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4. Climb, Cruise, Descent and Holding- Preface
This chapter outlines recommended operating practices and techniques used
during climb, cruise, descent and holding. Loss of an engine during climb or cruise
and engine inoperative cruise/driftdown is also addressed. The recommended
operating practices and techniques discussed in this chapter improve crew
coordination, enhance safety, and provide a basis for standardization.
Climb
Reduced Thrust Climb
Engine service life may be extended by operating the engines at less than full
climb rated thrust.
777-200 - 777-300ER
The FMC provides two reduced thrust climb selections on the THRUST LIMIT
page:
• CLB 1 is a constant 10% derate of climb thrust
• CLB 2 is a constant 20% derate of climb thrust.
787-8
The FMC provides two reduced thrust climb selections on the THRUST LIMIT
page
• CLB 1 depends upon the specific derate thrust limit options selected by
the customer
• CLB 2 depends upon the specific derate thrust limit options selected by
the customer.
Reduced thrust climb may also be automatically selected by the FMC depending
upon the amount of thrust reduction made for takeoff by either the fixed derate or
assumed temperature method.
Climb thrust reductions are gradually removed as the airplane climbs until full
climb thrust is restored. If rate of climb should drop below approximately 500 feet
per minute, the next higher climb rating should be selected.
Prior to takeoff, the pilot may override the automatically selected climb thrust
limit after the takeoff selection has been completed by selecting another climb
thrust limit on the THRUST LIMIT page. When the automatically selected climb
thrust limit is overridden, the previously selected takeoff derate is not affected.
Note: Use of reduced thrust for climb increases total trip fuel and should be
evaluated by each operator.
October 31, 2006
777/787 Flight Crew Training Manual
Climb, Cruise, Descent and
Holding
Copyright © The Boeing Company. See title page for details.
4.2 FCT 777/787 Preliminary (TM)
Climb Constraints
Climb constraints may be automatically entered in the route when selecting a
procedure, or manually entered through CDU entry. When the airplane levels off
at an MCP altitude, that altitude is treated as a climb constraint by the FMC.
All hard altitude climb restrictions, including “at or below” constraints, should be
set in the MCP altitude window. The next altitude may be set when the restriction
has been satisfied or further clearance has been received. This procedure provides
altitude alerting and ensures compliance with altitude clearance limits.
When relieved of constraints by ATC, use of FLCH or VNAV with MCP altitude
intervention is recommended in congested areas, or during times of high
workload. Altitude intervention is accomplished by selecting the next desired
altitude in the MCP altitude window, pushing the MCP altitude selector which
deletes the altitude constraint and allows the airplane to climb to the MCP altitude.
Low Altitude Level Off
Occasionally a low altitude climb restriction is required after takeoff. This altitude
restriction should be set in the MCP altitude window. When the airplane
approaches this altitude, the mode annunciation changes to ALT or VNAV ALT
and the airplane levels off. The autothrottle SPD mode engages and controls to the
target speed. If altitude capture occurs while still in the TO/GA pitch mode,
confirm the SPD autothrottle mode engages and set the desired command speed at
level off.
High Takeoff Thrust - Low Gross Weight
When accomplishing a low altitude level off following a takeoff using high takeoff
thrust and at a low gross weight, the crew should consider the following factors:
• altitude capture can occur just after liftoff due to the proximity of the level
off altitude and the high climb rate of the airplane
• the AFDS control laws limit F/D and autopilot pitch commands for
passenger comfort
• there may not be enough altitude below the intended level off altitude to
complete the normal capture profile and an overshoot may occur unless
crew action is taken.
To prevent an altitude and/or airspeed overshoot, the crew should consider doing
one or more of the following:
• use reduced thrust for takeoff at low weights whenever possible
• reduce from takeoff to climb thrust earlier than normal
• disconnect the AFDS and complete the level off manually if there is a
possibility of an overshoot
• use manual thrust control as needed to manage speed and prevent flap
overspeeds.
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787机组训练手册Flight Crew Training Manual 787(49)
