An unmanned airship was on a test flight in Keysborough, Victoria when its remote-pilot lost control before the aircraft flew into the controlled airspace of Moorabbin Airport.

The incident occurred on 28 October 2012, when a team comprising a pilot, observer and software engineer were conducting a test flight of the airship. The aircraft, weighing less than 8 kg, consisted of a 10 m long balloon with a gondola suspended below and was remotely controlled by the pilot using a portable radio-controlled transmitter. The crew planned to fly the airship below 200 ft and within 200 m of their location to ensure it remained clear of the Moorabbin Class D control area. 

Shortly after take-off, the crew noticed that the airship’s nose was tilting up due to its rearward centre of gravity. The pilot corrected the tilt but a minute later, when the aircraft was at about 130 ft off the ground, he realised that he could not turn it to the left, although it still could turn right. 

The pilot attempted unsuccessfully to contact the Moorabbin control tower by radio to advise them of the situation.

The pilot tried to land the airship, but the rearward centre of gravity resulted in it climbing. The airship’s elevator (or height) controls were also not responding. As it climbed through 200 ft above the ground, the pilot realised he had lost total control of the airship, He reduced the engine power, but the airship continued to climb and fly in a north-westerly direction toward the Moorabbin Airport. 

The pilot attempted unsuccessfully to contact the Moorabbin control tower by radio to advise them of the situation. He and the software engineer then got in a car with the portable radio-controlled transmitter to follow the airship by road. The observer remained at Keysborough and contacted the Moorabbin control tower and emergency services via telephone. 

The air traffic controllers at Moorabbin spotted the airship around 4 km to the south-east at about 1,000 ft above the ground. This was also confirmed by the pilot of an aircraft flying in the Moorabbin circuit. 

Thirty minutes later, the airship landed on the roof of a commercial building, sustaining minor damage. 

Data provided to the ATSB by the airship operator indicated that the airship reached a height of 1,930 ft and, at its closest, was 5 km from Moorabbin Airport.

The airship operators have advised the ATSB that they will take a number of measures to prevent similar incidents. This includes developing a pre-flight checklist and change management process to consider risks when changes are made to hardware or processes. They will also be locating a suitable site for flight testing away from populated areas.

There are regulations that set out the requirements for the operation of unmanned aircraft (including airships); however, the size of the airship’s balloon meant that it did not have to be registered, and it was not subject to airworthiness and flight crew qualification requirements. 

The Civil Aviation Safety Authority is currently working to provide more comprehensive guidance on the regulatory requirements and approval processes for the commercial operation of unmanned aircraft systems in Australia. The guidance will consider the long-term integration of unmanned aircraft systems into normal aviation operations in all classes of airspace.

More details of the safety actions and the civil aviation regulations can be found in the investigation report Airspace incursion involving unmanned airship, Airship 11, 2.7 NM east of Moorabbin Airport, Victoria, on 28 October 2012

Aircraft passengers are being reminded to fasten their seatbelts at all times while seated after a Virgin Boeing 737 encountered wake turbulence.

The incident occurred on 13 September 2012 when the aircraft, carrying 132 passengers, was en route from Bali to Brisbane. While in cruise, the 737’s crew spotted an aircraft above, approaching from the opposite direction. The aircraft passed about 0.9 Nautical Miles to the left and 1,400 ft above.

About one minute later, the 737 experienced cobblestone-like turbulence. It then rolled slightly to the right and then suddenly to the left to an angle of about 40°. The crew managed to arrest the roll and straighten the aircraft. The incident occurred as a result of wake turbulence from an Airbus A380 aircraft.

A wake turbulence encounter can be a surprising experience for both the crew
and passengers...

Fortunately all the aircraft’s passengers were seated at the time of the incident and there were no reported injuries. The flight continued without further incident.

