Originally Posted by
Bentiron
S61 engaged in vertical reference operation in 200' hover.
Aircraft began short sharp vertical jumps -R/H pilot suspects coll. bounce but collective was immobile - friction not needed.
L/H Pic says controls are siezed.
Primary and auxiliary hydraulic caution lights begin flashing - both hyd. press. guages show very rapid on/off indications.
R/H pilot selects pri.hyd. switch off - controls still siezed - pri.hyd. selected back on and aux. hyd. switched off.
Aircraft stops vertical jumps and controls are operational again.
Aircraft returned to landing barge - artificial horizon(eyeball) was seen to be spinning very fast during return flight.
Suspected cause - rapid erroneous AFCS inputs overpowered hyd. systems.
Front row passengers putting feet on the base of the collective on a 365 also passengers feet crushing the trim panels and trapping the control rods.
Hughes 500 stiff yaw controls. During avionics installation they tyrapped the aerial cable to the underfloor control rod!!!