The company behind drone shows at the Vivid Sydney festival says spectators were not in danger when nearly 90 devices fell from the sky during a demonstration on Monday night.
The Australian Transport Safety Bureau (ATSB) has launched an investigation into the accident, which British company SkyMagic blamed on radio interference.
Of the 1,000 glittering drones that invaded Darling Harbour, 83 landed in Cockle Bay.
Efforts are underway to fish drones out of port to minimize pollution caused by their lithium-ion batteries.
Six others landed on pavements and a bridge, but SkyMagic operations and production manager Dyfan Rhys said none of the errant vehicles escaped the exclusion zone.
“It is really important to emphasize that there were no security issues at this show,”
» said Mr. Rhys.
The festival immediately canceled shows scheduled for Tuesday and Wednesday, but has not yet decided the fate of Sunday's show.
Destination NSW CEO Karen Jones said whether the project would go ahead would depend on the outcome of a safety assessment.
How common are drone show incidents?
As drone broadcasts grow in popularity, more accidents are inevitable.
In 2023, more than 400 drones dived into Melbourne's Victoria Harbor at Docklands.
An ATSB investigation found the pilot failed to notice the wind was too strong for the plane.
In 2024, a rogue drone reportedly hit a boy in the face during a performance gone wrong in the US state of Florida.
Footage published by Vietnamese media shows drones falling on a crowd of spectators in Ho Chi Minh City last year.
The Australian Transport Safety Bureau (ATSB) has launched an investigation into the incident. (Provided)
How do drone shows work?
Nigel Brown is the CEO of Washington-based Drone Sky Shows.
Mr Brown said each drone was programmed with a flight path so it knew where to fly as part of the show.
He said the planes were monitored from a master computer by a pilot who could take control in the event of a failure.
Mr Brown said some drones were designed to perform the entire show without a signal.
He said drone shows were usually confined to a “geo-fence” to keep them away from the audience below.
“If a drone hits this imaginary wall, then it tries to return home, and if it doesn't succeed for some reason, then the software should turn off the motors so that it falls virtually, relatively vertically,” he said.
How does weather affect drone shows?
Although a Sunday show was canceled due to rain, there is no indication yet that weather played a role in Monday's incident.
Mr Brown said the threat rain posed to drones depended on the generation of device used. Some models could withstand rain, but electronics of other types could not.
Wind was the most pressing concern. The descent of the drones into Melbourne's Victoria Harbor was linked to winds above their rated power.
Nigel Brown says some drones can handle rain and stronger winds better than others. (ABC News: Supplied/Nigel Brown)
But as Mr. Brown explained, strong winds could prevent the drone from performing its routine due to the aircraft's power limitations.
He said the maximum headwind his drones could safely withstand was 8 meters per second, or 29 km/h.
“This is where wind limitation comes into play, because a small drone simply cannot fly that fast,”
he said.
How much would Monday's malfunction have cost?
The company did not disclose the cost of the lost drones, only saying they were expensive.
Mr Brown, of Drone Sky Shows, said drones used in exhibitions could cost between $1,500 and $2,400 each.
Multiply the cost by about 80, and Monday's malfunction looks significant.
Mr Brown said drones that ended up in the water could no longer fly.
