777 AIRCRAFT MAINTENANCE MANUAL
TMCS -AUTOTHROTTLE FLIGHT PROFILE
EFFECTIVITY BEJ ALL 22-31-00
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D633W101-BEJ Sep 05/2002
TMCS -A/T OPERATION -TAKEOFF
General During normal operation, as the airplane goes above 400 feet AGL, the A/T mode changes to THR REF.
To prepare the AFDS and the A/T for the takeoff phase of the flight, use the mode control panel (MCP) to set the necessary parameters. Use the EICAS display and the PFD to see the modes and mode changes.
Before the A/T mode can engage, the system must pass servo motor tests to ensure proper operation.
Mode Selection
The takeoff (TO) mode engages with these conditions:
*
Autothrottle (A/T) arm switches on
*
Airplane on the ground
*
Flap position not zero
*
Thrust limit mode takeoff (TO)
*
Push a TO/GA lever with less than 50 KTs air speed.
Takeoff Mode Operation
At the start of takeoff, the TMCF does the A/T stopper test. This test does a check for the ability of the TMCF to remove power from the servos.
The TMCF sends ASM commands to move the throttles to the TO thrust limit. The throttles move when the TMCF completes and passes the A/T stopper tests. The A/T mode is thrust reference (THR REF) on the PFD. At more than 80 KTs air speed, the A/T mode changes to HOLD.
EFFECTIVITY BEJ ALL 22-31-00
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D633W101-BEJ Sep 05/2002
777 AIRCRAFT MAINTENANCE MANUAL
TMCS -A/T OPERATION -TAKEOFF
EFFECTIVITY BEJ ALL 22-31-00
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D633W101-BEJ Sep 05/2002
TMCS -A/T OPERATION -VNAV CLIMB
Mode Selection The FMCF also sends pitch control commands to the autopilot
flight director system (AFDS) to control speed on elevator while The thrust limit mode engages in climb (CLB) with these
in climb. conditions:
*
Active route
*
Performance page complete
*
Vertical navigation (VNAV) armed
*
VNAV engages when the airplane is 400 feet above ground
level (AGL)
*
A/T armed
*
Flight director or A/P active.
Operation
At the thrust reduction altitude, the FMCF sends commands to the TMCF to move the throttles to the climb thrust position. This occurs at or above 400 feet for a flap or an altitude setting. The flap or altitude setting is preset in the airline modifiable information (AMI). The thrust limit mode changes from TO to CLB as the airplane goes through the preset altitude or at a preset flap position. You can change the preset altitude or flap position for a flight on the CDU TAKEOFF REF page 2.
The thrust limit cursor changes from green to magenta on the EICAS display when CLB thrust engages.
The A/T mode changes from HOLD to THR REF at 400 feet (BARO) when VNAV engages.
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D633W101-BEJ Sep 05/2002
777 AIRCRAFT MAINTENANCE MANUAL
TMCS -A/T OPERATION -VNAV CLIMB
EFFECTIVITY BEJ ALL 22-31-00
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D633W101-BEJ Sep 05/2002
TMCS -A/T OPERATION -VNAV CRUISE
Mode Selection
In VNAV, the thrust limit mode engages in cruise (CRZ) prior to cruise altitude capture. The change from CLB to CRZ is automatic with inputs from the FMCF to the TMCF.
Operation
When the airplane gets to the flight level altitude or MCP altitude, the thrust limit mode changes to CRZ and the A/T mode changes to SPD. The TMCF commands the throttles to move to a speed command with inputs from the FMCF. The magenta thrust limit cursor changes to green on the EICAS display.
EFFECTIVITY BEJ ALL 22-31-00
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D633W101-BEJ Sep 05/2002
777 AIRCRAFT MAINTENANCE MANUAL
TMCS -A/T OPERATION -VNAV CRUISE
EFFECTIVITY BEJ ALL 22-31-00
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D633W101-BEJ Sep 05/2002
TMCS -A/T OPERATION -VNAV DESCENT
Mode Selection
When the airplane nears the top of descent, the FMCF causes the A/T to go to the next flight phase, descent.
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