By BBC Newsline's Julian O'Neill

The City Airport is meeting airlines to reduce delayed flights

More than 600 planes broke the night-time flight curfew at Belfast City Airport last year, according to figures disclosed to the BBC.

Under the airport's operating agreement, it should close at 2130 BST, but the problem of late arriving flights has almost doubled in recent years.

The curfew was set to restrict noise, but some residents living nearby say it is being widely abused by the airport and its main airlines, Flybe, British Midland and British Airways.

Around 70% of flights in and out of the airport skirt the north Down coastline.

One residents' group based in Holywood claims the airport has "not properly respected and conformed" with the curfew.

"We have been talking to the airport for three years and the problem is getting worse," said David Babington of the Kinnegar Residents' Action Group.

An agreement between the Department of the Environment and the airport, signed in 1997, allows aircraft movements outside operating hours only in "exceptional circumstances".

"In our opinion, exceptional circumstances mean a life-threatening situation, not routine delays," Mr Babington said.

Diversion call

His group believes the flights should be diverted to Belfast International Airport at Aldergrove.

Late flights are a growing problem, due in large measure to the expansion of the City Airport.

In 2000 there were 334 air traffic movements after 2130 BST and in 2003 there were 648.

The Sydenham Environmental and Community Group, represents people living closest to the airport.

It also has concerns but is satisfied the City Airport is doing all it can to address the problem.

Spokeswoman Margaret McWilliams said: "A lot of this is down to what goes on at Heathrow Airport in London. We don't want it getting any worse but the City Airport is aware of the situation and seems to be doing what it can."

The City Airport, now owned by Spanish company Ferrovial, is meeting airlines with the aim of reducing delayed flights.

"The results have so far been encouraging with a 50% drop in the number of delayed flights over the last three months," a spokesman said.