Melbourne Airport has opted for its third runway to run north-south, dumping its previous preference for an east-west orientation.

The decision means thousands of homes in Melbourne’s north-west will have more than twice the number of flights overhead within six years.

By next week, more than 300,000 residents around the airport’s perimeter will receive leaflets from Melbourne Airport about plans for the new north-south runway to be built by 2025.

Colin and Kim Brown on their property at Keilor. Credit:Justin McManus

The Age revealed in July that the airport's owner, Australian Pacific Airports Corporation, had unexpectedly changed its preference for a new east-west runway at Tullamarine and instead favoured the north-south option. The airport announced the final choice on Thursday morning.