Swashplate Trunnion Bolts

When installing trunnion’s in any of the five positions on the swashplate be sure to install the inner retaining bolt first. The one on the end opposite of the bearing. There are two grooves, inner and outer on top and bottom of the trunnion. The inner one has a shallower radius than the outer one. When installing always align the inner groove first. The bolts should fit through the bolt holes with light hand pressure. If not, investigate why. If you had to drive out the bolts you may see the damage like the enclosed photo ( both inner bolts ). If you look close you can see damage on the threads closest to the shank and on the shank where the metal has been pulled. This damage can be transferred to the swashplater bolt bores. Possibly damaging the swashplate beyond repair. If the inner bolt is properly aligned and the bolt slides in with hand pressure the outer one should because of the increased radius on the trunnion bolt groove.

Peter Frinchaboy

Helicopter Maintenance Manager

Sacramento Metro Fire District