a spring-centered hover trim stick. One of the two
rotary knobs is marked ROLL BIAS, with
directional arrows for left and right. The other
rotary knob is marked PITCH BIAS, with
marked arrows for forward and aft. The hover
trim switch is outlined in its corners with the letters
R (for right), L (for left), F (for forward), and
A (for aft).
The hoist operator uses the knobs on the hover
trim panel to control helicopter drift. With the
hover stick centered, the hoist operator adjusts
the roll and pitch bias knobs to trim the aircraft
for hover. Signals introduced into the amplifier
by the hoist operator correct any slight drifting
of the helicopter while the aircraft is hovering.
To energize the hover trim circuits, the pilot must
depress the HOVER TRIM ENG button on the
ASE control panel with the cyclic coupler switch
modules, one yaw synchronizer module, one
in the DOPP position.
collective coupler module, and one vertical
DUAL-CHANNEL LAG AMPLIFIER. --
amplifier also contains nine gain capsules and a
The function of the dual-channel lag amplifier
yaw rate gyro. The ASE amplifier modules and
(fig. 8-37) is to delay (lag) applied signals to ensure
capsules are discussed below.
proper response in helicopter movement. The
vertical velocity, roll stick position sensor, and the
pitch and roll cable angle sensor signals are lagged
Modules. --The four basic ASE modules are
by this amplifier.
pitch, roll, collective, and yaw. They serve to
amplify, shape, and derive the rate signals
ASE AMPLIFIER. --The ASE amplifier (fig.
used during ASE operation. These modules are
8-38) compares pilot-selected attitude, altitude,
and heading with the helicopter's actual attitude,
altitude, and heading. The amplifier also provides
The pitch and roll coupler amplifier modules
error signals that maintain helicopter stability,
are used during pitch and roll coupler operation.
within limited authority, regardless of combined
These modules are also interchangeable.
The ASE amplifier integrates the input signals
from the sensors and directs control operation.
are also interchangeable. They provide steady-
It also provides an output to the hydraulic sections
state error signals during pitch and roll coupler
of the control system activating servo units. The
The collective coupler module amplifies signals
during collective coupler operation.
with selection of the CABLE ALT mode of
collective coupler operation. The vertical accel-
erometer amplifier filters, amplifies, and lags the
vertical accelerometer signal in the CABLE ALT
The yaw synchronizer modules keep the yaw
channel input nulled, except when ASE is
operating and the pilot's feet are not on the
Figure 8-37.-Dual-channel LAG amplifier.