Pilots receive six-monthly jet upset simulator training to prepare them for situations when an aircraft experiences pitch or roll conditions greater than normal. Both the captain and the first officer of the 737 had received their training within the past two months—the captain’s training took place within the week before the incident. They both reported that the training was invaluable, with the first officer remarking that his response to the wake turbulence had been instinctive and that the incident was similar to that experienced in the simulator.

A wake turbulence encounter can be a surprising experience for both the crew and passengers and usually results in induced rolling or pitch moments. A safety bulletin published by the ATSB, Staying Safe against In-flight Turbulence, noted that almost all turbulence injuries involve people who are not properly seated and do not have their seat belt fastened. This incident is a timely reminder to have your seat belt fastened, even when the seat belt sign is turned off, so that injuries during a turbulence encounter can be minimised.

Read the final report: Wake turbulence event involving a Boeing 737, VH-YIO, 258 km south-east of Bali International Airport (Denpasar), Indonesia, on 13 September 2012. The report includes links to valuable information on wake turbulence.

A fatal accident near Hallston, Victoria has illustrated the dangers of partial power loss after take-off in single-engine aircraft — a problem that the ATSB has been emphasising to the aviation community.

The accident occurred on 1 May 2012, when the pilot of a Piper PA25 was conducting agricultural operations from a local airstrip near Hallston. Shortly after take-off, the aircraft crashed near the base of a gully and was destroyed by fire. The pilot, the only person on board, died in the accident.

...partial power loss is actually a more complex situation than a complete failure, and can be much harder to manage.

The damage sustained during the impact and ensuing fire prevented the ATSB investigation from identifying specific reasons for the aircraft’s loss of power. ATSB General Manager Strategic Capability, Mr Julian Walsh, says that partial power loss is actually a more complex situation than a complete failure, and can be much harder to manage.

"The pilot is in a situation where the engine is still providing some power, but it may be unreliable, and the available power level might be difficult to assess," Mr Walsh says.

"As a result, pilots are uncertain about their aircraft's capabilities, and what their options are— a situation that can turn into disaster very easily."

A number of resources are available to help pilots prepare themselves for a partial power loss. One of the booklets in the ATSB’s Avoidable Accidents series, Managing partial power loss after take-off in a single-engine aircraft, provides information and strategies for dealing with such a situation if it arises.

Read the final report: Collision with terrain involving Piper PA-25-235/A9, VH-GWS, near Hallston, Victoria, on 1 May 2012

The swift actions of a jet’s flight crew following a shattered windshield in flight has shown how good flight planning can make all the difference.

On 15 January 2013, a Cessna Citation 750 was carrying two flight crew and five passengers from Faleolo, Samoa to Sydney, Australia.  The aircraft levelled off at 45,000 feet, when its system reported a problem with the windshield heating system.

The windshields were laminated glass with outer, middle and inner panes of glass. The pilot found that the windshield was warm to the touch, but the only advice the checklist gave was to leave icing conditions as soon as practical.

The cabin was prepared for a possible ditching, with the passengers directed by the flight crew to don their life vests and review the
safety briefing card.

Two minutes later, the outer ply of the windshield shattered with a loud bang. Cracks spread across the entire surface of the left pane.

The flight crew switched off both the left and right windshield heat switches, and completed the emergency depressurisation checklist. They donned their oxygen masks and deployed the passenger oxygen masks.

The pilots commenced an immediate descent along with a turn towards Nadi International Airport, Fiji, which was one of the planned alternate airports. The pilot declared a mayday which was acknowledged by Nadi radio. Once the descent was established, a flight crew member ensured the passengers were on oxygen and briefed them on the situation. The cabin was prepared for a possible ditching, with the passengers directed by the flight crew to don their life vests and review the safety briefing card.

During the descent, the windshield cracking did not progress further. The cabin did not depressurise, and once they were at 14,000 feet and with the cabin altitude stabilised, the passengers were directed to remove their oxygen masks. The flight continued to Nadi without further incident. There were no injuries to passengers or crew.

