Engine Pressure Ratio (EPR)
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ADTS 405 R/F Mk2 Instruction Manual-English | 37
a.
Press
LEAK MEASURE/CONTROL
to enter control mode. Press
SPEED/Qc
.
b.
If necessary, press
RATE
and enter a change of airspeed low enough to observe
switch operation.
c.
Enter an Aim value below the operating limits of the switch (i.e., airspeed switch
operating at 130 kts ± 2 kts set 127 kts).
d.
Press ENTER and observe the airspeed changing.
e.
Using the nudge facility, set to an appropriate step value, increase the Aim value.
f.
Increase the Aim until the switch operates (contacts close) and record the value.
g.
Change the Aim to above the airspeed operating range (i.e. 133 kts). Repeat (steps c.
to e.), decreasing the Aim value until the airspeed switch operates (contacts open)
and record value.
h.
This procedure can be repeated. If many operations of a switch are required use the
oscillating facility detailed in Full Setup, see Section 7.3.4, “SETUP, [OSC],” on page 84.
The above method (steps a. to g.) can be applied for the other parameters:
4.9 Engine Pressure Ratio (EPR)
The ADTS 405 Mk2 may be used to check EPR sensors and indicators. Use Ps for INLET
pressure and Pt for OUTLET pressure. To carry out an EPR check, the display must be showing
pressure units e.g, mbar or in Hg.
4.9.1 Example EPR Test
To enter an EPR of 1.8 with inlet pressure of 500 mbar (15 inHg), proceed as follows:
a.
If the display shows “Leak Measure”, press
LEAK MEASURE/CONTROL
to regain
control.
Note:
The pressure/vacuum pumps must be switched on.
b.
Press
ROC/Ps RATE
to select rate of change of static.
c.
Enter required rate of change e.g, 1,000 mbar/min, (30 inHg/min).
d.
Press
EPR
then
RATE
to select EPR rate.
e.
Enter required value e.g, 5 EPR/min and press
ENTER
.
f.
Press ALT/Ps.
g.
Enter 500 mbar (15 inHg) and press
ENTER
.
h.
Press
EPR
.
i.
The ADTS will control the pressures to the desired EPR value.
Airspeed Switch
Application
Altitude switch
Low altitude warning
Landing gear configuration warning
Height lock
Mach switch
Speed brake scheduling
Mach cruise lock
