Lowestoft Seafront Air Festival 2011
The Red Arrows and the Battle of Britain Memorial Flight are among the highlights of the Lowestoft Seafront Air Festival.
The annual event is taking place in the skies above Lowestoft beach on Thursday 11 and Friday 12 August.
The suggested voluntary donation for spectators has risen from £2 to £3.
Festival managing director Paul Bayfield said: "We appreciate it's an increase but we do make sure it's absolutely fabulous value for money."
Organisers said the event costs more than £300,000 to run.
Last year, an estimated 330,000 people attended over the two days.
"I'm aware that it's the same old song that we sing every year but we really do need that £3 in the bucket because we have to believe that if everybody does a little, a lot gets done," said Mr Bayfield.
The displays start at about 12:30 BST and finishes by 17:30 BST.
It is a busy time for St John Ambulance, who will provide 60 volunteers a day at the event.
Tony Curd, county commander in Suffolk, said: "It's mainly minor injuries - stings, bites, wounds, fractures - but also more serious medical conditions which can occur and we're prepared for any eventuality.
"We treat about 130 people a day at the event, especially in hot weather."
Lesley Dolphin will be broadcasting live from the event on BBC Radio Suffolk.