AutoGyro Calidus - Pneumatic System Functions

Pilot Operating Handbook
Calidus
SECTION 7
SYSTEM DESCRIPTION
AutoGyro_POH_Calidus Revision 4.0 – Issue Date 17.JAN.2019 7-4
7.5 Pneumatic System
Aircraft trim, rotor brake and activation of the pre-rotator is controlled by a pneumatic
system, consisting of an electrically driven air compressor with filter/dryer, a pressure gauge
in the cockpit, solenoid valves, air lines, pneumatic actuators, and the respective cockpit
controls.
Trim function
Trimming is affected by varying trim pressure in the pneumatic trim actuator which is
installed in parallel with the rotor head tilt for pitch control. Aft or nose-up trimming activates
the electrical compressor and increases trim pressure, causing the actuator to retract, and
tilting the rotor disc aft. Forward trimming opens the pneumatic valve to reduce trim
pressure and allows the rotor disc to flatten, due to the spindle head offset and the
gyroplane’s weight. The actual trim condition is indicated on the trim/brake pressure gauge
in the centre panel of the cockpit.
Lateral/roll trim is available as an option and works accordingly, using a lateral pneumatic
trim cylinder. With this option installed, lateral trim condition is indicated by a LED bar on the
instrument panel.
Rotor brake
With the pneumatic mode selector in BRAKE position the operation of the pneumatic trim
actuator is reversed so that increased pressure causes the actuator to push the rotor head
up (or level) and presses a brake pad against the rotor head disc (and in the case of
Rotorhead III, also engages the front brake pad). In order to increase brake pressure, move
the 4-way trim switch to aft. Note that this action will also push the control stick forward. At
full brake pressure the control stick will be maintained in its full forward position.
Activation of the pre-rotator
The pre-rotator is activated as long as the respective switch on the control stick head is
depressed provided the following pre-conditions are met:
 pneumatic mode selector set to FLIGHT
 control stick in full forward position
 trim pressure less than 3 bar
 “Canopy” light OFF (if installed, means that the canopy is closed and locked)
When activated the pneumatic clutch is activated and engine torque is transmitted through a
90° gearbox and drive to the pinion which is engaged by another small pneumatic actuator
into the geared ring of the rotor head. The drive pinion is sliding on a helical gear to provide
automatic lock-out in case of rotor RPM overrun. The pre rotator drives shafts feature sliding
splined elements to accommodate drive shafts length changes due to rotor head and
engine operational movement.
Activation of the pre-rotator in BRAKE position
The pre-rotator can be activated in BRAKE position to park the rotor blades fore-aft for taxi.
To do so, the pre-rotator switch and the overdrive/override switch in the cockpit panel have
to be pressed simultaneously. Avoid prolonged activation of the pre-rotator with rotor brake
engaged.