Overview
The pitch feel system supplies a simulated force at the control columns to help the pilots control the aircraft and is a function of the horizontal stabilizer position.
Pitch Feel Simulator
Two interchangeable pitch feel simulators (PFS) are adjacent to each other. Their outputs are added by the aircraft's pitch-axis control rod. The PFSs are found in the vertical stabilizer between the mid spar and the rear spar, directly above the aft quadrants. Each pitch feel simulator is connected to a hydraulic lockout rod. The hydraulic lockout rod pushes or pulls on the input lever of the PFS. The PFS then sends a simulated force to the control columns. This gives the pilot a signal of stall identification by a fast increase in feel force.
02/03/16
Hydraulic Lockout Rod
There are two hydraulic lockout rods installed between the PFS and the bottom surface of the horizontal stabilizer. The top ends of the rods attach to a point forward of the horizontal stabilizer pivot point. Hydraulic hoses from the left and right hydraulic systems connect to fittings at the top ends of the related left and right lockout rods. The rods are telescopic and fully extend with the aid of a large coaxial spring before the hydraulic pressure is applied. When the rods are energized, the hydraulic pressure compresses the spring and the length of the rods becomes shorter by approximately 1 in (2.5 cm).
02/03/16
Pitch Feel Stop Actuator
In usual operation, with hydraulic power available, the pitch feel stop acuator is in the extended position. In this configuration, the PTS input lever and the movement of the horizontal stabilizer is absorbed by the compression of the hydraulic lockout rods. When there is no hydraulic power available, the hydraulic lockout rods extend and the pitch feel stop actuator is in the retracted position. In this configuration, the PFS is in manual reversion.
System Operation
The pitch feel system supplies a simulated force at the control column for inputs to the pitch control system. The position of the horizontal stabilizer is given by the hydraulic lockout rods to the input levers of the pitch feel simulators. The hydraulic lockout rods absorb the initial hydraulic surge to make the control movement smooth. The feel force is a result of the position of the horizontal stabilizer and the preset tension of the pitch feel simulators. Control rods transmit the movement from the output levers of the pitch feel simulators to the aft quadrant. The forces at the aft quadrant are transmitted through the control system back to the control columns.


