According to Vietnam Air Traffic Management Corporation (VATM), the unmanned aerial vehicle sighting near Tan Son Nhat International Airport on August 11 affected 73 flights.
Tan Son Nhat airport control tower (Photo: Ngoc Tan).
The figure covers flights directly affected when the airport temporarily suspended take-offs and landings as a safety precaution.
More than 50 flights were forced to enter holding patterns, according to the Air Traffic Flow Management Centre. Of these, 27 were diverted or landed at alternate airports.
On the morning of August 12, airlines including Vietnam Airlines, Vietjet Air and Sun PhuQuoc Airways also issued notices about flights affected by the disruption at Tan Son Nhat.
After receiving reports from flight crews that a UAV had been spotted near the airport, VATM's air traffic control facility immediately activated the prescribed response procedures.
Take-offs and landings at Tan Son Nhat were temporarily restricted. Aircraft preparing to depart were held on the runway, while arriving flights were instructed to enter holding patterns in designated areas.
According to the Air Traffic Flow Management Centre, departure slots were reassigned for 71 flights scheduled to fly to Tan Son Nhat that had not yet taken off, as part of efforts to regulate air traffic.
A flight from Cam Ranh to Tan Son Nhat is forced to divert and land in Can Tho on the evening of August 11 (Photo: Flightradar24).
When the UAV was first detected, the air traffic flow management centre immediately imposed a ground stop from 6.25 pm, temporarily suspending departures from airports whose flights were scheduled to land at Tan Son Nhat.
It then introduced a ground delay programme, temporarily holding aircraft on the ground and rearranging departure sequences to reduce pressure on the destination airport.
After take-offs and landings resumed, the airport detected a second UAV at about 7.34 pm, just over 20 minutes after operations had restarted. Authorities again imposed a ground stop and ground delay programme.
Air traffic controllers also contacted air traffic control facilities in neighbouring countries, including Thailand and China, to report the situation and request that departures of flights bound for Tan Son Nhat be delayed.
Earlier on the evening of August 11, Tan Son Nhat twice suspended take-offs and landings after UAVs were detected entering the airport's restricted airspace.
The incident marked the first time Vietnam's largest airport had activated its emergency procedures in response to a UAV, adding to a growing list of Vietnamese airports affected by such aircraft.
