IAN COLLINS It’s goggles on and chocks away for the latest movie blockbuster starring Leonardo DiCaprio – a biopic about pioneering jet-setter Howard Hughes. Ian Collins booked a seat on its promotional flight.

IAN COLLINS

Ha! I bet there are a few of you out there who are starting 2005 still convinced that Leonardo DiCaprio is your favourite painter. Allow me to enlighten you. This Leonardo is DiActor.

Actually, you should be very ashamed of yourselves because he is Leonardo DiGreatBigMovieStar.

So big, in fact, that when hacking his way through the Amazon rain-forest recently, as GreatBigMovieStars and GreatBigPopStars tend to do, he was greeted by loincloth-clad natives with the word: “Titanic!”

Now if a stranger shouted that at me, I'd think it was an alternative to “Cholera!” or “Imminent Catastrophe!” or “Janet Street-Porter!”. I would scarper rather quickly. But our movie hero was dead chuffed.

Now I'm about to meet him, and I haven't even had to leave the concrete jungle. I'm off to a suite at the Dorchester. Yippee!

Of course, I've prepared very carefully for my supporting role in Hollywood's latest film promotion.

First, I've had to impose a draconian memory black-out on my last encounter with a movie star after “lunch” in the glam hotel on Park Lane. A plate of cold chips and a chillingly long delay may have left me immune to the charms of Viggo Mortensen.

Second, I have phoned a friend to find out whether Leonardo passes muster as a heart-throb. “No comment,” says Vanessa. “Which might tell you quite a lot. I'll ask around.”

After consulting some girlie chums she calls back. “No reaction at all, I'm afraid. We can talk forever about Brad Pitt, and Johnny Depp and Jude Law and Ewan McGregor and VIGGO MORTENSEN” – whoops, she seems to recall my last starry interview for this magazine rather too well – “but Leonardo has made no impression at all. I just think he looks odd.”

Thank you Vanessa.

My own view had been that he was the unthinking woman's Norman Lamont. A vision of chubbiness had been confirmed when I read an interview with the costume designer for his latest screen outing. She had squeezed him into a corset. (In which, I suspect, he'd look even less sexy than Madonna.)

Then it all came back to me. A decade or so ago he was really rather wonderful in the Baz Lurhmann film William Shakespeare's Romeo and Juliet – part Bard's saga, part West Coast Story. He looked about 12 then. He looks 11 now.

But what do we all think about Titanic, that 1998 epic, seven years on? Hasn't the film, which seemed to last longer than the ship, finally sunk without leaving a ripple or a bubble?

I'm only left wondering why, amid that marine shooting marathon, nobody found the time to drown Celine Dion.

My next piece of research has taken me to a screening theatre in Soho where, on a rainy afternoon, I seem to be seated among a convention of train-spotters. It appears that fellow film reviewers favour that nerdish Quentin Tarantino look. Anoraks with attitude. Oh for a life in the movies…

So I get to see Leo and Marty's new movie. (That's Mr DiCaprio and Mr Martin Scorsese to you – after all, you haven't even met them and I, along with a few hundred other media hacks, am their new best friend.)

The Aviator – in case all the hype has so far flown over you – tells the tale of Howard Hughes, the late American mogul best known to me for having a phobia about door handles. He hated handling them because of all the germs they might harbour.

He wiped everything (and everyone) down with Kleenex then wore the empty boxes on his feet in place of slippers during a long confinement in a Los Vegas hotel room. When the management tried to evict him – he was by now unkempt, unwashed, ulcerated and possessed of longer fingernails than Fu Man Chu – he simply bought the hotel. Money can be so liberating.

Hughes finally left his self-imposed prison to die on one of his private jets, which was pretty poetic because in his youthful heyday he had been a record-breaking pilot, a pioneer of aerial photographer in action-packed, budget-busting films, an owner of airlines and a man whose every whim took wing.

Happily, the film deals with the early glory of the Hughes story rather than the gory ending.

It opens with the shooting of Hell's Angels – the first world war flying aces epic with which an almost adolescent Howard Hughes, drill bits company mogul turned film director, became (in)famous.

Some of the dramatic images are amazing, as you might expect from a Scorsese movie – and a man whose chief masterpiece, Raging Bull, is regularly named among the Top Ten Movies Of All Time. (Personally I prefer New York, New York).

But they are all the more astonishing because Marty has a much-aired fear of flying. The later scenes in which the daredevil Hughes finally crashes a test plane into Beverley Hills, and crawls from the wreckage with appalling injuries, must have cost the film-maker dear. It left me feeling fairly wobbly, too.

Along the way there is a focus on two of the many stars and starlets with whom Hughes sought to have affairs. The better impersonation – and the best thing in the movie – is Cate Blanchett as Katharine Hepburn.

Cate doesn't look remotely like Kate – no other human being does either – but as soon as we hear that celebrated drawl, at a Hollywood golf match which our wise-cracking heroine naturally wins, we anoraks all burst out laughing in fond recognition. This role has the 2005 Oscar for Best Supporting Actress written all over it.

If any dame came close to the splendour of Katharine Hepburn then I suspect it was Ava Gardner, who combined classic beauty with a most unorthodox and highly appealing character. But Kate Beckinsale just can't inhabit such a gorgeous mind and skin.

Lots of famous faces appear in often-unrecognisable cameos – including Jude Law as Errol Flynn (though I'm sure Vanessa and her chums would have spotted him), Alec Baldwin as a ruthless airline executive, singer Gwen Stefani as Jean Harlow and Alan Alda as a corrupt senator.

So there are lots of good bits and several great clips. But unless you're fascinated by the corporate battle between TWA and Pan Am over trans-Atlantic flying routes, and the resulting Senate hearings, this 170-minute movie – made in and for America – is about 70 minutes too long.

I would also like to have cut the 70 minutes we had to wait for Leo and Marty to show up for the Dorchester interview they have granted to me and a mere 70 others. Having arrived in a downpour everyone sits there steaming. I sit there fuming.

Finally the double act appears with a flourish and what an arresting image they make. Can't wait to tell Vanessa that the leading man is far more handsome in the flesh than he has ever been on screen – there's not a hint of Norman Lamont jowls, and I'm sure he's had to hand back that corset. He looks at least 16.

Martin Scorsese looks like a film director being impersonated by Robert De Niro, if Mr De Niro ever a stickler for authenticity – had severed himself at the knees.

They are clearly great mates – although the hot news that their latest collaboration has landed a squadron of Golden Globe nominations must have bolstered their friendship no end.

Marty appears to think he is still in his native New York, for he tells us that he admired some of the more cheesy Howard Hughes movies when he was a kid growing up in the Garment district. Just back from the Big Apple myself, I can afford a smug smile – otherwise I would have thought that he spent his childhood in the closet.

But Marty pays public tribute to Leo who, it appears, having been obsessed with Howard Hughes for a decade, passed his enthusiasm to writer John Logan and Marty himself.

Result: a curate's egg of a movie rather than a flying success.

Leonardo, however, is wholly winning. He says how he'd known about the “wolfman-like” figure of the late reclusive years, but was amazed by all his early achievements.

And then he became obsessed with an obsessive character driven in everything he did, “whether it was designing a bra for Jane Russell… sleeping with as many women as he could… or breaking speed records”.

But while Leo wonders why all those women fell for Howard Hughes I am reminded of that late great creation of Mrs Merton, who once interviewed Debbie Magee on telly with the classic opening line:

“What first attracted you to the millionaire Paul Daniels?” t

t The Aviator (certificate 12A) is on national release from January 6.