56-101-01178 Revision K
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as a set point. If the user selects CAS touch zone and enters the Target for CAS then CAS
becomes the controlling parameter for the PITOT (Pt) channel. Similarly, if the user enters
a MACH Target value then MACH is the controlling parameter.
With a Target value entered for MACH “i.e. Constant MACH”, once the 1811NG reaches the
Target MACH value, the PITOT (Pt) channel controller will continue to maintain the MACH
value requested while the STATIC (Ps) Target value is changed by the user entering a
different ALT Target.
Note:
While operating in constant MACH mode (ie MACH Target set by user) each time
the user changes the ALT Target value you will noticed the equivalent CAS Target
will be automatically computed and updated as the equivalent CAS Target for the
given MACH and ALT Targets requested. You will also notice that when operating in
the constant MACH mode, the CAS Target parameter will be ghosted as a reminder
that CAS is not the controlling parameter during constant MACH mode.
1. If required, from the Main Menu select Display Setup and select ALT, ROC, CAS,
MACH display format.
2. Select Control mode.
3. Wait for Resuming Control to complete.
4. Enter the Target value for MACH.
5. Wait for MACH Target to be achieved.
6. The controller will maintain the MACH target value while the user selects various ALT
target values.
7. On completion of the Constant MACH testing, select Go To Ground and wait for the
Test Set to indicate “Unit is Safe at Ground” to be displayed.
8. At this time, hose can be disconnected from the Test Set.
H. AIRSPEED SWITCH TEST
1. If required, from the Main Menu select Display Setup and select ALT, ROC, CAS,
MACH display format.
2. Select
Control
mode.
3. Enter the Target CAS value below the operating limits of the switch.
Note:
For an airspeed switch with a 140 kts ± 2 kts trip point, start with a CAS Target
of ~136 kts.
4. If necessary, change the RtCAS Target low enough to observe the switch operation.
5. Wait for initial CAS Target to be achieved.
6.
Select CAS touch zone, on Target keypad select “Nudge Mode”.
7. Use the Nudge
Up
key to slowly increase the CAS Target value until the Airspeed
switch trip point is determined.
Note:
If required the Nudge value “CAS Nudge = 0.x kts” can be changed by selecting
the Define Nudge soft key.
8. Record the trip point where the switch contacts closed.
9. Use the Nudge Down key to slowly decrease the CAS Target value until the Airspeed
switch operates (opens).