What happened

On 14 March 2018 at 1006 Eastern Standard Time (EST), the pilot of a large remotely piloted octocopter was conducting stockpile surveys at a commercial salt field near Bajool, Queensland (Qld).

The aircraft, with propellers mounted on eight outrigger arms, had been built by the licensed operator and was powered by a 21-amp-hour, six-cell lithium-ion polymer battery. It had been configured to transmit to the operator a low battery warning at 3.5V per cell, return to home at 3.4V per cell and land immediately at 3.3V per cell.

Near the end of the mission the wind speed increased to 25 km/h, with gusts up to 35 km/h. The pilot received a low battery warning, indicating that half of the battery had been used, and switched to manual control to fly the aircraft home into the wind.

It was determined later that two of the battery’s six cells had a resistance of more than 9 ohms and as a consequence the aircraft’s battery voltage dropped much faster than expected. The pilot calculated that the aircraft had insufficient battery voltage to complete a 300 metre flight over the salt water ponds and instead chose to land it on an island approximately 250 metres away.

While landing the aircraft, the pilot misjudged its position above the ground and cut power at an altitude of 7 m. The aircraft landed heavily and sustained minor damage to its propellers, motors, gimbal and wiring. Some of the outrigger arms were also broken.

Safety action

As a result of this occurrence, the aircraft’s operator has advised the ATSB that they are taking the following safety actions:

• Implementing maintenance checks on batteries every six months
• Using seven-cell (rather than six-cell) lithium-ion polymer batteries in windy conditions
• Establishing an alternative landing zone at the other end of the mission plan
• In similar circumstances, allowing the aircraft to auto-land, rather than attempting to land it manually
• Considering a prohibition on flight operations when wind gusts exceed 30 km/h.

Safety message

This incident demonstrates the adverse effect that operating in windy conditions can have on remotely piloted aircraft. Windy conditions typically reduce flight endurance. Aircraft trying to maintain a steady position or fly into the wind expend more battery power than flight operations in calm conditions.

Operators of remotely piloted aircraft flying in windy conditions should consider the effect increased battery-expenditure may have and plan accordingly. Operators should consider using larger batteries, raising the low-battery return-to-home threshold and establishing alternative landing zones.

About this report

Decisions regarding whether to conduct an investigation, and the scope of an investigation, are based on many factors, including the level of safety benefit likely to be obtained from an investigation. For this occurrence, no investigation has been conducted and the ATSB did not verify the accuracy of the information. A brief description has been written using information supplied in the notification and any follow-up information in order to produce a short summary report, and allow for greater industry awareness of potential safety issues and possible safety actions.

What happened

On 1 February 2018, at about 1535 Eastern Daylight-savings Time (EDT), an OAS Parts LLC UH-1H helicopter was conducting fire control operations when the pilot noticed a strong smell of oil in the cockpit and oil droplets hitting the water, under the helicopter, in a dam. The pilot manoeuvred the helicopter to a paddock close by for a precautionary landing. In the last metre or so of landing, the hydraulic warning light indicated a loss of hydraulic pressure and the controls stiffened up during the last positioning movements onto the ground. The pilot was able to land the helicopter without incident. On landing, the hydraulic oil was diminished with an empty hydraulic tank and the belly of the aircraft was covered in oil.

On inspection it was found that two hydraulic lines had rubbed together causing one to split. Engineers replaced a hose that had been injected by the adjacent hose causing a hole. Both hoses and the hydraulic pump were also replaced as per the maintenance manual.

Safety message

Emergency situations can rapidly develop from initial signs and symptoms to a complete failure. The proactive response of the pilot to the initial signs of this malfunction enabled the helicopter to be manoeuvred into a much safer position by the time the full failure occurred.

About this report

Decisions regarding whether to conduct an investigation, and the scope of an investigation, are based on many factors, including the level of safety benefit likely to be obtained from an investigation. For this occurrence, no investigation has been conducted and the ATSB did not verify the accuracy of the information. A brief description has been written using information supplied in the notification and any follow-up information in order to produce a short summary report, and allow for greater industry awareness of potential safety issues and possible safety actions.

What happened

On 7 March 2018, at about 0810 Central Daylight-savings Time (CDT), an Evektor Sportstar Plus departed Naracoorte on a private flight to Mount Gambier, South Australia (SA). During the cruise at approximately 600 feet above ground level, 21 kilometres south of Naracoorte, the pilot noticed cattle in a paddock on his flight path and banked right to avoid overflying the cattle. During the manoeuver, the pilot’s flight bag fell from the passenger seat and became lodged between the seat and the control column, causing an abrupt pitch down.