The ATSB investigation found that the windshield had likely been affected by moisture seeping into the heating equipment, degrading the electrical connections. The manufacturer has taken measures to the address the issue.

While the failure of the windshield did not result in a depressurisation, the precautions taken by the flight crew to descend to a lower altitude and diversion to the alternate airport highlighted the importance of good flight planning.

Read the final report: Windshield cracking event involving a Cessna 750, VH-RCA, 460 km south-east of Nadi, Fiji, on 15 January 2013

Following an investigation into the partial separation of an express passenger train, the ATSB is reminding rail operators of the need for effective inspection regimes and to ensure that rail components meet service requirements.

The investigation was initiated in August 2011, after a scheduled Melbourne to Sydney express passenger train (XPT) partially separated as it passed over a dip in the track near Broadmeadows, Victoria. The train suffered a total loss of power and was unable to continue its journey, coasting for a short distance. Initial inspection of the train suggested that the electrical disconnection was a result of the leading power car decoupling from the carriages; but it was clear that the power car and carriages stayed close together because the brake lines remained connected.

The ATSB found that the problem lay in an element of the draft gear (the connecting assembly between cars). The element in question was the tail pin, a steel component 590 mm in length. The tail pin failed as a result of an overstress fracture that was initiated by fatigue cracking – cracking that, worryingly, recent routine ultrasonic testing had not detected. Post-incident material testing established that the mechanical properties of the tail pin were below the required standard.

As a result of the investigation, a new batch of tail pins has been manufactured to an upgraded standard which includes improved quality control and acceptance testing...

Following this incident, the ultrasonic testing procedure was revised to improve the detection of smaller cracks in the tail pin. However, the separation of another XPT near Seymour, Victoria, on 1 August 2012 in similar circumstances showed that the ultrasonic testing regime was still not detecting all fatigue cracks in critical areas of the tail pin.

On 3 August 2012, the ATSB issued a safety issue notice to RailCorp, the operator of the XPT fleet, warning of the preliminary findings. Although this sort of coupler failure was extremely unlikely to lead to a derailment, the consequences of such an event involving a passenger train, should it occur at speed, were potentially very significant. In response, RailCorp set about developing a new testing process and fitting newly designed tail pins.

As a result of the investigation, a new batch of tail pins has been manufactured to an upgraded standard which includes improved quality control and acceptance testing and RailCorp is currently in the process of fitting these new tail pins. RailCorp has also further revised the tail pin inspection regime with the aim of improving its effectiveness.

This investigation did not examine how the idiosyncrasies and condition of the track may have contributed to the partial separation of the train. Those issues will be considered as part of the ATSB’s broader safety issue investigation into the interstate rail line between Melbourne and Sydney.

Read the final report: Partial train separation of XPT ST24, near Broadmeadows, Victoria, on 11 August 2011

A runway accident involving a Cessna T210 reinforces the need for pilots to take extreme care when using unsealed runways.

The accident happened on 30 December 2012 when the Cessna, with a pilot and five passengers on board, was taking off from Cape Leveque airfield in WA. Cape Leveque is an unlicensed airfield managed by a tourist operator. It comprises a 972 m long and 40 m wide strip of compacted soil. There had been rain on the strip during the previous days and an early shower on the day of the accident. The airfield is monitored for serviceability and was deemed suitable on the day of the flight; however, after the accident an inspection of the airstrip revealed that there had been a substantial washout on the edge of the strip. The managers closed the airstrip for grading and repair.

Early in the take-off, the Cessna veered to the left. The pilot tried to straighten the aircraft with rudder and continue with the take-off, but ended up about a metre left of the runway centre line. About halfway down the runway the aircraft veered sharply to the left again. The pilot again tried to correct the veer, but the aircraft did not respond. He slowed the aircraft before the left wing clipped trees along the edge of the airstrip, making the aircraft swing almost 90 degrees before the right wing struck the ground. The nose-wheel collapsed in the soft sand on the edge of the airstrip resulting in the propeller striking the ground. One of the passengers sustained minor injuries and the aircraft was substantially damaged.

