Following a request from the New Zealand Transport Accident Investigation Commission, ATSB is providing assistance regarding the recorder data from a Metroliner which was involved in an accident in New Zealand on 03 May 05.

The pilot was reported to have conducted a similar low-level manoeuvre to that which preceded the accident on several previous occasions. On that basis, the investigation team considered that it was unlikely that the passenger was at the controls of the aircraft at the time of the accident. The manoeuvre left little or no margin for error and required sound judgement and skill. Although the pilot may have possessed those skills, no evidence was found of his ever having undertaken the appropriate check to assess those skills and obtain approval to conduct low-level aerobatic manoeuvres.

Repetition of the manoeuvre over a period of time may have led to the pilot gaining a false sense of security and may have led to the pilot becoming complacent about the inherent dangers involved with such manoeuvres. The manoeuvre performed by the pilot earlier that day at another location was commenced from a 'high-speed' flypast. The associated energy would have allowed the aircraft to convert speed to height and climb higher and attain a greater altitude for recovery than the manoeuvre performed during the accident flight. That manoeuvre was commenced from a take-off roll that did not use the full runway length available. When combined with a tailwind component, it was unlikely that the aircraft attained adequate airspeed to safely complete the intended manoeuvre by the end of the strip. It was also possible that the pilot was unaware of the windshear or had not considered its affect on the aircraft's climb performance.

Although the aircraft appeared to have stopped spinning to the right just before impact, the pilot had insufficient height to avoid a collision with the ground. Had the stall warning been operating, it could have provided the pilot with an earlier indication of the stall condition and thus enabled him to initiate a recovery earlier in the development of the manoeuvre.

The affect of the pilot's medical condition on his judgement or decision-making could not be determined. However, some aspects of the pilot's behaviour were not consistent with compliance with rules and regulations or good airmanship. These included conducting low-level aerobatics without approval, ignoring concerns expressed by peers, operating with an unserviceable stall warning indicator and ignoring weight and balance limitations. Furthermore, the pilot flew the aircraft knowing that he was suffering from a medical condition that was being reviewed by the Civil Aviation Safety Authority (CASA) and having been advised by CASA that he was not to fly until the results of the review were known. Disregard for the rules governing the conduct of flight and the operation of the aircraft removed safety defences that were established to prevent this type of accident.

On 15 May 2005, at 1535 Central Standard Time, an American Champion Corporation Citabria 7GCAA aircraft registered VH-TUF, with a pilot and passenger, took off from Stonefield private airstrip in South Australia for a local private flight. Shortly after becoming airborne, the aircraft crashed. Both occupants were fatally injured. The aircraft was destroyed by impact forces and a post impact fire.

After start up, the pilot performed a turn on the ground of more than 360 degrees before taxying on the north-east strip. The aircraft engine was heard powering up on the strip into the north-east and shortly after became airborne. After becoming airborne, the aircraft was observed to remain approximately 10 feet above the strip, and remained at that height until the end of the strip. At about this point, the aircraft was observed to enter a near vertical climb. At an estimated height of 500 feet above ground level, the aircraft stalled in the vertical position, before entering a right hand spin. The aircraft completed one and a half turns in the spin before it appeared to recover. At the point where the aircraft appeared to have recovered from the spin, it impacted the ground.

The investigation determined that the aircraft on the accident flight was 20kg over maximum all up weight (MAUW). The increased weight would have the effect of increasing the stall speed of the aircraft, thereby reducing its performance. It was also determined that the pilot took off north-east with a quartering down wind component, and attempted a vertical climb with a wind gradient of approximately 30kt and at 500 feet from the south, above ground level. This wind gradient would have significant impact on the aerodynamic performance of the aircraft, and the pilot may not have achieved the height he intended before it stalled.

At 1110 Eastern Standard Time on 12 May 2005, a Eurocopter EC120B helicopter, registered VH-ADC, departed Canberra for Jindabyne, NSW, with the pilot and two passengers. The pilot reported that about 30 minutes after departure, while in cruise flight at 5,000 ft above mean sea level (AMSL) in smooth flying conditions, the main rotor speed (NR) RPM audio warning sounded¹. The pilot reported that a scan of the instrument panel revealed that the NR was exceeding 450 RPM and that he then lowered the collective pitch lever. He reported that after entering an autorotation configuration, it took approximately 5 to 7 seconds to arrest the high NR rate by lifting the collective lever, which then reduce the NR and silenced the audio warning².

