Before it suffered the deadliest crash in South Korea¡¯s history, budget airline Jeju Air was moving fast: racking up record passenger numbers and flying its aircraft more than domestic rivals and many of its global peers, data shows.

The high ¡°utilization rate¡± of Jeju Air¡¯s planes ¡ª the number of hours they fly in a day ¡ª is not problematic in itself, experts say, but it means scheduling enough time for required maintenance is crucial.

Authorities have suggested a bird strike contributed to the accident, but as part of their probe into the incident aboard Boeing 737-800, police have raided the airlines¡¯ Seoul office to seize documents related to the operation and maintenance of the plane.