BMS F-16C/D 4.34, Flight Manual

Page: 24 / 234

T.O. BMS1F-16CM-1 BMS 4.34 Change 2.00
BMS 4.34 Dash 1
© Red Dog 2012-2019
Page: 24
1.2.1.10 EPU panel
The EPU is a self-contained system that simultaneously provides emergency hydraulic
pressure to system A and emergency electrical power to the emergency buses. The EPU
automatically activates (unless the EPU safety pin is installed) when both main and
standby generators fail or when hydraulic pressure falls below 1000 psi.
The EPU uses engine bleed air and/or hydrazine to operate. If engine bleed air is sufficient
to maintain operating speed
the EPU doesn’t use hydrazine. Hydrazine is only used as a
booster when bleed air is not sufficient.
The main switch for the EPU is a double guarded three-position switch. With the guard down the
switch is locked in NORM.
OFF - the EPU is prevented from running.
NORM - the EPU is armed for automatic start upon failure of the main and standby generators, if the
throttle is out of the CUTOFF position. The EPU will not start on shutdown (WOW and throttle in
CUTOFF). On engine start the EPU pin prevents the EPU from starting up. The EPU pin should be
removed via the ATC menu > Ground page prior to the EPU test.
ON - the EPU is commanded to RUN regardless of failure conditions.
As you see on the panel the switch is guarded, but any mouse click on the switch lifts the guard and
operates the switch at the same time. In other words the guard has no effect in BMS.
The EPU RUN green light comes on whenever the EPU turbine runs within the proper range and the
EPU hydraulic pressure is above 2000 psi.
The top indicator is telling the pilot if the EPU runs on engine bleed air and/or hydrazine.
When the yellow AIR indicator lights up (bottom light) the EPU is running on bleed air which is
sufficient to maintain operating speed. If possible when the EPU runs, engine RPM should be
maintained between 82 & 90% to prevent the EPU using hydrazine. Unfortunately in Falcon when the
EPU needs to run i
t’s usually because we’ve lost the engine.
When the yellow HYDRAZN (top light) comes on, the bleed air is not sufficient to maintain operating
speed and is being augmented by hydrazine. In that case both indicator lights will be on.
Hydrazine is limited and usually depletes in 10 minutes under normal load requirements. Increased
flight control movement reduces this operating time further. Also bear in mind that if the EPU is your
sole source of hydraulic pressure and power, when the hydrazine is depleted you lose everything. As
a consequence when you start running on hydrazine, plan to be on the ground within the next 10
minutes or tighten your straps ready for an ejection. For more information about the EPU and which
systems are powered by the emergency bus please refer to the Electrical and EPU section later in
this manual.
BMS Key Callbacks for the EPU panel:
SimEpuToggle
SimEpuOff
SimEpuOn
SimEpuAuto
SimEpuUp (step up)
SimEpuDown (step down)