Gsu 73 -Air Data Troubleshooting; Airspeed And Altitude Failure Indications - Garmin GDU 370 Installation Manual

9.4 GSU 73 –Air Data Troubleshooting
Under normal operating conditions, the GSU 73 provides the following air data information:
•
Total Air Temperature is measured
•
Outside Air Temperature (OAT)
•
Indicated Airspeed (IAS)
•
True Airspeed (TAS)
•
Barometric Altitude
•
Density Altitude
•
Pressure Altitude
•
Static Pressure
•
Differential Pressure
If the TAS and/or OAT indications are dashed out as shown in Figure 9-5:
1. Check the GTP 59 OAT probe wiring and connection for faults.
2. Check GSU 73 configuration module wiring for damage. Replace if any is found.
3. Replace the GTP 59 OAT probe.
4. If the problem persists, replace the GSU 73 with a known good unit
TAS information can only be displayed at speeds greater than 20 Knots (i.e. TAS is
invalid when the aircraft is sitting still).
If the Airspeed and/or Altitude is failed and shows a Red-X condition as shown in Figure 9-6:
Figure 9-6 – Airspeed and Altitude Failure Indications
G3X Installation Manual - Troubleshooting
190-01115-01
Figure 9-5 – No info for TAS & OAT
NOTE
Page 9-7
Revision A