yacht. The pilot was occupying the right side cockpit seat and the crewman occupied the cabin seat next to the left cabin door. The pilot reported that he briefed the crewman that he intended to descend to 50 ft and hover-taxi past the yacht at about 25 kts keeping it on the left side of the helicopter. The crewman was to drop the life raft short of the yacht and then drape a 100 ft length of rope that was attached to the activation line of the life raft across the yacht for its crew to haul in the life raft.

The pilot reported that when he arrived on scene, he initially tracked towards the yacht at 1,500 ft, from west to east along the line of surf breaking on the edge of the reef, but he could not see the yacht in the white water of the surf. He attempted a number of approaches before changing the approach direction so the helicopter was tracking from south to north, at right angles to the reef. The pilot reported that during the last pass, he saw the yacht about 1 NM from the helicopter and commenced descent from 1,500 ft.

The pilot stated that he had initially set the Radar Altimeter (RADALT) altitude warning to 200 ft and after the helicopter had descended through that altitude, he reset the warning to 50 ft. When the helicopter was about 600 m from the yacht, the crewman called the RADALT as passing through 200 ft then 150 ft. On this call, the pilot reduced speed to 50 kts and noted that the rate of descent was 700 ft per minute. During the latter stages of the approach, the pilot's attention was directed totally outside, using the searchlight set to maximum beam width for external illumination. He was satisfied that the approach was progressing well. The crewman then called 50 ft and very soon after, the helicopter impacted the water. The pilot stated that, at the time the helicopter was flying at about 45 to 50 kts. He had not issued any instructions to the crewman to open the door or deploy the life raft. The crewman reported that he estimated the helicopter to be about 400 m from the yacht when he called 50 ft and that the pilot said, "good" before, "everything went black."

Both the pilot and crewman reported that the helicopter was operating normally before it impacted the water. The crewman said that both cabin doors were closed prior to impact.

The helicopter came to rest submerged inverted. Although both crewmembers were initially disoriented and the pilot experienced difficulty in escaping, both crewmembers successfully exited the helicopter. The pilot, who had not inflated his life jacket, returned to the helicopter soon after and retrieved the life raft from the cabin.

At about 2345, the fishing vessel lost contact with Rescue 407. Rescue 500 was tasked at 0038 to also search for Rescue 407, arriving on scene at 0140. During their approach to dispatch a life raft to the yacht, the crew of Rescue 500 saw the inverted helicopter and the associated life raft nearby. Rescue 500 dispatched a life raft for the yacht crew and then departed for Heron Island to await daybreak before attempting a rescue. Just after daybreak, Rescue 500 recovered the yacht and Rescue 407 crews.

Crew information

The pilot held a Commercial Pilot (Helicopter) Licence, a night VFR Rating (Helicopter) endorsed with Non-Directional Beacon (NDB), a current Grade 1 Flight Instructor Rating (Helicopter), and an expired Command Single-Engine Instrument Rating (Helicopter). The pilot was endorsed on the Bell 407 helicopter type. At the time of the occurrence, the pilot had accumulated a total of 9,593 flying hours, including 46.6 hours on type. He had flown 44.6 hours in the previous 90 days, including 41.6 hours on type and 16.4 hours at night.

The pilot reported that he had significant prior search and rescue experience, conducted in several helicopter types. He also reported that he had flown over 600 retrieval missions with a high percentage at night. In particular, the pilot commented that he had performed many missions to the small cays on the reefs at night without incident. The pilot said that he had completed Helicopter Underwater Escape Training (HUET) when he was in the Australian Defence Force, which was over 5 years prior to the accident. The pilot had not completed Crew Resource Management (CRM) training during his tenure with the operator.

The pilot held a current Class 1 medical certificate with a requirement to wear corrective lenses for distance vision and to have reading glasses available. The pilot's 4-day history leading up to the accident revealed irregular sleeping patterns but he had obtained sufficient sleep over this period. The pilot reported no physiological or medical condition that was likely to have impaired his performance, and that he was adequately rested and medically fit for the flight.

The crewman was employed as an ambulance officer, as an Advanced Care Paramedic and served as a part-time crewman with the helicopter rescue service. He had been part of the rescue service for 2 years but he had not undertaken HUET training or Crew Resource Management (CRM) training.

Helicopter information

The Bell 407 helicopter was equipped and certified to operate Day and Night VFR. It was not equipped with helicopter flotation equipment, automatic stabilisation or automatic pilot systems, nor was such equipment required by regulation. It was equipped with a 'Nightsun' searchlight.

