787 Flight Crew Operations Manual
DO NOT USE FOR FLIGHT
Engines, APU -
Engine System Description
Copyright © The Boeing Company. See title page for details.
D615Z003-TBC 7.20.5
EEC Normal Mode
[Option – GE engines]
In the normal mode, the EEC sets thrust by controlling N1 based on thrust lever
position. N1 is commanded by positioning the thrust levers either automatically
with the autothrottles, or manually by the flight crew.
[Option – RR engines]
In the normal mode, the EEC sets thrust by controlling TPR based on thrust lever
position. TPR is commanded by positioning the thrust levers either automatically
with the autothrottles, or manually by the flight crew.
[Option – GE engines]
Maximum N1 represents the maximum rated thrust available from the engine. The
EEC continuously computes maximum N1.
[Option – RR engines]
Maximum TPR represents the maximum rated thrust available from the engine.
The EEC continuously computes maximum TPR.
Maximum rated thrust is available in any phase of flight by moving the thrust
levers to the full forward positions.
EEC Alternate Mode
If the required signals are not available to operate in the normal mode, the EEC
automatically uses the alternate mode. In the alternate mode, the EEC schedules
N1 as a function of thrust lever position. The alternate mode provides soft and
hard levels of control:
• Soft – When the EEC automatically switches an engine to the alternate
mode and the EEC mode switch remains in NORM, the EEC is in the soft
alternate mode (the switch position is NORM, the EEC mode is alternate).
At a fixed thrust lever position, thrust does not change.
• Hard – When ALTN is manually selected on an EEC mode switch, that
engine is switched to the hard alternate mode (the switch position is
ALTN, the EEC mode is alternate). Reference and target N1, and
maximum and commanded N1 values are displayed on the N1 indication
during the hard alternate mode. Thrust may change to set the commanded
N1 when ALTN is manually selected.
[Option – GE engines]
For the normal, soft alternate, and hard alternate modes; actual, command,
reference/target, maximum and red line N1 information is displayed.
[Option – RR engines]
For the normal, soft alternate, and hard alternate modes, the following TPR and
N1 information is displayed:
February 13, 2009
To Next Page
Loading...
