Patrick the pilot's voice came via a rubber tube into the makeshift earphones. "Are you ready to do some loops, mate?"

"Uh, I guess so”¦"

It wouldn't have mattered if I'd said no. Patrick already had the 1930s–era Tiger Moth biplane in a nosedive, pushing my back hard into the open cockpit's seat. The world began to rotate as he used speed from the dive to swing into a full loop.

Suddenly I was looking straight down at Australia's Great Ocean Road from a couple thousand feet above it, strapped into an aircraft that was built at least 30 years before I was born. It was, for lack of a better phrase, a "Holy fuck!" moment.

Patrick brought the plane back level, and even though he was seated behind me, I could hear the joy of flying in his voice. "Wasn't that great, mate? How you doing, Randall?"

Did that really just happen? Had I actually just hung upside down in a rickety old airplane? Was I really dressed in this butch-looking khaki flight suit? And had I just trusted my life to a pilot who looked all of 15 years old?

On the ground, my partner, Kevin, thought I was nuts to try this adventure. When I signed the waiver at Tiger Moth World Adventure Park, basically a grass airstrip and mini-golf course about 100 kilometres south of Melbourne, he gave me a look that said he really didn't want to collect on my life-insurance policy.

But here I was. I'd survived a loop! Patrick flew level for a few minutes, letting me gather my wits. I could see swirls of sand churning in the ocean below, along with tiny-looking surfers waiting for the perfect wave.

Suddenly: "Ready for another loop, Randall?"

"Bring it on, Patrick," I shouted, and he plunged the Tiger Moth into a dive before doing a full pair, true loop-the-loops. I thought to myself, in this brief moment on the bottom of the world, that I was actually right-side up with the people back home.

We hadn't planned for the sky to be our Australian travel theme, but we ended up handing over the credit card several times to get ourselves into the air. Australia offered an unusual assortment of aerial adventures, and each one proved to be both scenic and thrilling.

In Sydney, I found myself standing 134 metres above the gentle currents of Sydney Harbour, tethered to the arch of the iconic 75-year-old Harbour Bridge. Directly below my feet, six lanes of rushing traffic crossed between downtown and the North Shore.

I've always wondered what kind of wacko takes the job of changing light bulbs atop such structures, yet there I stood, wondering if I wasn't equally wacked as two massive Australian flags billowed above me.

Who but the Aussies would come up with a scheme allowing average people to plunk down upward of $150 to scale one of their national treasures? I was surprised to learn that a 98-year-old grandmother had done it. So have Prince Harry, Sarah Ferguson, Nicole Kidman, and Matt Damon. If Granny can do it, royalty find it worthy of their time, and the Hollywood set has climbed it without stunt doubles, I could too.

Bernie Wheatley, our climb leader, said people chicken out all the time. "It's usually in the early part of the climb," he said, when they psych themselves out before they even get going.

The climb started with training inside the bridge's concrete base, on solid ground. We signed the obligatory legal waiver; suited up in protective grey coveralls, cinched into a safety belt/tether system, and practised a series of exercises using a replica of the safety system installed on the bridge itself. (Participants remain attached to the bridge throughout the climb.)

After ascending a bunch of stairs and ladders, we popped out on the upper side of the bridge's arch beam at the bridge's north end. The view was already stunning: the Sydney Opera House below, a cruise ship sailing under our feet, and the Pacific Ocean in the distance.

"Just us and the birds, eh?" I said to Bernie.

"Nah, mate," he said laughing. "Too much wind, and they don't like the noise and vibration from the traffic. Mostly just us people up here."

As we climbed to the summit halfway across the bridge (you come back down the same end, but on the opposite beam), my fear of heights vanished, and I relished the scenery and the 3.5-hour experience. But I won't be applying for the job of light-changer for the Lions Gate Bridge.

The Great Barrier Reef was not something I expected to see from above; after all, it's supposed to be an underwater experience. But it's huge, with inner and outer reefs and loads of islands. So to get a sense of its scope, we plunked down the credit card at Cairns Seaplanes and took to the sky.

We were informed that we'd be sharing the trip with "two Japanese honeymooning couples". We arrived to discover the couples were far past typical marrying age. None of us could communicate well enough to establish if they had just tied the knot, but they laughed when Kevin called himself a gaijin (meaning foreigner), and became our new best friends.

Like Patrick, Captain Alan was a hottie. I was delighted to be his copilot in the DHC–2 Beaver seaplane. ("Just don't touch anything!" he said.) Alan flew us from Cairns Harbour over open ocean, eventually crossing over the inner reef at an elevation of about 90 metres–where suddenly the view changed from deep ocean blue to a million shades of turquoise, with coral formations easily visible.

Alan circled a spit of sand and landed the plane, gliding the pontoons perfectly onto talc-soft sand. "Welcome to the middle of the Great Barrier Reef," he said as he handed us snorkels and fins. "The fish are right out there." The legendary underwater paradise amazed us, but we were almost as impressed when Alan served us fruit and champagne back on the sand.

Flying back to Cairns, I watched the reef glide below, pleased that our Australian trip had taken on an airborne theme. Biplane loops, bridges, and seaplanes were all great ways to get over Down Under. I'm ready for more loops”¦

ACCESS: Tiger Moth World Adventure Park offers flights in its biplanes, with acrobatics ranging from mild to extreme. A ride with loops costs about AU$200. See www.tigermothworld.com/. Rates for BridgeClimb Sydney range from $160 to $295, depending on when you want to climb; see www.bridgeclimb.com/. Cairns Seaplanes runs a variety of scenic flights over the Great Barrier Reef. The Secluded Sandy Cay tour costs $361; information at www.cairnsseaplanes.com/. The writer was a guest of BridgeClimb Sydney, and received discounted rates on the other adventures.