The pilot further reported that he completed a left turn towards a cleared area and lined the helicopter up on a north-easterly heading, while rapidly losing altitude before turning towards the south-east over trees to the clearing. The pilot flared the helicopter for landing, but noted no perception of power from the engine (audible or torque) and the helicopter sank through the flare before it impacted the undulating ground. It then bounced back into the air momentarily, before it impacted the ground once more and slid to a halt. The pilot then applied the rotor brake to stop main rotor rotation and assisted the passengers to exit the helicopter. There were no injuries to the passengers and only minor injuries to the pilot. The elevation at the final resting place of the helicopter was about 4,340 ft AMSL.

The helicopter was determined to be within weight and balance limits and carried sufficient fuel for the flight.

The helicopter sustained damage to the main rotor blade tip caps, front skid landing gear, front bottom canopy and aft upper tail cone/fenstron area. During the landing sequence, the main rotor blades had contacted the aft upper tail cone/fenstron area as a result of the flaring of the helicopter. The initial impact ground scars of the helicopter skid landing gear were reported to have been about 35 m from the final resting place of the wreckage.

At the time of the occurrence, the helicopter had accumulated 195.9 hours total airframe time. The Turbomeca model Arrius 2F engine, serial number 34039, had been installed on 28 February 2005 with 736.8 hours time since new. At the time of the accident, the engine had accumulated 775.0 hours time since new. The engine was a replacement engine that had been provided by the engine manufacturer while the original engine was being repaired.

The original engine had been removed for an unrelated over-torque event. An examination the helicopter's operational and maintenance records conducted by the Civil Aviation Safety Authority (CASA) found that the helicopter had been maintained correctly and satisfactory records maintained.

Following the accident, the engine was removed and shipped to the engine manufacturer for testing, disassembly and examination under the supervision of the Bureau d' Enquetes et d' Analyses of France, on behalf of the Australian Transport Safety Bureau. The engine was placed into a test cell and operated to confirm operating parameters. The engine was tested through all operating parameters without any abnormal vibrations, high temperatures, overspeeding or other anomalies. The fuel control unit was then removed and bench tested with no anomalies found. Testing, disassembly and examination of the engine did not reveal any anomalies that could have contributed to the in-flight shutdown as reported.

The helicopter's on-board diagnostic equipment was accessed immediately following the event. The maintenance page of the equipment displayed only a fault code indicating that an over limit NR event to 462 RPM had taken place. No other faults were displayed.

The rotorcraft flight manual included a section entitled ENGINE FLAME-OUT, which detailed procedures in the event of an engine flame-out in cruise flight including:

AUTOROTATION PROCEDURES OVERLAND

1. Collective pitch…………REDUCE to maintain NR in green arc.

The rotorcraft flight manual also included a section entitled ENGINE GOVERNOR FAILURE which detailed emergency procedures for a rapid increase in NR as follows:

NR INCREASE

Simultaneously to maintain NR in green arc:

1. Collective……………….INCREASE
2. Twist Grip………………SLIGHTLY REDUCE

NOTE
During the flight, the pilot shall control NR using the twist grip.

The rotorcraft flight manual did not include procedures specifically related to a sudden increase in NR during cruise flight. However, the CASA requirements for the granting of a helicopter licence require a pilot to demonstrate the ability to control NR within rotorcraft flight manual limits. During this training, pilots are taught to control the NR utilising both the collective lever and the throttle twist grip.

1. An intermittent tone activated at 420 RPM NR. Normal operating range for NR was 390 to 415 RPM, the caution range was 415 to 447 RPM with 447 RPM the maximum with power off.
2. Increasing collective pitch of the main rotor blades using the collective pitch lever reduces the NR by slowing down the rotational speed of the blades for that given engine power setting.

At 1110 Eastern Standard Time on 12 May 2005, a Eurocopter EC120B helicopter, registered VH-ADC, departed Canberra enroute to Jindabyne, NSW, with the pilot and two passengers on board. The pilot reported that at about 30 minutes after departure, while in cruise flight at 5,000 ft above ground level in smooth flying conditions, the main rotor speed (NR) RPM audio warning sounded.