After the accident, the pilot of the second aircraft inspected the airstrip and reported substantial washout on the edge of the strip inside the cone markers.

As a result of this accident, the aircraft operator has reinforced the need for their pilots to:

• keep the nosewheel on the centreline of the runway at all times
• use the right rudder during take-off
• where possible avoid loose dirt and rough areas on the side of the runway
• close the throttle immediately, if the take-off needs to be rejected
• always use the checklist
• not to rush.

Read the final report: Runway excursion involving Cessna T210, VH DQI, at Cape Leveque, Western Australia, on 30 December 2012

A go-around is always a viable option when pilots experience any problems during landing. The ATSB emphasised this point after a pilot, partially blinded by glare, opted to continue his landing, and as a result his aircraft departed the runway and travelled through two fences before coming to a stop.

The accident occurred on 23 August 2012, at Urapunga in the Northern Territory. The aircraft was a Cessna 210N, carrying the pilot and two passengers on a charter flight. While the aircraft was descending, the sun created a glare on the windscreen that greatly restricted visibility.

The pilot was wearing non-polarised sunglasses, which helped only slightly. The aircraft’s sun visors were not effective because the sun was low on the horizon. Nevertheless, the pilot thought he could identify the runway through the glare and saw what he thought was the runway centreline, so he continued his approach.

The pilot reported intermittent 
sun glare during descent...

As the aircraft floated down above the runway, the pilot was unsure of the amount of runway that had been used. The aircraft touched down and the pilot applied heavy breaking in short bursts. The aircraft slowed a little on the runway’s gravel surface before leaving the end of the runway, and travelling through two fences.

The aircraft came to rest on the right side of the fuselage, right wing and right horizontal stabiliser. The pilot received minor injuries from barbed wire while he was evacuating from the aircraft.

There are several studies by the US Federal Aviation Administration and the ATSB on overruns and the value of being prepared to go around.

Links to those studies and related briefing notes can be found in the investigation report, AO-2012-107.

The continuing problem of road users failing to yield to trains at level crossings has been highlighted in the ATSB’s latest investigation into the fatal 2012 accident near Port Germein in South Australia.

The accident occurred on 19 March at the Port Flinders Causeway Road level crossing. A Pacific National ore train was travelling on the interstate main line between Port Augusta and Port Pirie. As the train drew closer to the level crossing, it slowed for a temporary speed restriction of 50 km/h. About 200 m from the level crossing, the train driver saw two motor vehicles travelling towards the crossing. He immediately sounded the train’s horn.

The first car, a yellow Hyundai Accent, appeared to be slowing; the train driver sounded the horn a second time just as the vehicle disappeared from his view behind some thick vegetation. As the car re-emerged from behind the vegetation, it looked as if it would stop at the crossing. The train driver sounded the horn a third time, continuously. However, the car continued and entered the level crossing into the path of the train. The train driver made an emergency brake application, but given the train’s closeness to the level crossing and its relative size and weight, it was unable to stop before colliding with the car.

Although they vaguely recalled hearing a horn, they did not relate this to the
approaching train...

The front of the train struck the passenger side of the motor vehicle and then continued to travel around 256 m past the level crossing. The car’s passenger died in the accident and the driver sustained serious injuries. The locomotive crew were shaken but not hurt. The motor vehicle was severely damaged, the train received minor damage. There was little damage to the track and fixed infrastructure.

The driver of the motor vehicle was a local resident and had regularly traversed the level crossing. Although they vaguely recalled hearing a horn, they did not relate this to the approaching train and could recollect little else regarding events prior to the accident.

