A magnetic propeller device for an unmanned aerial vehicle (UAV) includes a propeller and a shaft mount that engage with a motor shaft of a UAV. The propeller and shaft mount each have a magnetic element. When both magnetic elements are aligned, the propeller engages the shaft mount by way of a magnetic holding force between the magnetic elements. When a propeller contacts an object and the propeller is displaced, the magnetic elements passively disengage the propeller from the shaft mount due to misalignment of the magnetic elements. Passive disengagement allows the propeller to rotate independently of the motor shaft. Once the UAV moves clear of the object, the magnetic elements can realign, such that the propeller re-engages the shaft mount and resumes rotation with the motor shaft.