The ATSB advises all commercial balloon operators utilising vehicle‑assisted deflation to review their current operational practices with the aim of mitigating the safety risks associated with the procedure.
On 16 March 2019, two passengers were seriously injured when the basket of a Kavanagh B‑400 hot‑air balloon tipped over during vehicle-assisted deflation.
Prior to the accident, the balloon, operated as a scenic charter flight, landed without incident at a private property near Coldstream, Victoria.
Due to a lack of wind and the large size of the envelope, the crew elected to use the retrieval vehicle to assist by pulling the envelope over (by the crown line) during the deflation.
During this process, with 16 passengers and the pilot on board, the vehicle assisting inadvertently pulled the basket over, seriously injuring two passengers.
This accident was the third time since 2016 where occupants of a commercial balloon where injured as a result of similar events during a vehicle‑assisted deflation.
Why did it happen
During the vehicle-assisted deflation, the pilot put down the handheld radio to operate the vent line. The second ground crew member was not in an observable position for the driver, which led to a communications breakdown and limited the pilot and the second ground crew members’ opportunity to promptly command the driver to stop to avoid the basket tipping.
In addition, during the procedure, the majority of passengers were not in the landing position when the basket tipped, which increased their probability of injury.
The operator began using the vehicle-assisted deflation method around 12 months prior to the accident. At this time the operator did not conduct a risk assessment and had not developed procedures for safely conducting vehicle‑assisted deflation. This contributed to the crew’s lack of awareness of the risk of the basket tipping during the deflation.
Safety advisory notice
AO-2019-014-SAN-014: The ATSB advises all commercial balloon operators utilising vehicle‑assisted deflation methods to review their current operational practices in light of the findings in the ATSB investigation report AO-2019-014 with the aim of mitigating the risks associated with the procedure. This review should be conducted with emphasis on:
- reducing the risks associated with a communications breakdown between the pilot and vehicle driver, and
- include a review of the positioning of occupants within the basket to minimise the likelihood of injury if the basket tips during the vehicle‑assisted deflation.