What happened
At around 1209 local time on 14 October 2025, a Eurocopter AS350, with only the pilot onboard, was carrying an externally slung load between 2 sites in regional Western Australia, located approximately 6 km apart. The load weighed around 800 kg, and was secured using 4 strops, each rated to carry 3,000 kg.
The helicopter was transiting at around 60 kt, about 1,000 ft above ground level. Approximately midway through the flight, with the load stable, the pilot heard a sudden loud thud and felt the helicopter vibrate. At the same time, without the pilot’s command, the helicopter pitched forward into a nose down attitude. The pilot attributed this to a large change in the aircraft’s centre of gravity. In response, they immediately jettisoned the load, which restored full control of the helicopter. The pilot continued the short flight to the intended destination and landed without further incident.
The jettisoned load was later located and inspection revealed that one of the lifting strops had been severed by jagged metal material contained in the load. This resulted in a sudden and significant shift in the load’s orientation beneath the helicopter, leading to the uncommanded pitch change.
Figure 1: Load and lifting strop condition post-occurrence
Image shows the load as it was found after being jettisoned and the condition of the severed lifting strop. Source: aircraft operator
Safety action
The operator has initiated a review of its risk assessment for sling load activities, which will incorporate information learned from this occurrence. It also produced internal recommendations to avoid loads from shifting in flight or damaging lifting equipment including:
- using protective measures, such as rubber matting or edge protectors, wherever slings contact sharp or potentially abrasive surfaces
- testing the structural integrity of loads prior to lifting, including an inspection process for loads that may have structural weaknesses, fatigue, or brittle components.
Safety message
This incident highlights the importance of detailed consideration when preparing external loads for lifting. The nature of aerial construction/deconstruction work can make it difficult for pilots to conduct a detailed inspection of the prepared load prior to each lift operation. Operators are encouraged to ensure effective risk control processes are in place for load preparation, especially with irregularly shaped loads. On this occasion the flight was operating in a remote area and the consequence of jettisoning the load was relatively benign. However, falling loads have the potential to cause catastrophic/fatal outcomes, and the risk must be appropriately mitigated.
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.