Dozens of flights to northern Vietnam canceled over Laos smog

The Vietnam Air Traffic Management Corporation (VATM) said five flights on April 6, six flights on April 7 and eight flights on April 8 to Dien Bien had to be canceled. The cause was determined to be smog and ash coming from the Upper Laos region, where people often burn forests to make room for fields during the dry season. These have obstructed vision and restricted flights.

Every April, Dien Bien airport often experiences south-southwest winds at a speed of 11-14 kph, with few clouds, but plenty of fog that persists the entire day, obstructing vision. On average, 15 days of the month would have fog, reducing vision by 2,000-4,800 m.

From 2018 to 2022, before Dien Bien airport was closed for upgrades, every April the airport would see around 20 flights on average being either canceled or diverted, accounting for 20% of all flights coming in and out of the area.

Following the upgrades, VATM invested in automatic air quality monitoring systems that satisfy standards by the International Civil Aviation Organization. It has also instructed the aviation meteorology center to monitor weather conditions, especially wind speed and direction and the smog situation, for timely and accurate forecasts.

Since December last year, Dien Bien airport has begun to operate again after six months of upgrades. It is now capable of utilizing large plane models like the Airbus A320 or A321. The airport has served over 900 flights and 70,000 passengers since reopening.

Dien Bien shares 400 km of its border with Laos, and the airport is located around 20 km from the border.