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.
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.
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.
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.