APU/Fire Protection Flashcards
What and where is the APU on the Hawker?
Garrett GTCP36-150W Auxiliary Power System (don’t need to know) located in the rear equipment bay inside an enclosure
What does the APU provide?
DC electrical power and bleed air
Where is the information concerning the APU found in the AFM, and why?
Found in the supplements section, Hawker originally not certified with an APU so all APUs were installed via an STC
What’s the advantage of an APU versus a GPU?
Always have the APU available to you
Where is the APU control panel?
Cockpit entranceway behind the CA
What does the APU control panel monitor?
RPM, EGT, AMPS
What does the APU GEN annunciator mean?
APU generator offline
What does the BLEED AIR ON annunciator mean?
APU bleed air load control valve is open
What does the READY TO LOAD annunciator mean?
APU has reached operating speed
What does the MAIN TEST switch do?
Switch for APU maintenance testing
What does the LAMP TEST switch do?
Switch for APU annunciator lights test
What does the GEN SWITCH do?
Opens or closes the APU generator contractor, providing APU power to aircraft
What does the BLEED AIR SWITCH do?
Opens the load control valve, allowing the bleed air powered systems in the aircraft to run off APU bleed air
What does the MASTER switch do? What are its positions?
START: energizes the APU starter, initiates automated start sequence
ON: this position powers the ECU
STOP: shuts down the APU, used to shut down the APU during all normal operations
What happens when the APU MASTER switch is positioned in the STOP position?
Shuts down the APU, used to shut down the APU during all normal operations
What does the FIRE EXTINGUISHER SWITCH on the APU panel do?
Discharges an additional APU fire extinguisher bottle (beyond the automatically released shot)
What is the function of the APU FIRE SWITCHLIGHT?
APU off: tests fire indicators (lights and bells)
APU on: pressing shuts down APU
What are some conditions that would automatically shut down the APU?
APU fire, low oil pressure, high oil temperature, loss of power to ECU, ECU overcurrent, loss of EGT signal, high EGT, overspeed (above 110%), loss of speed signal
Where does the APU get its fuel?
Left fuel tank
What controls the APU fuel shutoff valve?
APU MASTER switch
What does the starter-generator do on the APU?
When acting as a starter, powered by the batteries or external power via the start bus
When acting as a generator, powers PS2 and PE buses (can power PS1 if bus tie contractor is closed)
What is the function of the APU EMERG SHUT-OFF switch?
Shuts down APU from the switch in the rear equipment bay
What are the APU starting cycle limitations?
1st Attempt: 30 seconds ON, 3 minutes OFF
2nd Attempt: 30 seconds ON, 3 minutes OFF
3rd Attempt: 30 seconds ON, 30 minutes OFF
What are the APU operating limitations (altitudes)?
Operating: 0-30,000’ Pressure Altitude
Starting: 0-20,000’ Pressure Altitude
What are the APU limitations? (Will be asked to list some on the quiz)
Maximum RPM 110%, Maximum Operating EGT 1,350ºF, Maximum Transient EGT 1,400ºF to 1,500ºF for 15 seconds, Shutdown APU if READY TO LOAD light not illuminated within 60 seconds, Do not attempt in flight start if both main generators fail, APU start prohibited with left engine shutdown due to fire or engine failure, Maximum Generator load 0.80, Maximum transient generator load 1.2 for less than 10 seconds, Simultaneous operation of APU and engine bleed air limited to 1 minute, Inflight operation of APU prohibited in icing conditions, APU must be shutdown during ground de-ice operations, APU operation must be attended with pax onboard, APU must not be started during refueling operations, APU operation refueling limited to single-point pressure refueling
What are some of the limitations in regard to bleed air? 1-2-3
1 minute with main air valves and APU bleed operations running simultaneously
2 minute run with “no load” before placing bleed air load on the APU
3 minutes in between start attempts
How many fire indications are in the cockpit? Why?
6 or 7 - 7 if engine instruments are on the SIC’s PFD, 6 if not
What is the engine fire protection system composed of?
Two sensing elements and responders per engine, roof panel indicators, warning bell, two engine extinguisher bottles, two test switches
What is the APU fire protection system composed of?
Four overhead detectors, warning light, warning bell, one fire extinguisher bottle
How are fires extinguished in the engines? Where are they located?
Two dual-head single use fire extinguisher bottles located in the rear equipment bay
How do the extinguishing bottles work and which engine does each extinguish?
Each bottle is capable of discharging its total contents into zone one of either engine, both bottles can be discharged into a single engine, or one bottle can be discharged into each engine
Which extinguisher shots are on which bus, and what bus are the warning circuits on?
SHOT 1 is powered by PE, SHOT 2 is powered by PS2. The warning circuits are powered by the PE bus
What is the most basic thing that the fire detection system is telling us?
Something is hot
What does each engine have for fire detection?
2 sensing elements, 2 responders, 2 zones
How can we vent excess pressure from the engines?
Thermal pressure will blow out pressure relief disks under the left engine pylon, and the extinguishing agent will vent overboard
What does the APU fire detection system compose of?
Four overheat detectors, warning light on APU control panel, fire bell, one fire extinguisher bottle
What happens in the APU when a fire is detected?
Detection of overheat condition will illuminate APU FIRE indicator, activate fire bell, and automatically shut down APU
When does the APU extinguisher bottle activate?
Automatically discharges 5 seconds after APU auto-shutdown due to overheat
How can the APU extinguisher bottle manually be activated?
Red guarded toggle switch on APU control panel
What does the REAR BAY OVHT annunciator indicate?
Overheat condition in rear equipment bay, red MWS flashers will activate, no fire extinguishing available.
