A wasp nest obstructed the Captain’s pitot probe after a short layover in Brisbane.

On 21 November 2013, after a flight from Singapore, an Etihad Airways Airbus A330, A6-EYJ landed at Brisbane airport and was taxied to the terminal. Approximately 2 hours later, the aircraft was pushed-back from the gate for the return flight to Singapore.

The captain rejected the initial take-off attempt after observing an airspeed indication failure on his display. The aircraft taxied back to the terminal where troubleshooting was carried out, before being released back into service.

During the second take-off roll, the crew became aware of an airspeed discrepancy after the V₁ decision speed and the take-off was continued. Once airborne, the crew declared a MAYDAY and decided to return to Brisbane where an overweight landing was carried out.

Engineering inspection after the overweight landing found that the Captain’s pitot probe was almost totally obstructed by an insect nest, consistent with mud-dauber wasp residue.

Engineering inspection after the overweight landing found that the Captain’s pitot probe was almost totally obstructed by an insect nest, consistent with mud-dauber wasp residue. The pitot obstruction had occurred during the 2 hour period that the aircraft was on the ground at Brisbane and was not detected during troubleshooting after the initial rejected take-off.

The aircraft operator has changed its policy on the use of pitot covers. They are now required to be used on all transits at Brisbane Airport, regardless of ground time.

The aircraft manufacturer has amended its maintenance troubleshooting manual to increase the likelihood that a blocked pitot probe will be detected.

The airport operator has extended its wasp inspection and eradication program and reviewed and updated its Wildlife Hazard Management Plan.

In addition, CASA has drawn attention to the safety implications of mud wasp activity through several publications.

Safety message

Operators can minimise the risk of pitot probe obstruction by consistently using pitot covers even during short transit periods.

Standard operating procedures include the cross-checking of airspeed during the take-off roll. These checks are an important last line of defence in preventing an aircraft from becoming airborne with airspeed indication problems.

Read the final report: Air data system failure involving Airbus A330-243, A6-EYJ, near Brisbane Airport, Queensland, on 21 November 2013

Two large ships’ sterns broke away from their berths when a common bollard holding their stern lines failed, damaging a rail bridge and a third vessel.

On 17 August 2014, Grand Pioneer (Figure 1) and AAL Fremantle (Figure 2) broke away from their berths when a thunderstorm passed across the Port of Fremantle. A bollard on the wharf holding both ships’ stern lines failed, most likely after Grand Pioneer’s vehicle ramp contacted it. AAL Fremantle contacted a ship at an adjacent berth, and parts of the Fremantle Rail Bridge nearby.

The ships were berthed again with tug assistance. The ships had suffered minor damage. The rail bridge, however, was closed for 3 weeks for inspection and repairs to track alignment and other non-structural damage.

Figure 1: Grand Pioneer

Source: Marcus, Shipspotting

Figure 2: AAL Fremantle

Source: Australian Transport Safety Bureau

The ATSB investigation concluded that Grand Pioneer moved off the berth slightly as the tension in its mooring lines increased, in response to the high winds associated with the passing thunderstorm. It is likely that its vehicle ramp then made contact with the bollard that held the stern lines of both ships. As a result of the contact, the bollard broke away from the wharf.

The investigation found that Fremantle Port Authority’s (Fremantle Ports) examination of the risks associated with a ship contacting the rail bridge contained limited analysis on keeping ships alongside in adverse weather, particularly at berths 11 and 12 where the wind is predominantly on ships’ beams. There was also no analysis of the means to assist a ship that got close to Wongara Shoal and the rail bridge.

The ATSB also found that Fremantle Ports’ adverse weather procedures were triggered only by specific Bureau of Meteorology (BoM) forecast categories and terms. There was no guidance for vessel traffic service (VTS) officers to take action based on actual weather conditions, or other weather terms used in BoM forecasts.

Another investigation finding was that BoM’s marine forecast at the time of the incident did not describe expected wind speeds using recognised marine terms, such as ‘gale force’. Further, the forecast title understated the wind speeds expected.  