The pilot tried to extricate the bag as the aircraft rapidly descended, but the aircraft struck a powerline and collided with terrain. As he exited the aircraft, the pilot stepped on the downed but still live powerline, causing burns to his foot.

The aircraft was extensively damaged, and the pilot suffered injuries to the knee, shin and foot.

Figure 1: Evektor Sportstar Plus damage

Source: South Australia Police

Safety message

Even a planned routine flight in good flying conditions can encounter unexpected hazards at any time. The cockpit should always be arranged to minimise the hazard of loose articles, regardless of the type of flight expected.

Unrestrained items in the cockpit increase the risk of both flight control interference during normal flight and injury to occupants during an accident. Pilots should take care to ensure that all items and cargo are adequately restrained to prevent movement during flight and improve survivability in the event of an accident.

About this report

Decisions regarding whether to conduct an investigation, and the scope of an investigation, are based on many factors, including the level of safety benefit likely to be obtained from an investigation. For this occurrence, no investigation has been conducted and the ATSB did not verify the accuracy of the information. A brief description has been written using information supplied in the notification and any follow-up information in order to produce a short summary report, and allow for greater industry awareness of potential safety issues and possible safety actions.

What happened

On 19 February 2018, just before 0910 Eastern Daylight-saving Time (EDT), the crew of a Boeing 737-800 was preparing for departure from Sydney Airport, New South Wales (NSW) to Gold Coast Airport, Queensland (Qld). There were six crew and 168 passengers on board. The planned flight time was 1 hour 20 minutes. To prepare for the short sector the crew programmed their anticipated approach for Gold Coast Airport into the aircraft’s Flight Management System (FMS).^[1] The approach was a series of waypoints described by the GREAV SIX Standard Arrival Route (STAR).^[2]

Prior to descent into the airport, the crew received and read back a different approach – the ROONY FOUR STAR – and were cleared to descend to flight level (FL) 250.^[3] As the aircraft passed ROONY it commenced a turn 11º to the left, deviating from the agreed route. Route 2 in the FMS carrying the GREAV SIX STAR was still active in the aircraft’s FMS. The crew did not detect the anomaly.

Air Traffic Control (ATC) identified the deviation and asked the crew which STAR they would like to follow. The crew, recognising the GREAV SIX STAR was already programmed and checked, requested that approach from ATC. The aircraft was re-cleared on the GREAV SIX STAR and a normal approach and landing was conducted.

Safety message

This incident highlights the importance of ongoing verification, by flight crews, of the data the aircraft is working with at various stages of flight. The route data that was entered into the FMS was correctly keyed and had an intended purpose at the time of entry; however, it was no longer suitable for use in the later stages of the flight, when a different clearance requiring different waypoint data was provided.

ATC was able to alert the crew to the flight path deviation. ATC was also able to support the crew at a critical time by providing the opportunity to continue the approach utilising the data that was programmed and active in the FMS. This changed the circumstance of the operation to render the data valid again.

The ATSB SafetyWatch highlights the broad safety concerns that come out of our investigation findings and from the occurrence data reported to us by industry. One of the safety concerns relates to data input errors.

About this report

Decisions regarding whether to conduct an investigation, and the scope of an investigation, are based on many factors, including the level of safety benefit likely to be obtained from an investigation. For this occurrence, no investigation has been conducted and the ATSB did not verify the accuracy of the information. A brief description has been written using information supplied in the notification and any follow-up information in order to produce a short summary report, and allow for greater industry awareness of potential safety issues and possible safety actions.

__________

1. Flight Management System (FMS): a navigation, operations and performance computer used by the crew to manage the aircraft and flight. (Skybrary)
2. Standard Arrival Route (STAR): a published approach procedure used to deconflict traffic, and provide predictable movement of traffic to simplify management of airport arrivals. (Airservices Australia)
3. Flight level: at altitudes above 10,000 ft in Australia, an aircraft’s height above mean sea level is referred to as a flight level (FL). FL 250 equates to 25,000 ft. (Airservices Australia)

What happened

On 20 January 2018, a remotely piloted aircraft (RPA) was being operated on a training exercise over water off Wategos Beach near Byron Bay, New South Wales.

