I cannot say that ever, in my edge-of-the-envelope aviation fantasies, had I dreamt that I would be where I was now standing. In another time and place I would have been shot on sight. Yet here I was, one hand on a huge pair of aircraft tyres, intimately surrounded by the hydraulics and metal doors of a plane that, when first wheeled out of the plant was covered with muslin (although it is hard to think what it could be mistaken for), test flights were done at night, and all negatives of photos taken had to be developed at a secure location in Washington, D.C The ultimate Cold War icon, the impossibly long wings, the eight jet engines, the slab sides, the tall angular tail fin; here was a real life B-52 Stratofortress and here I was, almost a part of it.

The day had started off slowly and easily. My idea of high living is a top bunk in a hostel dormitory (one where you have to get up before you go to sleep), and I had woken with a feeling of contentment, almost luxurious ease. I didn't have a flight to catch today, or be on time for a train or ferry. I could sleep in until, oh, seven o'clock or so.

In fact, I got up early, had a shower and shave, hauled my backpack past St Pauls and over Ludgate Hill to a Starbucks, where I drank coffee and surfed the wireless Internet until eight-thirty, when I returned to my hostel for breakfast.

Last April it was a choice of full English or Continental breakfast, which effectively meant both, and you could cram enough food inside to set you up until dinnertime, but now the sausages, eggs and bacon had vanished and the rather more spartan breakfast was not quite the superb value it had been. Still, it was a nice bonus and a pleasant way to begin the day, checking out the other hostel guests.

Mostly young folk, though there were some in my middle-aged group, and amongst the range of accents I could distinguish more than a few fellow Australians. Around me I could hear people planning their days, puzzling over maps with the aid of mugs of tea and jammy toast, exchanging tips and traps with temporary companions. That had been me last April, when I had walked around the British Monopoly board from Old Kent Road to Mayfair, but today all my planning had been done ahead of time on the other side of the world.

After breakfast I emerged into the bustle of the City getting down to work. The last few late commuters were hurrying to their offices, courier vans were doing a roaring trade, and everyone had a sense of purpose.

Including me, I suppose. But I wasn't committed to any set time. I breezed along the city streets, past St Pauls, past Mansion House, humming happily to myself. It was so good to be back in London on a bright spring morning.

To tell the truth, I would probably have preferred to just bum around London, spending the day with nothing to do but look in here and there. However, on this trip, I was committed to sites devoted to the American WW2 effort and I had found a good one in the UK.

Liverpool Street Station was my jumping off point for the train trip to Cambridge, and although I'd visited here last time on my Monopoly trip, I hadn't actually caught a train - just made my way up from the Tube, took a look around, left a book, and made my way back into the bowels of the Underground.

The place looked exactly the same this time around, with the big difference that my book had vanished some time in the intervening year. I worked out how to buy a ticket - for some reason I couldn't buy one from the ticket machines using my Australian bank cards and had to line up at a ticket window - found my platform and climbed aboard.

Seventeen pounds sixty for a return ticket. That's the same price as thetrainline.com's cheapest, so there's probably not that much advantage to booking early on the web except that you are guaranteed a seat.

As it turned out, my train wasn't anywhere near crowded, and I could relax and stare out of the window as we headed first east and then steadily north. This was really my first time out of London, unless you count trips to and from Gatwick. I caught glimpses of canals (and canalboats - one day I'd like to take a canalboat holiday), English villages and even wildlife amongst the rolling fields and small copses. All very pleasant, and occasionally a gentleman wandered along the corridor with a trolley full of snacks, which he advertised in a practised sing-song.

Cambridge Station, and I deboarded, wandered outside, and looked for my bus. Turns out that the C7 service is one name for the same route in two directions, and you have to take the one south to RAF Duxford. The bus runs every twenty minutes, so I guess I had just missed the previous one.

A very pleasant trip, passing through thatched villages and modern housing estates. Light industry, a huge hospital and towards the end, open countryside. A bit of a snapshot of modern Britain, I guess. No romantic old university buildings. Perhaps they were on the bus route not taken...

RAF Duxford turned out to be a collection of huge hangars, some of them pre-war. Show your bus ticket for reduced admission. Great green airstrip with aircraft operating. To my astonishment I recognised a deHavilland Dragon Rapide, an ancient airliner from the 1930s, doing circuits. Apparently you can buy joyrides on this elderly aircraft.

Another day, perhaps. I was on a mission.

My interest in coming here was the fact that RAF Duxford used to be a USAAF base during the war, and the Imperial War Museum keeps its aircraft collection here, including a display of American warbirds.

As a youngster climbing the promotion ladder of the Queensland University Regiment, we noncommissioned officer undergraduate types were occasionally shown a film to inspire us to leadership. Usually a warry movie with a discussion afterwards, the favorites were Zulu, showing a determined Michael Caine leading his redcoats to a desperate victory over endless hordes of natives, or Twelve O'Clock High where Gregory Peck whips a despondent bomber squadron into shape.

