Photo/IllutrationA CH-53E helicopter takes off from U.S. Marine Corps Air Station Futenma in Ginowan, Okinawa Prefecture. (Asahi Shimbun file photo)

  • Photo/Illustraion

NAHA--Authorities in Okinawa Prefecture reacted angrily to a delayed announcement by the U.S. military that a plastic window detached from a transport helicopter and fell into the sea while in flight.

Prefectural authorities called for the model of aircraft to be grounded for a week while an investigation is carried out.

On Aug. 30, Deputy Okinawa Governor Kiichiro Jahana met with Toshinori Tanaka, head of the Okinawa Defense Bureau, and other officials to protest the late notification. Jahana asked that the Defense Ministry request the U.S. military to ground all CH-53E helicopters operating out of U.S. Marine Corps Air Station Futenma in Ginowan for one week.

The latest incident is one of a spate of mishaps involving U.S. military aircraft in recent years that have infuriated Okinawans worried about their safety. The prefecture hosts around 70 percent of all U.S. military installations in Japan.

In this incident, a plastic window detached from a helicopter and fell into the ocean about 8 kilometers off the eastern coast of Okinawa Prefecture around 5:30 p.m. on Aug. 27, according to the Okinawa Defense Bureau and U.S. military. Weighing about 1 kilogram, the rectangular window measured 58 centimeters by 47 cm.

Okinawa prefectural government officials plan to lodge a formal protest with the U.S. military.

The Okinawa Defense Bureau informed the Okinawa prefectural government about the incident on the evening of Aug. 29, two days after the fact.

Jahana criticized the delay, saying: "We have asked, whenever we have had the opportunity, of both the Japanese and U.S. governments as well as the U.S. military for swift notification. I cannot but feel strong anger."

In December 2017, a window detached from a similar helicopter and landed in the grounds of an elementary school in Ginowan.

Referring to that incident, Jahana said efforts by the U.S. military to prevent a recurrence are clearly "extremely inadequate."

Tanaka was also angered by the U.S. military's delay in informing his bureau of the incident immediately after it occurred. He explained that the Okinawa Defense Bureau was notified by the Defense Ministry in Tokyo late on Aug. 28 about information it had received from the U.S. Embassy in Tokyo. After Okinawa Defense Bureau officials contacted U.S. military officers based in Okinawa, bureau officials were informed of the details of the incident on the afternoon of Aug. 29.

According to Okinawa prefectural government officials, since 2014 there have been 24 instances of parts falling from U.S. military aircraft. In June, rubber parts fell from another CH-53E helicopter onto the grounds of a junior high school in Urasoe.

A 50-year-old woman whose son attended the Ginowan elementary school when the window fell on the school grounds in 2017 said: "Nothing has changed about this extremely dangerous situation. We live in fear that something will fall out of the sky."

Ginowan Mayor Masanori Matsukawa questioned whether U.S. military authorities were serious about implementing measures to prevent a recurrence of such mishaps.

"They should not look on this lightly just because there were no injuries this time," he said.