Trio Avionics EZ Pilot - v 1.9 - Manual (Page 22)

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A preflight check on the EZ Pilot at this point would be to engage the servo by pressing the
SERVO POWER pushbutton momentarily and noting that the SERVO POWER LED illuminates.
The servo is now locked to the control system. The pilot should intentionally force the ailerons to
their extreme positions to verify the slip clutch on the servo will allow the pilot to continue to fly the
airplane in the event the servo malfunctions (Section 7.5). If this is not possible the aircraft
should be grounded until this discrepancy is resolved. If this check is satisfactory the
SERVO POWER button should be pressed again to disconnect the autopilot from the controls.
Verify that the LED is not illuminated and the servo is not engaged for takeoff.
Since the GPS is not yet powered up, after about 7 seconds the display shows the NO GPS
message. The pilot now applies power to the GPS unit that is connected to the EZ Pilot and
programs the GPS flight plan. On GPS power up, the display on the EZ Pilot may show
navigation data momentarily on the display, as some GPS receivers will send sporadic GPS data.
Typically, the NO GPS message will return as this data transfer ceases. When the GPS receiver
attains satellite acquisition and lock, the EZ pilot will display the power up default screen
previously illustrated. Some GPS receivers, even though they have obtained satellite lock, do not
put out valid NMEA or AVLINK data until a flight plan or “GO TO” waypoint is entered or a preset
groundspeed is attained (usually 2 to 5 kts). In this case either the “NO GPS” message or the
“NO FPLAN” mode will be displayed.
Some GPS receivers’ output data are capable of providing groundtrack and groundspeed
information to the EZ pilot after satellite lock, even before a flight plan is entered. The EZ pilot will
detect this and provide the pilot with a modified CRS mode capability. In this mode, manual
transition to the TRK or INT mode is inhibited and “NO FPLAN“ is displayed on the screen. In the
NO FPLAN mode the pilot may use the autopilot to fly a selected groundtrack. Once a flight plan
has been entered the TRK mode is automatically selected.
The flight plan is now entered and activated in the host
GPS unit. As the first “TO” waypoint
becomes active the EZ Pilot will display the parameters associated with navigation to that
waypoint. A check should be made to verify agreement between the data displayed on the EZ
Pilot and the host GPS system.
Important: If all of the above actions cannot be properly achieved, turn the EZ Pilot off and do not
attempt to engage the autopilot in flight. If there is any indication of an aileron control
system problem do not fly the airplane until it has been corrected.
Note: If the adjustment of servo rotation direction and servo neutral (section 7.6)
has not yet been accomplished, it must be done now, before flight.