Engines / Thrust Levers Flashcards
What controls the engines in all operating regimes?
FADECs (Full Authority Digital Engine Controls)
What functions does the FADEC control?
• Fuel metering • Engine limits based on thrust lever angle • Start sequencing • Provides engine indications and thrust limit displays on the E/WD
What redundancy does the FADEC have?
2x FADEC computers – one channel is active while the other is standby.
What is the power source for the FADEC?
• The system has its own alternator making it independent of the aircraft electrical system when N2 is above10% • If this alternator fails the FADEC automatically switches to aircraft electrical power
When will the FADEC abort an automatic start?
- Hot Start
- Hung Start
- Engine Stall
- No Light Off
The FADEC detects a fault during automatic start. What crew intervention is required?
There is no crew intervention necessary. The FADEC will discontinue the start, dry crank to clear the fuel from the engine, and attempt a restart (if warranted) automatically.
When does the FADEC command a higher engine idle speed?
• Bleed demands (Descent from Cruise) • Approach configuration
How many igniters fire during a normal automatic ground start sequence?
• One igniter with the other serving as a backup • The FADEC automatically alternates the igniters (A and B) at each start
How many igniters fire on manual or in-flight starts?
Two, both A and B
When does Continuous Ignition automatically operate?
- PW1100G
- Engine flame out detected
- Surge detected
- Thrust control malfunction detected
- Ignition delay during start
- IAE V2500
- Engine anti-ice PB switch ON
- Max TO thrust selected (EPR or Rated N1 mode)
- FLEX TO Thrust selected (EPR mode)
- EIU data failed (ignition and/or bleed config data)
- Approach idle selected
- Inflight unscheduled sub idle or surge
- Master lever cycled from ON to OFF then back to ON position
What are the 5 detent positions of the thrust levers?
• TOGA – Take Off/Go Around • FLX / MCT – Flex/ Maximum Continuous Thrust • CL – Climb • IDLE – Idle • MAX REV – Maximum Reverse Thrust
On the ground, how can the A/THR be armed?
• By setting the thrust levers in the TOGA or FLEX gate (with a FLEX temperature inserted in the MCDU) • At least one FD must be ON for A/THR to arm during takeoff
What is the active range of the A/THR?
• Just above IDLE to the CL detent (2 engines) • Just above IDLE to the MCT detent (1 engine)
What is the normal operational position of the thrust levers when A/THR is active?
The CL detent
What determines the maximum thrust the A/THR system will be able to command?
The thrust lever angle
What are three ways to disconnect the A/THR?
• A/THR pushbutton • Instinctive disconnect pushbuttons • Thrust levers to IDLE
What is the preferred method of disconnecting A/THR?
Set the thrust lever angle to the existing EPR and push the instinctive disconnect pushbuttons
How would the A/THR be disconnected for the remainder of the flight?
Press and hold the instinctive disconnect pushbutton for 15 seconds. The A/THR cannot be re-engaged once this is done. ALPHA FLOOR is also lost if this is done.
What happens to thrust and what annunciates on the FMA during ALPHA FLOOR?
• Thrust – TOGA • FMA – “A.FLOOR”
When does the aircraft leave ALPHA FLOOR and what does the FMA change to?
Upon reaching a lower angle of attack. The FMA changes to “TOGA LK”
Following ALPHA FLOOR, how would the crew return normal A/THR function?
• Press the instinctive disconnect pushbutton • Return thrust levers to CL detent • Push the A/THR pushbutton to engage A/THR
When will ALPHA FLOOR activate?
When the aircraft reaches a high AOA.
When would Thrust Lock occur?
• Thrust levers in CL detent and A/THR pushbutton on the FCU is pushed, or • A/THR disconnects due to a failure
How is A/THR normally armed?
By having at least 1 FD ON and advancing the thrust levers to TOGA or FLX detent.