Fremantle Ports has put into service 12 ShoreTension devices in the inner harbour. These devices maintain a constant tension in a mooring line to assist keeping a ship alongside its berth.

The port has subscribed to a customized weather prediction service for its area, and upgraded its weather station and VTS equipment to enhance monitoring. The VTS officers have been trained to use the new and upgraded equipment. The port has updated its ship weather warnings to include a broader range of meteorological terms and descriptions.

Fremantle Ports has also revised its weather warning distribution list to include the manager of the rail bridge, the Public Transport Authority (PTA). The port and the PTA have established direct, high level, points of contact with communication processes in place to manage any emergencies that could involve the rail bridge.

The BoM safety action includes undertaking to use standard terminology in marine forecasts and implementing a formal process to consult stakeholders to better identify and meet their needs.

Safety message

When analysing the risks to a port’s operation, its operator needs to consider the risk controls to avoid a serious incident as well as the recovery controls in case an incident does occur.

Read the final report: Breakaway of Grand Pioneer and AAL Fremantle, Fremantle, Western Australia, on 17 August 2014

Metal fatigue caused a welded boss on the No.2 engine to give way, resulting in a fuel-fed fire that was brought under control by the flight crew.

On 29 April 2014 an AVRO 146-RJ100 aircraft, registered VH‑NJI and operated by Cobham Aviation Services Australia (Cobham), was on a charter flight to Barrow Island Airport from Perth Airport, Western Australia. The aircraft sustained a mechanical failure of the No. 2 engine shortly after take-off that resulted in an in-flight fuel-fed engine fire.

The flight crew extinguished the engine fire by shutting down the No. 2 engine and activating the fire suppression system. The aircraft was flown back to Perth Airport, having sustained significant damage to the No. 2 engine and cowling. There were no injuries.

The Honeywell International Inc (Honeywell) LF507-1F (LF507) engine has four combustion liner locating pin welded bosses (welded boss) in the combustor turbine module (CTM) combustor housing (housing). The ATSB found that the welded boss located at the 2 o’clock position had cracked and fractured adjacent to the weld as a result of fatigue. The boss separated from the housing, allowing high-pressure combusting fuel to escape radially through the CTM housing, burning through the engine cowling.

The ATSB found that the normal scheduled visual inspection of the housing, which was designed to find cracks before they developed into a fracture, was ineffective in this case.

The ATSB also found that localised grinding of the inner and outer surfaces of the CTM housing, adjacent to the welded boss, had reduced its wall thickness from 0.050 to 0.035 inches. The reduced wall thickness increased local stresses and hence the likelihood of crack formation. The crack accelerated at an unpredictable rate until penetrating the full thickness of the housing. It is likely that the grinding was associated with a weld repair conducted during a CTM heavy maintenance visit. The grinding repair was not an acceptable repair to Honeywell for returning the component to the original design strength.

Finally, the ATSB found that the normal scheduled visual inspection of the housing, which was designed to find cracks before they developed into a fracture, was ineffective in this case. This was because the reduced wall thickness invalidated the original crack growth rate predictions.

In response to this occurrence Cobham proactively inspected all of their LF507 engines, focusing on the welded bosses. Of those engines, one spare engine had grinding at one of the welded bosses, similar to the occurrence engine, and was withdrawn from the availability pool. Although no cracking was found at the combustion liner location pin welded bosses, Cobham did find seven cracks at the location of the ignition bosses that had not been previously identified. These cracks were managed in accordance with the Honeywell maintenance manual.

Honeywell also instigated several actions in response to this occurrence. These included amendment of the LF507 engine maintenance and overhaul manuals to address crack limits and weld repair specifications, and the issue of a Service Bulletin to alert operators of possible welded boss cracking.

Safety message

This occurrence highlights the importance of repairing aircraft components in accordance with the manufacturer’s specifications and ensuring that the repair meets the design intent of the manufacturer.

Read the final report: In-flight engine fire involving AVRO 146-RJ100, VH-NJI, departing Perth Airport, Western Australia, on 29 April 2014

• A collision between a ute and aircraft shows why good communications is essential in all aircraft operations.

