Taxiing collision/near collision

What happened

On 30 July 2022, at about 1632 local time, the pilot of a Bell 206L LongRanger was relocating the helicopter from the fuel bowser to the operator’s parking area on the north-east side of a hangar at Newman Airport, Western Australia.

While lining up with marking aids on the taxiway, the pilot directed their attention towards a nearby parked helicopter to the right to ensure adequate clearance from the Bell 206L’s main rotor blade. As the pilot moved the 206L forward into the parking bay, there was a loud bang. The pilot reported there was no loss of control or abnormal movement after the sound and continued to land and shut down the helicopter without further incident.

During the post-flight inspection, it was identified that one main rotor blade had contacted the end of the gantry which supports the sliding doors of the hangar (Figure 1). The helicopter sustained minor damage to the rotor blade tip cap spanning about 10 cm (Figure 2).

Figure 1: Damage to hangar gantry

Source: Operator, annotated by the ATSB

Figure 2: Damage to main rotor blade

Source: Operator

Safety action

The operator has advised that it suspended helicopter operations around the apron area where the incident occurred, pending the outcomes of an internal investigation into the incident.

The operator will also review the risk analysis of the apron parking in the vicinity of the hangar and assess the current helicopter parking configuration.

Safety message

The FAA helicopter flying handbook^[1](2022) advises that when taxiing near hangars or obstructions, the distance between the rotor blade tips and obstructions is difficult to judge.

To reduce collision risk, operators should consider human limitations in assessing the hazards and ensure crews maintain situational awareness of the aircraft’s established safe distance for separation from all objects during taxi.

Risk assessments on apron parking areas should be reviewed periodically to re-evaluate risks and mitigations. 

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.

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1. Helicopter Flying Handbook (FAA-H-8083-21B) Chapter 8, Federal Aviation Authority, 2022.

What happened

On 25 August 2021 at 1115 local time, a pilot and engineer were conducting an engine ground run of a Bombardier Challenger 600 aircraft on the apron at Essendon Airport, Victoria. The aircraft was privately owned/operated and had not conducted any flights since 2017.

The nosewheel was chocked, with the left seat foot brakes applied instead of the required parking brake due to previous issues with releasing the park brake. The Challenger’s two turbofan engines were successfully started with normal system indications, and the power levers moved to the low idle position. The power levers were then moved to the high idle position for a short time and then back to low idle, after which the aircraft moved forward and rolled over the chocks.

The pilot was applying pressure onto the left seat foot brakes, and tried pumping them, but the aircraft continued to move forward. The pilot then tried using the rudder pedals to steer toward a grass area off the apron without success. The Challenger hit a parked helicopter and another parked aircraft before rolling through a perimeter fence and colliding with a building (Figure 1), bringing the Challenger to rest about 30 seconds after it started to roll.

Figure 1: Challenger path

Source: Google Earth, annotated by the ATSB

The pilot shut down the left engine by moving its power lever to the idle cut-off position. The right engine power lever could not be moved into the cut-off position, so the pilot activated the right engine’s fire extinguishing system, which successfully shut down the engine. The pilot and engineer then exited the aircraft.

The aircraft received substantial damage to the nose, wing leading edge, and winglets. Post‑accident testing of the Challenger’s brake system could not be performed due to hydraulic system damage from the accident.

Safety action

The pilot and engineer are considering the use of additional chocks during aircraft ground running.

Safety message

It is important to follow all operational procedures during engine ground runs, especially those related to securing the aircraft from moving. Positioning the aircraft away from obstacles during the ground run, for example at an airport’s run-up area, can also reduce the risk of colliding with obstacles should the aircraft unexpectedly roll. If this occurs, flight and maintenance crew must be prepared to initiate emergency actions, such as engaging brake systems and immediately shutting down engines.

After an extended period of inactivity, it is important to conduct full system checks before operating an aircraft.

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 25 March 2021, at about 2130 Eastern Daylight-saving Time,^[1] following a rostered day of flying duties, the pilot of the Diamond DA42 aircraft commenced taxiing at Bankstown Airport, New South Wales, for a session of night circuits to maintain currency.

After the aircraft had rolled forward slightly, the pilot noticed they had left their iPad on the apron and decided to retrieve it before proceeding any further. The pilot engaged the park brake with both engines running and exited the cockpit onto the aircraft’s wing. While the pilot was on the wing, the aircraft moved forward, causing the pilot to lose balance and fall backwards onto the tarmac. The pilot sustained minor hand and leg injuries.

The parking area had a slight decline and the aircraft rolled down the slope. The right wing struck a hangar, and the aircraft went through a perimeter fence, resulting in minor damage to the wing tip and various panels around the nose section of the aircraft.

The pilot reported being unable to regain entry to the cockpit as it rolled away. Once the aircraft had stopped moving, the pilot entered the cockpit and shut down the engines before securing the aircraft.

Park brake

Operation of the park brake is achieved by applying pressure to the toe brake pedals and moving the park brake selector down until it catches. This traps the hydraulic fluid in the brake units and the wheel brakes stay on. The pilot reported being unsure if sufficient pressure was applied to the brake pedals when activating the park brake. The operator advised that following the incident, the park brake was checked and reported to be serviceable.

Fatigue

The pilot reported that at the time of the incident they had been awake for 17 hours. The ATSB publication Fatigue experiences and culture in Australian commercial air transport pilots references studies that found periods of extended wakefulness increase the risk of experiencing a level of fatigue demonstrated to adversely affect performance.

