Auto Flight Q’s Flashcards
3 AP computers are considered
fail operable
versine signal is proportional to
1 - cos(bank angle)
the signal responsible for returning an aileron to its neutral position when an aircraft has reached its correct attitude as demanded by the AP is the
position feedback
with glide slope armed the control of the pitch channel can
only be by the engaged mode when deviated from the beam
heavy damping of dynamic stability will produce
a dynamically stable condition
a rate gyro senses disturbances in
1axis
the signal to the pitch channel of an autopilot during a turn is obtained from the
versine generator
GO around is initiated
only by pressing the GA throttle switch
an autopiot disconnect is indicated by
red light
in a triplex autoland system, loss of a nav receiver prior to caputure of the localiser results in
reverting to a CAT 2 approach
an autopilot slip-skid sensor signal goes primarily to the
rudder channel
with an aircraft in a 90 degree banked turn holding the longitudinal axis of the aircraft level
altitude cannot be maintained
IAS hold mode can only be engaged with altitude hold
disengaged
autopilot disengage switch is positioned on the
side of the control wheel farthest from the throttle levers
an aural warning in an autopilot system will sound when
autopilot is disengaged
what radio equipment can be used in an AFCS
VOR, ILS
when TURB is selected on the AP MCP
command signal is reduced 50% and manual modes only are available
the pitch attitude of an aircraft with autopilot engaged can be changed by the
pitch switch CWS altitude hold IAS hold
bank angle limiting applies restrictions to limit the angle of bank applied by limiting the
bank angle using the signal from the MCP selected bank angle
A category 2 landing RVR is
400m
profile or VNAV mode can be coupled to AT
if the flight director or AP is engaged
after VOR capture on a ground check aileron movement will depend upon
course select error radio deviation and bank angle
over amplification of the rate feedback signal will result in
sluggish operation of the servo
if the AP automatically disconnects during autoland the audible warning
is switched off by the operation of the autopilot disengage switches
the loss of the vertical gyro signal to an FD system would cause
aircraft to overbank
SAS
opposes the helicopters inherent instability
the requirement of the position feedback signal is to
provide a signal proportional to the input signal angular displacement
an electro-mechanical servo is powered
electrically
the signals too the rudder channel for a coordination turn are
computed yaw rate and derived yaw rate
the airspeed lock
controls the pitch attuned of the aircraft
a CAT 3B aircraft using fail operational automatic landing equipment with fail operational control and roll out guidance will have
no decision height
what are the AP inputs for VOR capture mode
nav receiver output
the effect of loss of washout on LOC with cross wind is that aircraft will
fly parallel to the track
in an triple autoland system separate power supplies are required to make the system
fail operational
for an AP system certified to.a DH of 50ft (15m) or greater requirements include
fail-passive autoland systeem
after localiser capture washout of the standing error signal is carried out on
course select error
in an AFCS which of the following does not control through the AP channel
touch control steering
ground roll guidance by the rudder is effective to about
80k ground speed
when using a rate gyro to detect pitch attitude change the gimbal ring axis is
vertical or longitudinal
automatic ground roll control primary signal is
localiser signal
minimum operating speed for the auto throttle system is derived from
AOA
the purpose of the auto throttle clutch is to
allow the pilot to override the autothrotle system
the sense of a control surface position feedback signal will
oppose the signal causing the displacement of the control surface
the output of a slvaed directional gyro ti an autopilot consists of
azimuth angle
the electrical signal from a dynamic vertical sensor during a coordinated turn will
be zero
if a localiser signal only is fed to the roll channel of an aircraft towards the outer limit of the beam the aircraft will
fly in a circle
if a constant rate signal is fed to a rate-rate servo the servomotor will
run at a constant speed
in a helicopter control channel the force gradient spring cylinder
provides a zero datum about which control movements occur
the glideslope receiver gives an output to the autopilot in
pitch only
modulation consists of converting
DC to phase sensitive AC
compatible autopilot modes are
alt hold and VOR
LOC freq command
yaw and roll channels
when the AFCS is operating in the LOC mode the yaw damper is supplied with signals from
aileron control channel through a cross feed circuit
a heading error signal is generated by the difference between
aircraft heading and datum
prior to engagement with AP power on the trim indicators will indicate
standing voltage on the servo control loop
a CAT 2 facility performance ILS has an intersect height of
15m
the signal from a VG is used in an AP to give an output which is proportional to angle of disturbance
angle of distrubance
with alt hold mode engaged a pitch error signal will reduce
to zero over a period of time
during autoland the system is programmed to leave the glideslope at
the start of the flare phase a rat
e/rate system the servomotor speed is
