Heather Cho, a former executive of Korean Air, appeared before prosecutors Wednesday to face questioning over charges that she may have violated aviation laws by causing a delay in a commercial flight.

The daughter of the country’s No. 1 air carrier’s chairman Cho Yang-ho appeared at the Seoul Seobu District Prosecutors’ Office as a defendant.

The summons came a week after prosecutors launched the investigation into the case when a civic group filed a complaint against her for violating aviation law and interrupting Korean Air’s commercial business.

The prosecutors will review the potential charges against her based on testimonies from witnesses, confiscating goods found during the raid on the airline’s headquarters and investigation results produced by the Ministry of Land, Infrastructure and Transport, which launched a separate probe into the case. 

The questioning will focus on whether Cho physically abused the cabin crew onboard, according to sources.

The chief steward Park Chang-jin who was forced by Cho to get off the flight on Dec. 5, and the junior flight attendant who had served nuts to Cho without regard to the service manual earlier said that Cho had pushed the attendant’s shoulder and poked Park’s hand with folder. Park also said that Cho made them kneel down in front of her.

Cho, however, denies the allegations. Under local aviation security laws, use of violence on a plane can lead to a prison sentence of up to five years. 

The prosecutors will also look into possible aviation law infringement and business obstruction for forcing the pilot to turn the plane back.

Cho so far claims that she did not demand the return of the flight, and that the pilot had volunteered. Witnesses, however, have stepped forward to say Cho had yelled at the crew to stop the plane.

On Tuesday, the Land Ministry announced that Korean Air could either be banned from operating its Incheon-New York route for 21 days, or face fines of 1.44 billion won ($1.32 million).

The so-called nut rage has stirred up a huge controversy here after media reports showed she allegedly ordered a flight to return to the boarding gate in New York on Dec. 5 to deplane a senior member of the cabin crew for failing to properly train a flight attendant who served nuts in a bag instead of on a plate, and also for serving without asking if Cho wanted them.

Cho, who joined the airline in 1999, was removed from all posts at the company’s affiliates following her resignation as vice president at the carrier where she was responsible for in-flight service.

By Park Han-na (hnpark@herladcorp.com)