| DESCRIPTION - The SCAS is a
three-axis, limited authority rate reference augmentation system. The
SCAS cancels undesired motion of the helicopter during flight. This is
accomplished by inducing an electrical input into the flight control
system to augment the pilot mechanical input.
CONTROL PANEL - The SCAS control panel contains a POWER
switch for applying dc (essential bus) and ac power to the system. The
circuits are protected by the SCAS POWER dc and SCAS PWR ac circuit
breakers. The panel also contains three channel engage switches which
energize electric solenoid valves controlling hydraulic pressure to the
system. The panel has three amber colored NO-GO lights, one associated
with each PITCH, ROLL, and YAW channel engage switch. These lights are
illuminated during the warm up to indicate the presence of current in
each associated channel actuator. Should an engagement be attempted
during this warm up period, the actuator may make an abrupt input to the
flight controls at the moment of engagement. When engagement is made,
the NO-GO lights are locked out of the circuit and do not operate as
malfunction indicators. Disengaging a channel, however, restores the
associated light to operation. The NO-GO lights have a built-in
press-to-test feature for ensuring that the indicator is operational,
but this feature works only prior to channel engagement. |