Safety action

As a result of this occurrence, the operator advised the ATSB that the company has introduced a refresher course for all flying staff regarding fatigue management and responsibilities.

Safety message

A more appropriate course of action would have seen the pilot shut down the engines before securing the aircraft with the park brake and then exiting the aircraft to retrieve the iPad from the apron. Lapses in decision making can result from extended periods of wakefulness. 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 is Fatigue.

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.

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

What happened

On 18 July 2020, at about 1000 Eastern Standard Time, a Piper PA-28 was taxiing to vacate the runway at Warrnambool Airport, Victoria. As the aircraft vacated the runway, the pilot proceeded towards the fuel bowser and aligned the aircraft on what was thought to be a taxiway guideline for the apron in front of the fuel bowser. As the aircraft slowed, it suddenly veered right and came to a stop. The right wing had contacted the shelter housing the fuel bowser, with further inspection revealing a dent in the leading edge of the wing. The pilot had mistaken the parking limit line for a taxi guideline marking and positioned the aircraft too far to the right, resulting in a collision with the structure as the aircraft approached the bowser (see Figure 1).

Figure 1: Warrnambool Airport apron markings

Source: Google annotated by the ATSB

As depicted in Figure 2 from the Manual of Standards Part 139 – Aerodromes Volume 1: Chapter 8, limit markings differ in presentation from taxi guideline markings. Taxi guidelines consist of a single solid yellow line, whereas parking limit lines consist of two solid yellow lines surrounding a solid red line with the words ‘Parking Clearance’ appearing at regular intervals. A list of markings and their meanings are available to pilots in the Aeronautical Information Publication (AIP) AD 1.1 4.10.

Figure 2: Apron markings – taxi guideline marking and parking clearance line

Source: Manual of Standards Part 139 - Aerodromes

Safety message

This incident reinforces the importance of maintaining situational awareness^[1], a good lookout while taxiing and a familiarity with apron markings.

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.

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1. Situational awareness: Situational awareness is an accurate understanding of what is going on around you, and what is likely to happen next. Source: CASA Safety behaviours: human factors for pilots 2nd edition

What happened

On 16 April 2020 at about 1300 Eastern Standard Time, an ATR 42-300 was taxiing to park on the apron at Pormpuraaw Airport, Queensland (Figure 1). The pilot of the ATR was aware that a de Havilland DHC-8 was due to arrive and with this in mind, was manoeuvring the aircraft to allow sufficient clearance for the parking of both aircraft on the limited apron area available.

During the manoeuvre, the right wingtip contacted a frangible flood light pole situated on the perimeter of the apron. The light pole gave way as designed. Initial contact was with the aircraft’s right navigation light’s perspex cover which cracked and became dislodged. Upon further inspection, a small dent was also identified on the leading edge of the right aileron control horn.

Figure 1: Pormpuraaw Airport, Queensland

Source: Google Earth, annotated by the ATSB

Safety message

This incident reinforces the importance of maintaining situational awareness and a good lookout while taxiing, particularly in circumstances when the manoeuvring area available is restricted or confined by infrastructure or other obstacles.

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 29 April 2018, at 1330 Eastern Standard Time (EST), a Cessna 172N commenced taxiing on the southern apron at Archerfield, Queensland, in preparation for take-off. At the same time, a fuel truck was fuelling a Cessna 172S to the left side of the taxiway. As the Cessna 172N taxied past, the leading edge of the left wing contacted the fuel truck. The Cessna 172N was immediately stopped and the engine was shut down. Damage to the windscreen of the truck and leading edge of the Cessna 172N’s left wing was identified upon inspection. The Cessna 172N was then pushed clear of the taxiway.

A flying competition and social event was in progress, resulting in higher than normal air and foot traffic in the aerodrome vicinity. Visibility was good, with scattered cloud and a light southerly breeze.

Figure 1: Damage post incident, to the Cessna 172N and fuel truck

Source: Pilot in Command

Safety message

A number of taxiing collisions have been investigated by the ATSB, including Taxiing collision involving a Cessna 172S, VH-EOT and a Cessna 172S, VH-EOP at Moorabbin Airport, VIC on 29 January 2015 (AO-2015-011), which is available from the ATSB website. These incidents reinforce the importance of maintaining situational awareness^[1] and a good lookout during taxiing, particularly in instances of higher than normal activity and distraction.

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.

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1. Situational awareness: being aware of what is happening around you, where you are, where you are supposed to be, and whether anyone or anything around you is a threat to your health and safety. Source: Health and Safety Executive (HSE)

What happened

On 10 March 2018, at about 1600 Eastern Standard Time (EST), an Agusta AW139 helicopter was ground-taxiing to its parking area when it struck a maintenance work stand with the main rotor blades. At the time of the impact, the helicopter was being positioned short of the refuelling area to allow another aircraft to utilise it.

The helicopter was travelling at a slow walking pace when the impact occurred. The impact was felt as a vibration through the rotor system and had no effect on the fuselage or forward movement. The crew conducted a normal shutdown.

Post-flight, engineers inspected numerous components of the helicopter. Damage was isolated to the tip cap assemblies of the main rotor blades (Figure 1).

Figure 1: Damage to main rotor blades

Source: Owner

Safety message

Even when operating in familiar environments, flight crew need to remain vigilant for potential hazards in the area and maintain a good look out to ensure distances from obstacles are maintained.

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.