Trio Avionics EZ Altitude Control - Manual (Page 5)

5
READY
ALT
HOLD
with a green ALT HOLD message on the LCD display. (At this time servo activation should be
detected by resistance to manual yoke or stick movement forward or backward)
To disconnect the EZ altitude control system servo activation either the REMOTE AUTOPILOT
DISCONNECT switch or the LCD SWITCH may be momentarily pressed.
During normal operation in the altitude hold mode the ENCODER knob may be used to dial in
very fine corrections to the engaged altitude. Rotating the knob clockwise will cause an altitude
increase, rotating the knob counterclockwise will result in an altitude decrease.
In addition to the servo disconnect function the REMOTE AUTOPILOT DISCONNECT switch can
be used to “fly to” another altitude. This is accomplished by pressing and holding the REMOTE
AUTOPILOT DISCONNECT switch for a period of more than three seconds. When pressed, the
servo will immediately disengage so the airplane can be flown to a different altitude and will rearm
after the three second delay period. While in the armed mode the LCD switch will flash the
amber backlight and will display ALT HOLD. On the EZ-1 system, releasing the remote
disconnect switch (after the 3 second interval) will engage the servo, show a green LCD ALT
HOLD message and hold the aircraft at the proper altitude. The EZ-2 and EZ-3 systems add a
VS rate capture or an airspeed capture as additional options to this sequence (section 8.1.4)
3.1 Startup
It is strongly recommended that a 3 to 5 amp switch or circuit breaker be used to power
the EZ altitude control system. This switch or circuit breaker will provide absolute
emergency disconnect of the altitude hold servo should all other disconnect measures
fail. Once the aircraft engine is started, part of the pre-taxi checklist should be to apply
power to the system by engaging the switch or circuit breaker. Power should be applied
as soon as possible after engine start to ensure the inertial components within the
system are stabilized prior to takeoff.
After power is applied, the system will undergo a brief startup
sequence which will last approximately 8 seconds. During this
time the amber SYSTEM TEST message will be displayed.
After this short period the unit will become fully functional and
the LCD switch will display a green READY message.
3.2 “ALT HOLD” Mode
The altitude hold function is activated by momentarily pressing
the LCD switch which will then annunciate a green ALT HOLD
message on the LCD display. (During pre-taxi checks, servo
activation can be detected by resistance to manual yoke or
stick movement forward or backward).
IMPORTANT: Prior to taxi, momentarily press the remote
disconnect switch to disengage the servo. The LCD switch will
then display the READY message. A pre-flight checklist item
should be created to ensure the altitude hold system is disengaged (in the READY
mode). An additional safety feature available on the EZ-2 and EZ-3 systems is an
automatic servo disconnect on takeoff.
Once the aircraft is in flight, and the desired altitude has been reached, the aircraft should
be trimmed for stable, level flight. The pilot may then simply press the LCD switch and
the EZ altitude control system will enter the altitude hold mode and the LCD switch will
display ALT HOLD while it is employed. The servo will engage the elevator system and
control the elevators to maintain the desired altitude.
To disconnect the EZ altitude control system, the pilot may momentarily press either the
LCD switch or the REMOTE AUTOPILOT DISCONNECT switch on the stick or yoke.