787 Flight Crew Operations Manual
DO NOT USE FOR FLIGHT
Flight Management, Navigation -
Flight Management System
Operation
Copyright © The Boeing Company. See title page for details.
11.31.36 D615Z003-TBC
Condition 2: Execute the ENG OUT modification. Then, set the clearance altitude
(lower than EO MAX) in the MCP and push the MCP altitude selector.
Result: The airplane remains at the MCP altitude until the altitude is set lower and
the MCP altitude selector is pushed, the pitch mode initially changes to VNAV
ALT, the reference thrust limit becomes CON, and the autothrottle adjusts thrust
on the operative engine to maintain FMC-commanded EO SPD. After setting the
MCP altitude window and pushing the altitude selector, the operative engine
increases thrust to CON and the airplane descends in a VNAV SPD driftdown to
the clearance altitude in 1L. Initial descent rate is low, depending on the gross
weight and on how much the airspeed has decreased before pushing the altitude
selector. If the airspeed has decreased below EO SPD, the descent rate increases
to regain the airspeed.
Condition 3: Set the clearance altitude (lower than EO MAX) in the MCP, push
the altitude selector; then, after the descent is established, execute the FMC
modification (ENG OUT selection).
Result: After pushing the altitude selector, the airplane descends in a normal
VNAV SPD cruise descent at two–engine cruise speed. The reference thrust limit
is CLB/CRZ and the autothrottle maintains cruise descent airspeed. The cruise
altitude is set to the MCP altitude when the altitude selector is pushed. Executing
the FMC modification while above EO MAX altitude sets the driftdown descent
airspeed to EO SPD. The reference thrust limit becomes CON and the autothrottle
increases thrust to CON on the operative engine. The airplane initially descends
at economy cruise airspeed and approximately 1,250 fpm. After executing the
ENG OUT modification, the commanded airspeed is EO SPD. The rate of descent
decreases to a minimum of 300 fpm.
When VNAV captures the EO MAX altitude (Condition 1 only), the VNAV cruise
page title becomes EO CRZ and the pitch annunciation is VNAV PTH, regardless
of the MCP altitude window setting. Predictions for EO Step Climb display at 2R.
Thrust limit remains in CON.
Condition: FMC in engine out mode, more than 50 NM from T/D, set a lower
MCP altitude, push the altitude selector.
Result: VNAV cruise descent at approximately 1,250 fpm at EO SPD. When the
EO cruise descent intersects the planned descent profile, descent mode becomes
active.
Required Time of Arrival (RTA)
VNAV controls cruise speed to arrive at a specified waypoint within ± 6 seconds
of a specified time. If the RTA is not achievable, the EICAS message FMC
UNABLE RTA is displayed.
3
Engine Out Cruise
4
Subsequent Cruise Descent
August 14, 2009
To Next Page
Loading...
