What happened

On 2 May 2011, a Boeing 717 aircraft, registered VH-NXE and operated by Cobham Aviation, was on a scheduled flight from Perth to Newman, WA. During the climb, the left engine failed. After completing safety checks and declaring a PAN, the crew returned the aircraft to Perth and landed without incident. An engine inspection identified blade failures in the left engine's high-pressure turbine (HPT) module. After disassembly, it was determined that the loss of a single HPT blade due to a fatigue failure had occurred.

The engine manufacturer had implemented a number of modifications to the HPT blades since 2003; culminating in a new-design blade, designated the Mk II. The subject engine had not been retrofitted with Mk II blades at the time of the occurrence.

The manufacturer had issued three service bulletins (SB) to operators regarding the installation and modification of engines with previous-design HPT blades. The operator is complying with these SB requirements; modifications have been scheduled to the engine fleet and are in progress with the manufacturer.

What happened

At about 1410 EST, on 30 April 2011, the crew of an Aerospatiale AS350FX2 helicopter registered VH-RTV (RTV) was replenishing gas well-head inhibitor tanks using sling load operations from Ballera Airport, Queensland. During one such operation to a well-head that was surrounded by water, the tail rotor blades struck two pipes that extended above the other pipework. 

At the time, the pilot was descending the helicopter prior to releasing the sling. Both he and the crewman were focusing on maintaining clearance from other parts of the well-head and neither saw the two pipes that the tail rotor struck.

Immediately following the occurrence, the operator introduced procedures which specifically addressed inhibitor tank replenishment to supplement the external and sling load procedures which were already in place.

What happened

On 23 April 2011, at 1644 Eastern Standard Time, a loss of separation assurance (LOSA) occurred between a Boeing B737-8BK (737), registered VH-VOB, and an Airbus Industrie A320-232 (A320), registered VH-VGZ, near Armidale Airport, New South Wales (NSW).

Both aircraft were conducting scheduled passenger services at flight level 320 on the same one-way air route, H62, until position Mount Sandon, where the leading 737 aircraft would continue tracking south for Sydney, while the following A320 aircraft was flight planned to track left to Williamtown.

As the 737 was required to enter a holding pattern for sequencing into Sydney, the air traffic controller approved a speed reduction for the aircraft, but did not identify that the longitudinal separation between it and the following A320, was closing.

When the 737 flight crew provided the controller with their aircraft's speed information for the benefit of the following traffic, the controller identified the potential confliction and issued the A320 with a vectoring instruction to maintain separation. Although the separation between the two aircraft did not reduce below the required standard, a LOSA had occurred due to the closing longitudinal proximity between the two aircraft.

Airservices Australia (Airservices) advised that a review of LOSA and breakdown of separation occurrences would be undertaken to determine whether speed differential and aircraft performance were significant contributing factors and if additional refresher training was required for controllers.

This occurrence highlights the need for awareness of the effects of low workload on performance, identification of lowered vigilance and subsequent action or implementation of strategies to maintain safe operations. It also demonstrates how appropriate flight crew communication enhanced the situational awareness of the controller. In addition, the knowledge and application of effective compromised separation recovery techniques by the controller was integral in managing the situation.

Safety summary

What happened

At 1706 on 29 April 2011, the Panama registered bulk carrier Dumun grounded while departing the port of Gladstone, Queensland.

Prior to the grounding, the ship's steering appeared to stop responding to bridge commands when the linkage between the tiller and rudder angle transmitter became detached. The steering gear continued to operate normally, but the transmitter lost its input signal and, as a result, the bridge mounted rudder angle indicator stopped working.

The bridge team assumed that the steering had failed, so the pilot ordered the main engine stopped and then started astern. However, these actions were not enough to prevent the ship from grounding.

What the ATSB found

The ATSB determined that the ship's builders did not identify that the rudder angle indicator transmitter and tiller linkage were not installed correctly. More broadly, the ATSB found that the analysis of shipping operations in Gladstone, carried out by the relevant authorities, had not appropriately considered all that could be done to prevent the grounding of a ship as a result of steering gear or main engine failure. In addition, it was found that a comprehensive safety management system had not been implemented in Gladstone with the aim of identifying, evaluating and controlling pilotage related risk.

What has been done as a result

Dumun's shipbuilder has sent a bulletin to the owners of all ships built by the company advising that the rudder angle indicator linkage should be checked to ensure that it is correctly fitted. The company has also modified its procedures to ensure that these checks are carried out during the building of all future ships.

Maritime Safety Queensland (MSQ) and its pilots have worked with Gladstone Port Corporation and terminal operators to improve ships' readiness for departure by implementing rigorous pre-departure checks. MSQ is also in the process of developing a single pilotage safety management system covering all of the ports in which the organisation provides pilotage operations.

Safety message

Safety regulators and port authorities should consider all the risks associated with the passage of deep draught ships within their ports and have appropriate contingency plans in place to deal with foreseeable emergencies.

What happened

On 26 April 2011, a Beech Aircraft Corporation A36 (Bonanza) aircraft, registered VH-CKX, departed Geraldton on a charter passenger flight to East Wallabi Island (in the Abrolhos Islands group), Western Australia.

When on final approach, the pilot reported that the aircraft was about 50 ft lower than normal, but he was not concerned. Soon after, the pilot glanced to the left at a maritime channel marker for about 2-3 seconds to ensure separation with the aircraft was adequate. The pilot then looked back at the runway and realised that the aircraft was too low. He immediately applied rearward pressure on the control column in an attempt to clear sand dunes. The aircraft collided with the sand dunes and bounced, before landing 50-60 m along the runway.