The pilot reported that a scan of the instrument panel revealed that the NR was exceeding 450 RPM and that he then used the collective pitch lever to reduce the NR. The pilot noted that it took approximately 5 to 7 seconds to arrest the high NR rate, which then silenced the audio warning. The helicopter was flared for landing as it lost altitude and impacted the undulating ground It then bounced back into the air momentarily, before it impacted the ground once more and slid to a halt. The pilot then applied the rotor brake to stop main rotor rotation and assisted the passengers to exit the helicopter. There were no injuries to the passengers and minor injuries to the pilot.

The helicopter was determined to be within weight and balance limitations and carried sufficient fuel for the flight. Testing of the engine could not duplicate the in-flight engine shutdown as reported.

On 7 May 2005, a Fairchild Aircraft Inc. SA227-DC Metro 23 aircraft, registered VH-TFU, with two pilots and 13 passengers, was being operated by Transair on an instrument flight rules regular public transport service from Bamaga to Cairns, with an intermediate stop at Lockhart River, Queensland. At 1143:39 Eastern Standard Time, the aircraft impacted terrain in the Iron Range National Park on the north-western slope of South Pap, a heavily timbered ridge, approximately 11 km north-west of the Lockhart River aerodrome. At the time of the accident, the crew was conducting an area navigation global navigation satellite system (RNAV (GNSS)) non-precision approach to runway 12. The aircraft was destroyed by the impact forces and an intense, fuel-fed, post-impact fire. There were no survivors.

The accident was almost certainly the result of controlled flight into terrain, that is, an airworthy aircraft under the control of the flight crew was flown unintentionally into terrain, probably with no prior awareness by the crew of the aircraft's proximity to terrain. The investigation report identifies a range of contributing and other safety factors relating to the crew of the aircraft, Transair's processes, regulatory oversight of Transair by the Civil Aviation Safety Authority, and RNAV (GNSS) approach design and chart presentation. It also details safety action taken by various agencies to address the identified safety issues, and includes safety recommendations relating to those safety issues that had not been addressed by relevant agencies at the time of publication of this report.

Recommendations

R20070002 | R20070003 | R20070004 | R20070005 | R20070006 | R20070007 | R20070008 | R20070009 | R20070010 | R20070011 | R20060019 | R20060020 | R20060021 | R20060022 | R20060002 | R20060003 | R20060005 | R20060006

Although there was no applicable minimum distance standard specified for visual separation, the controller was unable to maintain continuous visual separation between the 152 and the 717. The decision by the pilot of the 152 to turn directly onto the base leg of the circuit, and not continue on the downwind leg as instructed, contributed to the infringement of separation standards.

This analysis examines the development of the occurrence and highlights the safety issues that became evident as a result of the investigation.

The controller did not provide the pilots of the 152 or the crew of the 717 with traffic information, or a number in the landing sequence as required by the Manual of Air Traffic Services (MATS). The provision of traffic information was not mandatory and the MATS did not provide any guidance to controllers on the circumstances under which the provision of traffic information would be appropriate. While the controller had intended to provide this information to the pilot of the 152, he relied on a pilot report prior to turning base as a prompt, and this report was not received.

Without the timely provision of traffic or sequence information, the situational awareness of the pilots of both aircraft was reduced. They were effectively excluded from participating in the separation process as described in the Aeronautical Information Publication (AIP) and the MATS. Consequently, the pilots of the 152 were not aware of the broader consequences of their actions once they turned their aircraft onto the base leg. They simply did not recognise that a potential conflict between their aircraft and the 717 existed.

While the flight crew of the 717 was not provided with directed information by the controller, they had been monitoring the radio transmissions between the controller and the pilots of other aircraft in the area. That, together with active scanning of the circuit area for traffic using the traffic alert and collision avoidance system and visual observations, assisted in the resolution of the situation.

The MATS provided no guidance as to whether routinely issued sequencing and separation instructions, such as 'continue downwind', required a read-back. While it may be impractical for the controller to obtain a read-back for every circuit instruction, emphasis should be placed on obtaining a read-back of safety critical instructions. Had the controller requested a read-back of the instruction to continue downwind, and provided a reason for the action, the likelihood of any misunderstanding would have been significantly reduced.

