(Reuters) -Uncertainties surround the deadliest crash on South Korean soil, experts said on Sunday, questioning initial suggestions that a bird strike might have brought down the Jeju Air flight. The apparent absence of landing gear, the timing of the twin-engine Boeing 737-800's belly-landing at Muan International Airport and the reports of a possible bird strike all raised questions that could not yet be answered. The single-aisle aircraft was seen in video broadcast on local media skidding down the runway with no visible landing gear before slamming into a wall in an explosion of flame and debris.