The Okinawa prefectural government announced on April 21 the results of its two-month survey on the number of takeoffs and landings by all U.S. military jets at the U.S. Marine Corps Air Station Futenma, which is located in a crowded residential area of Ginowan. The results show that the number of takeoffs and landings by U.S. military helicopters increased even when the controversial MV-22 Osprey transport aircraft were deployed outside of Okinawa for drills, indicating that aircraft noise has not been mitigated.

According to the prefectural government, the central government has conducted surveys on Ospreys in the past. But this was the first time that the number of takeoffs and landings by all aircraft at Futenma was surveyed. The survey was conducted by setting up videocameras on the north and south sides of the runway and recording for 24 hours over two months starting on February 1.

Though nighttime flights after 10 p.m., except for those necessary for the U.S. military’s operations, are supposed to be restricted under agreements on aircraft noise abatement countermeasures signed by the U.S. and Japan, the prefectural government confirmed a total of 31 takeoffs and landings after 10 p.m. The latest landing was made after 11 p.m. and the daily average number of takeoffs and landings was 43.8. But while the Ospreys were deployed outside of Okinawa for drills from March 6 through 17, the number of takeoffs and landings of other U.S. military helicopters increased and the daily average rose to 46.7.