Jet blast/prop wash

Occurrence Briefs are concise reports that detail the facts surrounding a transport safety occurrence, as received in the initial notification and any follow-up enquiries. They provide an opportunity to share safety messages in the absence of an investigation. Because occurrence briefs are not investigations under the Transport Safety Investigation Act 2003, the information in them is de-identified.

What happened

On 11 March 2025 a Bell Helicopter 412EP was conducting a flight from a hospital in Hobart, Tasmania to another hospital in Latrobe, Tasmania. In addition to the pilot, there was an aircrew officer (ACO) and 2 medical personnel on board. At about 1430, the pilot flew downwind adjacent to the helicopter landing site (HLS) and checked the area around it, paying particular attention to a construction site within the hospital grounds. Visibility in the area was good.

After turning and commencing their approach to the HLS, the pilot noticed a temporary roadworks sign beginning to move. The sign had been positioned outside the hospital grounds on a nearby road. The pilot, ACO and the medical personnel on board the helicopter later recalled that they did not detect the sign until it began to move. The pilot considered that the application of power required for a go‑around would exacerbate the movement of the sign, and continued their approach to the HLS without delay. The helicopter landed safely and there were no injuries or property damage from the sign’s movement, which had been blown about 15 m from its original position.

It was later determined that the temporary roadworks sign was of the corrugated plastic ‘corflute’ type and was not secured or weighted to prevent movement. 

Arrivals to the HLS are normally communicated to ground staff 45 minutes and 10 minutes prior. At these times ground staff inspect the area around the HLS and inform any staff that may be working there. On the day of the occurrence, the presence of the sign was not detected by ground staff during their inspections.

Safety action

The operator established contact with the roadworks contractor to inform them of the hazards associated with helicopter operations around the HLS and to request that the contractor take action to prevent further occurrences. Acting on the operator’s request, the contractor took actions to prevent the movement of its signs in the future. Additionally, the operator communicated the occurrence to its pilots and crewmembers and reiterated existing procedures.

Safety message

To advise helicopter medical transport operators and hospital helicopter landing site operators of the hazards associated with helicopter rotor downwash, the ATSB published aviation data and analysis report Safety risks from rotor wash at hospital helicopter landing sites (

) with an associated safety advisory notice ( ) on 27 September 2023. While this report was primarily focused on incidents that occurred after the introduction of AgustaWestland AW139 helicopters for medical transport, the report provides strategies to manage the risk of rotor downwash at hospital HLS. From the air, pilots operating into hospital HLS may not be able to see hazards in the vicinity that could be affected by the helicopter’s rotor wash during approach or departure. Hospital HLS operators should ensure these hazards are mitigated by implementing ongoing risk controls, such as ensuring that a comprehensive inspection of the surrounding area is conducted prior to a helicopter’s arrival or departure. 

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.

Occurrence Briefs are concise reports that detail the facts surrounding a transport safety occurrence, as received in the initial notification and any follow-up enquiries. They provide an opportunity to share safety messages in the absence of an investigation.

What happened

On 28 October 2021 at about 1550 local time, an AgustaWestland AW139 helicopter was conducting a landing at The Alfred hospital helipad, with two crew on board. The crew approached the helipad from the west, using a steep approach profile aligned with Commercial Road.

During the approach, a pedestrian walking along Commercial Road, about 50 m west of the helipad, was blown over by rotor wash from the helicopter which resulted in serious injuries. The pedestrian was taken to The Alfred hospital for treatment.

The helicopter crew were unaware that downwash from the landing had resulted in any injury to the pedestrian.

The Alfred helicopter landing site is located on an elevated platform approximately 8 m above Commercial Road, a publicly accessible thoroughfare with both vehicular and foot traffic. This design is unique in Australia, exposing public vehicles and pedestrians to the possibility of helicopter downwash on landing.

Figure 1: The Alfred hospital HLS

Source: OzRunways HLS database

The ATSB has received reports of 5 rotor wash events at various hospital helicopter landing sites since 2016. Of these, 3 occurred at The Alfred hospital helicopter landing site and all involved AW139 helicopters.

Safety action

The operator immediately ceased operations to The Alfred hospital helicopter landing site following the incident. Before re-commencing operations at the helipad, the operator:

• reduced the maximum number of helicopters on the helipad from two to one, removing the requirement to hover taxi away from the centre of the helipad
• implemented pedestrian marshalling procedures for all helicopter movements, so that operations will only occur when no pedestrians are within 30 m of the helipad.

Further, The Alfred hospital has engaged a helipad consultant to review the design of the helipad.

Safety message

Helicopters produce significant main rotor downwash, especially during hover taxi, take-off and while approaching to land. It is important that the risk of downwash related injuries, either by direct exposure or by being struck by loose items, be assessed prior to using a helicopter landing site (HLS).

As pilots have limited ability to reduce rotor downwash during these phases of flight, securing loose items in the vicinity of the HLS and keeping people a safe distance away are the most effective ways of preventing injury.

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.