56-101-01175 Revision P Page | 35
Main Menu: Go To Ground (refer to Figure 37)
Figure 37
Go to Ground Confirm Screen
1.
The user can select “Go To Ground” from the Main menu, while in either Leak Measure
or Control mode. At the conclusion of Go To Ground (refer to Figure 38), the Test Set
will perform an AutoZero function to trim off any small Qc pressure offset that may have
crept into the Qc transducer typically due to thermal component (Test Set Warming or
cooling). The AutoZero function greatly improves the low airspeed (< 50 kts)
measurement accuracy. Also, the Test Set will remain vented to ambient until the
Control mode is selected.
Note:
There are two circumstances where an AutoZero function is performed: (1) at
the conclusion of Go To Ground function and (2) approximately 1 minute if CAS
is < 50 kts while the Test Set is in the Leak Measure mode.
Figure 38
Conclusion of Go To Ground
2. When the AutoZero function is performed, the CB valve (Sv_CB) is OPEN.