Engines Flashcards
How much thrust does each engine produce?
4,660 Lbs of Thrust, static, at sea level up to 73 deg F
50R-1H engines are flat rated to a higher altitude and temp
What is the engine designator for the 900XP?
Garrett TFE731-50R-1H
What five components comprise the bypass section?
Fan spinner support Fan rotor assembly Fan bypass stator Fan duct assembly Bypass fan support and shaft section
What drives the fan?
Low pressure N1 spool through the planetary gear section
How many stages are in the LP N1 spool?
Four
What two components comprise the LP N1 Spool?
Compressor
LP turbine
Describe the LP N1 spool compressor
Four stage, low pressure, axial flow
Describe the LP N1 turbine
Three stage, low pressure turbine
What does a stage consist of?
A paired rotor and stator
What does the HP N2 spool consist of?
Single stage centrifugal compressor
Single stage turbine
What drives the HP N2 spool?
Outer concentric shaft
What three components comprise the N2 compressor?
Impeller (rotor)
Diffuser
Compressor manifold
What happens when air reaches accelerating air reaches the N2 diffuser?
Velocity is reduced, converting kinetic energy into pressure
What additional component does the HP spool drive?
Accessory gearbox
How is the accessory gearbox driven?
Through a tower shaft and transfer gear reduction system
How many fuel nozzles are there in each engine?
12
What are the primary fuel nozzles used for?
All phases of engine operations including engine start
What are the two types of fuel nozzles?
Primary and secondary
What are the secondary fuel nozzles used for
All phases of engine operation except engine start
How many igniter plugs are there and what are their positions?
Two; six and seven o’clock
How many turbine wheels does the turbine contain?
One high pressure
Three low pressure
Where does gas go after leaving the turbine section?
Gas enters the nozzle system
Why are hot and cold air flows mixed through the convergent-divergent nozzle?
Results in more efficient use of thermal energy in hot core flow and also benefits smoke and noise reduction
How many thermocouples are located in the gas path between the high pressure turbine and the first stage of the low pressure turbine?
10
Where are the thermocouples located?
Between the high pressure stage and first low pressure turbine stage
What do the thermocouples do?
Measure the interstate turbine temp (ITT)
Send signals to the cockpit indicator and fuel computer
What six components does the accessory gearbox provide shaft power for?
Hydraulic pump Starter/generator Alternator Fuel pump Fuel control unit Oil pump
What are the seven powerplant systems?
Engine oil Ignition Fuel control Power controls Bleed air Automatic Performance Reserve Thrust reverser
What are the eight components of the engine oil system
Oil tank and sight gauge Oil pump Oil filter and bypass valve Air/Oil cooler and bypass valve Fuel to oil cooler Oil to fuel cooler Breather pressurizing valve Pressure and temperature transmitters and indicators
Where is the oil pump assembly located?
On the accessory drive gearbox
How many and what kinds of pumps does the oil pump assembly consist of?
One oil pressure pump
Four scavenge pumps
Where do the scavenge pumps collect from?
Planetary gear assembly and forward engine bearings
Aft engine bearings
Transfer gearbox and Mid engine bearings
Accessory drive gearbox
How does the oil pump assembly compensate for pressure changes due to aircraft altitude
Through the adjustable pressure regulator
Where is the oil filter located?
In a metal housing on the right side of the accessory drive gearbox
What is the capacity of the engine oil reservoir
1.65 US Gals
Where is the engine oil reservoir located?
On the right side of the engine fan bypass housing
What prevents the oil filter bypass indicator valve from actuating under cold oil conditions?
A thermal lockout device
Where is the fuel heater located?
On the left side of the engine
What does the fuel heater prevent?
Provides oil-to-fuel heat exchanging to prevent ice formation in the fuel system from clogging the fuel filter and other components
Where are the air/oil coolers located?
In the engine bypass duct
What device directs oil to or around the air/oil coolers?
The temperature control valve
What does the fuel/oil cooler do?
Uses aircraft fuel to maintain the oil at a constant temperature
What are the two components of the fuel/oil cooler?
