陸自ヘリ、墜落原因特定できず　左右エンジン相次ぎ出力低下―近く報告書公表へ・防衛省

　沖縄県の宮古島周辺で昨年４月、陸上自衛隊のＵＨ６０ＪＡヘリコプターが墜落、１０人が死亡した事故で、陸自が、事故原因を特定できなかったとする調査報告書をまとめたことが１１日、防衛省関係者への取材で分かった。ヘリに２基あるエンジンの出力が相次いで低下していたという。近く公表する。
　防衛省関係者によると、企業と協力し、回収したフライトレコーダー（飛行記録装置）の解析などを進めたところ、事故直前にヘリ右側のエンジンの出力が急低下していたことが分かった。配管などの不具合で出力が徐々に低下する「ロールバック」という現象が起きたとみられるという。間もなく左側の出力も低下したため、機体の高度を維持できず墜落していた。（2024/03/11-11:26）

Japan's Ground Self-Defense Force has failed to identify the cause of last year's helicopter crash off an Okinawa Prefecture island in an investigative report on the incident, Defense Ministry officials said Monday.
   The GSDF will soon release the report on the crash of a UH-60JA helicopter near Okinawa's Miyako Island that killed all 10 people on board, including Yuichi Sakamoto, then head of its 8th Division.
   An analysis of a flight data recorder recovered from the helicopter found out that the output of its right side engine had dropped rapidly shortly before the crash, according to the ministry officials.
   This was apparently caused by a phenomenon known as rollback, where engine output drops gradually due to a pipe problem. As the output of the left side engine also decreased soon after that, the helicopter became unable to maintain its altitude and crashed.
   The cause of the incident could not be pinpointed because part of the flight recorder data was damaged and it thus was not possible to determine whether the power loss of the left side engine was caused by a malfunction or a pilot error, the officials said.