APU and Fire Flashcards
what is the engine fire protection system composed of
two sensing elements, responders, roof panel indicators, warning bell, two engine extinguisher bottles, two test switches
what is the apu fire protection system composed of
four overheat indicators, warning light, warning bell, one fire extinguisher bottle
what is the “fire” detection actually sensing
overheat
what annunciator goes off when there is a “fire”
ENG1/2 FIRE
MWS Lights
warning bell
how can the fire bell be turned off
BELL CNCLD button
how many thermal switches are in the rear equipment bay – what is the protocol
6 – land asap!
what type of fire extinguisher is in the aft equipment bay
dual head, single shot
(right bottle to left engine)
What are shot 1 and 2 powered by
Shot 1: PE bus
Shot 2: PS 2
how many overheat detectors in the APU
4
what happens if the APU overheat detects something
fire bell and automatic shut down
APU bottle discharges automatically after shutdown
what is the APU
Garrett GTCP36-150W Auxiliary Power System
purpose of APU
provides DC power and environmental air bleed on ground and flight
what conditions will cause APU shutdown to occur
fire, low oil pressure, high oil temperature, loss of power to ECU, ECU overcurrent, loss of EGT signal, high EGT, overspeed, loss of speed signal
APU MAx RPM
110%
APU max EGT
1350F
APU max transient EGT
1400 to 1500 for 15 seconds
APU operation altitude
0 - 30,000 ft pressure altitude
APU starting altitude
0 - 20,000 pressure altitude
APU shutdown if READY to LOAD light not illuminated within
60 seconds
if both main generators fail can you attempt an in-flight start
no!
When is APU start prohibited
when left engine has been shut down for fire or engine failure
if automatic shutdown has occurred
max generator load .8
max transient load 1.2 for less than 10 seconds
refueling operations (but can operate just not start)
can you have the APU on in icing conditions (ground or air)
NOOOOOOOOO apparently
how was the APU added to the hawker
supplemental typer certificate
what does the APU provide
bleed air and DC electrical power
what do you always monitor on the app panel
RPM, heat
how long “should” the apu run before loading it
2 minutes
APU On annunciator
the apu switch is in the “on” position
what is the preferred way to shut down the APU
stop button
then off switch
allows monitoring for engine shut down
automatic ECU shutdown of apu will occur in flight or on ground if any:
apu fire
low oil pressure
high oil temperature
DC power interruption to ECU
overcurrent to ECU
Loss of EGT signal
high EGT above red line
overspeed in excess of 110%
loss of speed signal
as a generator, the apu powers
Ps2 and PE bus
how does the apu power PS1
manual closing of the bus tie
aPU starter limitations
30 seconds on 3 minutes off
30 seconds on 3 minutes off
30 seconds on 30 minutes off
max transient EGT
1,400 to 1,5000 EGT for 15 seconds
do not attempt in-flight start of APU if
both main generators have failed
(attempting to start will drain battery)
do not attempt start of APU if ____ engine has been shut down due to _____
left engine, engine fire or failure
max generator load APU
.8
max transient generator load
1.2 for less than 10 seconds
simultaneous operation of APU and engine bleed air
limited to 1 minutes
in flight operation of apu is prohibited in:
icing conditons
with main air valves and apu bleed operations running simultaneously
1 minute
no load before placing bleed air load on apu
2 minutes
between start attempts
3 minutes
how many lights of fire indication
6 or 7
it will be 7 if engine instruments are one Copilot’s PFD
fire condition is indicated by
ENG 1 or ENG 2 FIRE look up
ENG FIRE annunciator on FIRE panel
FIRE message on N1 gauge
REd MWS lights
Associated HP cock warning lights
fire bell
fire bell can be canceled by
pressing appropriate BELL CANCEL switch light
locks switch into cancel position - white annunciator
where are the fire extinguishers
located in rear equipment bay
what is a dual head single use fire extinguisher
each bottle is capable of discharging its total contents into the ozone one of either engine
both bottles can be discharge into a single engine, or one bottle into each engine
SHOT 1 is powered by
PE bus
SHOT 2 is powered by
PS2
recommended to push this one first in event of loss of generator power
warning circuits powered by
PE
fire system:
what does it tell us
2 sensing elements, 2 responders, 2 zones
something is hot - NOT that there is a fire
fire extinguisher pressure relief indicator
located under left pylon
if apu detects fire
automatically discharges within5 seconds after apu auto shutdown due to overheat
Engine fire extinguisher bottles are in the
rear equipment bay
the exterior preflight check of the fire extinguishers includes
checking the condition of two engine discharge indicators
the engine fire bell can be silenced
by pressing the BELL CANCEL switch
which statement is true regarding discharge of the fire bottles
when a visual fire warning appears, discharge SHOT 1 first then SHOT 2 if neccessary (Purdue recommends shot 2 before shot 1)
the following bus bars provide DC power for engine fire extinguisher operation
PE and PS2
a portable handheld fire extinguisher is stowed in the
cockpit and baggage compartment
for a fire in the apu
a switch on the apu control panel controls the firing of a separate fire extinguisher
the apu fire extinguisher automatically discharges _____ seconds after detection of the apu fire alarm
5 seconds
