Time is running out for people to submit their views on a major redraw of route maps for aircraft.

Residents living under the flight path of Heathrow's southern runway could face more air noise under the new plans.

Those affected have less than a month - until May 22 - to respond to the public consultation by the UK's air traffic manager, NATS.

Launched in February, the consultation seeks the public's views on proposals to overhaul airspace across a large swathe of south east England.

One change that could affect people is tied to a move to reduce congestion over Brookmans Park in Hertfordshire by altering Heathrow departure routes.

NATS proposees to send more planes over the southern part of the borough, arguing that the move is designed to cut delays and make air travel greener.

Head of air space at NATS Jonathan Astill said airports had grown considerably in the past 20 years.

"Redrawing the routes enables us to make them more efficient," he said.

Feedback on the proposals, which could be introduced even if plans to expand Heathrow are dropped, will be considered before a final plan is put forward to the Civil Aviation Authority.

Approved changes would take effect in 2009.

Respond to the consultation online or write to TCN Consultation, NATS, Freepost NAT22750, Reading, RG1 4BR.