Flight controls Flashcards
(48 cards)
GVII uses fly-by-wire technology.
How does this work?
Pilot inputs are read by a computer that in
turn decides how to move control surfaces
to best achieve what the pilot wants.
How is trim accomplished?
Pitch and roll trim is accomplished by
actuating switch mounted on sidestick;
pedestal mounted PITCH TRIM switch is
also used to control pitch.
What’s the purpose of A/P DISC
switch?
It disengages autopilot and stops runaway
trim in all three axes.
What’s the function of FLT CTRL
RESET switch?
Used to reset flight control computers,
sidesticks, and control surface actuators
when directed by checklist
What effect does loss of one hydraulic
system have on flight controls?
Loss of one spoiler pair
What are control laws?
Software in FCCs that translate electrical
commands from cockpit control sensors
and aircraft motion sensors (inertial/air
data) into flight control surface commands
How many computers control the flyby-wire flight control system?
Three (3) computers: two (2) flight control
computers for normal operation and
Backup Flight Control Unit in case both
flight control computers fail.
What’s the minimum number of FCC
channels that can command all flight
control surfaces on the aircraft.
One.
What’s the purpose of Backup Flight
Control Unit (BFCU)?
It’s designed to provide what Gulfstream
calls “get home capability” if both primary
FCCs fail.
What happens once the BFCU
becomes active?
It communicates directly with EBHA
remote electronics units (REUs) on
separate backup data buses, and is active
for duration of flight.
Describe Electric Backup Hydraulic
Actuator (EBHA).
It’s a special actuator with self-contained
electric motor/pump and hydraulic
reservoir.
What type of sensor input is provided
to FCCs?
Input from IRSs, AHRS, ADSs and radio
altimeters
Describe AOA limiting feature.
In this mode, full stick input commands
maximum nose angle-of-attack of 0.95.
Which mode protects from surface
flutter and separation that would occur
greater than Vdive speed?
High speed protection
What’s the auto-retract feature?
It retracts speed brakes at high power
settings
Name the four (4) flight control
modes.
Normal, alternate, direct, and backup
When would flight control mode
change from normal to alternate?
Loss of multiple air data or inertial
sensors; may also revert to alternate mode
if FCCs lose communication with REUs
that control HS MCE.
What happens if all four (4) FCC
channels are invalid?
Flight control system reverts to direct
mode
What happens if all four (4) FCC
channels are unable to compute the
control law?
Backup Flight Control Unit (BFCU)
activates to provide “get home” capability
What term is used to describe the
amplification, attenuation, boosting,
or magnification that’s applied to
forward signal to achieve desired
aircraft response?
Gain
Normal mode has four (4) primary
operating sub modes. What are they?
On ground, In flight, AOA limiting, and
High speed protection
Describe how the flight control
system operates in alternate mode.
Pitch, roll, and rudder pedal inputs are
multiplied by set of fixed gains to
command elevator, ailerons, roll spoilers,
and rudder
How many sets of gains are associated
with degraded flight control modes?
Two: one set of generally smaller numbers
used when flap handle and gear handle are
up (and aircraft is presumed to be
traveling at higher speed – 340 kts), and a
set of generally larger numbers that are
used if flap handle or gear handle is down
(and aircraft is presumed to be traveling
slower – 250 kts).
What functions with ailerons to
improve roll response?
Mid and outboard spoiler panels extend to
a maximum of 55°
