190-01639-00
GSU 75 ADAHRS Installation Manual
Rev. 6
Page 2-4
2.7 Pneumatic Plumbing
The GSU 75 has two stainless steel ports that are connected to the aircraft’s pitot pressure source and static
pressure source. The two ports are labeled on the unit (Figure 2-1). 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 75 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.
Figure 2-1 GSU 75 Air Hose Fitting Locations
2.8 Cooling Air
No cooling air is needed for the GSU 75 or GMU 44.
2.9 GTP 59 Icing
The GTP 59 OAT probe has no icing protection. If ice accumulates on the GTP 59 OAT probe air
temperature measurements may be incorrect. Furthermore, computations dependent upon air temperature
measurements may be affected (e.g. true airspeed and delta-ISA).
PITOT AIR FITTING
1/8-27 ANPT FEMALE THREAD
STATIC AIR FITTING
1/8-27 ANPT FEMALE THREAD
P751
340095
The document reference is online, please check the correspondence between the online documentation and the printed version.
