Joe Rickey Hundley, 60, of Idaho, entered a not guilty plea in federal court in Atlanta Wednesday.
Hundley is accused of assaulting 19-month-old Johah Bennett on a Delta flight from Minneapolis to Atlanta on Feb. 8.
The child was sitting in the lap of his adopted mother, Jessica Bennett, when she told police Hundley told her to "shut that 'N-word' baby up."
"I was having trouble comforting him and that's when the guy had made his comment to me," said Bennett.
Marcia Shein, Hundley's attorney, said Hundley made the derogatory statements because he was stressed and grieving.
"He said something inappropriate to Mrs. Bennett he shouldn't have said even in his darkest hour," said Shein. "We hope for Mrs. Bennett's sake and our client's sake that everyone will forgive him for what he said and to heal."
Bennett said Jonah started crying when the plane started its final descent into Atlanta. She told police Hundley reeked of alcohol. He reportedly yelled another racial slur at her and then slapped Jonah in the face.
"I could not believe that he would say something like that to or about a baby, and then to hit him? I felt like I was in another world," said Bennett.
"She said what he said and he's admitting that, but that wasn't a crime, that was just an inappropriate statement in a very difficult time for him," said Shein.
CBS Atlanta asked Shein if Hundley slapped Johah. She responded by saying they entered a guilty plea in court and they are going to trial.
The incident cost Hundley his job as a top executive with Oklahoma-based AGC Aerospace and Defense.
Bennett and her husband want Hundley to pay for what he allegedly said and did to their son.
"We hope he is punished as much as he possibly can be," said Bennett.
Hundley's trial date is May 13.
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