The helicopter was fitted with a Bendix King KRA 10A radar altimeter receiver/transmitter unit and a KI 250 indicator. The indicator unit displayed height directly above the surface beneath the helicopter using a needle and dial-type analogue display. The 8.28 cm dial displayed height from 20 ft to 2,500 ft, although published specifications only assured accurate indications between 50 and 2,000 ft.

Meteorological information

Following the accident, the Bureau of Meteorology (BoM) provided the ATSB with an estimate of actual weather conditions at the accident site at 2330. The estimates were based on synoptic patterns and meteorological information for Gladstone. The BoM assessment indicated that visual meteorological conditions (VMC) would have existed at sea level with wind from 120 degrees true at 10 knots, no precipitation, good visibility, scattered cloud with a base of about 2,000 ft and some cloud at mid-levels.

The pilot reported that he was advised by the Meteorological Office at Rockhampton airport that the weather at Rockhampton and the area seaward of the coast would be fine with no cloud all night. The pilot did not report flying through cloud during the descent from 7,000 ft.

The pilot of the fixed-wing aircraft that had been dispatched to locate the ELT prior to the arrival of Rescue 407 reported that the visibility was good, with clear sky and that it was a dark night with only a small sliver of moon visible. The pilot returned to the area at about 0230 and reported that the weather conditions were similar to that observed earlier in the evening.

Astronomical data indicated that the moon was waxing crescent with 13 percent of the moon's visible disk illuminated. The moon set at 2025.

The crew of Rescue 500 reported that, while enroute to the search area, there was broken cloud at about 2,500 ft, no moon, extensive sea haze, and poor visibility.

Night VFR operations

There were no aviation regulatory requirements for pilots to consider the amount of external visual reference that was likely to be available for a flight conducted at night under VFR, with the exception of considering forecast cloud below the lowest safe altitude. The pilot was not required by the regulations to consider the amount of celestial illumination, amount of terrain lighting, and/or the presence of a visual horizon. Aviation weather forecasts did not provide information on the amount of celestial illumination nor were they required to do so. This information, however, was available from a variety of other sources.

There was no regulatory requirement for the night VFR rating competencies to be demonstrated during regular flight reviews or otherwise at recurrent intervals. There was no requirement for the holder of a night VFR rating to have demonstrated any recent instrument flying proficiency prior to conducting a flight at night.

Wreckage examination

When the helicopter wreckage was sighted from the air during the following morning, it was reported as being located about 200 m from the yacht, at an angle to the reef. A straight-line debris trail lying on the sandy seabed was visible through the shallow water. The salvage crew reported that the helicopter's initial impact point appeared to be 600 m south-southwest of the yacht on the reef edge with the debris lying in an approximate straight line between the two points.

The main transmission and remains of the main rotor were lying in an area of breaking surf just near the initial impact point and were not recovered during the salvage. The water depth at the point of impact varied between about 0.6 m and 1.8 m depending on the tide and the sea state.

The tail boom was broken in two places, with the mid portion recovered from deep water northeast of the reef.

An inspection of the helicopter components revealed that the tail rotor drive shaft had been severed by twisting in the direction of normal rotation at a position forward of the oil cooler fan. The tail rotor gearbox housing had cracked and split at the thrust bearing housing for the input drive shaft. The tail rotor drive shaft exhibited torsional damage consistent with the tail rotor slowing or stopping while the drive shaft continued to rotate while under power. This was consistent with the tail rotor striking the water while under power. The tail rotor balance weights, pitch links and blades did not exhibit damage consistent with having contacted the water under high power.

Photographs taken the morning after the accident showed that the locker door was open but still attached. The door's main structure hinge attachments were still attached to the door and evidence of doorframe fractures was consistent with the locking mechanisms being forced from the closed and locked position. Evidence also indicated that engine and main transmission cowls and tail rotor drive shaft tunnel cover fasteners were secure prior to impact.

Operator's procedures and training

The operator had an air operator's certificate (AOC) issued by the Civil Aviation Safety Authority (CASA) 3 months prior to the accident. The AOC permitted the operator to conduct Search and Rescue but it did not specify permission to drop lifesaving equipment from the helicopter by day or night as required by the Civil Aviation Orders (CAO) 29.5. CASA advised that the operator had not approached the Authority for permission to conduct such operations.

