What does #1 indicate if it remains illuminated after stowing the TR?
Memory aid: ATIS
-Auto–restow circuit has been activated
-Thrust reverser sleeve(s) are not in commanded state
-Isolation valve or thrust reverser control valve not in commanded position
-Synchronization shaft lock circuitry failure has been detected
What does #2 indicate?
Illuminated (amber) – engine control system is not dispatchable due to faults in the system.
Light operates when: engine is operating and, airplane on ground and below 80 kts prior to takeoff or, approximately 30 seconds after touchdown
What does the “ON” portion of #3 indicate?
ON – in view (white)
-indicates normal control mode is selected
-engine ratings calculated by EEC from sensed atmospheric conditions and bleed air demand
-when ON is not in view, the EEC has been manually selected to the alternate mode.
What does the “ALTN” portion of #3 indicate?
ALTN – in view (amber)
-indicated EEC has automatically switched to alternate control mode or it has been selected manually
-EEC provides rated thrust or higher.
Note: Both ON and ALTN may be in view if EEC has automatically switched to soft alternate mode.
Note: EGT limits must be observed in both normal and alternate control modes.
What mode is the EEC in?
EEC has automatically switched to the SOFT alternate mode. It could also be in HARD alternate mode if this occurred in flight and the thrust lever was moved to the IDLE position
What mode is the EEC in?
EEC has been switched manually to the HARD alternate mode
Will you see #2 in flight? Can the aircraft be dispatched with #2 illuminated?
No and No
How many channels does each EEC have?
When does the EEC alternate between control channels?
At each engine start or start attempt.
If an EEC fails, how do you switch to an operating channel?
You don’t, it is automatic.
How many EEC control modes are there and what are they?
2, Normal and Alternate
How many EEC alternate modes are there, and what are they?
2, Soft and Hard
How does the EEC operate in normal mode?
In the normal mode, the EEC uses sensed flight conditions and bleed air demand to calculate N1 thrust ratings. The EEC compares commanded N1 to actual N1 and adjusts fuel flow to achieve the commanded N1.
What are the indications that the EEC is in soft alternate mode?
When this occurs, the ALTN switch illuminates and the ON indication remains visible.
How does the EEC operate in the soft alternate mode?
In the soft alternate mode, the EEC uses the last valid flight conditions to define engine parameters which allows the mode change to occur with no immediate change in engine thrust. Thrust rating shortfalls or exceedances may occur as flight conditions change. The soft alternate mode remains until the hard alternate mode is entered by either retarding the thrust lever to idle or manually selecting ALTN with the EEC switch on the aft overhead panel.
How is the hard alternate mode selected?
The soft alternate mode remains until the hard alternate mode is entered by either retarding the thrust lever to idle or manually selecting ALTN with the EEC switch on the aft overhead panel.
What do the switches look like in hard alternate mode?
If the hard alternate mode is entered by reducing the thrust lever to idle while in the soft alternate mode, the ALTN switch remains illuminated and the ON indication remains visible. When ALTN is selected manually, the ON indication is blanked.
How does the EEC operate in hard alternate mode?
When the hard alternate mode is entered, the EEC reverts to the alternate mode thrust schedule (factory pre-programmed data). Hard alternate mode thrust is always equal to or greater than normal mode thrust for the same lever position.
Does the EEC provide N1/N2 redline overspeed protection and EGT redline exceedance protection?
The EEC provides N1 and N2 redline overspeed protection in both normal and alternate modes. The EGT limit must be observed by the crew because the EEC does not provide EGT redline exceedance protection.
What are the different types of idle operation that the EEC can select automatically?
The EEC automatically selects ground minimum idle, flight minimum idle, and approach idle.
When is approach idle automatically selected?
Approach idle is selected in flight if flaps are in the landing configuration or engine anti–ice is ON for either engine. At the same airspeed and altitude, N1 and N2% RPM will be higher for approach idle than for flight minimum idle.
In flight, if a fault prevents the EEC from receiving flap or anti-ice signals, when is approach idle automatically selected?
15,000 feet MSL
When does #1 illuminate during normal operations and how long does it stay illuminated?
It illuminates when the thrust reverser is commanded to stow and extinguishes 10 seconds later when the isolation valve closes.
Any time the REVERSER light illuminates for longer than ___, a malfunction has occurred and the MASTER CAUTION and ENG system annunciator lights illuminate.
Any time the REVERSER light illuminates for longer than 12 seconds, a malfunction has occurred and the MASTER CAUTION and ENG system annunciator lights illuminate.
How does the engine start switch function in the GRD position?
-opens start valve
-closes engine bleed valve
-for ground starts, arms selected igniter(s) to provide ignition when engine start lever is moved to IDLE
-for inflight starts, arms both igniters to provide ignition when engine start lever is moved to IDLE
-releases to OFF at start valve cutout.
How does the engine start switch function in the OFF position?
-ignition normally off
-both igniters are activated when engine start lever is in IDLE and:
-an uncommanded rapid decrease in N2 occurs or,
-N2 is between 57% and 50% or,
-in flight - N2 is between idle and 5%.
How does the engine start switch function in the CONT position?
-provides ignition to selected igniters when engine is operating and engine start lever is in IDLE
-in flight - provides ignition to both igniters when N2 is below idle and engine start lever is in IDLE.
What is the power source for the left igniters?
AC transfer bus 2
What is the power source for the right igniters?
Standby AC bus