Jastram ENGINEERING SCA 300 - Page 23

Setup and Testing
Page 22 of 31
Doc No.: MAN01502, 27-02-01 SCA 300 Manual
g) Slowly turn the FFU input device towards hard over while observing the
rudder movement; take care not to allow the rudder to reach its
mechanical hard over limit.
h) Adjust the FDBK GAIN trim pot in the SCA clockwise (CW) to reduce
rudder angle or counter-clockwise (CCW) to increase rudder angle. This
is to achieve a condition where the FFU input device is at hard over and
the rudder is a few degrees inside the desired internal limit angle (see
Fig. 2).
i) If oscillations continue turn the DEADBAND trim pot CW until oscillations
cease.
j) Carefully turn the FFU input device to the opposite hard over position and
ensure that the rudder stops a few degrees inside the desired internal
limit angle. Adjust FDBK GAIN trim pot CW as necessary to ensure
rudder does not reach its mechanical hard over limit.
k) Return FFU input device to center.
l) Place NFU/FFU switch in NFU position. If optional NFU input device is
not installed then turn off HPU.
5. RAI Gain Adjustment (RFU in “Stand Alone” mode)
a) If RFU is not operating in “Stand Alone” mode then proceed to step 6.
b) Refer to RFU owner’s manual and complete “RAI Gain Adjustment”
section in RFU manual.
6. FFU Steering Input Calibration
a) With HPU on and NFU/FFU switch in FFU position confirm that port and
starboard operations of the FFU input device correspond to port and
starboard turns of the rudder. If this is not the case a reverse polarity
condition exists at the FFU input device. To correct for reverse polarity,
turn off HPU and DC power supply then refer to the FFU input device
owner’s manual and reverse +V and -V connections.
b) Place NFU/FFU switch in NFU position. If optional NFU input device is
not installed then turn off HPU.
c) If Rudder Order Indicator (ROI) is not installed then proceed to step 8.
d) Turn FFU input device to hard over port and record angle displayed on
ROI.
e) Turn FFU input device to hard over starboard and record angle displayed
on ROI.
f) If the two recorded angles are acceptably balanced proceed to step 7.
g) Calculate the average of the two recorded angles.
h) Refer to FFU input device owner’s manual and adjust potentiometer so
that the ROI displays the average angle.
i) Swing the input device to its hard over positions and confirm that the ROI
angles now match. If the ROI angles are still unacceptably unbalanced
repeat the above procedure from step (d).