.fbx file imported to unity objects separates

i am trying to import .fbx file of a helicopter made in blender
there is a single bone on my helicopter blades to rotate them it absolutely works fine in blender but when i import .fbx file in unity with animation the blades got separated from helicopter yet it still has animation and it still rotates but at new position

  1. first picture is of my blender model
  2. second one is the game scene in unity with ( helicopter blade highlighted in oval )

sorry for poor english
any help would be appreciated
thank you !

Is the blade part becoming a separate game object from the helicof topter? If so, you could make the blade object a child object of the helicopter object, by dragging the blade object onto the helicopter object, and modifying the transform (location) of the blade. Then when the helicopter moves, the blade would also follow along…

Agree with jtok4j. Alternately - To fix your current set up the rig needs to have two bones. One bone with the body of the helicopter weighted to it and the other with the blade weighted to it. It looks like maybe you only have one bone, and possibly are only parenting the blades to the bone, rather than weighting the vertices.