On 17 September 2015, the pilot of an Air Tractor 502B aircraft, was conducting aerial application (spraying) operations on a property about 23 km to the west of Hay Aerodrome, New South Wales.

As per normal procedure, while en route to the spray application area, the pilot made a broadcast on UHF Channel 25 advising that spraying operations were about to commence, and also, the area where that would occur. UHF Channel 25 was monitored by employees on the property, and used for general communications.

The driver of a tractor operating in the southern part of the spray application area responded to the pilot’s broadcast. The pilot advised the tractor driver that they would be able to safely continue in that southern area for about another hour.

After a short time, the pilot departed the spray application area and reloaded the aircraft with more chemical mixture at a nearby property. The pilot then returned to the spray allocation area at about 1130. This time, the pilot did not make another UHF broadcast, but noted that the tractor was now in transit between work areas, with a Toyota Hilux Double-Cab utility vehicle following closely behind.

At about 1145 as the pilot was conducting a spray run to the east, the pilot reported seeing the Hilux turn onto an irrigation channel crossing ahead of the aircraft. However as the vehicle appeared to be slowing to a stop short of the intersection, the pilot assumed the Hilux driver had seen the aircraft, so continued with the spray run. After checking the spray nozzles on the wings, and the spray pressure gauge, the pilot initiated a short climb to clear the raised channel bank.

The pilot then sighted the Hilux on the highest part of the channel bank. The pilot immediately ceased the spray and initiated a steeper climb. During this attempt, the left wheel of the aircraft struck the tray headboard of the Hilux from behind.

The pilot radioed for assistance for the driver and flew to a nearby property to land.

As a result of this occurrence, the agricultural company have revised some procedures, roles and responsibilities.

This accident highlights the importance of effective communication by all parties involved with aircraft operations.

ATSB Research and Analysis Report AR-2015-031 Aerial application safety: 2014 to 2015 year in review, provides statistical data regarding aerial application accident rates, and summarises a number of accidents that occurred during aerial application operations.

Read the final report: Collision with a vehicle involving an Air Tractor AT-502B, VH-FNX, 23 km west of Hay, New South Wales, on 17 September 2015

A fatal accident involving an amateur-built aircraft has prompted the ATSB to issue a formal safety recommendation to Australia’s aviation regulator, the Civil Aviation Safety Authority (CASA). The recommendation urges CASA to take action to require builders of amateur-built experimental aircraft to produce a flight manual, or equivalent, for their aircraft following flight testing.

The accident occurred on the afternoon of 10 October 2014, when the pilot of an amateur-built One Design DR-107 aircraft was performing low-level aerobatic manoeuvres. The manoeuvres were being performed to the east of Goolwa Airport, South Australia.

Witnesses described the aircraft performing a series of similar manoeuvres. Each involved a vertical climb and tumbling manoeuvre followed by a vertical dive and a low altitude recovery.

Witnesses reported that, during recovery from the last vertical dive, the aircraft collided with terrain. The aircraft was destroyed by the impact and the pilot was fatally injured.

The ATSB found no evidence of pilot incapacitation or a mechanical fault with the aircraft that could have contributed to the accident. There was insufficient evidence to determine why the recovery was not accomplished above the pilot’s minimum authorised aerobatics height.

CASA recommends that pilots performing low-level aerobatics undertake regular peer reviews due to the high level of skill and fine safety margins involved. The ATSB found no evidence of the pilot undertaking a peer review of their aerobatic performance in the 15 months prior to the accident.

The ATSB identified a safety issue that CASA does not require builders of amateur-built experimental aircraft to produce a flight manual, or equivalent, for their aircraft following flight testing. Without a flight manual, the builder, subsequent owners and other pilots do not have reference to the operational and performance data necessary to safely operate the aircraft.

In response to this safety issue, the ATSB has issued a safety recommendation to CASA to take action to require builders of amateur-built experimental aircraft to produce a flight manual, or equivalent, for their aircraft following flight testing. CASA has 90 days to formally respond to the ATSB’s safety recommendation.

