Drones drop from sky during performance

A video of a number of drones falling from the sky during a performance in Xi’an, Shaanxi province, went viral online, embarrassing a new Guinness World Record winner, Ehang Egret, a drone-maker in Guangdong province.

The drones were supposed to stage a light show on Tuesday called Xi’an in Spring, highlighting the opening of the 2018 Xi’an City Wall Culture Festival. The show included 1,374 drones that created formations such as the city wall and the Chinese characters of Xi’an.

The drones on the left side of the formation were disorganized and out of sync when they flew over the city wall, and some fell rather than landed as planned.

Ehang Egret, the company responsible for the performance, said on Wednesday that the communications controlling the drones were disrupted by the heavy use of electronic devices by the crowds who came to watch the show.

On Sunday, the company won a Guinness World Record for “most unmanned aerial vehicles airborne simultaneously”, using the same number of drones as in Xi’an.

“The drones were in arrays, like lights in LED billboards. The patterns and formations of the drones were illuminated by lights on the drones,” said Wang Shanwu, a drone engineer at China Aerospace Science and Technology Corp.

He said that every drone is equipped with differential GPS sensors and controllers, and the movements are directed by codes programmed into the controllers.

“I guess the positioning system or link control may have been affected by high-power transmissions,” he said. “Faults in the codes or procedures may also have caused the accident.”

However, the incident didn’t have much influence on people’s passion for the show.

“It did seem strange when I saw the patterns,” said a 25-year-old female spectator surnamed Cao. “But I thought it was part of their arrangement as the show was too romantic and breathtaking for me to be distracted.”