At about 1318 Eastern Daylight-saving Time (EDT),^[1] while maintaining 100 ft above ground level, the crew detected a propeller malfunction on one of the RPA’s six propellers. The crew elected to conduct a precautionary landing of the RPA into the water about 200 m offshore. The RPA operator indicated that this was in accordance with their emergency procedures for a propeller malfunction in order to reduce the risk to the beach-going public.

The RPA was recovered from the water and inspected by the operator. The initial inspection indicated that bolts fastening the propeller to the motor unit had failed. Figure 1 shows the failed bolts (left) along with a picture of a non-damaged propeller assembly (right). The RPA has been sent back to the manufacturer for further examination.

Figure 1: Failed bolts that secure the RPA propeller to motor (left) and example of an undamaged propeller and motor assembly (right)

Safety message

The ATSB’s research report A safety analysis of remotely piloted aircraft systems 2012 to 2016: A rapid growth and safety implications for traditional aviation found that, there has been rapid growth in the number of RPA systems in Australia. This incident highlights the importance of contingency planning for RPA operations. While the manufacturer indicated that, for this RPA configuration, control could be maintained in the event of a single propeller failure, a loss of a control surface would result in a degradation of performance. In this case, the crew identified the reduced performance and acted accordingly by landing the RPA offshore, thereby reducing the risk to third parties.

The Civil Aviation Safety Authority has published guidance on the operation of RPA’s in the advisory circular, Remotely piloted aircraft systems – licencing and operations. Section 4.6 specifically states that, procedures to be followed in the event of an engine/propeller failure should be in place and included in the RPA system mission plan.

About this report

Decisions regarding whether to conduct an investigation, and the scope of an investigation, are based on many factors, including the level of safety benefit likely to be obtained from an investigation. For this occurrence, no investigation has been conducted and the ATSB did not verify the accuracy of the information. A brief description has been written using information supplied in the notification and any follow-up information in order to produce a short summary report, and allow for greater industry awareness of potential safety issues and possible safety actions.

__________

1. Eastern Daylight-saving Time (EDT): Coordinated Universal Time (UTC) + 11 hours.

What happened

On 15 January 2018, at 1245 Eastern Standard Time (EST), a Vans Aircraft RV-7A commenced take-off from runway 15 at Atherton airport, Queensland (Qld) for Charters Towers, Qld. The pilot was the sole occupant.

The pilot reported that upon rotation,^[1] the aircraft encountered a dust devil^[2] and was pushed to the left. The pilot then applied full power in an effort to regain directional control and land the aircraft. The left wing, however, contacted the ground, and the aircraft came to rest inverted. The aircraft was substantially damaged and the pilot received minor injuries.

A row of trees to the left of the runway combined with hot weather was conducive to the formation of dust devils. There was no visual indication of debris or dust plumes to indicate the sudden formation or location of the dust devil, causing difficulty in identification and avoidance measures.

Figure 1: Vans Aircraft RV-7A post-accident, including damage to the left wing

Source: Queensland Police Service

Safety message

The ATSB has investigated multiple take-off and landing accidents associated with dust devils, including Loss of Control; Mt Vernon Station, WA; 1 September 2006; VH-RIL, Cessna 172L (200605133), which highlights the risk of this phenomenon and how light aircraft may be affected. Further information on The Dangers of Dust Devils is available on the ATSB website.

About this report

Decisions regarding whether to conduct an investigation, and the scope of an investigation, are based on many factors, including the level of safety benefit likely to be obtained from an investigation. For this occurrence, no investigation has been conducted and the ATSB did not verify the accuracy of the information. A brief description has been written using information supplied in the notification and any follow-up information in order to produce a short summary report, and allow for greater industry awareness of potential safety issues and possible safety actions.

__________

1. Rotation: The action of raising the nose wheel by applying back pressure to the yoke.
2. Dust devil: A dust filled vortex similar in shape to a tornado but of much less strength. Source: Bureau of Meteorology

What happened

On 13 February 2018, the pilot of a de Havilland DHC-1 departed Luskintyre, New South Wales (NSW) after conducting ground power tests. The pilot was the only occupant on board.

During initial climb, at about 100 ft above ground level (AGL), the engine lost partial power. The pilot lowered the nose of the aircraft while manipulating the throttle in an attempt to correct the power loss. Due to the proximity of fencing, trees, housing and roads immediately past the landing strip, the pilot elected to attempt a forced landing on an adjacent paddock 90 degrees to the right. The aircraft entered a stall, impacting the ground in a nose-down, right wing low attitude.

The pilot subsequently reported that an inspection of the carburettor identified a loose part had caused the priming float to jam in the open position, resulting in an excessively rich fuel-air mixture.

