IN AN ERA when the motto for success in the entertainment world would seem to be, "It's excellent to be eerie, great to be grotesque," pratfall pastmaster Dick Van Dyke is a refreshing maverick.

Perhaps the most extraordinary thing about the lean, onetime airman in the U.S. Air Force is that he has risen to the crest of his profession without appearing particularly extraordinary.

During the filming of "Chitty Chitty Bang Bang" at Rothenburg ob der Tauber, he had no coterie of pamperers trailing in his wake; his dress was no more gaudy than that of other cast members, and he was relaxed, calm and smiling, a behavior generally regarded as alien to full-fledged stars of the mercurial entertainment world.

Among other maverickish qualities: The lean 41-year-old did his own pratfalls on the five years of TV's prizewinning "The Dick Van Dyke Show"; he is still married to his former high school sweetheart and they have four children; he is active in youth work, and he could easily pass for a happy milkman or a genial insurance salesman.

The Missouri-born son of a public relations rnan, whose career began when an impressive performance in an Air Force show earned him a successful audition as a radio announcer, possesses not only a ready smile, but also an equally ready penchant for involvement in such controversial realms as politics and religion.

After his discharge from the service, Van Dyke went into the advertising agency business, but insolvency turned him toward the entertainment world where he formed a pantomime duo with Paul Erickson in 1947.

Six years later, Van Dyke auditioned for CBS-TV, was placed under contract, and before long spread his talents into other media — stage and film, with his performance in the stage musical, "Bye Bye Birdie" serving as a major springboard onto film.

His film credits: "Bye Bye Birdie," "The Art of Love," "What a Way to Go," "A Garden of Cucumbers," '-Lt. Robinson Crusoe, U.S.N.," "Mary Poppins," "Divorce American Style" and "Never a Dull Moment."

ALTHOUGH VAN Dyke has abandoned his TV show, his brother Jerry now has one of his own, so the Van Dyke family continues to be represented in American living rooms.

Have they ever worked together, Dick and Jerry? "Yes," said Dick; "In fact, Jerry had a couple of spot parts on my TV show. He played, of all things, my brother!"

When he recently confirmed that he had been asked to play the role of late President John F. Kennedy in the film version of Pierre Salinger's book, "With Kennedy," Van Dyke said he had actively campaigned in Democrat Salinger's losing 1964 fight for senator against George Murphy, another ex-screen hoofer.

Although involving himself in politics, Van Dyke laughed when asked if he foresaw a day when he might run for office. "When Shirley Temple said she'd run, that tied it. Any more of us try and it'll just be a big joke."

His youth work is connected to the non-sectarian (he's a Presbyterian) Young Life group, which meets regularly at his Spanish-style home in Encino, Calif. It has been a participation that has given Van Dyke some insights into contemporary teen-agers.

"These kids today are more aware more alert, I think, than we were. They know so much more, and they're all searching for some values in life."

Have they rejected the values of their elders? "It would seem so, and I think they may be right, don't you? They often claim we say one thing but do another."

He smiled as he said it, but there was no mistaking the seriousness of his conviction.

When asked whether the church could play a significantly dynamic role in dealing with currently volatile social problems in the U.S., Van Dyke took an affirmative position — with one reservation.

He shook his head doubtfully when the racial issue was brought up: "The Negro today tends to regard the church as a white man's drug."

Moving aside as a movie prop was carried past, Van Dyke lowered his voice as a scene was being shot nearby showing "The Child Catcher" (played by Robert Helpmann) capturing Caractacus Potts' (Van Dyke) two children after tempting them with ice cream.

"Look at that man," Van Dyke said, pointing toward Helpmann. "A real genius. A fine actor, choreographer — did you know he choreographed 'The Red Shoes'? A fantastic man.."

Sticking to the entertainment world, Van Dyke said that he accepted the role of wacky inventor Caractacus Potts in "Chitty Chitty Bang Bang" (a name derived from, the noise made by the marvelous automobile around which Ian Fleming's children's fantasy was built) on the condition that he could stick to his native American accent (Potts is an Englishman).

Van Dyke winced when he thought back on his part of all-purpose chimney sweep Hubert in award-winning "Mary Poppins."

Although he had nothing but praise for Julie Andrews, who played the remarkable governess Mary Poppins, his bout with Hubert's Cockney accent was another matter.

"I had this Cockney fellow working with me, teaching me how to speak it properly," Van Dyke reminisced, "but when I got back to the studio in Hollywood. they gave one listen and said, `Look, our American audience will never understand what you're saying. You've got to modify it.' So I modified it. Then, when I came to England for this picture ("Chitty Bang"), people in London kept coming up to me and saying they saw me in Mary Poppins, and said that I must have been all over England because sometimes I sounded. North Country, sometimes Wales, sometimes somewhere else. So when this picture came up, I said fine, as long as I didn't have to sound English."

Someone remarked that Miss Andrews wasn't sexy in the classical sense, but that she had some quality that was exciting.

"It is true, isn't it, that most of the sex symbols today are imported. Now we seem to be looking for actresses who can act."

Van Dyke said that his current commitments carry through 1971, after which he may devote his considerable energies to personal projects.

Among other things, he would like to do a few things directed toward youngsters — perhaps dramatizations which are brisk and entertaining, but which have some special point or meaning.

"We're so afraid today of anything messagy," he said, a trifle sadly.

Van Dyke has a better chance than most to get messages across; he gets a lot of moral mileage out of an engaging smile.

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