A Japan Ground Self-Defense Force (JGSDF) AH-64D that crashed in Kanzakion Feb. 5 had its main rotor head replaced just before it went down.
By TAKA@P.P.R.S (RED BULL AIR RACE CHIBA 2017-30.jpg) [CC BY-SA 2.0], via Wikimedia Commons
The rotorcraft had accumulated 1,733 flight hours and maintenance requirement is that the main rotor is to be replaced at 1,750 flight hours.
It was the first time that the aircraft had done a swap on the main rotor head since entering service in March 2006.