Engines Flashcards
(29 cards)
What engines are used on the e190?
CF34-10E5A1
Describe the CF34-10E5A1 engine
High bypass, axial flow, dual rotor turbofan
How are the engines controlled?
By a FADEC
How many channels does the engine FADEC have?
2
What are the two possible paths fuel can take?
- through the high pressure pump and back to the fuel tank
- through the FOHE, through the filter and into the FMU
What does the engine starting system consist of?
- air turbine starter
- starter control valve
How many igniters are there per engine?
2
How many igniters are used when starting an engine?
On ground = 1
In flight = 2
What does the OVRD position do on the ignition selector knob?
Ignites both igniters
What are the 4 stages to an on ground engine start?
1) FADEC initiates ignition at 7% N2
2) fuel flow metering valve (FMV) opens between 20-25% N2
3) after light off, FADEC commands starter cut out at approx 50% N2
4) FADEC commands FMV to accelerate engine to ground idle speed
During an on ground engine start what happens if there is no light off within 15 seconds of fuel on?
FADEC turns ignition off and dry motors for 30 seconds
What is the only difference between a cross bleed start and an on ground start?
FMV opens if N2 has not reached 15% after 15 seconds
What is the only difference between an on ground start and a windmill start?
FMV opens at min 7.2% N2 or 15 seconds (whichever comes first)
During a windmilling start when should the start be manually aborted?
If no light off within 15 seconds of fuel on
What does the FADEC not protect for during starts in flight?
Hot, hung or no light off starts
What icon is shown on the EICAS during an auto relight?
WML
When should an auto relight be manually aborted?
If no light off within 30 seconds or N2 falls below 7.2%
If one thrust reverser has failed what happens if both thrust levers are selected to max reverse?
Only minimum reverse thrust is available
If one thrust reverser has failed what happens if the operative thrust lever is selected to max reverse?
Max reverse is given on the operative engine
What is the configuration of the FADEC channels?
2 channels in active/standby configuration. The active one is switched at every engine start
How is the FADEC powered?
- PMA above 50% N2
- 28V DC below 50% N2
When does ATTCS command reserve power?
- difference between n1 values is greater than 15%
- one engine failure during takeoff
- one engine failure during go around
- windshear detection
How can ATTCS be manually activated?
By moving the thrust levers to max
What is minimum flex takeoff thrust?
75% max rate takeoff thrust or CLB-2 +1% (whichever is highest)