I preferred the bomber squadron, being an aviation nut, and it was grand to see formations of Boeing B-17s flying over Germany, knocking the spots off the Nazis. Gregory Peck drove his men hard, hard as nails on the outside, but behind that stern front he was tearing up. I especially liked the beginning and end of the movie, where the non-flying intelligence officer returns to England years after the war and visits the old airfield, poking amongst the decaying buildings and recalling the glory days. The movie is effectively one long flashback.

South East England is littered with old USAAF airfields. Most of them were grass fields with a square brick control tower, a couple of hangars and a town of tents. And a nearby village that effectively became the personal property of the young airmen. RAf Duxford was one of the larger bases, with some impressive prewar hangars, and it didn't take much to recall the old days when high performance piston and rotary engines ripped the sky apart. Even today, a lone Mustang at an air show has the power to thrill me, and in those war years there must have been dozens of them here, along with mighty formations of Fortresses and Liberators.

I let my imagination roam and soar, and with the Dragon Rapide and the elderly hangars and office buildings, it's not all that hard to go a certain distance into the past.

The hangars are lined up one after the other, and the tourist wanders freely through all, including those where restoration is taking place, and the air twitches the nose with tangs of solvents and paints. Like a giant plastic model, whole aircraft lie scattered into components, and one can imagine a giant hand coming down from the roof and inserting tailfin A into fuselage assembly B, perhaps with a squirt of glue from one of the metal drums piled in the corner.

There are every variety of aircraft imaginable here. Civil and military, jets and propellers, bombers and fighters, Axis and Allies. Some are posed in tableaux, complete with uniformed mannequins swinging props or scrambling into the cockpit. It's a little boy's Airfix collection come to life, and for the second time in my life, I see a Hawker Hurricane, one of the rarest of the old warbirds, because most of them got turned into Hurricats and were catapulted off merchant ships in the Battle of the Atlantic. I used to have a whole squadron of them in 1:72 scale.

But for sheer elegance, a perfect harmony of design, the Spitfire is peerless. It is a sonnet of an aircraft, rounded and sleek. Pure sizzling sex in every line. I love it, and there are Spits aplenty here. The later marks, with their sawn off wingtips, bubble canopies and gigantic props, may have had higher performance, but it is the early marks, the ones that triumphed in the Battle of Britain, that make my heart sing.

I wander, and I linger, and I buy a sandwich from one of the canteens, but the big modern building at the western end of the ramp is my objective today.

This is the American hangar. It's an odd circular domed shape, and it's sunk into the ground at one end, and to the south is a huge glass wall, letting in the daylight. Inside is a fabulous collection of all the greats of American military aviation.

The B-52 I've mentioned, and it was fabulous to see it in the metal. Even the Smithsonian doesn't have one of these on public display. Other big birds include a B-17 Flying Fortress, a B-29 Superfortress, a Liberator, and a SR-71, which still looks like something out of science fiction, even though it's an aircraft of the Sixties. Smaller aircraft in plenty, including a Mustang and a Huey. and a whole bunch of other fabulous planes.

What got me was that they weren't roped off. You could go up close, run your hands along their bellies, inspect details. There was even a set of steps up to the round glass nose of the Superfort, and you could peer into the cockpit. It was stunning, and I was in plane-nut heaven for the hour or so I spent wandering around.

Off the main gallery was a little annex devoted to the men who flew these warbirds. Leather jackets, logbooks, gloves, all the little bits and pieces of uniforms, lucky charms and so on. You could almost imagine the young men who had first owned this kit when it was brand new from the stores, and gradually wore it in, stitched on badges and patches, took it up into the sky a hundred times, and brought it all back to rest here for our curious latter-day eyes.

And at each end of the room was a wall of names, alphabetically ordered. These were the men who didn't come back, and they number into the thousands. I left a book about the air war under one of these sad lists.

Such a waste. These young Americans should have been at home, going to college, starting families, sitting down to Thanksgiving dinners, and instead they came to England, where they devoted their lives to killing other young men. Sure, it was all part of a crusade to save the world, and I don't downgrade their sacrifice at all, but I do regret it.

From this distance, it all seems so pointless. Germany and Japan are friendly nations now. If only they had been so then, without the necessity of bombing them flat.

I wandered regretfully back out into the daylight, past a row of faded British airliners. A de havilland Comet and a Vickers VC10, once at the cutting edge of jet airliner technology, now just hulks, beaten by time and distance and weather into shabby greyness.

There's Concorde inside another big new display hanger at the eastern end of the field, but that isn't open yet. I'll save that for another trip.

I browsed briefly through the bookshop, found my bus stop and took the morning's trip in reverse, all the way back to London, where I met another Canberran at Marble Arch for a beer or two in a corner pub.

He'd been down to Portsmouth and seen Nelson's Victory, and we swapped travel stories before parting, me back on the tube to St Pauls, where I packed my bags and snored my way into the hearts of my room-mates.