Engine Flashcards
What happens when you turn the Ignition Selector Knob to the OFF Position in flight?
FADEC disregards command
What does OVRD command on the Ignition Selector Knob?
enables FADEC to continuously activate both exciters
when the engine is running
What does the word OFF in CYAN color on the N1 EICAS indication indicate?
The cyan OFF indication is displayed when the engine is
shut down by pilot action.
What meters and distributes the proper amount of fuel for combustion to the injectors?
Fuel Metering Unit (FMU)
Where is oil pressurized?
In the oil lubrication pump then passes through the filter then heat exchanger (bottom RH side of engine) then dispersed through engine
What are the 2 major components of the starter system?
- Air Turbine Starter (ATS)
- Starter Control Valve
When does the SCV close?
When starter cutout speed is reached (normally 50% N2)
What is the purpose of the SCV?
Opens to allow bleed air from APU, X-side engine, or ground source to power the ATS
What commands the SCV to open?
FADEC
Which igniters are excited for in-flight restarts?
Both igniters are energized
Where are Exciters 1B and 2B CMD located?
SPDA
Where are Exciters 1A and 2A CMD located?
AC STBY BUS in EICC
Does the FADEC provide automatic shutdown protection against hot, hung, or no-light starts in flight?
No, only on the ground
An auto relight occurs in flight when what happens?
In the event of an engine flameout, the FADEC commands both igniters on
After how many seconds should a relight attempt in flight be manually abort?
30 seconds after fuel flow began and bring the START/STOP selector knob to the STOP position
How are the thrust reversers actuated and what type are they?
They are actuated by hydraulic power and are of the Cascade type
Inadvertent thrust reverser deployment in flight limits thrust to what?
Thrust is commanded to idle
What is the name of the sensor that measure engine inlet temp?
T2 sensor
What 4 scenarios does the ATTCS command RSV power?
Automatic:
1. 15% difference of N1 values
2. OEI TO
3. OEI GA
4. Windshear
Manual:
1. Thrust Levers to Max Detent
What types of engines are on the aircraft?
2 GE CF-348E5 Hi-Bypass, 2 Spool, Axial-Flow, Turbofan Engines
How much thrust do the engines produce?
14,200 lbs of thrust
Describe the N1 spool?
Single-stage Turbofan and 4 Low Pressure Turbines (1:4)
Describe the N2 spool?
10 Stage, axial-flow compressors with 2 stage High Pressure Turbines (10:2)
How many igniters per engine?
2 igniters per engine
Can the igniters be turned off in flight?
The FADEC ignores the command if the Igniter switch is moved to the OFF position
What does the cyan line on the N1 gauge represent during approach and when does it appear?
It is the min N1 to meet bleed requirements and will appear when configured for landing < 1200’ RA when A/I is on
What sources are available for engine starting
- APU
- Ground Source (huffer cart or air bottle)
- X-side bleed start
- WML start
Above which ITT will the FADEC not allow FF for initial engine start?
> 120º C and FADEC will auto dry motor engine until temp is below 120º C
What does WML next to the N2 mean on the EICAS?
- Engine is currently windmilling
- FADEC has determined a flameout and is attempting a re–light or
- Assisted start has been commanded
What within the FADEC provides the under and overspeed protection and at what percentages?
The FMU in the FADEC at 52% (underspeed) and 102% (overspeed) N2
What happens after 3 overspeed detection events?
FADEC will not re-light the engine
What heats the fuel and cools the engine oil
Fuel-Oil Heat Exchanger
When is thrust reverse available?
- WoW
- Thrust levers idle
Can the FLEX thrust be reduced lower than CLB-2 thrust?
No. Min Power is 75% for TO or Climb-2 + 0.5% N1, whichever is higher
How many fan blades are on the CF-348E5
28 Fan Blades
What are the Thrust Reverser Lockouts used for?
They are red, and used to denote an MEL’d TR
What is Vx and Vy for the 175?
Vx = Green Dot
Vy = Green Dot + 50 kts
TLA must be below which angle for FADEC to give the OK to an Engine Shutdown on ground?
Thrust Levers less than 5˚
How many oil sumps are there and how many bearings?
A Sump = Bearings 1,2,3
B Sump = Bearing 4
C Sump = Bearing 5
What does the oil system lubricate?
AGB and 5 bearings
Describe the Variable Geometry Actuators
2 VGAs per engine, master/slave configuration, fuel pressure driven that control compressor stator vanes stages 1-4
What happens to engine power at 1200’ RA?
N1 goes into Final Approach Idle, cyan tick mark for min bleed air requirements displayed on N1 at 1200’ RA
What is max oil qty and usable oil qty?
max = 10.5 qts
usable = 7.2 qts
Describe the interlock function of the FADEC
Prevents inadvertent deployment of the TR 2 main actuators and cowl lock. The cowl lock itself is the main defense again TR deployment.
How many idles does the engine have?
- Ground idle
- Flight Idle
- Approach Idle
- Final Approach Idle
Which idles increase min N1 due to ice speeds?
Flight Idle and Approach Idle for bleed protection
What is on the AGB?
FISH Oil Plus
1. Fuel EDP
2. IDG
3. ATS
4. Hydraulic EDP
5. Lube & Scavenge
6. Chip detector
