“It’s not that strong:” Why the wind closed runways at Sydney Airport forcing flight cancellations and delays

Thousands of passengers were affected by delays and cancellations over the weekend as wind conditions affected operations at Sydney International Airport.

While the changes were frustrating for those travelling, others were confused as to how the wind can take one runway out of action.

The answer makes sense once explained.

Sydney International Airport usually operates two runways which are just a few degrees off pointing perfectly north and south.

So, when the wind is coming from a predominantly northern or southern direction, then both of these runways can be used, allowing for maximum take-off and departures from the airport.

However, if the wind is coming from the east or west – as it was at the weekend – then all airport operations have to switch to an east/west direction, and for this, there is only one runway, massively reducing the number of flights that can take off or land within a period of time.

Figures from Air Services Australia show that by far the most common runways used are for those which operate in a north/south direction.

Last month, just 4.89 per cent of arrivals and departures took place in an east-to-west direction and 0.2 per cent in a west-to-east direction.

Dominant wind directions are taken into consideration when airports are designed, so it’s no surprise that the most common runways in use are the ones heading north and south.

In fact, travellers into Sydney International Airport could consider themselves lucky the airport even has a runway for east/west operations.

Many major airports around the world don’t, and that’s when you end up with landings like this: