There are conflicting views on the cause of the Korean Air Flight 801 crash during its approach to Agana Airport, Guam Wednesday. Korean Air said the main cause might have been bad weather caused by Typhoon Tina, coupled with a faulty Glide Slope of the ILS at Agana Airport. The ILS is a device that maintains the proper angle of the aircraft. The airlines also said that the VOR, a device that directs the final direction and degree during the final 3.5 miles before the landing strip was also out of order.

Some experts said that ILS or VOR problems were not the cause of the crash as the pilot already new the Glide Slope was not working when the plane left Kimpo through the 'Notice to Airmen' and there are many other alternative methods to safely land a plane.

Others are citing bad weather. At the time of the accident there was a heavy shower in the vicinity of the airport with unstable air currents. Professor Song Byun-hun of Korea Aviation College said if there is thunder with a strong, sudden downward air stream it is possible for an aircraft to drop to the ground. This again was countered by the fact that visibility at the time of the crash was eight kilometers, far exceeding the required 1.2 km visibility for safe landing.

Some pilots presumed there may have been an instrument error, citing a report that someone said 'emergency' in the last communication between the tower and pilot.

Government authorities are maintaining that they cannot completely exclude the possibility of terrorists, as North Korea has threatened the South several times following the defection of Worker's Party Secretary Hwang Jang-yup.