On Tuesday, May 1, China-based drone company EHang flew 1,374 drones above a 600-year-old city wall called Xi’an and set a new Guinness World Record for the “most number of unmanned aerial vehicles airborne simultaneously,” according to South China Morning Post. EHang broke Intel’s previous record from the 2018 Winter Olympics by 156 drones, but the flight encountered some synchronization problems. Before viewing the drones that flew out of sync, here is the record-breaking flight video showing various LED-illuminated drone formations: