G900X/G950 Installation and Maintenance Manual – Troubleshooting
Page D-59
190-00719-00
Revision D
NOTE
If any of the three measurements (Altitude, Vertical Speed, Power On Time) are
outside of their respective displayed limits, the displayed measurement will appear in
red, and the ‘OK’ button will be unavailable (grayed-out). If successful calibration is
not achievable, clicking ‘Cancel’ will halt the program and produce the below popup
message.
Figure D-7. Calibration Failed Screen
14.
After the 0 feet calibration is complete, the ‘Set altitude to 11,000 ft’ screen appears.
15.
Per the on-screen instructions, set the pressure control system to a pressure altitude of 11,000 feet.
16.
Allow the on-screen altitude reading to stabilize, then click ‘OK’.
17.
After the 11,000 feet calibration is complete, the ‘Set altitude to 30,000 ft’ screen appears.
18.
Per the on-screen instructions, set the pressure control system to a pressure altitude of 30,000 feet.
19.
Allow the on-screen altitude reading to stabilize, then click ‘OK’.
20.
After the 30,000 feet calibration is complete, the ‘Set altitude to 41,000 ft’ screen appears.
21.
Per the on-screen instructions, set the pressure control system to a pressure altitude of 41,000 feet.
22.
Allow the on-screen altitude reading to stabilize, then click ‘OK’.
23.
After the altitude calibrations are complete, the ‘Program Calibration to Unit?’ screen (Figure
D-8) appears. Click ‘OK’ to program the new calibration to the GDC 74(X) unit.
NOTE
Before the new calibration is written to the unit, the program stores the current
calibration to a file named CAL_(serial_num)_YYYYMMDD_ HHMMSS.txt that
can be used to restore the original calibration back to the unit if needed (refer to the
“To Restore Original Calibration” section).
