Photo/IllutrationKansai International Airport is flooded on Sept. 4. (Asahi Shimbun file photo)

A passenger terminal building returned to full operations at Kansai International Airport after being paralyzed in flooding caused by Typhoon No. 21 earlier this month. Nearly all scheduled flights, except some cargo services, have resumed at the airport in Osaka Bay.

The disaster has not only exposed the weaknesses of an offshore airport but also highlighted problems with separating the ownership and operation of airport facilities.

An in-depth investigation is needed to determine what exactly happened, while Kansai International Airport should review its disaster management measures. Lessons should be drawn that could be useful for Chubu, Kita-Kyushu and other offshore airports.

An access bridge, which links the airport on a man-made island with the Honshu mainland, was damaged and rendered impassable. Questions should be raised about the extent to which authorities had anticipated such a situation.

A tanker anchored nearby was set adrift by strong winds and struck the bridge, thereby isolating the airport.

The government’s Japan Transport Safety Board is investigating the cause of the crash.

The access bridge, which accommodates railroad tracks and an expressway, is a lifeline for the airport. It should have been prepared for a worst-case scenario.

About 8,000 people were forced to spend the night on the airport island. But the airport operator initially failed to quickly determine their numbers.

The stranded people were eventually brought ashore by high-speed ferry and by bus along an expressway lane that could be used, but it took a lot of time to transport them all.

The confusion was exacerbated by an extensive power outage in terminal buildings and elsewhere.

Lighting and air conditioning went off, and information through a public-address system was stalled, leaving many people, including overseas tourists, extremely anxious.

A storm surge caused seawater to flow onto the island and directly strike the airport’s electrical equipment in the basement of a building. The space allocation for the equipment, which could be likened to the heart of the complex, was perhaps based on too much optimism.

The government is planning urgent inspections of key infrastructure, including international airports. A government panel of experts will also review measures taken against storm surges at Kansai International Airport.

The inspections should cover not only the facilities and equipment but also the system for conveying information, the setup for guiding people along routes, the storage of emergency supplies, and rescue methods.

Levees have been raised repeatedly at Kansai International Airport in response to land subsidence and flooding damage since the airport was opened in 1994.

Airport officials have argued the levees are enough to withstand high seas that occur only once in 50 years. The disaster damage estimates and countermeasures must be rewritten.

The airport’s operations are complicated. Its facilities and runways are owned by New Kansai International Airport Co., in which the government holds a 100-percent stake. But since two years ago, they have been operated by Kansai Airports, a private-sector company.

It appears unclear how the owner and the operator are supposed to split their responsibilities and expenses when faced with the need to take unplanned measures.

This practice of spinning off airport operations to a private-sector entity has spread to other airports in Japan.

Airports should not be allowed to prioritize profits at the cost of disaster management measures. How Kansai International Airport will deal with the matter will serve as a touchstone.

--The Asahi Shimbun, Sept. 26