The Civil Aviation Regulation (CAR) 215 required operators' operations manuals to, "contain information, procedures and instructions with respect to flight operations ... to ensure the safe conduct of the flight operations." This operator's operations manual had no information regarding procedures for dropping a life raft by day or night. The manual contained little detail or guidance for night operations, profiles or procedures required for descending the helicopter below minimum descent altitude over water at night, except as provided for in an exemption to CAR 174B provided by CASA. The exemption stated, in part, "The aircraft may only descend below 1,000 ft above the highest terrain within 10 miles after ground definition is established by use of the Nitesun (sic) searchlight using wide beam or the aircraft is established within three miles of destination." The manual did not provide advice, for example, on required crew interaction, the use of stepped descent profiles, maximum rates of descent, or minimum heights at which the helicopter could be flown over water at night.

The manual provided procedures for long over water flights. Flights over water more than 50 NM from a land mass suitable for landing were authorised provided that the flight could be conducted under VFR or night VFR procedures and navigated using two methods as described in the manual.

The operator did not require its pilots to hold a current command instrument rating on helicopters. There was very little information on restrictions or precautions when flying at night in remote areas or over water on dark nights, or considerations of the criteria for deciding whether to conduct operations involving long distances over water at night.

There was only a very brief and general section in the operator's operations manual pertaining to search and rescue operations. There was some additional information in the manual detailing considerations for long over water flights. Such considerations included the statement that "The Bell Long Ranger is not ideally suited to long flights over water. Pilots are to use common sense regarding retrievals from any point more than 50 miles from a place suitable for landing." The operator was not operating a Bell Long Ranger but rather a Bell 407. Although the Bell 206 Long Ranger and 407 share a common heritage, they are different helicopters with significant differences in performance and handling.

The operator did not have a formal risk management procedure to provide guidance to crew to assess risks associated with missions that may have been considered outside normal operations or a decision-making protocol for determining task acceptance or rejection.

None of the operator's personnel had received training regarding life raft deployment techniques, including the patterns to be flown, rigging of equipment, crew interaction, and release parameters. Neither the pilot nor the crewman had previously dispatched a life raft from a helicopter at night and had not received training from the operator in that procedure.

Night operations

Under certain conditions, external visual reference may be lost while flying an aircraft at night under VFR. These conditions are conducive to spatial disorientation and include operating over remote areas, in moonless or near moonless conditions, over water, and at times when the celestial horizon is obscured by cloud.

Spatial disorientation refers to an individual's failure to sense correctly the position, motion, or attitude of the aircraft or of him/herself. When spatial disorientation occurs, pilots experience great difficulty processing, believing, seeing, or interpreting the information on the flight instruments due to the erroneous information provided by their senses. In addition, the risk of spatial disorientation is high during instrument meteorological conditions (IMC) and night flying in either VMC or IMC.

There has been some research into visual illusions during night helicopter approaches. Previous visual illusion accidents have indicated that it is very difficult for a pilot, in dark-night conditions, to visually assess closing speed, rate of descent and glide path. Moreover, unaided night visual approaches may be as difficult as instrument approaches.

There are substantial difficulties with judging the approach glide path to a small illuminated area at night, particularly over an unlit area such as water. The 'black hole' phenomenon is particularly relevant to approaches over the sea because the intervening area is dark. The 'black hole' effect can provide an illusion of height, therefore, the pilot may perceive that the aircraft is higher than it actually is. In addition, the effect can entice pilots into keeping the visual angle of an approach constant by fixating on a source of light. The approach path will be too steep at first and then flatten out and result in a touchdown short of the nominated point.

Hazy or misty conditions can also influence the judgement of distance. Aerial perspective is affected by the dimming of the image of objects with distance. This, together with the reduction in colour contrast of distant objects, acts as a perceptual clue to distance. Distances therefore tend to be overestimated in low visibility or at night.

These false perceptions are considered to be very powerful. Even when pilots are aware of the 'black hole' effect, they may reject their instrument indications and believe the false impressions of glide path and height that the effect induces. The pilot reported that he was aware of the 'black hole' effect. The pilot also reported that he did not feel disorientated at any stage during the approach or at any other time during the flight.

'Nightsun' searchlight and Radar Altimeter (RADALT) operations

The operator's operations manual outlined some procedures for the use of the 'Nightsun' searchlight. As well as the requirements noted in the CAR 174B exemption provided by CASA, the operations manual also required that when the helicopter was below 500 ft, as indicated on the RADALT, the searchlight be operated on maximum beam width. On approach to land, the searchlight was not to be manipulated in azimuth or elevation below 200 ft RADALT altitude. Azimuth checks of the approach path were to be effected by yawing the aircraft. The RADALT warning was to be set to 200 ft.

