Yes, Harrison Ford is tired of hearing the term "after all these years ..."

"I am," the 65-year-old superstar says in a conference room at the Santa Monica Airport, where the ardent pilot keeps his assortment of personal aircraft. "It's as good a way to start as any, though."

We're talking, of course, about "Indiana Jones and the Kingdom of the Crystal Skull." The long-awaited fourth entry in the blockbuster action-adventure series comes 19 years after the third installment, "Indiana Jones and the Last Crusade."

While the other films came in an eight-year span, "Crystal Skull" acknowledges that nearly two decades have passed since Indy's prewar, Nazi-fighting days. This meant making his main antagonist a ruthless Soviet operative, Irina Spalko, played by Cate Blanchett.

Then there's also the subject of Indy's - and Ford's - age. As the years passed, the prospect of the sexagenarian actor running through jungles cracking a whip grew increasingly absurd. But Ford, who looks incredibly trim and muscular months after the shoot ended, says getting in shape for the role was no problem.

"I believe in training for injury prevention more than anything else," he explains. "I'm an old fart and I need to protect myself, so I trained quite a bit. I had an exercise trailer rigged for me, and I worked out every single day before going to work. And I was lucky enough not to become injured at all.

"I think I'm probably in as good shape now as I was for the last one - but don't forget, I was old then!"

The reason for the gap between films was that the franchise's three principal talents - Ford, creator-producer George Lucas and director Steven Spielberg - refused to take up the fedora and bullwhip again until they all agreed they had the right script. After many drafts from a slew of writers, a screenplay by David Koepp ("Spider-Man," "Jurassic Park") "got close enough for everybody to get really enthusiastic about it," Ford says.

"I was looking for a great movie for the audience, that had the same characteristics (as `Last Crusade,' `Temple of Doom' and the film that started it all, 1981's `Raiders of the Lost Ark') while bringing something new to the table," Ford explains.

Set in the 1950s, "Crystal Skull" brings back Marion Ravenwood (Karen Allen), Indy's love interest from the first film, and introduces a new character, Shia LaBeouf's Mutt Williams, who may or may not be more than just the grizzled archaeologist's young sidekick. Ford isn't saying, or giving away much else in the way of specific plot details.

Ford had already earned a good degree of notoriety as Han Solo in Lucas' "Star Wars" before Indy shot his career into the stratosphere.

"The `Star Wars' films didn't have nearly the impact on my career that these do," he acknowledges. "Those were ensembles, these are not, and they've been enormously important for the longevity of my career. I've been living off them ever since."

Ford has actually been in a number of hits or landmark films since "Raiders": "Blade Runner," "Witness," "Presumed Innocent," "Patriot Games," "The Fugitive," "Clear and Present Danger" and "Air Force One" among them. But he hasn't had a successful movie since "What Lies Beneath" in 2000, which gives the heavily anticipated "Crystal Skull" the air of a career-resuscitator.

"It doesn't hurt," he admits. "Whenever you have a film that breaks out, it's good for your career. But it's probably good form not to talk about the success of a film before it happens, so I'm not counting my chickens."

Ford does have some thoughts as to why "Crystal Skull" is so eagerly awaited, though.

"The films in the past have been hugely entertaining, and I think people are looking forward to an entertaining film," he reckons. "I've said before and I'll say it again, these movies are more about movies than they are about anything else. They're about the pure joy that can be had in a dark theater with a bunch of other people. They're big round meals."

Enough so that people would want to come back for fifths? Or that Harrison Ford would again?

"I don't know at this point; I really don't," he says. "But I suppose I'd be a fool not to be interested."