The investigation could not establish whether any aspect of the occurrence sequence could be attributed to the effects of fatigue. However, due to the instructor's non-aviation working commitments, the possibility that fatigue contributed to the occurrence could not be discounted.

On 30 April 2005, at about 1033 Eastern Standard Time¹, a Cessna Aircraft Company A152 (152) aircraft, registered VH-PVX, was being operated on circuit flying training at Hobart Airport, Tasmania. On board were a student pilot and an instructor. The pilot had been issued with a clearance by the aerodrome controller (controller) to conduct right circuits from runway 30 and to operate not above 1,000 ft above mean sea level.

At 1037, a Boeing Company 717-200 (717) aircraft registered VH-LAX, en route from Melbourne to Hobart, commenced the final leg of the Hobart runway 30 VOR² instrument approach. The crew had been issued a clearance by the controller to conduct the final approach. The aircraft was being operated under the instrument flight rules. At about the same time, the controller instructed the pilot of the 152 to make a left orbit to enable the controller to visually separate the 152 with both the inbound 717 and another jet aircraft departing from runway 30. At that time the 152 was at the end of the downwind leg of the circuit.

At about 1039, the pilot of the 152 reported that the orbit was complete and the controller instructed the pilot to continue on the downwind leg and to report prior to turning on to the base leg. However, the pilot had not completed a full orbit but had 'rolled out' of the orbit after completing only a 270 degree turn, directly onto the base leg of the circuit. At that time the 717 was on the final approach leg of the circuit, 90 degrees to the left of the flight path of the 152 and converging.

At about 1041, when the pilots of both aircraft became aware of the potential conflict, the minimum horizontal distance between the two aircraft had reduced to between 400 and 500 m. The 717 was about 300 ft below the 152, and the pilots of both aircraft commenced avoiding action.

The Manual of Air Traffic Services (MATS) 4.5.1.1 stated that visual separation shall be achieved by the use of visual procedures, or by assigning visual separation responsibility to a pilot. The MATS did not specify any minimum distance requirement for the application of visual separation. As the controller was unable to continue to visually observe separation between the 152 and the 717, and had not assigned separation responsibility to the pilot of the 152, there was an infringement of separation standards.

The routine aerodrome weather report (METAR) for Hobart issued at 1030, recorded the cloud as few³ at 3,000 ft and broken at 5,000 ft with visibility greater than 10 km. The pilot in command of the 717 and the controller later reported that the cloud was scattered at 4,000 ft while the 152 instructor believed the cloud base to be broken at about 3,000 ft.

The 152 instructor reported that he had a total of about 270 flying hours including 15 to 20 hours as an instructor. He was relatively new to Hobart and worked about 5 to 10 hours a week flying. He also worked casually in another non-aviation position with shifts that finished late at night or in the early morning.

The instructor believed that his inexperience, together with the cockpit workload involved in instructing the student pilot and controlling the aeroplane in moderately difficult crosswind conditions, reduced his situational awareness. He reported that he was not aware of the 717 on final, and believed he would not have had any opportunity to observe the aircraft until it was established on the final approach because of the low cloud in the area.

The controller had extensive experience in the provision of aerodrome control services at Hobart, and reported that the workload at the time of the occurrence was both moderately busy and complex.

The controller reported that he was applying visual separation between the 152 and several other aircraft. The MATS specified that:

The requirement to provide traffic information was changed from 'mandatory (and)' to 'optional (and/or)' by Airservices Australia in April 2003. On 1 September 2005, Airservices Australia amended the MATS to completely remove the previously amended section 4.5.2.3 relating to the provision of aerodrome traffic information, with the concurrence of the Civil Aviation Safety Authority (CASA), to remove ambiguity over separation responsibilities in the aerodrome traffic zone.

On 16 September 2005, the Civil Aviation Safety Regulation Part 172 Manual of Standards was amended, after agreement between CASA and Airservices Australia, to state:

When aircraft are operating visually as aerodrome traffic ATC must issue 1 or more of the following:

(a) clearances designed to maintain separation

(b) sequencing instructions

(c) relevant traffic information

The issue of the provision of traffic information is subject to an Australian Transport Safety Bureau (ATSB) safety recommendation⁴ (see also Safety Actions section of this report).

