Powerplant And Fuel Flashcards
Power plant description
Reverse flow, dual spool, free turbine
4 stages of jet engine
Suck
Squeeze
Bang
Blow
Igniters on this engine?
Primary and secondary
How does the engine work? (What drives what?)
Power turbines drive prop shaft
Where is ITT measured?
Power turbines
Where is the chip detector located?
Reduction gearboxes, behind the prop
Np
Prop rotation (rpm)
When is the air separator opened?
Start, Taxi, takeoff,
approach, landing
Icing and precipitation
What happens to ITT when the separator is opened?
Increases
Is the prop self governing?
Yes, except at spool up
What fuel pumps are located on the engine assembly?
High pressure and low pressure
Which generator is the starter on the Ng and Ngx aircraft?
2
What is stabilized Ng after start?
63%
What does the torque limiter measure?
Oil pressure
How many fuel nozzles?
14
What happens when the high pressure fuel pump fails?
Engine stops
What does the fuel-oil heat exchanger do?
Warms cold fuel
What are 3 ways to move fuel on this AC?
Motive flow
Gravity flow
Fuel pumps
What provides fuel during startup?
Primary and secondary manifolds
RPM at idle on ground
1060
Prop speeds at what rpm are prohibited?
Below 950
How does beta work?
Oil is pulled from the beta valve, which causes the propeller pitch to flatten
What happens to prop pitch on shutdown?
Prop feathers, provided power is on
Where are the igniters located?
4 o clock and 9 o clock positions
Where does the oil level need to be to operate?
Above the red
What is the engine fire detector made of?
Helium filled with a hydrogen core
What is the only way to control prop pitch?
Feather on condition lever
What kind of temp increase will trigger a fire alarm?
General overheat of 250 C
What actuates the fire switch?
Localized temperature increase of 500 C
What lights illuminate with the fire test?
2 master caution
2 master warning
1CAWS Engine Fire
1 CAWS Fire Detect
If fire is suspected, what system must be turned off?
Air cycle machine
When will you get the aural ‘fire-fire-fire’ during a fire test?
Only if GPU plugged in
Idle maintains a minimum prop pitch of what?
6 degrees
What is the MOR lever?
Manual override
What will happen if CL accidentally moved to feather and then back to idle?
Hot start
Why would you need to use the MOR lever?
Fuel control unit failure
What is Ng?
Engine speed
What is torque?
Measures engine torque pressure
What happens at engine start?
Fuel pumps operate, prop spins, oil pressure comes up
During start, when is the condition lever moved to the ground idle position?
At 14% Ng
What indicates a hot start?
Rapidly rising ITT to 1000
What is a hung start?
No ITT or Ng rise within 10 seconds of CL to ground idle
Takeoff power is limited to how long?
5 minutes
Max cruise and climb horsepower?
1000
Max takeoff torque?
44.4
Max takeoff ITT
800 C
Max cruise ITT
720 C
Max cruise torque
36.9
Where can you look to see what types of fuel and oil are approved for the engine?
Pratt and Whitney service bulletin
WHat are 3 propeller protections from overspeed?
Prop governor
Overspeed governor
Nf governor
What are the tanks in the fuel system?
Main tanks
Collector tanks
How is fuel balancing achieved?
Automatically or manually
What keeps the fuel system running once the aircraft is started?
Motive flow from pumps in the collector tanks
What allows fuel flow via gravity from the main tanks to the collector tanks?
Flapper valve
What pumps move fuel from the main to the collector tanks via motive flow or low pressure pump?
Transfer jet pumps (1 ea wing)
Is there a backup for failure of the low pressure boost pump?
Yes, one of the electric fuel boost pumps
When engine is running, what delivers fuel to the engine driven pump?
Delivery jet pumps
What fuel valve would prevent the fuel inspection door from being closed?
Maintenance shutoff valve
What psi causes the filter nipple to pop?
8 psi
Where is the firewall shutoff valve?
Fuel inspection panel, LH side of AC
If the EIS fuel gauge fails, what do you lose?
Fuel balancing computer
What level triggers the fuel low level switches?
Below 133 lb (20 gal)
What fuel pressure triggers a CAWS message?
Below 2 psi
What provides fuel to the engine under normal conditions?
Low pressure fuel pump via jet pumps and motive flow
How many fuel pumps in the system?
8 total
1 high pressure
1 low pressure
2 electric
2 transfer jet pumps
2 delivery jet pumps
Where are the electric boost pumps located?
Collector tanks
What are the electric fuel pump switch positions?
Auto and on
What does an illuminated left or right fuel boost pump CAWS message (green) in flight indicate?
Fuel is being transferred from tank to tank
What would indicate loss of the low pressure engine driven boost pump in flight?
Both green electric pump CAWS lights and a master caution
With loss of the low pressure pump, what else do you lose?
Auto balancing
If the low pressure pump is lost, but you need to balance fuel, how could it be accomplished?
Pull receiving tank CB (if directed by proceedure)
How is contaminated fuel expelled?
Burned and exhausted out (?)
