Descending on a field and braving the elements for a weekend's entertainment is a British summer tradition for thousands of thrill-seekers.

But while some search for high-decibel delights at music festivals, others opt for the high-octane sights and sounds at air shows organised by the various aviation museums.

The largest aviation museum is Duxford in Cambridgeshire. Acquired by the Imperial War Museum (IWM) in 1976, the site comprises a mixture of the old and new - from the fully-preserved Battle of Britain operations room to the Norman Foster-designed American Air Museum, and AirSpace, which is the vast £25m home for countless iconic aircraft.

This year Duxford celebrates 90 years of both the RAF and flying at the site, whose reputation and scale make it the airborne equivalent of the Glastonbury music festival.

"As our stage is a mile long and every move the pilots make is carefully choreographed, it's probably a little more like the National Ballet outdoors," says museum director Richard Ashton.

"But we aim for a similar scale of sensory overload. As well as the spectacle in the air, people can meet pilots and veterans and get close to the planes. This is all about commemorating ordinary people who lived in extraordinary times and we must never forget that."

IWM Duxford earns around £1.8m from its air shows, which attract up to 28,000 visitors per day. But putting on a show is an expensive and - because of the climate - a high-risk exercise, says Ashton, whose team budgets for the loss of at least one show day a year to bad weather at a cost of £100,000.

On top of that, there are the ground crews and logistics to consider; the museum's on-site flying partners who provide the working planes, the traders and shops, the emergency services and caterers - the traffic police alone costs £8,000 at every event.

Shows are aimed at different audiences, from enthusiasts, who never tire of seeing old warbirds in flight, to families who - attendance statistics reveal - make spur-of-the-moment decisions to drive for an average two-and-a-half hours to attend a Duxford display.

"Once here, they can experience the lovely, sweeping turns of the Battle of Britain memorial flight, the graceful run and distinctive sound of the Spitfire and the latest variant of the new Typhoon fast jet, which bangs on its afterburners and sets off every car alarm on the site," says Ashton.

Just 2.5km from the Duxford runway is a patch of land earmarked to become Hanley Grange, one of the government's proposed eco-towns. The IWM trustees are worried that any development there could seriously curtail their commercial flying activities, making life difficult for the Duxford operation and very noisy for future residents.

"While some people might think it amazing to see a B-17 coming in 600 feet over their houses - which they're perfectly allowed to do - other people might get upset," says Ashton, who awaits the next round of deliberations about the national eco-town project later in the autumn.

He also believes the future of shows run by smaller institutions is up in the air. "People do it for love, rather than money, but there are only so many weekends in the year and a lot of the older planes, while they are expertly maintained, simply weren't built for this kind of longevity. I see a scenario, particularly with the current economic climate, where fuel and insurance costs may become too prohibitive in some areas."

Smaller museums have looked at other ways of getting air shows off the ground. The National Museum of Flight, based on a former RAF airfield in East Lothian, keeps costs down at its annual extravaganza with a fuel sponsorship deal.

"We hold an air show for audience development, rather than simply trying to make a profit," says general manager Amanda Jopling. "We're aiming at people who wouldn't necessarily consider a museum visit as their first-choice leisure activity."

To that end the museum ensures that the activity on the ground is just as entertaining as what happens in the skies. There's a children's tent, competitions and dozens of free displays are available for the 13,500 paying plane-spotters and casual visitors alike.

Planning for a show begins as soon as the runway smoke has cleared from the previous one. Once a theme has been established, the project team hands over to an air-show management company to organise the aerial performance and to look at what's available for its slice of the £150,000 budget.

Ancient and modern

"We treat it like a business and look at events of all kinds to see how they try to break even - not just other air shows. We put revenue streams into place to cover the costs while being aware of the risks such as the weather," Jopling says.

While popular groups such as display teams and wing walkers often amaze, it's the Typhoon's headlining solo performance that again steals the show at East Fortune airfield, she adds.