Figure 1: de Havilland DHC-1 post accident

Source: Pilot in Command

Safety message

Data illustrates that partial power loss in single-engine aircraft occurs three times more frequently than total engine failure. Due to unreliability of engine power in these circumstances, it can be advantageous to treat partial power loss as total engine failure and act accordingly. The ATSB website publication 'Managing partial power loss after take-off in single-engine aircraft' provides guidance on managing these situations. Pre-flight self-briefing is an important tool in reinforcing planned emergency actions, including in circumstances of unfavourable terrain immediately past the aerodrome.

About this report

Decisions regarding whether to conduct an investigation, and the scope of an investigation, are based on many factors, including the level of safety benefit likely to be obtained from an investigation. For this occurrence, no investigation has been conducted and the ATSB did not verify the accuracy of the information. A brief description has been written using information supplied in the notification and any follow-up information in order to produce a short summary report, and allow for greater industry awareness of potential safety issues and possible safety actions.

What happened

On 4 February 2018 at 1200 Eastern Standard Time (EST), the pilot of an Aeroprakt 22LS was conducting solo training in the circuit area of Townsville Airport, Queensland (Qld). Having completed three of five planned circuits, with touch and go landings on both runways 01 and 07, the pilot commenced the fourth circuit. Due to a departing commercial jet on Runway 01, Air Traffic Control (ATC) instructed the pilot to extend the downwind leg of the circuit and, to avoid the jet’s wake turbulence,^[1] change runways again to Runway 07.

During this approach, the pilot encountered a rain shower and associated downdraft increasing the control workload required. The pilot did not acknowledge a call from ATC with instructions for a full stop landing. As the pilot was approaching the flare, ATC repeated the call. The pilot acknowledged the radio call and continued with the landing. The aircraft bounced and landed heavily, coming to a complete stop on the runway. The pilot exited the aircraft without injury.

The aircraft sustained substantial damage with a bent nose leg and damage to the firewall and the fuselage skin adjacent the main undercarriage.

The operator later advised that the pilot did not conduct a go-around as ATC had instructed them to make a full stop landing and they thought this precluded them from conducting a go-around.

Related occurrences

A search of the ATSB database revealed a number of similar occurrences including:

AO-2016-049

On 16 May 2016, the pilot of a Maule MT-7-235 aircraft, registered VH-DRS, conducted a private flight from Greenfields airstrip (near Noosa), Queensland, with two passengers on board.

On final approach to land, the pilot noticed they were getting low on the approach path and at about 500 ft, they increased the power to regain their approach path. The pilot subsequently assessed that the aircraft was too high and lowered the nose to re-intercept the approach path. The pilot flared the aircraft for landing, the aircraft landed heavily and bounced into the air. As the aircraft landed again, the nose wheel touched down first (before the main landing gear) with sufficient force that the nose wheel strut fractured. The nose landing gear and propeller then dug into the ground and the aircraft rotated over its nose and slid a short distance inverted before coming to rest. The pilot and one passenger were uninjured, the other passenger sustained minor injuries, and the aircraft sustained substantial damage.

AO-2012-107

On 23 August 2012 at 1733 Central Standard Time, a Cessna 210N, registered VH-WPD, departed Numbulwar for Urapunga, Northern Territory, on a charter passenger flight with the pilot and two passengers on-board. The pilot reported intermittent sun glare during descent to Urapunga, when at 3 NM for runway 28. On late final the sun glare on the windscreen greatly restricting visibility. During the flare, the pilot identified a runway edge marker in line with the nose of the aircraft. The pilot maneuvered the aircraft back in line with the centre of the runway and the aircraft continued to float down above the runway.

The sun glare increasingly restricted visibility during the landing. The aircraft touched down and the pilot applied heavy braking in short bursts. The aircraft departed the end of the runway and travelled through two fences before coming to a stop. The pilot and two passengers evacuated the aircraft. The pilot received minor injuries and the two passengers were uninjured.

Safety message

All pilots, regardless of their experience level, should be prepared to undertake a go-around rather than continuing with an unstable approach. The Flight Safety Foundation released a briefing note Approach-and-landing accident reduction Briefing Note 6.1 to remind pilots of the importance of being prepared to conduct a go-around during all approaches.

About this report

Decisions regarding whether to conduct an investigation, and the scope of an investigation, are based on many factors, including the level of safety benefit likely to be obtained from an investigation. For this occurrence, no investigation has been conducted and the ATSB did not verify the accuracy of the information. A brief description has been written using information supplied in the notification and any follow-up information in order to produce a short summary report, and allow for greater industry awareness of potential safety issues and possible safety actions.

