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?
• Dual channel redundancy – 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
- Stalled start
- No ignition
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, clear the engine, and attempt a restart (if warranted) automatically
When does the FADEC command a higher engine idle speed?
- Bleed demands
- Approach configuration
- High engine or IDG temperatures
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?
- Engine anti ice ON
- Approach idle
- Engine flameout detection
- MAX/FLEX power selected
- Failure of the EIU
- In-flight unscheduled sub idle or surge
- Master switch 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 is ALPHA FLOOR protection active?
• From lift-off through 100 feet RA on approach
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 advancing the thrust levers to TOGA or FLX
