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