As a result of this occurrence, the aircraft operator has advised the ATSB that they have incorporated a checklist into their check and training procedures that details the assessment requirements when determining a pilot's competency for operating at the Abrolhos Islands.

This accident demonstrates the importance of establishing and maintaining the desired approach path by simultaneously adjusting the aircraft's power setting and attitude. It also highlights the unexpected nature of distractions and the impact they can have on aircraft operations.

What happened

On 3 March 2011, a Tiger Airways operated Airbus Industrie A320-232, registered VH-VNG (VNG) and a Pilatus Aircraft Ltd PC-12/45, registered VH-FMP (FMP), were on approach to Alice Springs Airport, Northern Territory. Both aircraft were operating under instrument flight rules (IFR).

The Alice Springs tower was closed, giving the pilots responsibility for organising their own separation. Both flight crews provided a number of updated estimates for their arrival into Alice Springs during the approach. The pilots of VNG estimated their position to be established on finals at time 11 (1941 CST) and FMP estimated their position established on the Instrument Landing System (ILS) at the same time. The conflict between the estimates was not initially recognised by either crew.

As both aircraft approached the initial approach fix, the potential conflict was realised, and separation was organised. During the separation manoeuvring, the pilot of FMP turned towards VNG, and a Traffic Collision Avoidance System Resolution Advisory warning was activated. The pilots of VNG conducted a missed approach and FMP continued the turn behind VNG.

Tiger Airways have conducted a risk assessment on operating into non-towered aerodromes. As a result of that assessment, they have rescheduled all Alice Springs flights so that they operate within active tower hours. They have also made a policy decision that flights will not be scheduled into CTAF aerodromes outside of tower hours for all future schedule developments.

What happened

On 18 April 2011 at about 1320 Eastern Standard Time, the pilot of Eagle Aircraft DW-1 bi-plane aircraft, registered VH-FTB (FTB), departed the Ingham authorised landing area (ALA) to conduct aerial agricultural work about 28 km to the south.

During the second application run, FTB impacted a tree with the right lower wing leading edge. The tree was void of foliage and stood to the foreground of other leaved trees, making it difficult to see from ground level.

The pilot was able to control FTB and fly the aircraft to an adjacent field where it landed in an upright position. On contact with the ground, FTB cart- wheeled before coming to rest. The pilot sustained serious injuries to the head, back and right leg. The aircraft was seriously damaged.

The accident highlights the inherent risks associated with operating at low-level, the need for quick decision making and the importance of adequate safety equipment.

Abstract

On 24 April 2011, at about 1816 Eastern Standard Time, a Robinson Helicopter R44, registered VH-RUR, with a pilot and one passenger on board, collided with the sea off the northern headland of Lilli Pilli Bay, New South Wales.

The helicopter was being flown after last light and was on approach to a helicopter landing site when the accident occurred. The pilot was not approved, nor was the helicopter equipped, to fly at night.

The occupants escaped from the helicopter after the impact with the water. A witness to the accident assisted the pilot onto nearby rocks but the passenger was fatally injured.

The investigation did not identify any organisational or systemic issues that might adversely affect the future safety of aviation operations. However, the accident does provide a timely reminder of the importance of appropriate flight planning and informed in-flight decision making.

Abstract

During a scenic charter flight and while operating at low level, the pilot of a Kavanagh Balloons E‑210 hot-air balloon, registered VH-OTZ, was unable to arrest the balloon's descent and initiate a climb in time to avoid powerlines, requiring an emergency descent and landing. The balloon landed hard in a paddock with the basket not orientated correctly to the direction of flight. It bounced, dragged and inverted along a distance of 60 m, resulting in injuries to the occupants and minor damage to the basket.

The investigation identified a minor safety issue, in that the procedural and guidance framework for commercial balloon operations generally did not provide a high level of assurance in regard to the safe conduct of low flying. Action by the Civil Aviation Safety Authority will, once in place, adequately address that safety issue. In addition, the operator of the balloon revised the content of its operations manual.

The Australian Transport Safety Bureau (ATSB) has completed its download and replay of the cockpit voice recorder (CVR) from a Bombardier DHC-8-311 aircraft, registered ZK-NEQ. The work was conducted on behalf of the Transport Accident Investigation Commission (TAIC) of New Zealand, in support of their investigation into the failure of the aircraft's nose landing gear, and subsequent diversion to Woodbourne Aerodrome, New Zealand, on 09 February 2011.

The TAIC is responsible for investigating this occurrence and requested assistance from the ATSB to download and replay the CVR. To facilitate the ATSB's involvement, an accredited representative was appointed to the investigation, in accordance with clause 5.23 of Annex 13 to the Convention on International Civil Aviation.

To protect the CVR audio and other information supplied by the TAIC, the ATSB initiated an investigation under the Transport Safety Investigation Act 2003. The CVR was downloaded at the ATSB's technical facilities in Canberra and a copy of the recovered audio was provided to the TAIC on 16 February 2011. A download and replay of a CVR fitted to ZK-NEZ was also carried out at the ATSB on 16 Mar 2011 to assist the investigation.

The TAIC is responsible for releasing a final investigation report regarding this occurrence.

Contact details for the TAIC are available at www.taic.org.nz

______________

Released in accordance with section 25 of the Transport Safety Investigation Act 2003.