Prints with no supports, if yours is fused too hard to break loose, try the extra tolerance version. 4 rotors spin, arms do not pivot.
Depending on your settings, you might have to POP them loose the first time.
Also available:
Original PIP Helicopter: https://www.printables.com/model/510524-print-in-place-helicopter-no-supports
Chinook Helicopter https://www.printables.com/model/516098-chinook-helicopter-no-supports-print-in-place