BANGKOK — Ly Tong, a South Vietnamese Air Force veteran who dropped anti-Communist leaflets over Vietnam from hijacked planes long after the war’s end, playing out the fantasies of many defeated soldiers of the south, died on Saturday in San Diego. He was 74.

The cause was lung disease, his family said.

A man who never accepted defeat, Mr. Tong considered it his personal mission to take back his country from the Communists, who have ruled it since winning the Vietnam War in 1975.

“I have the duty to liberate my country!” he said in an interview more than 30 years later. “You cannot enjoy yourself when your whole country is in pain, in torture.”

Mr. Tong became a hero to many Vietnamese refugees in 1992, when he hijacked a commercial airliner after takeoff from Bangkok, ordered the pilot to fly low over Ho Chi Minh City — known as Saigon, South Vietnam’s capital, before the Communist victory — and dumped thousands of leaflets calling for a popular uprising.