Safety message

This accident highlights the risks inherent in performing low-level aerobatics. Applying the recommendations in CASA civil aviation advisory publication CAAP 155-1(0) Aerobatics will reduce these risks. Specifically, pilots are encouraged to always maintain minimum approved heights above the ground when performing aerobatics and to engage in regular peer reviews.

Owners of amateur-built experimental aircraft are also encouraged to ensure a comprehensive and accurate flight manual, or equivalent, is available for reference by themselves, subsequent owners and other pilots who may fly the aircraft.

Read the final report: Collision with terrain involving One Design DR-107, VH-EGT, Goolwa Airport, South Australia, on 10 October 2014

A runway excursion involving a Fairchild Industries Metro 23 aircraft shows why it’s important that maintenance and inspection programs adequately provide for the detection of corrosion and cracking.

On 20 February 2014, the aircraft was being operated on a charter flight from Avalon to Portland, Victoria with 10 passengers and two crew on board.

Shortly after touch-down, the torque link on the left, main landing gear (MLG) failed. This resulted in the aircraft veering left and coming to rest beside the runway. Fortunately no one was injured.

The runway excursion resulted from failure of the lower torque link attachment lug on the left main landing gear’s yoke. This allowed the wheels to rotate through 90 degrees, producing a large braking effect on the left side.

The flight crew were unable to counteract this and the aircraft veered to the left and off the runway.

The failure of the lug on the yoke resulted from pre-existing cracks that had progressively grown until the part had insufficient strength to support normal landing loads.

The cracks initiated principally from areas of pitting corrosion in the lug’s bore and were propagated by cyclic stresses imposed during operation.

The ATSB found the maintenance and inspection program for the aircraft’s landing gear did not adequately provide for the detection of corrosion and cracking in the yoke lug bore.

This occurrence highlights the importance of developing and conducting appropriately detailed maintenance inspections on susceptible parts and assemblies.

The Civil Aviation Safety Authority (CASA) has released Airworthiness Bulletin AWB 32-023 to alert all Fairchild Swearingen Metro and Merlin operators of the need for detailed inspection of the internal bore of the landing gear torque link lugs for any signs of corrosion or wear outside of the manufacturer’s specified limits and to take appropriate action per the aircraft’s structural repair manual, where necessary.

In addition, the aircraft’s Type Certificate Holder has drafted service bulletins 226-32-083, 227-32-065, CC7-32-030 titled “inspection of Main Landing Yoke for Corrosion and/or Damage” that will significantly increase the effectiveness of maintenance inspections for the affected parts.

This occurrence highlights the importance of developing and conducting appropriately detailed maintenance inspections on susceptible parts and assemblies.

Read the final report: Runway excursion involving a Fairchild Metro 23, VH-UUB, at Portland, Victoria, on 20 February 2014

This shipboard fire quickly got out of control causing extensive damage and several injuries due to smoke inhalation. An open cabin door and a stairwell fire door left hooked open were contributing factors.

On the morning of 9 October 2014, a fire started in Ocean Drover’s crew accommodation while the livestock carrier was berthed in Fremantle, Western Australia. The fire quickly spread across both accommodation decks. The ship’s crew and shore emergency response teams responded, and fire-fighting efforts continued for the rest of the day.

By the time the fire was extinguished late that evening, the ship’s accommodation areas and its navigation bridge had been extensively damaged. Four of the ship’s crew sustained injuries that required medical treatment.

The ATSB found that the fire started in a centrally located forward cabin on Ocean Drover’s upper deck. The intensity of the fire and the severity of the damage made it impossible to identify an exact point of origin or source of the fire.

The ATSB investigation found that the cabin door was left open after the fire was discovered allowing smoke and flame to spread beyond the cabin. Further, the bridge deck stairwell fire door was hooked open, which allowed the fire to rapidly spread and engulf both the upper and bridge decks.

The investigation also identified that the ship’s crew did not complete a muster and accurate head count when responding to the fire.

While cigarette smoking was not identified as a contributing factor, it was found that the smoking policy and associated risk controls on board were not effectively managed.

