FUTABA GY501 Instruction Manual page 25

B U
EFORE SE
26
AVCS gyro
This following describes how the AVCS system works when the
helicopter is exposed to a side wind while hovering, the same as the
preceding item. When the helicopter is exposed to a side wind, the
tail begins to drift. The gyro controls the servo so that the movement
of the tail stops, the same as a conventional gyro. At the same time, a
sensor is controlled so that the tail is rotated in the opposite direction
(returns to the original position). In short, the conventional gyro
performs an operation known as "drifting stop", but the AVCS
system performs an operation that "stops drifting and returns to
original position". The "return to original position" operation added
to the AVCS system improves rudder trim operation. In other words,
the gyro can automatically trim the rudder against side winds. This
also applies to reverse flight. When a helicopter is flying in the
forward and reverse directions, the rudder trim is changed to ad-
vance, but with the AVCS system, this trim change is performed
automatically and instantaneously so that the tail remains extremely
stable even during high-speed reverse flight.
The AVCS system requires a high-precision angular velocity sensor.
The GY501 realizes a high-precision angular velocity detection
function and extremely small output drift by using a new type of
gyro sensor. This minimizes rudder neutral position drift during
flight and eliminates the need to trim the rudder during flight.
• The tail remains extremely stable.
Forward
Side wind