Chapter 4. Operation
38 | ADTS 405 R/F Mk2 Instruction Manual-English
© 2017 General Electric Company – All Rights Reserved.
Note:
EPR testing can also be performed by specifying the actual INLET and OUTLET
values.
4.10 Testing Aircraft Systems or UUT
a.
Connect the applicable hoses and adapters to the aircraft system or UUT.
b.
Do a leak test detailed in the appropriate aircraft or component manual, to make sure
that the connections to the aircraft system or UUT are not leaking.
4.10.1 Go To Ground and Shutdown
At the end of testing and, before disconnecting from the aircraft system or UUT, the
pressures in the system must be taken to the local atmospheric pressure (ground) with zero
airspeed, as follows:
a.
If the display shows “Leak Measure”, press
LEAK MEASURE/CONTROL
.
b.
Press
GROUND
,
F1
[Go To Ground].
c.
Wait for the display to show “Safe At Ground”.
d.
It is now safe to disconnect the aircraft system or UUT.
The pressure in the system changes towards ground. The ground pressure or “Ground”
replaces the static or altitude aim value.
4.10.2 While Going to Ground
If required, new rates of change can be entered while going to ground.
a.
To change the ROC or static rate, press
ROC/Ps RATE
and enter the new value.
b.
To change the airspeed or Qc rate, press
SPEED/Qc
then
RATE
and enter the new
value.
4.10.3 Resuming Testing after Going to Ground
When the airspeed reaches zero and the Ps channel pressure nears ground, the system re-
measures atmospheric pressure to update the recorded ground pressure (QFE). During this
period, the display shows the message “Checking Ground”. The ADTS 405 Mk2 then
reconnects to the aircraft system and equalises the system pressures. Commands cannot be
entered when these two messages are displayed.
The Ps channel pressure is then taken to the new recorded atmospheric pressure and, at this
new pressure, the display shows the message “Safe At Ground”. The ground vent and zero
valves remain open to keep the aircraft system vented to atmosphere.
a.
Press
CLEAR/QUIT
to continue with normal operation. The ground vent and zero
valves automatically close.
a.
Press
LEAK MEASURE/CONTROL
to return to Control mode.
CAUTION
Observe the appropriate safety instructions and procedures
detailed in the aircraft maintenance manuals or component maintenance
manuals.
