NAHA, Okinawa — A canopy fell from a Japan Air Self-Defense Forces F-4 Phantom fighter jet Monday, forcing the two crewmembers to make an emergency landing at Naha International Airport.

A JASDF spokesman said the incident occurred about 8:52 a.m. over the ocean; he said the plane landed at the airport, which the JASDF shares with commercial aircraft, at 9:11 a.m. No injuries were reported.

Following the incident, all F-4s at the air base were grounded for inspection, he said.

The emergency landing forced a short runway closure, delaying three outbound and four inbound commercial flights for 24 minutes, according a spokesman for the Naha Airport Office, Ministry of Land, Infrastructure and Transport.

According to a preliminary report, the canopy over the fighter’s rear seat ejected after the jet took off for a training flight. The canopy was about 56 inches long, 40 inches wide and weighed about 110 pounds, the spokesman said.

He said the canopy probably fell into the ocean near the airport but hadn’t been found as of Tuesday morning. The JASDF is investigating the accident’s cause and the damage to the jet.

Monday’s incident was the second emergency landing of a JASDF F-4 at the airport this month. On Sept. 7 another fighter made an emergency landing when a warning light came on in the cockpit.

On Monday afternoon Toyoaki Kinjo, mayor of Tomishiro city — adjacent to the JASDF base — filed a protest concerning the incident and demanded a thorough investigation and adequate safety measures to prevent future mishaps.

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