Ocean Drover underwent extensive post-fire repairs before it could return to service. During the repair period, the ship’s managers took pro-active safety action to avoid a similar incident in the future. All cabins in the ship’s accommodation were fitted with smoke detectors. The bridge deck stairwell fire door was replaced with one that is not fitted with a hold back arrangement (to comply with mandatory regulations). Notices posted on both sides of the door require it to be kept closed.

The ship’s managers have revised the shipboard smoking policy and restricted smoking to designated rooms, which exclude crew cabins. Designated smoking rooms are provided with safety ashtrays and sand bins, and warning signs have been posted in accommodation areas. The managers promulgated the lessons learned from the fire and safety action taken across the fleet through procedural changes and safety meetings.

Safety message

Containing a shipboard fire in the compartment where it originates is critical to firefighting.

Effective containment relies on maintaining the integrity of fire divisions, including bulkheads, decks and doors. In this regard, particular attention must be paid to ensuring fire doors, designed to limit or prevent the spread of fire, are never latched/lashed open, or otherwise compromised.

Read the final report: Fire on board the livestock carrier Ocean Drover, Fremantle, Western Australia, on 9 October 2014

A track worker who was fatally struck by a passenger train in Guildford, Western Australia had no form of protection such as a lookout, at the work site, according to the ATSB’s final investigation report.

On 10 February 2015, a Public Transport Authority (PTA) maintenance crew commenced work at Meadow Street in Guildford. The crew was maintaining the pedestrian gates adjacent to the level crossing.

At about 10.35 am, one of the track workers was struck by a Perth-bound suburban passenger train. Tragically, the track worker died in the accident.

The ATSB investigation found that the PTA maintenance workers had not implemented any form of track worker protection at the work site. This was partially due to the PTA not having documented instructions specifying the level of protection required, preferring that track workers make their own assessment based on their knowledge of the Network Rules. The ATSB found that, under these arrangements, track workers could make an incorrect assessment, placing themselves at a greater risk of being struck by a train.

A review of the safeworking training provided to the track workers found that the training material did provide a suitable level of safe-working knowledge.

Following the occurrence, the toxicology report on the deceased track worker identified the presence of amphetamine and methamphetamine; methamphetamine being a prescribed drug under the Rail Safety Regulations 2011. The use of stimulants such as methamphetamine is associated with a range of neurocognitive effects in humans that may affect performance.

The ATSB found that in this instance, the presence of a prescribed drug within the worker’s system appeared to be a relatively isolated case. An examination of the company’s drug and alcohol policy/procedures found them to be generally effective in managing drugs and alcohol in the workplace.

The PTA issued a safety alert following the incident to highlight the importance of implementing the correct level of track worker protection. The subsequent introduction of new safeworking rules, track access accreditation levels and training further supported this.

Further, the PTA has created the role of Workplace trainer and assessor with the task of ensuring track workers comply with the network rules by way of competency-based assessments. Implementation of a new track access accreditation system, with improved training and job mentoring, has also commenced.  

Safety message

This incident strongly emphasises the need for rail transport operators to provide clear and concise work instructions to employees working within the railway corridor. It also highlights the potential for recreational and other drug use to impair performance and affect workplace safety.

Read the final report: Collision between track worker and passenger train, Guildford, Western Australia, on 10 February 2015

Learn more about Safe work on rail

Oil on the windscreen due to an unsecured engine oil filler cap prompted the pilot of a Cessna T210N to attempt a go-around, with tragic results.

On 4 July 2014, the owner/pilot of a Cessna aircraft and two passengers were conducting a private flight from Inverell Airport to Bankstown Airport, New South Wales.

Shortly after take-off, oil appeared on the windscreen and the pilot rejected the take-off with the intent of landing back on the runway.

With the oil obscuring the pilot’s forward vision, the pilot looked to the left of the aircraft to assess their position along the runway. The pilot realised they were a lot further along the runway than expected and had insufficient runway distance to land safely. The pilot attempted a go-around but later reported the engine did not respond. During the subsequent forced landing, the aircraft impacted a shrub beyond the end of the runway overrun and flipped, before coming to rest inverted.

