Gsu 73 Air Hose Fitting Locations - Garmin GDU 370 Installation Manual

4.5.1 Pneumatic Plumbing
The GSU 73 has two ports that are connected to the aircraft's pitot pressure source and static pressure
source. The two ports are labeled on the unit (see Figure 4-2). The pressure ports have 1/8-27 ANPT
female threads. The mating fitting must have 1/8-27 ANPT male threads.
Use appropriate air hoses and fittings to connect the pitot and static lines to the unit. Avoid sharp bends
and routing near aircraft control cables. The GSU 73 should not be at the low point of the pitot or static
plumbing lines, to avoid moisture or debris collecting at or near the unit. Ensure that no deformations of
the airframe surface have been made that would affect the relationship between static air pressure and true
ambient static air pressure for any flight condition. Refer to part 43, Appendix E for approved practices
while installing hoses and connections.
4.5.2 Pneumatic Connections
The following steps should be used to aid in the fabrication of pneumatic hose connections and in
attaching the aircraft pitot pressure source and aircraft static pressure source to the GSU 73.
Check pneumatic connections for errors before operating the GSU 73.
Incorrect plumbing could cause internal component damage. Observe
the following cautions when connecting pneumatic lines.
1. Make sure the aircraft static pressure port is plumbed directly to the unit static pressure input port and
the aircraft pitot pressure port is plumbed directly to the unit pitot pressure input port.
2. Seal the threads of pneumatic fittings at the connector ports. Use caution to ensure there are no
pneumatic leaks.
3. Use care to avoid getting fluids or particles anywhere within the pitot and static lines connected to the
GSU 73.
The installer must fabricate any additional mounting equipment needed. Use outline and installation
drawings in Appendix C for reference.
G3X Installation Manual – GSU 73
190-01115-01
Figure 4-2. GSU 73 Air Hose Fitting Locations
CAUTION
J732
J731
Page 4-5
Revision A