Gemfan Hobby Hurricane 51466-3 V2 (MCK Edition)

The Gemfan Hurricane 51466-3 V2 in the MCK Edition is a robust three-blade polycarbonate propeller from Gemfan Hobby for freestyle flying with 5 in FPV quadcopters and a widespread choice in that class. The type code gives 5.1 in diameter and three blades; V2 marks the second version of the model.

The disc diameter is given as 131.8 mm. The weight is 4.2 g, the bore 5 mm and the hub centre thickness 6.8 mm. The propeller does not fold. Three blades give more thrust and grip at 5 in than two but cost efficiency and raise the current draw. On freestyle propellers the pitch decides the balance between response and speed: low values give more pull from standstill, higher values more top speed at higher current.

Freestyle is flown in the open category, where the rules are: visual contact with the aircraft, no more than 120 m altitude and, with video goggles, an observer who keeps the aircraft in view. Take-off mass including battery and camera decides the classification; from 250 g the operator must register. Classes C1 to C3 require direct remote ID, and the distance from uninvolved people depends on the subcategory.

On selection: the 5 mm bore fits 5 mm motor shafts. Freestyle wears propellers quickly because trees, gates and ground are hit; after every contact the blade tips, leading edges and hub should be checked. Bent or nicked blades are replaced, not straightened, and changes are made by the set with two propellers per direction of rotation, so that thrust and vibration pattern stay uniform.