The Aeronautical Information Publication (AIP) GEN 2.14.3 also specified that:

ATC will provide relevant traffic information to aerodrome traffic to enable pilots, while complying with ATC instructions, to maintain separation from other aircraft.

The controller reported that the initial orbit instruction given to the pilot of the 152 was to allow for the departure of another jet aircraft and his plan was for the 152 to then extend on a downwind leg until it was possible for the 152 to safely follow the 717 on final. He had intended to pass the pilot of the 152 a number in the landing sequence when the pilot reported prior to turning base. However, as this report was not received, the pilot was not provided with either a number in the sequence or traffic information.

AIP GEN 4.4.1 specified that 'pilots must transmit a correct read-back of ATC clearances, instructions and information which are transmitted by voice' and ensure 'sufficient detail is included to indicate compliance'. The MATS 6.1.13 specified that ATC 'shall ensure that a correct read-back in sufficient detail is obtained'.

Both documents indicated that only key elements relating to certain clearance items must be read back, including 'level instructions, direction of turn, heading and speed instructions'.

The pilot of the 152 did not read back the instruction to continue on the downwind leg, nor did the controller request the read-back. There was no specific requirement in either the AIP or the MATS for the read-back to be provided.

The controller later acknowledged that a sequence number and traffic information should have been provided to the pilot of the 152 and that he believed that a read-back of the downwind instruction would have been beneficial.

Airservices Australia had an annual refresher training program for tower controllers that detailed several mandatory and optional training modules. One mandated module relating to separation assurance was not available to the Hobart controllers at the time of the occurrence.

The 717 flight crew was not provided with traffic information by the controller, but reported that they had been monitoring the radio transmissions between the controller and other pilots. Additionally they had observed the 152, initially on the traffic alert and collision avoidance system (TCAS),⁵ then visually, before commencing avoiding action.

1. The 24-hour clock is used in this report to describe the local time of day, Eastern Standard Time (EST), as particular events occurred. Eastern Standard Time was Coordinated Universal Time (UTC) + 10 hours.
2. Very high frequency omnidirectional radio range.
3. Cloud amounts are reported in oktas. An okta is a unit of sky area equal to one-eighth of total sky visible to the celestial horizon. Few = 1 to 2 oktas, scattered = 3 to 4 oktas, broken = 5 to 7 oktas and overcast = 8 oktas.
4. ATSB occurrence investigation report 200205540 and associated safety recommendation R20040063 available at www.atsb.gov.au.
5. TCAS is an independent onboard collision avoidance system. It is designed as a backup to the ATC system and the 'see and avoid' concept.

On 30 April 2005, the pilot of a Cessna Aircraft Company A152 (C152) aircraft was conducting circuit training at Hobart. The C152 was on the downwind leg of the circuit when the crew of a Boeing Company B717-200 (B717) aircraft commenced the final leg of an instrument approach to the same runway.

The Hobart aerodrome controller was applying visual separation standards and had instructed the pilot of the C152 to make an orbit, and then continue downwind, to separate the C152 from other aircraft. The C152 pilot did not complete a full orbit, but turned onto the base leg of the circuit when the B717 was on final approach. The minimum distance between the converging aircraft reduced to between 400 and 500 m horizontally and 300 ft vertically and required the pilots of both aircraft to commence avoiding action. There was an infringement of separation standards.

The pilot of the C152 did not read back the instruction to continue on the downwind leg to the controller, nor did the controller request this read-back. There was no specific requirement in published documents for the read-back to be provided.

The controller did not provide the pilot of the C152 or the B717 with traffic information, or a number in the landing sequence as required by published documents. This led to a reduction in the situational awareness of the pilots of both aircraft and excluded them from participating effectively in the separation process.

Airservices Australia has advised that they are addressing the issue of obtaining read-backs, when necessary, through controller education and have developed a roving check and standardisation programme for regional towers. As part of that programme, check and standardisation officers place emphasis on the use of correct phraseology and read-back.

The ATSB issued a safety recommendation to Airservices Australia to enhance pilot situational awareness.