Richard Nelson, 77, the radio operator aboard the Enola Gay, the B-29 Superfortress bomber that dropped the atomic bomb on Hiroshima, died here Feb. 1. He had emphysema.

He was the youngest of a dozen men aboard the Enola Gay, whose historic mission on Aug. 6, 1945, helped end the Pacific conflict with Japan during World War II.

The Enola Gay flew a six-hour, 2,000-mile trip from an American air base in the western Pacific Ocean. Flying at about 33,000 feet, it dropped its payload, a 101/2-foot, 9,700-pound bomb nicknamed "Little Boy."

After the bomb detonated about 1,900 feet above the port city, Mr. Nelson sent a coded message that was forwarded to President Harry S. Truman that read: "Results excellent."

The bomb from the Enola Gay destroyed about five square miles of Hiroshima and instantly killed about 68,000 people.

Three days after the bombing of Hiroshima, another Army Air Forces bomber dropped an atomic bomb on Nagasaki, persuading the Japanese to surrender.

Mr. Nelson said he had no regrets about participating in the historic flight.

"War is a terrible thing. It takes, and it destroys," he told the Riverside (Calif.) Press-Enterprise on the 50th anniversary of the bombing. "Anyone feels sorry for people who are killed. We are all human beings. But I don't feel sorry I participated in it. If I had known the results of the mission beforehand, I would have flown it anyway."

Mr. Nelson, who was born in Moscow, Idaho, moved to Los Angeles with his family as a young boy. He attended the University of Idaho before joining the Army Air Forces in August 1943.

His plans to become a pilot ended at the Santa Ana Army Air Base because of poor eyesight. Transferred to radio school in Iowa, he graduated near the top of his class.

He was assigned to the 509th Composite Group, a secret, hand-picked group. The crew was taken to Tinian, a small island in the Marianas chain, where it practiced missions over Japan.

Mr. Nelson later recalled that he heard no noise when the bomb was detonated over Hiroshima, but he felt twin jolts from shock waves. The flash from the bomb, he said, was visible from six miles high.

Navigator Theodore "Dutch" Van Kirk, pilot Paul W. Tibbets and weaponeer Morris Jeppson are the only surviving Enola Gay crew members.

After his discharge, Mr. Nelson majored in business administration at the University of Southern California and became a salesman in Arizona for the Imperial Brass Co.

He later worked in industrial sales until retiring in 1986. He and his wife, who had lived in Palos Verdes Estates, bought a 20-acre orange grove in Riverside in 1976.