In an accident that confirmed warnings that have long been sounded, a metal window frame of a large U.S. military helicopter based at U.S. Marine Corps Air Station Futenma in Okinawa Prefecture fell into an elementary school close to the base.

The eight-kilogram window of a U.S. Marines’ CH-53E helicopter narrowly missed children on the playground of the Futenma No. 2 Elementary School.

It was only by luck that none of the some 60 children who were doing exercises in their gym class at that time was hit by the object in a terrible tragedy.

The city of Ginowan, where the base is located, has been warning about the possibility of such accidents, pointing out that the operations at the air base would not be allowed in the United States due to the danger they pose to local residents.

There should be “clear zones” at the ends of a U.S. military base runway where no houses or schools stand. But this rule is not applied to the Futenma base.

In the areas that should constitute the Futenma clear zones, there are some 800 residences and 18 public facilities including the elementary school.

The agreement made by the Japan-U.S. Joint Committee that U.S. military aircraft should avoid flying over schools and hospitals as much as possible has become a dead letter.

Mindful of the danger, the school has been regularly carrying out evacuation drills to prepare for the hypothetical situation in which a U.S. military aircraft has crashed, causing the release of poisonous gas within the school.

Where in any other part of Japan are children who have to do such drills as part of their daily school life?

The helicopter in question is the same type as the one that crash-landed and went up in flames in Takae, a rural community on the northern part of the Okinawa island, in October.

The U.S. military resumed flight operations of the CH-53E heavy-lift helicopter a week later without offering an explanation for the cause of the crash.

The latest accident, which again threatened the safety of local residents, has undermined the credibility of the announcement made two months ago by the U.S. military when it resumed operations of the aircraft. According to the announcement, aviation experts checked the helicopter’s maintenance record, but found no procedural or operational problems.

The U.S. military should make a sweeping review of its repair and maintenance system and explain the measures it will take to prevent a recurrence directly to the local communities threatened by both accidents.

It should not be allowed to return to normal after the kind of temporary flight suspension that is usually imposed after such an accident merely for form’s sake.

It is hard not to be maddened also by the Japanese government’s response to the accident.

Just a year ago, a U.S. Marines’ Osprey tilt-rotor aircraft crash-landed off the coast of Nago, a city in the prefecture, during a night air-to-air refueling drill.

Following such accidents in the past, the same series of steps were taken like a ritual. The Japanese government requests that the U.S. military suspend the operations of the aircraft involved, and the U.S. abides by the request just for a brief period before unilaterally resuming the flights with tacit approval by Tokyo.

The way the Japanese government responds to accidents involving U.S. military aircraft doesn’t befit a sovereign nation. It is a form of shameful subordination to the United States.

The administration of Prime Minister Shinzo Abe has been claiming that the proposed relocation of the Futenma base to areas around Henoko, a district in Nago, should be carried through for the elimination of the dangers posed by the base, which it describes as the top security policy priority.

But the relocation would only move the danger to areas around Henoko and do nothing to ease the burden imposed on people in Okinawa.

William Perry, who was the U.S. defense secretary when Tokyo and Washington reached an agreement in 1996 on the return of land occupied by the Futenma base to Japan, recently said to the effect that maintaining U.S. bases in Okinawa is not necessarily vital for U.S. deterrence.

The Abe administration should pay serious attention to such views and make all-out efforts to reduce the burden of the heavy U.S. military presence shouldered by Okinawa.

A serious accident involving U.S. military aircraft would endanger the foundations of the bilateral security alliance. The administration should confront this reality.

--The Asahi Shimbun, Dec. 14