Cheong Wa Dae said Wednesday it plans to ask the U.S. aircraft manufacturer Boeing to look into what caused the presidential jet to make an unprecedented emergency landing shortly after takeoff Saturday.

The Presidential Security Service is examining the maintenance problem that forced the Boeing 747-400 leased from Korean Air to turn back, resulting in a two-hour delay of President Lee Myung-bak’s arrival in the United Arab Emirates.

As soon as Lee returned home Tuesday, PSS chief Kim In-jong held a meeting with Air Force officials and senior executives of Korean Air to discuss how to examine the cause of the maintenance problem and how to prevent such incidents in the future.

“It was decided in the meeting to ask Boeing to conduct the probe for greater objectivity and agreed that the results should be announced as soon as possible,” Lee’s spokesperson Kim Hee-jung said.

About news reports that Cheong Wa Dae may terminate the lease contract with Korean Air, Kim said there was no mention of the contract during the meeting.

The plane, code-named Korea Air Force One, made an emergency landing at the Incheon International Airport due to a continued noise in its front part and resumed flight about two hours after what presidential officials described as a ventilation-related device with a minor malfunction was repaired.

Cheong Wa Dae leased the aircraft, manufactured in 2001, from Korean Air last year under a four-year contract in which the company provides crew members, maintenance and in-flight services. The Air Force supervises the maintenance and the PSS is responsible for the overall operation of the jet.

By Kim So-hyun (sophie@heraldcorp.com)