__________

1. Wake turbulence: turbulence from wing tip vortices that result from the creation of lift. Those from large, heavy aircraft are very powerful and persistent, and are capable of causing control difficulties for smaller aircraft either following or below.

What happened

On 5 March 2018, as boarding for a domestic flight from Melbourne to Sydney was nearing completion, a passenger noticed his mobile phone was smoking and emitting popping and crackling sounds.

The mobile phone was dropped on the cabin floor in front of seat 23C and the cabin crew were alerted. Those passengers already aboard were directed to leave any personal items behind, move towards the front of the aircraft and exit through the forward door. The flight crew were advised, and they requested that the Aviation Rescue and Fire Fighting Service (ARFFS) attend.

Cabin crew poured bottled water sourced from passengers and the galley onto the mobile phone and by the time the ARFFS arrived through the aircraft’s rear door the device (shown in Figure 1) had ceased smoking.

After the burned mobile phone had been removed from the aircraft by the ARFFS the operator’s engineering services employees cleaned up the spilled water and conducted an inspection for any damage. Passengers were subsequently allowed to return to the cabin to retrieve their belongings and the operator arranged for another aircraft to work the scheduled service.

Figure 1: Damaged mobile phone after removal from aircraft by ARFFS

Source: ARFFS

Safety message

This incident is a dramatic reminder of the hazards of transporting personal electronic devices powered by lithium or lithium-ion batteries, and a demonstration of the importance of including mobile phones, laptop computers, power banks, wireless headphones, watches and cameras in carry-on baggage, rather than checked baggage.

If the overheating device had been included in the passenger’s checked baggage and placed in the aircraft’s cargo hold it may have presented a much greater hazard. A significant quantity of water was required to contain the thermal runaway event that developed as the mobile phone short circuited and overheated and Figure 2 shows the water bottles emptied onto the device by the cabin crew.

While the risk of these devices catching fire and exploding in-flight is low, airlines and flight crews have well-established procedures and methods to contain battery fires in-flight. The Civil Aviation Safety Authority web page Travelling safely with batteries and portable power packs provides information on the safe transport of devices with lithium or lithium-ion batteries on aircraft.

Figure 2: Water bottles emptied to cool and extinguish mobile phone

Source: ARFFS

Other ATSB news stories and investigations about lithium or lithium-ion batteries are available:

• Personal electronic device fire in-flight involving Boeing 747, VH-OJS, 500 km WNW of John F. Kennedy International Airport, United States, on 21 June 2016
• Crew’s prompt in-flight response to smoking device.

About this report

Decisions regarding whether to conduct an investigation, and the scope of an investigation, are based on many factors, including the level of safety benefit likely to be obtained from an investigation. For this occurrence, no investigation has been conducted and the ATSB did not verify the accuracy of the information. A brief description has been written using information supplied in the notification and any follow-up information in order to produce a short summary report, and allow for greater industry awareness of potential safety issues and possible safety actions.

What happened

On 1 February 2018, at about 1631 Eastern Daylight-saving Time (EDT), an Airbus A330-202 was pushing back^[1] from the gate for a scheduled departure from Sydney, New South Wales (NSW) to Melbourne, Victoria (Vic.).

During the pushback, the tow was disconnected and an aircraft engineer instructed the flight crew to apply the park brake. The brakes were applied by the flight crew while the aircraft was still moving. The aircraft stopped suddenly and the nose subsequently pitched upwards, resulting in multiple minor injuries and one serious injury to cabin crew who were standing at the time.

Safety message

ATSB report

Ground and flight crews need to maintain situational awareness and communication during pushback procedures to ensure the most appropriate actions are taken.

Operators should ensure cabin crew are made aware of the hazardous nature of conducting duties while the aircraft is moving on the ground.

About this report

Decisions regarding whether to conduct an investigation, and the scope of an investigation, are based on many factors, including the level of safety benefit likely to be obtained from an investigation. For this occurrence, no investigation has been conducted and the ATSB did not verify the accuracy of the information. A brief description has been written using information supplied in the notification and any follow-up information in order to produce a short summary report, and allow for greater industry awareness of potential safety issues and possible safety actions.

__________

1. Pushback is where an aircraft is pushed backwards away from an airport gate by external power. It involves a tug connected to the nose wheel, or a power unit connected to the main landing gear.