A court has sentenced the former Korean Air executive in the "nut rage" case to a year in prison after finding her guilty of violating aviation law.
The court said Cho Hyun-ah was guilty of forcing a flight to change its route, the most serious of the charges she faced.
Cho, the daughter of Korean Air's chairman, achieved worldwide notoriety after she ordered the chief flight attendant off a December 5 flight, forcing it to return to the gate at John F Kennedy Airport in New York.
She was angered that she had been offered macadamia nuts in a bag instead of on a dish.
The court also found her guilty of obstructing the flight's captain in the performance of his duties and forcing a crew member off a plane.
Prosecutors had called for three years in prison.
The court in Seoul found Cho not guilty of interfering with a transport ministry investigation into the incident.
Her behaviour caused uproar in South Korea, where the economy is dominated by family-run conglomerates that often act above the law.
A heated and physical confrontation with members of the crew in first class developed as the incident unfolded.
Cho, in custody since December 30, wiped away tears with a tissue as a letter expressing her remorse was read to the court by head judge Oh Seong-woo.
It included details about how Cho, one of the richest women in South Korea who regularly flew first class, was adjusting to the basic conditions in prison and reflecting on her life. “I know my faults and I’m very sorry,” the letter said.
Business chiefs convicted of white collar crimes have typically received suspended prison sentences and later on, presidential pardons. Courts have often acknowledged the contribution of such industrialists in transforming South Korea from an economic backwater into a developed economy.
But the Cho case indicates that South Korean society is less indulgent of second and third generation members of high-profile business families. Heirs to fantastic fortunes such as Cho quickly ascend the executive ladder but few believe their rise is based on merit.
In her letter to the court, Cho said she was given only toilet paper, soap and underwear after being detained but was humbled that other prisoners had given her their toiletries.
“People there lent me their toner, lotion, shampoo and rinse. I was so thankful,” the letter said. “They didn’t ask me anything about this case. I felt that this was indeed being considerate for others.”
The judge said the court took into consideration that Cho’s actions undermined the flight’s safety, that the flight attendants who were verbally and physically abused are still struggling to return to work and worldwide media reports about the case damaged South Korea’s reputation.
But the court also recognised that Cho showed remorse and the airline was making efforts to help the affected flight attendants.
The court sentenced Yeo Woon-jin, a Korean Air executive who pressured employees to lie about the case, to eight months in prison.
Transport ministry official Kim Woon-sub was found guilty of leaking the ministry’s investigation to the airline. He received a six-month sentence suspended for a year.