Temperature control valve
Heat exchanger
What are the five components of the ignition system?
Ignition unit Igniter leads Igniter plugs ENG IGNITION switches IGN ON annunciators
From where does the ignition unit receive power?
PE busbar
What are the three positions of the ignition switch?
OFF-AUTO-ON
Under what conditions should he ignition switch not be in AUTO, and what position should it be in?
Icing conditions; ON
At what point does the DEEC send an ignition request to the subject engine?
When N2 drops 500RPM when not commanded by the pilot through power lever movement
What is the approximate rate of fire for each igniter?
2 sparks per sec
From what ignition system device do the igniter plugs receive power?
From the ignition unit via independent high-tension leads
Where are the igniter plugs located?
On the combustion chamber
What are the five components of the fuel control?
Fuel pump assembly Hydromechanical Fuel Control Unit (FCU) Digital Electronic Engine Control (DEEC) Fuel Flow Divider Assembly Fuel atomizers
What are the five components of the fuel pump assembly
Booster pump element Fuel filter Filter bypass valve High pressure pump element Relief valve
Where is the fuel control unit located?
Attached to the rear of the fuel pump assembly
What does the fuel anti-ice valve do?
Mixes warm fuel from the fuel heater with the discharge flow of the booster pump to prevent icing of the fuel filter element
What does the fuel filter bypass do?
Allows fuel to bypass the filter if an excessive pressure drop across the filter occurs
What does the ENG # FUEL light indicate?
Excessive differential pressure or excessive fuel temp
Indicates ONLY a potential filter bypass
What event occurs if a fuel filter starts to become clogged with a differential pressure of 6-8 PSI?
Amber annunciator on MWS
What occurs if the fuel filter starts to clog with a differential pressure of 9-12 PSI?
The filter bypass opens to deliver fuel to the HP pump
What are the six components of the fuel control unit?
Fuel monitoring section Power lever input pot Shutoff valve Outlet pressurizing valve Ultimate overspeed solenoid Mechanical governor (N2)
What are the two modes of the mechanical governor?
As an overspeed governor for the HP rotor if the fuel computer is operative
As a Hydromechanical control when the fuel computer is Inop.
What devices operate the two FCU shutoff valves?
The throttle
Electronic engine computer
What happens if the DEEC senses an ultimate overspeed condition?
The DEEC closes the shutoff valve, fuel flows stops and the engine shuts down
Where is the inlet pressure and temperature sensor located?
On the cowling forward of the fan inlet
What powered the anti-icing for the inlet pressure and temperature sensor?
Electrical power from the PE bus bar
What is the control parameter for the DEEC?
N1
How many DEEC’s are there and where are they located?
2, located in therear equipment bay
What does the DEEC control?
Engine acceleration and deceleration
What are the modes of operation for each ENG CMPTR?
AUTO
OVRSPD PROT
(OFF)
What powers each DEEC when in the automatic mode?
28VDC from the PE busbar
What are the six inputs to each DEEC?
Engine inlet pressure (PT2) Engine inlet temperature (TT2) Interstage turbine temp (ITT) N2 speed N1 speed Power lever angle (PLA)
The DEEC commands an engine shutdown at what N values?
107% N1
107.7% N2
What happens if the DEEC malfunctions?
FCU switches to manual mode and the ENG # CMPTER annunciator will illuminate
How many total CMPTER MWS annunciations are there?
7
What are the two red computer annunciations?
ENG # COMPTER
When does the red ENG # CMPTER annunciator illuminate?
During a total failure of the corresponding DEEC
What is the memory action in the event of a red ENG # CMPTER annunciation?
ENG # CMPTER switch to OFF
What happens when the ENG CMPTER switch is set to off?
Engine control is totally manual
Engine overspeed protection limited to the FCU mechanical governor
Ultimate overspeed protection is not available
What does a yellow ENG # CMPTER annunciation indicate?
The respective DEEC has an internal fault but the the computer is still functional, to include ultimate overspeed protection
Is any action required in flight for a yellow ENG # CMPTER annunciation?
