US military helicopters flying at low altitudes over downtown Tokyo: Mainichi probe

TOKYO -- U.S. military helicopters have been spotted repeatedly flying at low altitudes of 300 meters or less between Tokyo skyscrapers, contravening aviation regulations for Japanese aircraft, according to a Mainichi Shimbun investigation.

The investigation found at least one instance where a helicopter passed over Shinjuku Station in central Tokyo at a height of approximately 200 meters, while coming perilously close to surrounding buildings. Danger lurks in this area including the world's busiest train station used by around 3.5 million people a day.

In an investigation conducted over about half a year from July 2020, the Mainichi Shimbun confirmed helicopters belonging to U.S. forces flying at low altitudes over Shinjuku. On 12 occasions, the flights clearly contravened regulations for Japanese aircraft under Japan's Civil Aeronautics Act, which state that the minimum safety altitude for flying is more than 300 meters above the upper edge of the highest obstacle within a 600-meter radius of the aircraft in densely populated areas. There were also five occasions when U.S. military helicopters were strongly suspected to have breached aviation law standards.

The minimum safety standard specified in the Civil Aeronautics Act, which is applicable to Japanese helicopters, is based on the assumed height required for a forced landing without imposing danger on the ground in the event of an accident or mechanical failure. Japan's aviation law adopts the same standard as the International Civil Aviation Organization.

The standard has not been applied to U.S. Forces Japan due to a special provisions law based on the Japan-U.S. Status of Forces Agreement (SOFA), which was implemented in 1952. However, frequent sightings of low-altitude flights by U.S. military aircraft in the capital could spark new discussion.

The SOFA stipulates a duty to respect the laws of Japan, and U.S. officials provided a de facto apology following a 2018 case where it was revealed that a fighter jet flew at an altitude below the safety standard in Iwate Prefecture, northeastern Japan.

Toshiyuki Kusuhara, a visiting professor at Daiichi Institute of Technology and former senior aircraft accident investigator at the Japan Transport Safety Board, said, "Low-altitude flights in urban areas require high maneuvering skills, and when mistakes such as human errors are made during flights that contravene the law, they almost always end up causing accidents. Not only do such flights endanger the lives of the crew, but also the lives of those living on the ground."

Low-altitude flights by U.S. military aircraft and noise problems have been repeatedly occurring in the southernmost prefecture of Okinawa, where roughly 70% of U.S. military-dedicated facilities are located. Meanwhile, in downtown Tokyo, issues including noise problems have been reported around the heliport of the Akasaka Press Center, a U.S. military base in the Roppongi area in the capital's Minato Ward.

The Akasaka Press Center serves as a base for transporting top officials of the U.S. government and the U.S. military to the heart of Japan's capital, from suburban locations including Yokota Air Base in western Tokyo, as well as Camp Zama, Naval Air Facility Atsugi, and Yokosuka Naval Base in Kanagawa Prefecture, south of Tokyo. The trip takes around 10 to 20 minutes one-way. The Akasaka Press Center was also used by former U.S. president Donald Trump when he visited Japan.

The military base in Roppongi has been used to this day since the Japanese government provided the property as a facility and zone for the U.S. military in 1952 following the demilitarization of the country after the end of World War II. Although the Minato Ward Office has repeatedly demanded the Japanese government to remove the military base, there has been no progress on the issue.

Since July last year, the Mainichi Shimbun has examined the flight status of U.S. military aircraft from multiple points in 200 meter-class buildings, including the observatory in the Tokyo Metropolitan Government Building's Main Building No. 1 in Tokyo's Shinjuku Ward, to find out how they are actually being flown.

The problematic flights over the Shinjuku Station area were confirmed 17 times during a total of 10 days, counting instances of aircraft passing by on trips to and back from their destinations. Cases where aircraft were seen departing or landing at the Akasaka Press Center, about 4 kilometers away from Shinjuku Station, are not included.

The aircraft are all believed to be the U.S. Army's Black Hawk helicopters, and the majority of them came from the direction of Kanagawa Prefecture, south of Tokyo, where there are numerous U.S. military bases. Although the main duties of Black Hawk helicopters in Japan are the transportation of personnel and training with the Japanese Self-Defense Forces, they also join combat in battlefields including that involving shooting and launching missiles.

Of the 17 low-altitude flights observed, helicopters in 12 flights flew at an altitude lower than the height of the NTT Docomo Yoyogi Building, known as Docomo Tower, which stands at roughly 270 meters. There were also six cases with helicopters flying at around the same height as the metropolitan government building's observatory, standing at 202 meters. Aircraft passed by almost directly above Shinjuku Station eight times, and another case was observed where a helicopter nearly brushed against a commercial building connected to the station at a height of approximately 170 meters.

The remaining five instances saw helicopters fly just above Docomo Tower, among other routes, and it is highly possible the aircraft flew at heights below Japan's safety standards.

U.S. Forces Japan explained in an interview that "U.S. Forces in Japan adhere to bilateral agreements (between the United States and Japan)" and that "all flights conducted by U.S. Forces are either mission-essential or for training and readiness requirements." They commented, "Weather, wind speed/direction, or other factors may affect an aircraft's approach, altitude, speed, descent, etc. as all options are considered when determining the safest possible flight protocol within our bilateral agreements," and emphasized that "at no time will a military flight be authorized for sight-seeing or leisure purposes."

Meanwhile, the Status of U.S. Forces Agreement Division of Japan's Ministry of Foreign Affairs, said, "If this is true, we'd like to check the situation with U.S. forces."

(Japanese original by Hiroyuki Oba, Atsushi Matsumoto and Toshiaki Uchihashi, City News Department)

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Investigation method:

The Mainichi Shimbun investigated the flight status of U.S. military helicopters in downtown Tokyo between July 2020 and January 2021. Investigations were conducted on 90 weekdays selected arbitrarily, with each session lasting three to five hours a day. Therefore, it is possible that there is a greater number of low-altitude flights happening in the area. Flights were observed from the ground, from Mainichi Shimbun helicopters, and from multiple points of 200 meter-class buildings in central Tokyo, including an observatory of the Tokyo Metropolitan Government building which stands at 202 meters. Flights where the aircraft was confirmed to be flying at a height lower than buildings from multiple investigation points, and flights where the aircraft was positioned below or level with the investigation point were deemed low-altitude flights. The Mainichi Shimbun only counted cases which were able to be filmed.