NAHA--Increasing flights of outside military planes into U.S. Kadena Air Base are jangling the nerves of local residents and officials who have long complained of noise pollution and dangers.

The increased activity is occurring as experts point out that the U.S. military has actively been conducting exercises amid China’s increasing assertiveness.

It is believed that more than 100 U.S. military aircraft are assigned to Kadena Air Base.

In addition, more than 30 other airplanes of five types, which are not among those based at Kadena, were seen flying in from overseas or outside the prefecture between May 26 and June 2, according to the Defense Ministry’s Okinawa Defense Bureau and Kadena town officials.

A visual inspection by the Okinawa Defense Bureau confirmed there were 32 non-assigned aircraft of four types at the base as of midday on June 2.

Those included F-16 jets, EA-18G Growlers and F-22 jets. It is believed that they had flown from other U.S. military installations such as Misawa Air Base in Aomori Prefecture and Marine Corps Air Station Iwakuni in Yamaguchi Prefecture, as well as from the United States.

The U.S. military hasn’t told the Okinawa Defense Bureau which bases these aircraft belong to, citing security reasons.

According to the town of Kadena's records, the last time the number of U.S. military’s non-assigned aircraft flying into the base reached this level was in 2007, when 30 arrived.

“It is rare that such a large number of outside aircraft are flying into the base," a town official said. "This time it is even rarer as they are fighter jets.”

Local residents have voiced their concerns and protests over the additional noise generated by the outside aircraft.

According to the Okinawa prefectural government, a noise level meter near the base registered 110.2 decibels at around 8 a.m. on June 2, when three U.S. fighter jets flew into the base in the span of five minutes.

It’s been said that “the sound of a car horn from two meters away” is as loud as noise registering 110.2 decibels.

One meter nearby recorded 93.7 decibels during the same five minutes.

ADDITIONAL DANGER POSED

On May 30, a fuel tank measuring around 5.3 meters in length and around 80 centimeters in width washed ashore on a beach of Higashi village in the northern area of Okinawa's main island.

The U.S. military told the Defense Ministry and Okinawa prefectural government that the tank is used on a U.S. Navy FA-18 fighter-bomber. It reported that an FA-18 dropped the tank outside Japanese territorial waters around 28 kilometers off the beach on May 29, “to ensure the safe landing” of the plane.

The fighter-bomber landed at the Kadena base after jettisoning the fuel tank. It is not assigned to the base.

Okinawa Governor Denny Tamaki said on June 2, “The non-assigned U.S. aircraft must not cause such dangerous incidents when on an exercise,” and “We have demanded that the burden caused by U.S. airplanes assigned to the bases in local areas be reduced. If outside military aircraft impose additional burdens on us, it is unforgivable.”

On June 3, Okinawa prefectural senior officials handed a letter in person to Foreign Ministry and Defense Ministry officials saying that the situation in the prefecture is "extremely unusual."

The town of Kanade is also considering lodging a protest in conjunction with nearby municipalities.

Since 2007, the Japanese and U.S. governments have implemented measures to reduce the burden caused by the U.S. aircraft deployed to the Kadena base.

One of these measures is to conduct exercises involving these planes at bases outside Okinawa.

However, according to the Defense Ministry, U.S. aircraft not assigned to Kadena landed in or departed from the base 11,155 times in fiscal 2019, 11,061 times in fiscal 2020 and 11,974 times in fiscal 2021.

Kadena town officials said, “Local residents don’t feel the effects of the measures to reduce the burden caused by aircraft stationed at the base because more outside aircraft are flying in instead.”

Courts recognized the illegality of noise pollution stemming from aircraft operating out of the Kadena base in a series of lawsuits lasting for 40 years.

In the third lawsuit, the government was ordered by a court to pay around 26.1 billion yen ($199 million) to a total of around 22,000 local residents in Okinawa Prefecture. The order was finalized in 2021.

Tomoya Nakasone, 57, chair of the association of residents living near the base, 57, said, “Living in Kadena makes you directly aware of the impact of global affairs.”

He said that he hears more noise from the base when the media reports on the U.S.-China conflict or other international tensions.

“The more I feel the importance of the Kadena base, the more nervous I become thinking that it could be attacked at any time," Nakasone added. "That’s how I feel as someone living his life in the vicinity of 'international affairs.’”