At about 1050 Eastern Standard Time on 31 August 2013, the crew of a Bell Helicopter Co. 412EP helicopter, registered VH-VAS, were tasked to pick up a patient who was reported to have sustained injuries during a fall in the hills around Macs Cove, near Mansfield, Victoria. Due to the confined winch area and the possible fouling hazard associated with nearby trees, the crew elected to conduct a double-lift extraction with the patient in a rescue strop, accompanied by a paramedic. As the paramedic and patient reached the helicopter’s skid‑landing gear, the patient became increasingly unresponsive and began slipping from the rescue strop. The paramedic and winch operator attempted to restrain the patient however, despite their efforts, the patient slipped out of the rescue strop and fell to the ground, sustaining fatal injuries.
What the ATSB found
The ATSB found that, due to the compressive nature of the rescue strop around the patient's chest, combined with the patient’s weight and pre-existing medical conditions, the patient probably lost consciousness during the winch operation. While the rescue strop was serviceable at the time, it was not suitable for the patient and contributed to them falling from the strop following their loss of consciousness.
The ATSB also identified that the operator and Air Ambulance Victoria had limited documented guidance to assist rescue personnel select the most appropriate winching rescue equipment.
What's been done as a result
Concurrent with the release of its preliminary investigation report on 10 October 2013, the ATSB issued a safety advisory notice to helicopter winch operators, noting the circumstances of this accident. The notice advised operators to consider the risk to patients, or other persons being winched, of slipping out of a rescue/retrieval strop and the implications for their operations.
Following this accident, the operator and Air Ambulance Victoria introduced a seat-type harness for patient recovery via winch and issued guidance to their crews on the order of priority of use for rescue equipment during over land winch operations. The Civil Aviation Safety Authority also issued an Airworthiness Bulletin clarifying the use and application of rescue/retrieval strops. In addition, various helicopter emergency medical service providers have improved information sharing to communicate operational knowledge and lessons learnt.
The ATSB advises helicopter emergency medical service and other operators carrying out winching operations to note the circumstances of this accident and consider the implications for their operations of the risk of patients or other persons being winched slipping out of a rescue/retrieval strop. In this context the size, weight and medical condition of the person(s) being winched may indicate that other recovery options offer reduced risk.