The document describes the components and operation of the Engine Indication and Crew Alerting System (EICAS) installed on the 757 aircraft, including the display units, computers, control panels, and operational modes for displaying engine and aircraft system information to the crew. It provides details on the alert messages, exceedance data, maintenance functions, built-in test equipment operations, and standby engine indicator that serves as a backup if the primary EICAS fails.

1. 757 EICAS
R
M&E Instructor
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2. 757 EICAS
• DESCRIPTION AND OPERATION
• COMPONENTS
• MAINTENANCE
• Q&A
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3. The engine Indication and Crew Alerting System
(EICAS) includes two color Display Units
(DU), two computers, and two control panels. In
addition to these components we have
cancel/recall switches , and captain’s and first
officer’s master caution lights, jointly perform
the various EICAS functions.
The EICAS computer process and formats data
to display all engine and airplane system
information required by the crew. Only one
computer is used at any particular time for
displaying the data on both display units. The left
computer is always the primary one and right is
secondary. Manual computer selection can be
done on the display control panel.
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5. EICAS DISPLAY CATEGORIES
EICAS is designed to categorize alerts and displays
according to function and usage. This results in three
modes of display:
•Operational Mode
•Status Mode
•Maintenance mode
Operational Mode display those engine parameters
required on the ground and in flight operation and
provide monitoring of the airplane and engine
subsystems. The upper DU is dedicated full time to
primary engine parameters and alert messages for
monitoring by the crew. The lower DU shows
secondary engine parameters.
Status Mode provide subsystem parameters as well
as status messages on the lower DU. This are used
by the crew to determine readiness of the airplane
for dispatch and closely associated with the MEL.
Maintenance Mode provide airplane subsystems
parameters and maintenance messages on the lower
DU. This data is available on the ground only for
post-flight maintenance and troubleshooting action.
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6. EICAS OPERATIONAL MODE
Primary engine parameters displayed on the upper DU
are EPR, N1 and EGT.
This are required to set and monitor thrust. All primary
parameters are displayed by a digital readout and an
analog pointer.
Alert Messages are display in the upper DU left corner.
Secondary Engine Parameters – N2, N3, fuel flow, oil
pressure, oil temperature, oil quantity and vibration –
are displayed on the lower DU at power up or when
manually selected on the display selector panel.
Secondary parameters are displayed by a digital
readout and an analog pointer.
EICAS automatically display engine exceedance
condition and the respective color for fast crew
attention and action.
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7. EICAS ALERT MESSAGES & CANCEL/RECALL
Alert messages displayed on the upper DU are divided by Cancel and Recall switches control the display of this
priority: messages, Cancel remove any caution and advisory messages
• Warnings - Red required immediate action. from the upper display and will show the next page of Messages
• Cautions - Yellow. if any. RECALL switch will return to view those Messages that
are still applicable.
• Advisories -Yellow and are indented.
Warning Messages can not be canceled due to the level of
• White - data or communication. importance related to them.
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8. EICAS DISPLAY CONTROL PANEL
The display select panel provides all control function to the
EICAS computer units system operation both in flight and on the
ground. The display select panel functions include:
• Display format selection: • Display brightness control:
ENG and STATUS. upper and lower.
•Recording subsystem parameters: • Thrust reference setting control:
 EVENT RECORD
 AUTO/MANUAL
• Computer source selection: • Clearing/display engine exceedance data:
 L, both and R.  MAX IND RESET
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9. EICAS STATUS MODE
The Status Mode display is selected by manually pressing
the STATUS switch on the display select panel. Data
needed by the crew to determined readiness for dispatch is
displayed on the upper left corner.
On the upper right corner the following are displayed
• HYD QTY and PSI.
•APU RPM/EGT all displayed in digital format.
• Crew O2 PSI.
In addition on the lower left corner analog pointers are
used to indicate the position of the Rudder, Elevators and
Aileron control surfaces.
The status mode can be useful in flight for anticipating
possible ground maintenance action that will be required if
equipped or activated prior dispatch. For this function, a
STATUS cue is provided in the upper left corner lower DU
whenever a change in status Msg occurs while the status
page is not being displayed.
For specific messages refer to the FIM, if a DU fails in
flight, the status cue and status displays are inhibited until
airplane is on the ground.
