The number of passengers using Korean Air Line Co., South Korea's top flag carrier, dropped in December apparently affected by the so-called "nut rage" that has tarnished its image among travelers, industry data showed Saturday.

Cho Hyun-ah, the eldest daughter of Korean Air chairman Cho Yang-ho, resigned as a vice president for cabin service four days after a national uproar over her conduct aboard a Seoul-bound Korean Air flight from New York on Dec. 5.

The plane had already been taxiing when she ordered the chief flight attendant to deplane over the way she was served macadamia nuts -- in an unopened pack instead of on a plate. She was indicted for jeopardizing flight safety and the incident has tarnished the airline company's brand image significantly, with some customers boycotting its service.

According to the data provided by Incheon International Airport Corp. and Korea Airports Corp., Korean Air transported a total of 482,000 passengers through its domestic lines last month, down 6.6 percent from a year earlier.

The decline contrasted with a 13.2 percent hike for its smaller rival Asiana Airlines Inc., which flew 358,000 customers last month. The gap between the two largest airlines in terms of passengers narrowed from 158,000 to 76,000 over the past one year.

This also comes despite an 11.5 percent on-year increase in the total number of passengers using domestic flights provided by seven carriers.

Industry experts attribute the lackluster results of Korean Air to customers' avoidance of its service in the wake of the incident.

"It seems that there are not a few passengers opting for other airline services following the incident, given that there are many options available when it comes to domestic flights," an industry expert said.

Korean Air also underperformed next to other airliners on international lines.

The company transported a total of 1.38 million passengers through its international flight services last month, up 2.5 percent from a year earlier. This is lower than the industry-wide 9.2 percent hike in the number of passengers traveling overseas, the data showed.

In particular, Asiana Airlines seems to be basking in its rival's setback with the number of international passengers using its flights growing 9 percent. Low-cost carriers also saw their international passengers jump across the board.

Korean Air said that there is no marked change in its booking ratio and that there is no relations between the number of passengers and the incident since most of tickets were booked months earlier. It expects that bookings for February and March are about 5 percent higher than last year. (Yonhap)