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In addition to the throttles, the C-130H is equipped with a condition lever for each engine to
control engine operation and propeller feathering/unfeathering:
Condition Levers in Run Position
RUN: (detent position): Allows engine and propeller to operate
GROUND STOP (detent position) If the touchdown system is in the ground mode, closes
electrical fuel shutoff valve to engine.
FEATHER (detent position)
Sends propeller controls a feather signal
Operates auxiliary feather motor
Closes electrical fuel shutoff valve to engine
AIR START (condition lever must be held in airstart position):
Allows engine and propeller to operate (same as RUN)
Operates auxiliary pump, providing hydraulic pressure to unfeather the propeller
In a variable-pitch propeller, the blades are turned in the hub about their longitudinal or pitch-
change axis. The mechanism provided to produce this pitch change must be capable of exerting
sufficient force to overcome any mechanical or aerodynamic opposing force set up by the blades
themselves. The strongest force is the centrifugal twisting moment (C.T.M). The centrifugal
twisting moment is a turning couple brought about by the fact that the blade sections are inclined
at an angle to the plane of rotation. The centrifugal twisting moment will cause the heaviest part
of the blade, the leading edge, to move in line with the plane of rotation. This serves to decrease
blade angle. When the blade pitch is reduced, the propeller torque force (force opposing rotation)
is reduced, and if nothing is done to the gas generator (engine), the reduction in propeller torque