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10. EICAS MAINTENACE MODE/PANEL
There are five maintenance formats with on the EICAS
Maintenance Mode. They are designed to provide maintenance • Environmental Control Systems/Messages - ECS/MSG
information to aid the ground crew in troubleshooting and • Electrical/Hydraulic - ELEC/HYD
verification testing of the major subsystems. They are also used to
record systems parameters on the ground or at the time of an in- •Performance/Auxiliary Power Unit – PERF/APU
flight fault for later readout on the ground • Engine Exceedance – ENG EXCD
The five different formats are displayed in the lower DU and •The Configuration Porting – CONF/MCDP
access from the EICAS Maintenance Panel this provides all the
controls functions for maintenance and troubleshooting The EICAS maintenance panel contains BITE switch to initiate
information , the I/O signals interfaces with the air-ground relay the SELF bite function of the two computers.
and the display panel: Also on the Maintenance control panel contains the
AUTO/MANUAL EVENT read switches and REC/ERASE
switches.
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12. EICAS AUTO AND MANUAL EVENT DISPLAY & RECORDING
EICAS feature automatic event recording of
the subsystems parameters . Whenever certain
auto or manual events messages are initiated
by one of the following subjects:
• APU subsystem.
• Electrical subsystem.
• Engine performance
• Environmental control system.
• Hydraulic subsystem.
This events are recorded on a nonvolatile
memory for later readout and evaluation. The
AUTO (or MANUAL) switch on the
maintenance panel is use to access and erase
this pages.
The Manual Event recording will store
discrete from engine parameters or either the
ECS/MSG, ELEC/HYD, or PERF/APU
maintenance formats. The last data stored
overwrites previously stored data, only the last
data is available for review.
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13. RH IDG High out temp
Date and time
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14. ENGINE EXCEEDANCE DATA
To erase the auto recorded values of engines exceedance, call up the Since the Stored exceedance are automatically displayed when the
ENG EXCD page by pressing the ENG EXCD switch on the form is called up, the AUTO or MAN events read switches do not
maintenance panel and then press the ERASE switch. have to be used. You must also clear exceedance from the Display
Select Panel.
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15. EICAS COMPUTERS
The EICAS computer are located in the main electronic and the circuit breakers are located on the overhead P11 panel.
equipment compartment on the E4-2 rack. The computer unit Normally (AUTO) the left computer is on command of displays
perform all interface, data processing, control and display and the right computer is on backup mode in case the left fails.
generation function required and is software controlled. Manual selection of the active computer is provided by selecting
L or R rather than the AUTO position .
The front case has no system lights, BITE or controls. There is a
connector for software load with the appropriate tool or Care should be taken when replacing this computer due to
equipment. There is also a data load point in the flight deck electrostatic sensitivity devise.
behind the F/O on P61.
115 VAC is supplied from the respective right and left ac buses
P61 data port
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17. DISPLAY UNITS (DU)
The EICAS display units (DU) provide a multicolor
(red, yellow, cyan (light blue), magenta (pink), white, and green)
CRT presentation of EICAS data.
Video display and deflection signals from the EICAS switching
modules are provided to drive the CRTs.
Manual and automatic intensity signals are provided from the
display select panel and from remote light sensors in the upper
right corner of the front panel.
EICAS DU problems that are detected within each unit
like, beam stuck on or off, failure discrete, or over temperature
will cause the unit to shut down automatically.
The DU are interchangeable, to remove, unscrew the handle, lift
and pull out, refer to the AMM for proper procedure.
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19. EICAS BITE OPERATION
EICAS BITE test can only be accomplished when the airplane is on the
ground and the parking brake set.
The EICAS self test mode is initiated by pressing the TEST switch on
the EICAS maintenance panel.
After depressing the TEST switch, the DUs will display:
•Identical formats with the message “TEST IN PROCESS”.
•Master CAUTION lights and the beeper tone are acute.
•Level B aural command output signal are generated.
•The master WARNING lights, the CONFIG light and siren are
activated.
•The takeoff ground signal is generated.
•The SEI comes on if selected on auto.
The computer will test the interface and circuits of the complete
EICAS system and will display all characters and colors. The FIM is
used for any faults noted.
When the test is completed a massage: TEST OK, SELF TEST
COMPLETED or TEST FAIL is displayed.
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21. STANDBY ENGINE INDICATOR
The Standby Engine Indicator(SEI) provides primary
Engine information to the flight crew in the event of an
EICAS failure, which will result n the loss of the normal
primary engine Parameters displays.
When operating , the SEI presents digital LCD Displays
of the primary engine parameters. This displays include
EPR, N1, EGT and N3 and the max values are shown on
red decals next to the digits. The SEI is controlled by a
switch on the front with two positions, ON and AUTO.
To perform a display test, a spring loaded switch located
opposite to the On/off switch is used, the digital numbers
will read ones and eight.
This is a LRU and does not required special software. The
engine placards must be removed from the old and
installed on the new one.
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22. Q&A
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