Atlanta ? Wendy Greene can’t remember her first flight across the Pacific Ocean, but this trip she will never forget.

The Atlanta woman was among 21 war orphans who left Sunday for Vietnam to commemorate the 30th anniversary of “Operation Babylift,” in which 3,000 Vietnamese children were airlifted to the United States at the end of the Vietnam War.

Greene, 30, said at the airport that she didn’t get much sleep the night before her journey – she kept imagining the moment of her arrival in Ho Chi Minh City, formerly called Saigon. But she couldn’t complete the picture in her mind.

“My head is spinning right now,” said Greene, who was lifted out of Vietnam when she was 5 weeks old and grew up in Charlotte, N.C. “We’re going to embark on this crazy experience. This is an incredible, amazing, happy and sad feeling I have.”

Atlanta-based World Airways arranged to fly the adoptees to Vietnam on an aircraft specially painted with the red and white design and logo the company used in the 1970s. Pilots Ken Healy and Bill Keating, who flew the original Operation Babylift out of Saigon on April 2, 1975, and other former crew members joined them on the flight.

Vietnam war orphans Tiana Mykkeltvedt, left, Tanya Bakal, center, and Wendy Greene board a plane at Mercury Air Service in Atlanta. The three will join other Vietnam war orphans for the commemorative return flight to Vietnam for adoptees of the 1975 Operation

“After two years of planning, we are finally on our way for what will be the second journey of a lifetime for many of these individuals,” said Randy Martinez, chief executive of World Air Holding Inc.

As Saigon was falling in early April 1975, a World Airways flight took off under cover of night with 57 children – mostly babies, all orphaned or given up by their parents – on board. Thousands more children followed in the next few weeks.

Shirley Peck-Barnes, author of “The War Cradle,” which documents the legacy of Operation Babylift, called it the greatest humanitarian gesture of the last century.

Not all the children survived the trip. One C5-A cargo plane that was part of the lift crashed, killing almost half the 330 children and adults on board.

“I’m very fortunate to be going back,” said Greene, who is traveling with her adopted mother. “We almost didn’t get out.”

For Tiana Mykkeltvedt, the trip will mark her second return to Vietnam. In 1997, she visited for a study abroad program.

“I remember how emotional that was for me,” she said. “Now since I’ve gone and been there, I would definitely like to be there and share this experience with everyone else.”