Suvarnabhumi and Don Mueang airports switched the direction of take-offs and landings on Saturday due to the change of wind direction during the cold season.
The change means people in Bangkok may see airliners flying low in downtown skies, said the Aeronautical Radio of Thailand (Aero Thai) on Monday.
Aero Thai chief Nopasit Chakpitak said the reversed runway directions came into effect on Saturday and would last until February. Planes taking off and landing at Don Mueang have switched from Runway 21 to Runway 03, he added.
The switch is necessary because the prevailing northeasterly wind changes direction and strengthens to 10-15 knots (20-30 kilometres per hour) during the cold season, potentially affecting aircrafts' manoeuvrability.
“From October to February, aircraft at Don Muang will take off from the north side and land on the south side of the airport, giving Bangkokians the unusual sight of planes approaching over the downtown area. Suvarnabhumi Airport will adopt the same practice,” said Nopasit.
If the wind weakens to below 10 knots (18kph), Aero Thai will consider allowing passenger jets to switch back to their usual landing and take-off routine.