No in flight action required
What does the yellow ENG # CMPTER MM indicate?
A failure of the respective computer, and it had reverted to manual mode,
or:
The ENG CMPTER switch is off
What does the ENG CMPTER OVSOD PROT mode provide?
Ultimate overspeed protection only
What does a white ENG DEEC MINOR light indicate?
A minor fault but the computer is totally in control of the engine, ultimate overspeed protection is still available
What does the surge bleed valve do?
Provides surge protection for the engine by opening the valve to allow bleed air into the bypass duct to smooth pressure through the engine to prevent compressor stalls and surges
What device controls the surge bleed valve
The DEEC
For what conditions does the DEEC normally position the surge bleed valve to open?
Start
Idle
For conditions does the DEEC normally position the surge bleed valve to closed?
High RPM conditions
What position is the surge bleed valve set to when the DEEC is OFF or failed?
1/3 open
How does the DEEC position the surge bleed valve during transient rpm conditions?
DEEC modulates the surge valve in response to impending stall conditions
Where is the fuel flow divider assembly?
Between the FCU and the fuel atomizers
What does the fuel flow divider assembly do during engine start?
Routes fuel at a reduced rate to the primary atomizers
How many fuel atomizers are there per engine?
12 duplex (primary and secondary)
How many fuel manifolds are there per engine?
Two
How does the fuel heater work?
Diverts a portion of engine fuel supply through fuel heater by the thermostatically operated anti-ice valve located in the fuel pump to prevent ice formation in the fuel system from clogging the fuel pump assembly fuel filter
What does a yellow ENG # FUEL light indicate?
The fuel filter is blocked and is being bypassed
What four components does the fuel flow indicating system consist of?
Fuel flow transmitter
Signal conditioner
Flow rate indicator
Fuel flow/fuel used indicator
How does the fuel flow indicating system operate?
The transmitter is turbine-driven motor that rotates and generates an AC electric signal as fuel flows past it. From the transmitter a signal conditioner converts the AC signal to DC for the indicators
What five components does the engine power control system consist of?
Throttle levers HP fuel cocks Fuel control unit DEEC Engine synchronization
How are the throttles connected to the FCU?
Mechanically through cables and a tele-flex control
What position must the HP cock be in to allow full travel of the throttle?
Forward position
What happens to the throttle when the HP cock is closed?
The associated throttle is locked in the IDLE position
At what N1 setting will a warning horn go off if the gear is not down?
65%
When will a warning horn sound if you are advancing the power?
If the air brakes are extended and gear is down
What is the mechanical limit for power when the elevator gust lock is installed?
60% for both engines, though a single engine can be advanced without limit
What two items are controlled by the HP cock
FCU
Hydraulic supply valve
Closing the HP isolates the engine of what?
Hydraulic and fuel supplies
Removes power to the igniter unit via a microswitch in the lever
What are the three positions of the ENG SYNC switch?
N1, N2, OFF
What engines are the master and slave for synchronization?
Left is master
Right is slave
What is the engine synch max authority range at mid-throttle?
+- 2.5% N2
Does the engine synch have any effect at full throttle?
No
What position must the ENG CMPTR switches be in IOT use engine sync?
Both switches must be in AUTO
Does engine sync work when the APR is armed?
No
What powers the engine sync system?
28VDC from the PE busbar
What are the two bleed air ports for airplane services?
LP port is just aft of the last stage of axial compression
HP port is just aft of the centrifugal compressor
Dedicated engine anti-ice supply on top of the engine (900XP only)
What four events happen when the ENG ANTICE switch is set to ON?
The anti-icing valve deenergizes open and HP air from the HP compressor is ducted forward to anti-ice the nacelle inlet cowl
Electric power is supplied to PT2 and TT2 sensor prove heaters
In flight, DEEC’s are reset to a schedule that incorporates raised idle rpm to compensate for the effect on thrust
The temperature provided by the A panel windscreen film is uplifted to ensure adequate anti-ice performance
In the event of an electrical malfunction, what position does the anti-ice valve deenergize to?
