The noise is overwhelming, the wind is blowing so hard that my cheeks are beginning to shake and I’m so terrified I can barely see straight, let alone follow my instructor’s hand signals. I cross my arms over my chest and allow myself to fall forward on to the mesh. Just before I hit the floor, an overpowering 100mph stream of air whacks me off my feet. I’m flying.

If you’ve ever wanted to skydive but don’t want to take your life in your hands, the 35ft-high (11m) Airkix wind tunnel in Milton Keynes might be the solution. Steve Ward, the award-winning skydiver and director of Airkix, opened the centre last December, and believes that indoor skydiving could soon be as popular as indoor skiing.

“It’s excellent training for the real thing, but indoor skydiving is also a sport in its own right,” he says. “It’s completely safe and not just for extreme sports enthusiasts; we’ve had fliers aged from 5 to 85.” And advocates claim that an hour in the tunnel has the same benefits of an hour-long workout in the gym. Ward is already looking for locations for two more Airkix tunnels, in Glasgow and in London, with the hope of opening nationwide.

Flying in a wind tunnel may not be dangerous but it does require some training beforehand, so not long after I arrive I am sent to join my group of six for the beginners’ session. Our instructor, Kermet, immediately has us climbing on to low benches to practise the beginner’s flying pose: stomach down, head up, back arched, arms and legs gently bent. It seems simple enough but, according to Kermet, the difference between “Superman arms” and the correct position (arms outstretched and bent at the elbow, palms down) will be the only thing between me and the bottom of the tunnel. And, bizarrely, he points out that the more we arch our back, the higher we will rise; clenching your stomach muscles apparently has the same effect.

After a quick run-through of the hand signals for “bend legs”, “arch” and “relax” — once you are in the tunnel it is impossible to hear — and assuring us that you can still breathe in free-fall, Kermet kits us out in cotton jumpsuits, goggles, crash helmets and, to my surprise, ear plugs. As we leave the training room and climb the stairs to enter the tunnel I start to feel very nervous.

On the viewing platform surrounding the glass-walled chamber, I just have time to gaze dubiously at the tough wire mesh at our feet separating fliers from the ferocious fans 10ft below before we are shown how to enter the tunnel by approaching the door-less entry points, and then falling on to the air flow. By now, the tension is palpable.

Graham Davis, 24, is first in. Nervously stepping up to the chamber, he takes a deep breath and falls on to the air flow, and immediately drifts towards the mesh. Kermet, who is standing in the entry point, signals to him to “bend legs” and “arch” to get him airborne. More signals and Davis begins to rise. A few seconds later he’s flying above us, and grinning from ear to ear. A few more seconds in the air and then Kermet guides him to the exit, where we all want to know what it was like. After “Wow” and “Bloody hell”, Davis settles on “That was really, really intense” before collapsing on to a bench.

It’s my turn next and I’m terrified. Although the mesh is more than sturdy enough for me to stand on, and it’s impossible to fall on to the fans, I don’t feel reassured. As Kermet helps me to fall on to the air flow, I realise that nothing can prepare you for the noise and the sheer force of the wind flow. Air rushes into my nostrils and my cheeks begin to ripple: it feels as if I’m trying to balance on a hurricane. As the wind whips my arms and legs about I attempt to keep the flying position but I can’t stay more than two or three feet off the mesh. In fact, the whole experience is so overwhelming that I barely have time to realise I am actually flying.

Beginners typically stay in the tunnel for one minute on their first attempt, and two on their second, but the amount of energy and concentration required just to stay off the mesh means that it feels much longer. I am given a couple of tips, such as to try relaxing in to the flying position as I will find it easier to move around, and then I’m back in the tunnel for my second attempt.

This time I’m ready for the physical assault but after only a few seconds I slow-motion dive-bomb on to the mesh and Kermet has to help me into the middle of the chamber. Arching my back, I manage to rise 5ft, until I’m high above Kermet’s head. This time I feel that I am flying. It’s brilliant.

When my two minutes are up, Kermet signals for me to straighten my legs and I begin to glide towards the door. Outside the tunnel, I’m exhausted, heart pounding and arms aching — but exhilarated. Claire Scott, three times world champion and leader of the British Women’s Skydiving Team, is not surprised. She uses the tunnel for speed drills, attempting as many different free-fall formations as possible in 35 seconds, and says that there are health benefits. “The tunnel is like going to the gym, but much more fun,” she says. “It really helps muscle tone, and once you’ve mastered flying you quickly work up a sweat.” It’s a great workout because, like swimming, it doesn’t place too much stress on your skeletal and muscular systems.

Scott, who has been skydiving for 13 years, and has more than 1,600 jumps under her belt, last month won gold in the women’s four-way formation team event at the 2006 Skydiving World Championships in Germany.

She spends at least an hour a day, six days a week, practising formations and changes in the tunnel. “You need to be quite fit in the first place,” she says, “but if you’re in the tunnel every day you don’t need to go to the gym.”

As for how it compares to the real thing, she admits that nothing beats the rush of jumping out of a plane, but says that the wind tunnel is actually much better exercise. “It’s much more physically intensive because you can be in the air for so much longer, so you really feel it afterwards in your arms, legs, back and stomach muscles.”

Judging from my all-over ache I can only agree. I still don’t think that I’ll be jumping from a plane anytime soon but indoor skydiving beats an hour with a personal trainer. Next time I’m going to see if I can manage some intentional, rather than accidental, somersaults.

For more information visit: www.airkix.com; beginner flights start at £33 for an hour

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