OSAKA -- Six years after opening, Kansai International Airport is struggling to stay above water -- literally and figuratively.

The airport's problems range from a sinking passenger terminal and mounting debts due to decreased usage, to criticism of the airport's high costs and threats to postpone construction of a planned second runway.

Earlier this month, officials of Kansai International Airport Corp., the operator, and the Osaka Prefectural Government visited Tokyo to appeal for central government assistance for the troubled facility, which has over 1 trillion yen in outstanding loans that must be repaid with interest.