London

LONDON'S Heathrow airport aims to boost capacity even before a new runway opens, with the rejigging of the way two existing landing strips are used to add 25,000 aircraft movements a year.

The project, revealed on Tuesday as part of a consultation process on the £16 billion ($20 billion) third runway, may stir controversy at Europe's busiest airport due to added disruption to local residents years before the planned infrastructure comes into use in 2026.

The extra flights would represent about 5 per cent more than a current cap. A key change would allow jets to use existing runways for both landing and take-offs in the same direction from 2022, breaking from an arrangement that sees one used for arrivals and the other for departures.

While that would boost punctuality, "flight paths could overfly areas that are not affected by Heathrow arrivals today", the airport said in the study on proposed airspace changes.

Heathrow also proposes that a limit of 480,000 flights a year from the existing runways be scrapped once planning permission for the third strip is received.

The third runway itself will lift annual capacity by almost 75 per cent to 135 million travellers. BLOOMBERG