GE Druck ADTS 405 User Manual page 100

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When GROUND is pressed, a menu gives a choice of three ground functions:
[GO TO GROUND]
Note: The Go-to-Ground operates only in Control Mode.
Selecting [GO TO GROUND] automatically enters an altitude or static aim equivalent to
local atmospheric pressure (QFE) and an airspeed or dynamic pressure aim of zero.
The system pressures will then be controlled towards these aims, in the normal way, at
the rates set by the ROC/Ps Rate and RATE keys. At any time when going-to-ground,
a new rate of change can be entered, the ADTS 405 continues going-to-ground.
At any time during going-to-ground, a new value aim for ALT, CAS, TAS, Mach, Ps, Qc, Pt
or EPR can be entered. This causes the procedure to stop and normal controlling
operation to start.
When the airspeed is zero and the Ps channel pressure is close to ground, the QFE is
re-measured to update the stored "ground" pressure value, the display shows the
message "CHECKING GROUND". The ADTS 405 then reconnects to the system under
test and equalizes the pressures.
The display shows the message "Safe At Ground"; the ground and zero valves remain
open so that the aircraft system permanently vents to atmosphere. No commands
can be entered when these two messages are displayed.
Press CLEAR/QUIT to continue with normal operation. The ground and zero valves
then automatically close.
[DISPLAY QFE]
When [DISPLAY QFE] is selected, the local atmospheric pressure recorded during the
power-up sequence is displayed as QFE in the default units set in configuration.
Press CLEAR/QUIT to return to the normal user display.
[DISPLAY QNH]
When [DISPLAY QNH] is selected, the local atmospheric pressure recorded during
power-up is converted to the equivalent sea level pressure. The display shows QNH, in
the default units set in configuration, together with the station (airfield) altitude.
The station (airfield) altitude can be changed in full set-up mode by using SETUP,
GROUND.
K114 Issue No. 9
Reference and Specification