The reflection, scattering, or other distortion of the searchlight beam by particles in the atmosphere over water, such as sea salt or sea haze may have produced what is sometimes called the 'fishbowl' effect. The pilot reported that during the passes over the stranded yacht, the searchlight seemed to make conditions a little blurry, like looking through a milk bottle.

Helicopters are rarely manually flown to low levels over water at night and those helicopters that are intentionally operated in such operations are normally equipped with automatic pilot and 'coupled' systems. These systems automatically conduct the approach, hover and departure with the pilot(s) monitoring the profile and system operation.

The student pilot of a Grob 115 C aircraft was authorised by his instructor to conduct solo night circuits at Merredin, WA. Shortly after take-off from runway 28, and as the student commenced his after take-off checks (at about 300 ft AGL, including flap retraction and engine power reduction), he noticed that the aircraft was becoming difficult to control. As he scanned the aircraft's flight instruments he decided that the attitude indicator was unreliable and noted the directional indicator turning quickly to the left. Control inputs applied to reduce the rate of turn were unsuccessful. The student recalled that the airspeed indicator was indicating 140 kts.

The student reported that despite applying back-pressure to the control column and maintaining the pitch attitude for a climb, the aircraft continued to descend and impacted the ground beyond the aerodrome boundary. Immediately following the ground impact, the aircraft became airborne and the student recalled applying full power and commencing a climb. An instructor on the ground established radio communication and provided instructions to assist the student. The student stated that the attitude indicator remained unreliable for the entire circuit but, with the instructor's assistance, he was able to complete a normal approach and landing. As the nose was lowered to the runway during the landing roll, the propeller struck the runway and stopped. The accident occurred at approximately 2000 Western Standard Time. The student was not injured and vacated the aircraft without assistance.

Examination of the aircraft indicated that the nose wheel and oleo had been damaged during the initial impact with the ground and had detached from the aircraft prior to landing. The nose oleo was subsequently recovered from a paddock in the vicinity of a left base position for runway 28.

Last light at Merredin on the night of the accident was 1802. It was reported to be a dark night, with no discernible natural horizon. During the initial climb from runway 28, the student had no significant external visual reference available and was using the flight instruments to maintain control of the aircraft.

Following the accident, the operator contracted an independent maintenance organisation to examine the aircraft flight instruments, engine driven vacuum pump, and other associated systems. No pre-accident defect was detected.

The flying roster for the day indicated that the student was scheduled to complete two separate exercises, a navigation phase check during the afternoon, followed by solo night circuits. The student had arrived at the aerodrome at 1000 to prepare for his phase check.

A delay in departure time for the phase check meant the aircraft arrived back at Merredin after last light. Prior to concluding the phase check, the instructor completed three circuits with the student for the purpose of authorising his solo night flying. The total flight time for the phase check was recorded as 3.3 hours, of which 0.2 hours was logged at night. By 1845, all tasks associated with the phase check were completed and the student took a short meal break before recommencing duty for the night circuits.

The operator had a detailed flying training syllabus for the conduct of training. It was reported that a gap in the flying program had permitted some students to progress through their training at an accelerated rate, which introduced night flying at an earlier stage of training than was usual. The student had been previously assessed proficient in the required syllabus items for solo night circuit operations and had attained this standard in less than the minimum flight time contained in the operator's flying training syllabus.

At the time of the accident, the student's flying training included 3.6 hours dual night instruction, 2.5 hours night pilot-in-command, 4.4 hours instrument flying and 2.7 hours in a synthetic trainer. The syllabus indicated that a student required at least 9 hours in a synthetic trainer prior to commencing his night training, including a requirement for 5 hours of night simulation in the synthetic trainer. There was no provision for an exemption against those operations manual requirements.

The Beech 1900D (B1900) accelerated to V1 (111 kts), when the crew noticed a flock of wood ducks crossing their path. At the same time there was a loss of aircraft performance so the crew rejected the take-off. The aircraft was brought to a stop without further incident.

Six wood ducks had impacted the aircraft in the vicinity of the right engine and caused extensive damage to the right engine and wing. Minor damage was evident in the left engine oil cooler.