OPEN, IOT act as a fail-safe
DC supplies for the engine anti-ice system comes from what busbar?
PE
What four services are provided with LP air, and supplementary HP air at low power settings?
Air conditioning
Normal pressurization
Emergency pressurization
Hydraulic reservoir pressurization
What system is provided with LP air only?
Rudder bias system
What does the APR system do?
Allows an automatic increase in engine performance in the event of:
a go-around during a singles-engine approach
or
an engine failure or transient fault during takeoff
Under what conditions will there be no increase in thrust from the APRIL?
When N1 limited
What powers the APR system?
PE busbar
What are the two indications the APR is armed?
The APR ARMED switch light
On pilot MFD, a white box displaying APR ARM between N1 and ITT gauges
What uncommanded engine split will trigger the APR activation?
15% N2
What is the indication of an automatic triggering of APR?
Boxed green APR on MFD between N1 and ITT
NOTE when is the only time the APR OVRD switch will illuminate in a 900XP?
When manually selected
What must the ENG CMPTR be set to IOT respond to APR?
AUTO
If an engine computer fails or is set to manual when APR is armed, what does the engine difference trigger become?
5%
What thrust reverser system is installed on the 900XP?
Nordam TR5050
Describe the thrust reverser system
Electromechanically controlled, hydraulically operated, target-type thrust reverser
What are the five basic components of the thrust reverser system?
Clamshell doors Hydraulic actuators and linkages Latches to hold doors in stowed position Fan flaps Thrust reverser accumulator
What is the min psi for the thrust reverser accumulators?
1500 psi
What are the three phases of reverser operation?
Initiation
Deployment
Stowing
What conditions must exist for the ARM light to illuminate when the thrust reverser power switch light is depressed?
Weight on wheels
Throttle idle
Minimum of 400 psi hydraulic pressure
NOTE: what is the tendency of the exhaust forces when the thrust reverser doors are deployed
Deploy
NOTE: When engaged, the thrust reverser latches cannot be disengaged unless…
The overstow condition can be realized
A mechanical stop is set to limit thrust when using reversers to a maximum of what?
65-70% N1
What three things are inhibited when the reverser is deployed?
Rudder bias
Air brake warning horn
ELEV/AIL trim annunciator
What triggers a reverser autostow?
If two latch position switches on the same side (inboard or outboard) indicate an unlatched condition
How is an autostow actuated?
The isolation and stow valves are energized to provide stow pressure
ARM, UNLCK, and REVERSER lights illuminate
The affected throttle is moved to IDLE
How long will an autostow procedure continue?
Until one of the two latches senses a latched signal
How does the automatic throttle retard work?
Hydraulic pressure from the reverser system is used to force the engine fuel control mechanism toward idle when a stow signal is generated
Where is electric power for the thrust reverser taken from?
PE busbar
What is the reverser restriction for unpaved surfaces?
Reverse idle thrust only
CAUTION: can the thrust reverser doors deploy without the engine operating?
Yes
CAUTION: can you start the engine with the thrust reverser doors deployed?
The engines must not be started when the reverser doors are deployed
CAUTION: what is required to shut the reverser doors when the engine is not operating?
One crew member must observe while another operates the system
NOTE: when must thrust reversers be reduced to idle when stopping?
50 knots
What are the five limitations of the thrust reversers?
Ground operations only
No engine starts with reverser doors open
No power backing
Idle thrust reversing only on unpaved surfaces
Full reverse minimum speed is 50 knots
N1 takeoff operating limit
100%
N1 Max continuous operating limit
100%
NOTE: Thermal binding of the LP rotor can occur if engine restarts are attempted within…
25-45 minutes
If engine restarts are to be attempted within 25-45 minutes of shutdown, what should be done?
The fan should be rotated 90 degrees by hand
Or:
A motoring cycle should be conducted
NOTE: during an engine restart within 25-45 minutes of shutdown, start should be aborted if no N1 rotation is indicated before…
20% of N2
N2 takeoff operating limit
100.8%