The level crossing was controlled by passive approach warning signs and a ‘Stop’ sign at the crossing. These required a road user to stop the vehicle at the ‘Stop’ sign and detect the presence of any train through direct visual observation.

The ATSB concluded that the motorist’s attention may have been diverted during a critical period when they would normally have stopped to look for a train.

The ATSB urges all drivers of motor vehicles to be vigilant and obey road traffic signage, especially at level crossings where accidents can easily result in fatalities, serious injuries and extensive damage to infrastructure.

Read the final report: Collision involving a motor vehicle and train 4460S, 10 km south of Port Germein, South Australia, on 19 March 2012

On 9 December 2012 the pilot of a Robinson R22 helicopter took off from a fishing camp at the mouth of the Normandy River in Queensland on a private flight.

The pilot was flying north along the coastline at about 600 ft above the ground when he saw an object in the water about 100 m from the coast. The pilot turned the helicopter towards the object and descended to take a closer look.

As the pilot approached the object the helicopter’s tail rotor hit the water which caused the helicopter to rotate to the right before the pilot lost control. The pilot closed the throttle, and the helicopter settled into the water, before rolling over to the right. Unharmed, the pilot escaped via the passenger door and swam to shore before walking back to the fishing camp he left earlier.

Flat light can completely obscure features of the terrain, creating an inability to distinguish distances and closure rates.

The pilot reported that the wind was about 20 knots with a high smoke haze and flat light conditions. Flat light is an optical illusion also known as ‘sector or partial white out’ that causes pilots to lose their depth-of-field and contrast in vision. Flat light conditions are usually accompanied by overcast skies inhibiting good visual clues. These conditions can occur anywhere in the world, primarily in snow covered areas but can also occur in dust, sand, mud flats or over water. Flat light can completely obscure features of the terrain, creating an inability to distinguish distances and closure rates. It can give pilots the illusion of ascending or descending when actually flying level.

The dangers of flying helicopters over water have long been recognised. In July 1985 Robinson Helicopter Company issued 

about the hazards of flight over water, making special reference to the potential for pilots’ loss of depth perception over water. The safety notice recommended maintaining a height of 500 ft AGL and avoiding manoeuvres over water below 200 ft AGL.

Read the final report: Loss of control involving a Robinson R22, VH-HTD, Princess Charlotte Bay, Queensland, on 9 December 2012

An accident involving a Cessna 172N highlights the importance of lodging a Search and Rescue Time (SARTIME) Plan or flight note before flying.

The accident occurred on 7 November 2012, when the pilot of a Cessna 172N crashed his aircraft in a remote paddock near Brisbane while practising for a flight test. The pilot had not submitted a flight plan, nor had he left a flight note with a responsible person or lodged a Search and Rescue Time (SARTIME) with Airservices Australia. The pilot reported having little memory of the flight but said he had planned to fly to the southern training area to practise holding heading and altitude for his upcoming flight test.

Basic safety preparation before each flight could save your life and, at the very least, speed up your rescue.

Following the accident the pilot recalled regaining consciousness and crawling to the aircraft to broadcast a distress call on the aircraft radio. The aircraft was fitted with a personal locator beacon (PLB) but the pilot was unable to locate it after the accident to activate it.

An aircraft in the area reported hearing two faint mayday calls on the Brisbane Centre Frequency. These were not heard by the Brisbane Centre. The area controller requested the pilot of another aircraft in the area to track south from Kagaru to investigate. At about 1410, the crashed Cessna was spotted in a paddock. The pilot was the only person on board and had suffered severe injuries as a result of the accident. The ATSB assessed that the aircraft had been airborne for around 45 minutes, placing the accident about 3 hours before the aircraft was located.

The flight had not been authorised by an instructor prior to the flight. The flying school has now amended their procedures to ensure that no student pilot is provided with aircraft keys before the flight is authorised.

Read the final report: Collision with terrain involving Cessna 172N, VH-JGR, near Kagaru, Queensland, on 7 November 2012