Julie Andrews, who is a board member of the American private aid group Operation California, will spend a week visiting orphanages, schools and hospitals in Vietnam and Cambodia, according to a spokesman for the group, Richard Walden.

The actress left Bangkok yesterday for Ho Chi Minh City, formerly known as Saigon, and will spend four days in Vietnam and three in Cambodia before returning to Thailand.

Walden said, "It's a private, low-key trip" during which Andrews hopes to meet many of Vietnam's "Amerasians," the children of American servicemen. Andrews adopted two Vietnamese orphans in 1975.

"This is something I've always wanted to do," said Ross Perot Jr., 23, before departing from Dallas this week in a $1 million modified Bell helicopter in an attempt to be the first person to circle the globe by helicopter.

Perot, the son of entrepreneur H. Ross Perot, is competing with Dick Smith, an Australian storeowner who left Fort Worth three weeks ago on a year-long around-the-world helicopter tour. Smith has already crossed the Atlantic and was greeted in Britain by Prince Charles, but Perot says he will overtake him in a week and complete the whole trip in 30 days.

Perot and Jay Coburn, 35, a pilot from his father's computer firm, the Dallas-based Electronic Data Systems, plan to stop in 26 nations during the 26,000-mile journey. The most difficult part of the journey may be completing the 1,600-mile stretch from Japan to the Aleutian Islands without landing. Associates of the elder Perot are speculating that he may supply a ship to help his son refuel the helicopter.

The elder Perot, 52, himself no stranger to helicopters, instigated a 1979 mob assault on an Iranian prison that led to the escape of 11,000 prisoners, along with two of his employes who had been jailed without charges. Perot also organized an unsuccessful 1970 attempt to get supplies to American POWs in Vietnam.

When asked about his reason for the trip, the younger Perot said, "Since America has always been the leader in aviation, I thought it was a shame for someone who is not a citizen of the United States to set the world record." He added, "But the hardest part was convincing my father to let me."

Conductor Lorin Maazel, the first American director of Vienna's prestigious Opera House, began his four-year job today with an appeal to all opera house employes to help maintain and improve the quality of the opera, which has been criticized in recent years for declining artistic standards.

He told the technical staff: "I am here with you now, ready to work for this house, and I'll be always here with you, and together we want to keep up and improve the standard of the opera."

Maazel, who succeeds retiring opera director Egon Seefehlne, is the first active conductor to become opera director since Herbert von Karajan left the opera in 1964. He has said that he will conduct at least 30 performances during the opera season.

Fire swept through the 500-year-old country home of Rolling Stones guitarist Keith Richard for the second time yesterday. The structure also burned down in 1973, almost nine years ago to the day.

Richard was in the United States but the caretaker, George Papageoreiou, was in the building when the fire was discovered.

Sixty-five firemen spent six hours bringing the fire under control. Three-quarters of the thatched roof was destroyed, as well as half the contents of the building. The guitarist had had the house rebuilt and rethatched after the previous blaze.

Richard bought the home, Redland, a five-bedroom house in West Wittering, Sussex, in 1966.

No one was injured by the blaze and there were no signs of arson, according to a fire brigade spokesman.

Rock and roll singer-musician Ted Nugent was slightly injured yesterday when the front axle snapped on his four-wheel drive vehicle in Jackson, Mich.

Jackson County sheriff's deputies said Nugent, 33, was driving on a county road about 10 miles from Jackson shortly after 5 p.m. when the axle on his automobile broke.

Nugent lost control of the Ford Bronco and ran into a tree, police said.

He was reported to be in good condition at a local hospital. The extent of his injuries were not known, but were believed to be minor. Police said he was alone in the car.

Nugent, a guitarist known as the Motor City Madman, is popular for songs such as "Cat Scratch Fever" and "Great White Buffalo" and is also known for his stage presence. He has started concerts by swinging onto stage dressed in a loincloth.

Helene Tunney, 50, was exhausted but happy in a Laflin, Pa., nursing home yesterday after her "dream-come-true" meeting Wednesday night with country and western singer Willie Nelson.

Tunney, an emphysema victim, traveled 525 miles by ambulance to hear Nelson perform at the New York State Fair in Syracuse. Attending the concert as Nelson's personal guest, Tunney was accompanied by three physicians who administered oxygen throughout the concert.

"I've only had two hours sleep, but I'm so bubbly I can't sleep," said Tunney, who watched from a hospital bed in the wings of the stage as Nelson dedicated the concert to her. "It was out of this world," she said. "He made me feel like I was the only one in the whole stadium."

Tunney, a Scranton native and divorced mother of six, has suffered from emphysema for 13 years. She is waiting for a donor so she can receive a lung transplant.

Former first lady Bess Truman was hospitalized last night at Research Medical Center in Kansas City, Mo., for the second time in five weeks, officials said.

Truman, 97, had spent several days in the Kansas City hospital in early August for treatment of hyperkalemia, a buildup of potassium caused by diminished kidney function.

Other than to say Truman was at the Medical Center, hospital officials would not release any details on the reason for her admittance or her condition.

Judges at the Miss America pageant like singers and contestants with green eyes, two reasons why George Miller predicts Elizabeth Williams -- Miss North Carolina -- will win this year's contest.

"She comes closest to the mold this year," Miller said yesterday after reciting a list of factors shared by most winners.

Miller, a business professor at Northern Illinois University, twice in the last three years picked the winners with the help of a computer. His choice last year placed fifth.

Williams is a 5 to 1 favorite, Miller said, with Miss Texas 7-1, Miss Colorado 12-1, Miss Maine 13-1 and Miss Washington 15-1.

The winner of this year's pageant will be selected Sept. 11.

The filming of a modern version of the 1932 gangster movie "Scarface," which was to be pulled out of Miami because of Cuban community opposition, will stay in the city following an agreement announced yesterday by city officials.

Miami Mayor Maurice Ferre said at a news conference that producer Martin Bregman has agreed to film the movie in Miami despite earlier threats to move it elsewhere.

The remake of the film classic is to be about a Cuban convict who comes to this country during the "Freedom Flotilla" boatlift from Cuba's Mariel harbor and moves up the underworld ladder to become a drug kingpin, a plot that some in Miami said would give the city and Cubans a bad image. The film is to star Al Pacino.

The finished film will be reviewed by a committee of six prominent Cubans. The panel will determine whether a disclaimer will be added to the film stating that the movie is based on a fictitious situation and does not represent the Cuban community in Miami, the mayor said.

But "Mr. Bregman said that after his film is seen, there will be no disclaimer needed," Ferre said.