Ejecting USB HDD

I Just brought a USB HDD and am facing a problem with it. when i want to unplug the HDD i eject it from task bar ‘safely remove…’ the drive dissapears from my computer. However the LED will be on and the hard disk does not power down completly until i remove the cable. is it ok to remove the cable like that when the hard disk is still rotating? (as it never stops)?