Rotor head immobiliser

Working on the pitch adjustment of the main rotor blades requires a few conditions. First of all your helicopter must be standing on a flat level surface; the flybar must be horizontal and remain so throughout the procedure. The smooth running of all components with bearings makes this an almost impossible task because the slightest movement during pitch setting can cause changes in the rotor head level.
The rotor head immobiliser locks the rocker and keeps it from moving in the centre piece. This is the basis for further work on settings. The immobiliser must be removed before the next flight, very important!