"The engines roar like thunder and you know it's there only because of the glow of the after-burners and the red lights on the wingtips. Suddenly it breaks the sky and 'draws' a perfect square in the air. You have to wonder about the G-force the pilots are experiencing."

On the ground, there are vintage aircraft and staff and volunteers - some of them veterans - are on hand to explain how the cockpits work, which switches do what and what used to happen when someone shouted, "Chocks away!"

"The number of people who sit in a pilot's seat and then start making engine noises is incredible," says Jopling. "Suddenly, they imagine they're engaging the enemy; it's amazing when people let their spirits soar in that way."

Derring-do also flourishes at the Museum of Army Flying. Situated alongside Middle Wallop airfield in Hampshire, its collection traces the history of soldiers taking to the air - from man-lifting kites and observation balloons to modern attack helicopters.

The annual air show is designed to raise the profile of both the registered charity, which has recently acquired museum accreditation, as well as the resident Army Air Corps (AAC). This year the air show starred the Red Arrows, historic aircraft and pleasure flights, vintage cars and a funfair, all set to the rousing strains of the AAC band.

The enterprise relies on a lot of goodwill. The museum, which pays a cut of its proceeds to its Ministry of Defence landlords, also hires out its facilities for conferences and parties.

A fundraising trust organises the air show, at a cost of about £120,000, to which existing and potential benefactors and ever-supportive military personnel receive VIP invitations.

"A lot of pilots used to come and do things for us, but the numbers are limited now because they're sent on so many missions abroad," says acting chief executive Marion Paviour.

The show features the usual array of displays and distractions, simulators and trails for the young and old alike, alongside stands dedicated to forces charities and army recruitment. She also reveals that any day can be an air display day at Middle Wallop.

"The Blue Eagles helicopter display team is based here and after training has finished for the day, they come out to barrel roll, fly on their backs, nosedive and dance in the air."

Detailed planning

Authenticity is the key to a successful air display, says Mark Selwood, an events manager at the Royal Armouries, Fort Nelson, who helped stage Dropzone, the dynamic D-Day finale to English Heritage's Festival of Living History in July at Kelmarsh Hall in Northamptonshire.

As a finishing touch to the dogfights between Spitfires and Messerschmitts, props, stuntmen and Hollywood-inspired sound effects of the literally explosive showpiece, Selwood knew he had to have practised parachutists descending in genuine 1944 battledress.

"There can't be that many historical re-enactors who have been trained to jump out of a plane, so you have to turn to the military and be very specific about what you want," says the man brought in to ensure the event went with a bang - and safely so.

"The problem is the period parachutes; you can't steer them and where you land is down to the elements. On D-Day itself, we had paratroopers scattered all over Normandy, but that would be a poor show for a public display.

"So we compromised with modern square canopies and sufficient numbers of men landing in a 75 metre square to give audiences a taste of what it must have been like."

The increasing sophistication of film and TV dramas - combined with video game developers' obsession with recreating the gorier aspects of the second world war - means Selwood has his work cut out to provide realistic thrills.

"People running around shooting blank-firing guns can be great, but we introduced a new dimension - vehicles on the ground, pyrotechnics and mushroom clouds of fire, the kind of thing you wouldn't see unless you were on a film set or unlucky enough to go to war," Selwood says.

"Expectations have changed and the challenge for events managers is to match that in live performances. There is no fatigue with the basic themes, but the days of bank holiday crowds being entertained by two knights slugging it out over a fair maiden are gone."

As for the climate, he "prepares for the worst and hopes for the best". "Your marketing literature has to be quite clear about 'weather permitting'. D-Day itself was postponed for 24 hours because of inclement conditions, but that sort of excuse is not going to cut any ice with a family of four who have travelled 100 miles and paid a lot of money to be entertained."

John Holt is freelance journalist.

The Imperial War Museum Duxford's 90th anniversary air show is on 6-7 September