The Civil Aviation Safety Authority required airports handling aircraft of thirty seats capacity or larger to have a recorded bird hazard management program. At the time of the occurrence, Cooma airport had regular scheduled services by aircraft that did not exceed nineteen persons, however during the ski season aircraft with a capacity exceeding thirty persons operated into Cooma.

Bird dispersal control had been applied early in the morning, approximately twelve hours before the B1900's departure.

Analysis of bird hazard reports since January 2001, indicated an increase in bird numbers at Cooma airport. The airport operator had implemented a bird hazard management program but records showed that the program was not being applied consistently.

During door disarming of the Boeing 747SP aircraft after landing, the cabin crew notified the flight crew that although the levers of main cabin doors L3 and L4 had been moved to the disarm position, the doors failed to disarm. The captain directed the flight attendants to remain at the doors and advised ground engineering to limit catering access. The flight engineer was directed to ensure a safe disarm. The flight engineer found the door slide girt bars still partially engaged into the girt bar receivers. He then used tools to safely disengage the girt bars and disarm both doors.

Line maintenance personnel examined the doors and, after repeated arm/disarm cycles, were unable to duplicate the anomaly. The flight crew elected to continue operations with additional precautions, referred to as "girt bar disengagement inspection", taken to ensure the operational status of the doors. That action included the flight engineer confirming arming of the doors before departure and disarming following arrival. That precaution was taken to prevent inadvertent activation of the slide during normal door opening.

Following landing at the next sector airport, the cabin crew again could not disarm main cabin doors L3/L4. The flight engineer again used tools to physically disengage the girt bars from the girt bar receivers in order to disarm both doors. A maintenance entry was made in the aircraft technical log requiring visual confirmation of the door arming/disarming during each transit. The Master Minimum Equipment List (MMEL) was reviewed and the aircraft returned to service without restrictions.

Over the next three days, the aircraft completed twelve sectors with the girt bars of main cabin doors L3/L4 requiring the girt bar disengagement inspection. Following the last of those twelve sectors, the operator's maintenance department issued an Authority to Proceed (ATP), stating a requirement that the doors not be opened from the outside or left unattended until maintenance personnel confirmed the girt bar was completely disengaged from the girt bar receiver. The ATP was applicable for two sector overwater flights only. Upon completion of those sectors, maintenance personnel corrected the girt bar discrepancy by adjusting the escape slide skirts and returned the slides and doors to normal operation.

B747SP main cabin door configuration

The aircraft's main cabin was configured with four doors per side. The doors were arranged in sequential order, with numbering starting at the nose of the aircraft. The doors were identified by lettering indicating `L' for the left side of the cabin looking towards the nose, and `R' for right.

Discrepancy history of main cabin doors L3/L4

Five days prior to girt bar disengagement inspection implementation, the technical log noted an entry that said, "L4 unable to move mode select to auto". Corrective action stated that an obstruction was found in the girt bar and had been removed, with door operations now normal.

Four days prior to disengagement inspection implementation, the technical log noted an entry, "Door L4 selector switch handle will not engage arm position or sweep seal is remaining outside the door sill". Corrective action stated that the lower skirt aft side was found fouling the girt bar, and that the skirt appeared to be distorted. The skirt was repositioned and operations reported as normal.

Two days prior to girt bar disengagement inspection implementation, the technical log noted an entry, "L4 lower bustle has skirt damage". Corrective action stated that the lower bustle sweeper seal was trimmed.

Door mounted escape slide normal operation

When the crew selected the door to the armed mode (automatic), the girt bar mechanism positioned the girt locks into the floor brackets. As the door handle was moved towards the open position (at approximately 45 degree's of rotation) it lifted the lower gate and girt lift mechanism. When the girt lift mechanism separated from the girt lock, the girt bar springs protruded, locking the girt bar to the floor brackets. The escape pack was then attached to the floor. The door was then forced open by use of an emergency pressure cylinder. That opening of the door, with the girt still attached to the aircraft, caused the slide to release from the door and initiate the inflation sequence of the slide.

Authority to proceed

The Civil Aviation Safety Authority (CASA) issued authorisation under Civil Aviation Regulation (CAR) 37 to delegates of the operator permitting those individuals to authorise continued operation of aircraft with known discrepancies. That authorisation was designed to address aircraft discrepancies not covered by the MMEL or other documentation and was subject to the conditions outlined in the ATP. Such discrepancies must not constitute a concession against an operational requirement of a CAR nor conflict with the design standard of the aircraft. An authorised delegate of the operator who annotated the discrepancy, signed the ATP. A copy of that ATP was provided to the local CASA office.