The U.S. military resumed flights of Osprey aircraft in Japan on Thursday amid lingering concerns over the safety of the tilt-rotor planes following a deadly crash late last year.

The resumption came after Washington last week lifted a worldwide flight ban on the aircraft put in place after a U.S. Air Force CV-22 Osprey transport plane crashed off Kagoshima Prefecture’s Yakushima Island on Nov. 29, killing all eight crew aboard.

The Defense Ministry had said late Wednesday that the U.S. and the Self-Defense Forces would resume flights of the aircraft in Japan.