The city police's Security Investigation Agency opened a criminal case against Than Van Tan on Aug. 27 and detained him the following day on suspicion of obstructing air traffic.

The offense carries three to ten years in prison under Clause 2, Article 278 of the Penal Code, and investigators' initial assessment puts the damage in the billions of dong, or hundreds of thousands of dollars.

At 7:40 p.m. on Aug. 13, the Region III Flight Operations Center reported an unidentified object in restricted airspace above the airport. Controllers stopped accepting arrivals while ground units searched for it.

Three whistling kites, a traditional Vietnamese design that carries a bamboo reed, were flying at about 400 m with flashing lights attached, inside the clear-airspace corridor used by aircraft on final approach.

Aircraft inbound from Pleiku in Gia Lai, Da Nang and Cam Ranh in Khanh Hoa held in designated airspace until it cleared. Operations returned to normal at 8:15 p.m.

Than Van Tan (R) is questioned by a police officer in Ho Chi Minh City. Photo courtesy of Ho Chi Minh City Police

Police located Tan at a vacant lot beside Tan Binh Industrial Park in Binh Hung Hoa Ward, about 2.5 km from the airport, and took him and two other men in for questioning. Only Tan has been named as the accused.

All three admitted the violation and told investigators they had come to the lot that evening as members of a Facebook group for whistling kite enthusiasts in the city.

Drones had shut down takeoffs and landings at the same airport twice on the evening of Aug. 11, two days earlier, disrupting more than 100 flights and stranding tens of thousands of passengers.

To Tu Ha, deputy general director of Airports Corporation of Vietnam, has put preliminary losses from that night at roughly VND60 billion (US$2.3 million) and said the aviation sector logged 28 drone-related incidents over the past year.

Tan Son Nhat sits about 8 km north of central Ho Chi Minh City, hemmed in by dense urban development. It is Vietnam's busiest airport, moving 42.1 million passengers in 2025 against 33 million at Hanoi's Noi Bai, according to Airports Corporation of Vietnam figures.