Instruction Manual

G500H Flight Display System 190-01150-11 Rev. 2
Instructions for Continued Airworthiness Bell 206A/B Series Page 17 of 19
Return to Service
After removing and reinstalling the GMU 44, the following return-to-service checks should be performed.
1. Power up the G500H system with the GDU 620 in normal mode.
2. Verify that the GDU displays valid heading within approximately one minute. Note that heading
can remain invalid if the magnetometer is near a large metal structure such as a hangar wall or if
the magnetometer is close to a large ground power cart.
3. Verify that no unexpected alerts are present. If alerts are present, troubleshoot using Section
2.6 of this ICA.
2.7.4 GDC 74H Unit
2.7.4.1 Removal
1. Disconnect the pitot/static plumbing from the rear of the unit. Disconnect the single connector.
2. Remove the two (2) screws on the mounting plate near the pitot/static ports. Loosen the other two
(2) screws.
3. Carefully remove the unit from its mounting location.
2.7.4.2 Installation
1. Place the unit in the mounting tray.
2. Position the unit and fasten using the four (4) screws.
3. Connect the pitot/static plumbing.
4. Inspect the connector and pins for damage. Repair any damage.
5. Connect the connector to the unit, ensuring that each jackscrew is secured.
Original GDC 74H is Reinstalled
If the original GDC 74H is re-installed, then no software loading is required. This does not include
units that were returned for repair as their software and configuration files are deleted during the
repair testing process.
New, Repaired or Exchange GDC 74H is Installed
If a new, repaired, or exchange GDC 74H unit is installed, then software must be loaded to the unit.
Refer to Section 5.4.4 of the G500H STC Installation Manual for more information.
GDC 74H Configuration Module is Replaced
If the GDC 74H Configuration Module is replaced, the GDC 74H must be configured. Refer to
Section 5.5.8 of the G500H STC Installation Manual
2.7.4.3 Return to Service
After removing and reinstalling the GDC 74H, the following return-to-service checks must be performed.
1. Power up the G500H system with the GDU 620 in normal mode.
2. Verify that the GDU displays valid air data within approximately one minute.
3. Verify that no unexpected alerts are present. If alerts are present, troubleshoot using Section
2.6 of this ICA.
4. Perform a leak check of the pitot-static system and observe the airspeed, altitude, and vertical
speed for proper operation.