747 AutoThrottle, Speed Brake &|
by jerome meriweather
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- DN (Detent) - Retracts all spoiler panels. On the ground, Speed Brake lever moves to the UP position and all spoiler
panels extend when the reverse levers are moved to the reverse idle position.
- ARM - Arms the Speed Brake lever to move to UP, extending all spoilers when the airplane is on the ground and the
throttles are in idle. Lever moves to DN, retracting spoilers, when throttles are advanced on the ground.
- Flight Detent - Flight spoilers extend to their maximum inflight position. Lever is interlocked so that it cannot
be moved past FLIGHT DETENT in flight.
- UP - All spoiler panels extend to their maximum on-ground position. On the ground, Speed Brake lever moves to DN
and spoiler panels retract if Throttle 1 or 3 is advanced.
Reverse Thrust Lever
Controls reverse thrust.
Controls forward thrust.
- Takeoff - Engage the flight director and Autothrottles in the takeoff mode.
On the ground, with no autopilot engaged and both flight director switches OFF, the takeoff mode is, armed when the first
flight director switch is positioned ON. The respective PFD displays FD as the engaged AFDS status, and TO/GA as the pitch roll
modes. The command bars are displayed on the PFDs.
During takeoff, the FMC records a barometric reference altitude as the airplane accelerates through 100 knots. this reference
altitude is used, to engage LNAV and VNAV, enable A/T engagement if not, engaged, command acceleration for flap retraction,
and set climb thrust if an altitude has been selected.
Pushing a TO/GA switch with airspeed less than 50 KIAS, engages the autothrottle in the THR REF mode. If the Autothrottle
is not engaged by 50 KIAS, it cannot be engaged until 400 feet.
On takeoff, prior to 65 knots:
At 65 knots:
- Pitch commands a fixed-pitch attitude (8° nose up).
- Roll cornmands wings-level.
- Autothrottle engages in the THR REF mode.
- Throttles advance to takeoff thrust.
- PFDs annunciate THR REF for autothrottle mode and TO/GA for pitch and roll mode.
- Autothrottle mode annunciates HOLD.
- Pitch commands attitude to maintain a target speed of V2 (Airspeed window) + 10.
- If the Current Airspeed remains above the target airspeed for 5 seconds, the target airspeed is reset to a maximum Of V2.+ 25.
- If engine failure occurs, pitch commands:
- V2 if Airspeed below V2.
- Existing airspeed, if between V2 and V2 + 10.
- V2 + 10, if Airspeed above V2 + 10.>
- Roll commands bank to maintain ground track.
- At 50 feet, LNAV engages if armed. Roll commands bank to track the active route.
- AT 400 feet, VNAV engages if armed. Pitch commands the current Airspeed until reaching acceleration height.
- Autothrottle remains in HOLD mode at takeoff thrust until VNAV or FLCH engagement. The Autothrottle then sets the selected reference thrust.
- FD AFDS engaged status is terminated by engaging an autopilot.
- TO/GA mode is terminated by selecting any other pitch and/or roll mode.
- At acceleration height, pitch commands a reduced climb rate and the greater of: 260 knots, VREF + 100 knots,
or the speed transition associated with the origin airport.
- At thrust reduction height or Flaps 5, the FMC reduces the reference limit to armed climb thrust.
- Go-Around - Engages the go-around mode of AFDS and Autothrottle, if mode is armed and airplane is above 5 feet radio altitude,
or within 2. seconds after having descended below 5 feet radio altitude. The mode arms when the glide slope is captured or flaps are selected.
There is no annunciation of mode arming, 19. The mode can be used for flight director only, or single or multiple autopilot operation.
operation with a single push:
TO/GA mode operation with a second push:
- PFD shows roll and pitch modes engaged in TO/GA mode.
- PFD shows Autothrottle engaged in THR mode. THR mode provides thrust up to the reference thrust limit to establish a 2000 FPM climb rate.
- AFDS increases pitch to hold the greater of the current Airspeed or selected speed. If current Airspeed remains above the target
speed for 5 seconds, the target airspeed is reset to current Airspeed, to a maximum of IAS/MACH indicator plus 25 knots.
- When 2000 fpm climb is established, the Autothrottle controls thrust to maintain climb rate.
Level off from TO/GA pitch modes (not normally done):
- PFD shows Autothrottle engaged in THR REF for full go-around thrust. Mode remains engaged even though airplane touches
down during go around.
TO/GA mode termination:
- At selected altitude, AFDS pitch mode changes to ALT, and all autopilots, except the first in CMD, automatically disconnect.
- Autothrottle remains at the current power setting in THR or THR REF mode until maximum speed is reached or SPD mode is
- TO/GA roll mode remains engaged until another mode is selected.
If the autopilots are compensating for an asymmetric thrust condition when they revert to a single autopilot engaged configuration,
the rudder will return to the Rrimmed position unless the pilot exerts the rudder pedal force required to maintain the rudder position.
- Below 400 feet radio altitude, disengage the a.utopilots, and turn off both flight directors.
- Above 400 feet radio altitude, select another pitch or roll mode. If either pitch or roll is selected, the other mode remains
in go-around. All autopilots except the first engaged, automatically disengage when either pitch or roll is selected.
- Switches - Control Fuel and ignition to the associated engine.
- RUN - Opens engine fuel and spar valves. Energizes igniters selected by the AUTO IGNITION selector or the STBY IGNITION selector.
- Closes engine fuel and spar valves.
- Discontinues any existing ignition.
- Commands associated Hydraulic demand pump to operate if demand pump selector is in AUTO.
- Fire Lights - Lights in the switches come on with fire warning for the associated engine, and go off when the fire warning ceases.
Stab Trim Cutout Switches
- ON - Allow pressure from the associated hydraulic system to power associated trim module.
- AUTO - Normal guarded position. Allow pressure from the associated Hydraulic system to power associated
trim module. Automatically shut off hydraulic power if unscheduled trim is detected.
- Cut Out - Shut off hydraulic power to the respective Stabilizer Trim module.
ALTN Stabilizer Trim Switches
Provide Stabilizer Trim in desired direction using alternate control channel.