Thrust Asymmetry Protection (TAP) is only available when the flight controls are operating in normal mode, and the EEC is in normal or alternate modes.
Ice crystal idle is selected in flight when:
There are no flight crew procedures based solely on a response to low oil quantity.
There is no minimum oil quantity limit (no amber or red line limit); however, a low oil quantity causes automatic display of the secondary engine display and reverses the display indication to show black numbers on a white background. There are no operating limitations for the engine oil quantity; therefore, there are no flight crew procedures based solely on a response to low oil quantity.
Simultaneous engine start is only allowed when the APU is running and both APU starter/generators are operational. If both engines are commanded to start with an inadequate power configuration, the second start command is ignored.
For in–flight starts, the autostart system temporarily discontinues the start by cutting fuel if:
If one of these conditions is detected, autostart windmill motors the engine for 30 seconds before making another attempt. The starters are re–engaged on the following start attempt. Autostart takes corrective action if some start problems are detected, but does not abort the start. During the second or subsequent start attempts autostart re–introduces fuel and ignition when the EGT falls below 200 deg. C.
During engine start load shed:
Load shed always occurs during engine start. Shed systems appear on their respective synoptic with the majority appearing on the electrical synoptic.
On the ground, thrust control malfunction will:
Airplane is on the ground, and thrust lever is at idle, and engine is above idle speed and not decelerating normally.
Fuel flow is measured after passing through the engine fuel valve. Fuel flow is displayed on the secondary engine display. Fuel flow information is also provided to the FMS.
Primary and secondary engine indications are provided only on the EICAS display. The EICAS is normally displayed on the inboard MFD window of the left or right inboard display unit.
If EGT reaches the maximum continuous limit, the digital indication, box, pointer, and dial all change color to amber. EGT indications are inhibited from changing to amber during takeoff or go–around for _____.
The EGT indication has a maximum takeoff limit displayed by a red line. If EGT reaches the maximum takeoff limit, the digital indication, box, pointer and dial, all change color to red.
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During engine start, initial EEC power is supplied by the airplane until a Permanent Magnet Alternator (PMA) is able to provide sufficient power. The airplane also serves as an alternate EEC power source whenever a PMA is unavailable.
For an engine-out condition, Thrust Asymmetry Protection (TAP) reduces thrust on the operating engine to ensure there is sufficient rudder for directional control. TAP reduces thrust when the airspeed decreases above approximately V2 on a takeoff or above approximately VREF on a go-around.
For an engine-out condition, TAP reduces thrust on the operating engine to ensure there is sufficient rudder for directional control. TAP reduces thrust when the airspeed decreases below approximately V2 on a takeoff or below approximately VREF on a go-around. Once speed is increased above V2/VREF, TAP increases thrust.
Thrust Asymmetry Protection (TAP) is an automatic feature that provides protection against asymmetric thrust during takeoff only by limiting thrust on the higher thrust engine.
TAP is an automatic feature that provides protection against asymmetric thrust during takeoff or go-around by limiting thrust on the higher thrust engine.
Approach idle increases engine acceleration time for go–around. Approach idle is maintained until after touchdown when the EEC selects minimum idle
Approach idle decreases engine acceleration time for go–around. Approach idle is maintained until after touchdown when the EEC selects minimum idle.
The EGT indication has a maximum continuous limit represented by an amber band. The maximum continuous limit does not apply during takeoff or go–around.
For airspeeds where Thrust Asymmetry Protection (TAP) limits thrust:
For airspeed where TAP does limit thrust, climb gradient is higher with TAP limiting thrust than it would be if TAP did not limit thrust.
During ground starts, the autostart system monitors engine parameters and aborts the start for any of the following:
Each engine has a electrically actuated fan air thrust reverser. Reverse thrust is available only on the ground.
Each engine has a hydraulically actuated fan air thrust reverser. Reverse thrust is available only on the ground.
In EEC Alternate mode, which of the following is true?
Thrust protection is not provided and maximum rated thrust is reached at a thrust lever position less than full forward. Thrust overboost can occur at full forward thrust lever positions.
Thrust Control Malfunction Accommodation is an EEC function that provides protection against idle thrust asymmetry conditions while on the ground. The EEC commands shutdown of the affected engine when the:
The EICAS caution message ENG FAIL (L or R) is displayed with an aural beeper once the engine falls below idle speed.
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When is Thrust Asymmetry Protection (TAP) available?
The engines can only be started using the autostart system.
For single–engine operations, if EGT reaches the maximum continuous limit, the digital indication, box, pointer, and dial all change color to amber. EGT indications are inhibited from changing to amber during takeoff or go–around for _____.
The EGT indication has a maximum takeoff limit displayed by a red line. If EGT reaches the maximum takeoff limit, the digital indication, box, pointer and dial, all change color to red.
A maximum start limit line (amber) is displayed on the EGT indication when the FUEL CONTROL switch is moved to CUTOFF or the engine is not running and the respective fire switch is not pulled.
This is a red maximum start limit line (not amber).
During ground starts, the autostart system monitors engine parameters and attempts to correct the start for any of the following:
If an N1, N2 or EGT red line is exceeded:
The red box color can be canceled to white or recalled to red by pushing the cancel/recall switch on the display select panel.
The EEC alternate mode N1 reference/target values are computed by the:
Each engine has two igniters. The EEC automatically selects the appropriate igniter(s) for successive engine ground starts. Dual igniters are always used for in–flight starts.
Approach idle is selected in flight when:
Which of the following is true about overspeed protection?
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Which of the following have both digital and vertical indication/moving pointers?
All digital readouts are enclosed by boxes. The dial and vertical indications display the normal operating range, caution range and operating limits, as applicable.