The pilot and a passenger were hospitalised with serious injuries and the second passenger received minor injuries. Tragically, the seriously-injured passenger later succumbed to their injuries. The aircraft was destroyed by the impact forces and a post-impact fuel-fed fire.

Examination of the aircraft found the engine oil filler cap detached from the oil filler tube but hanging by its chain. Further examination of the tube and cap determined that it was most likely the cap was not secure before the flight commenced.

The Cessna T210N pilot’s operating handbook advised pilots to check the engine oil level during a pre‑flight inspection but not the security of the separate oil filler cap. The ATSB could not establish the extent to which a specific checklist item about oil filler cap security would have assisted in identifying the unsecured cap in this case, although it would probably have increased the likelihood of detection.

Witness observations and the pilot’s assessment of the aircraft’s position along the runway during the rejected take-off indicated that the take-off was longer than normal. The reason for this could not be determined.

Examination of the engine and turbocharger found no mechanical defect or failure that would have precluded normal operation. While it was possible that a temporary issue occurred, resulting in the reported lack of engine response during the go-around, this could not be established.

The ATSB also determined that the engine manufacturer’s oil change interval had been exceeded by 3 months but it was very unlikely that this had any effect on the operation of the engine.

Safety message

This accident highlights that, prior to take-off, pilots should have in mind a go/no-go decision point along the runway by which time the aircraft should become airborne. If at that point the aircraft is not airborne, the pilot should reject the take-off. Having such a point assists pilot decision making during a critical phase of flight. This is particularly important when operating in conditions that may affect aircraft performance, such as tailwind conditions.

In addition, the ATSB highlights the importance of being aware of the daily inspection requirements when operating aircraft under a CASA maintenance schedule. In particular, how this may differ from the aircraft manufacturer’s pre-flight inspection procedure.

Read the final report: Collision with terrain involving Cessna T210N, VH-ZFW, near Inverell Airport, New South Wales, on 4 July 2014

A recent ATSB investigation shows how unexpected developments or confusion about procedures can contribute to decisions and actions that increase the safety risk to the aircraft.

In the incident, the crew of a Cobham Airline Services Boeing 717 aircraft, was conducting an instrument approach to land on runway 03 at Perth Airport.

The aircraft was conducting an approach in instrument meteorological conditions after a flight from Paraburdoo, Western Australia. When they reached the decision altitude, the crew initiated a missed approach procedure as they had not obtained visual reference with the runway.

Almost immediately, however, they obtained visual reference with the runway, discontinued the missed approach procedure and landed, despite the aircraft being in an unstable condition.

The ATSB found that the onset of fog at Perth Airport at the estimated time of arrival was not forecast until after the aircraft had passed the point in the flight when it had insufficient fuel remaining to divert to a suitable alternate aerodrome. Before that point, there had been no requirement for the aircraft to carry fuel to continue to a suitable alternate.

Under the circumstances, the flight crew considered that the better option was to discontinue the missed approach procedure and land, in spite of the aircraft being in an unstable condition due to the initiation of the missed approach.

This incident highlights the risk of an unstable approach from not following a missed approach through to its conclusion.

Unstable approaches are a frequent factor in approach and landing accidents, including controlled flight into terrain. The Flight Safety Foundation has developed an Approach and Landing Accident Reduction Tool Kit(Opens in a new tab/window) to reduce the risk of approach and landing accidents.

‘Handling approach to land’ is also a top safety concern in the ATSB’s SafetyWatch initiative. The ATSB has identified an increasing trend where pilots mishandle or mismanage their aircraft and flight profile when unexpected events arise during the approach to land.

The occurrence also highlights that during a flight, the forecast weather at the destination may change and it is advisable to obtain the most up-to-date weather forecasts. However, pilots should be alert to the fact that the actual weather can differ significantly from forecasts.

Read the final report: Weather-related operational event involving Boeing 717, VH NXO, Perth Airport, Western Australia, on 1 June 2012