proportional to the rate at which the disturbance takes place
operation of the AP trim controller
moves the trim tabs
in the AFCS when two channels are engaged in roll if a handover in one actuator occurs what indications will show
one API shows a hardover in direction while the other API shows a hardcover in the other direction
in a steady coordinated turn the heading signal to the autopilot is
opposed by the VG Signal
the purpose of duplex servo motor is to
prevent hardover or runaway
a series actuator has
limited authority eg 10%
on an AP ground check loss of servo motor rate feedback will
cause the control to oscillate about its datum
what is the main purpose of a servo in an autopilot system
move the control surface as commanded
with the AP in disconnect mode in a coordinated turn the
pilot operates the controls freely
after an automatic landing reverse thrust is applied
only if reverse thrust is manually selected
a course washout us used for
crosswind
an automatic landing system is fail operational if in the event of a failure
the landing can be completed automatically
marker beacon signals are used by the AFCS to sense the
distance from the runway
a two speed horizontal stab servomotor operates on high speed
when flaps are not retracted
signals used during the flare phase are
rad alt and integrated pitch
in a displacement AP system the position feedback
totally opposes the demand when the control surface is at the demand position
an AP turn control primarily controls
ailerons
the term model reference in an AFCS refers to
gain programming
the minimum reliability value for an autoland system is
1 in 10 power 7
in a pitch mode the VG signal will
oppose servo signal
the circuit used for washout is a
integrator
the speed of operation of a series actuator compared to a parallel actuator is
faster
a manometric airspeed lock will require
pitot and static pressure
a fail operational autopilot system will ensure that
the aircraft will continue its automatic landing in the event of a single failure
in a coordinated turn
the pilot operates the controls freely
during an autoland approach after localiser capture if the pilot presses the instinctive disconnect button
there is no aural warning
in an autopilot an integrator could be used to
prevent the aircraft from standing off a radio beam
version can be generated using a
resolver
the correct seq in autoland is
LOC, G/S attitude hold, Flare
during the autopilot reengagement the synchronisation circuits ensure that the
autopilot control circuits are at zero demand conditions prior to engagement
the two parameters which are used for an autoland category classification are
DH and RVR
on approach the aircrew operates the instinctive control wheel AP disconnect switch this results in
aural and visual warnings
an AP three-axis rate transmitter produces signals proportional to
yaw rate pitch rate and roll rate
in an AFCS system using auto trim movement of the pitch switch
will move both the control column and trim wheels
with fail operational AP the electrical power supplies are
isolated
when VOR/LOC mode is engaged a helicopter is controlled in the
roll axis onyl
the pilot cannot use the AP to control the aircraft with
TCS
successful synchronisation would be displayed by the trim indicator showing
zero
the pitch signal on a glide slope capture
increases
a failure during automatic landing with a fail passive system results in
system disconnect and the approach must be flown manually
during the landing phase with AT engaged when does the system enter THR CLP
at G/S capture
bank angle limiting concerns
maximum aircraft angle of bank that the AP can demand
when operating in turbulence mode
the gain of the control channels is decreased
when entering a banked turn to the right under autopilot control the aileron to rudder crossed will apply
right rudder
if GA is initiated during autoland the aircraft will
pitch nose up and increase speed
a voter system is used to ensure that
in multiplex systems a faulty channel is automatically disengaged
what signal may be added at touchdown
nose-down bias
during a ground check the vertical gyro is tilted in roll the versine signal will
give up elevator
an autopilot three-axis trim indicator shows out of trim condition by sensing
primary servomotor loads
in the approach mode and after glideslope capture the altitude hold facility
is inop because the signals from altitude hold are automatically switched out when the beam is captured
the flare phase of an autoland approach is controlled by the signals from
rad alt
in a typical AFCS the units consist of
VG DG amplifier
loss of rate feedback signal results in
oscillation of the control surface
trim indications are actuated by
DC milliammeters
on an autopilot ground check loss of control surface position feedback will cause the
control surface to move to its maximum position
a helicopter autopilot uses
rad alt for height hold and barometric altitude for altitude hold
two main AT control modes are engine thrust and
speed
an autopilot using a vertical gyro will automatically disengage with
loss of VG signal
an auto trim system controls the aircraft about the
lateral axis
what controls are used in response to the PVD display
nose wheel steering or rudder pedals
during autoland if one channel of a multichannel system detects an error between a control command signal and the control surface response all channels will disconnect if it Is a
duplex system
the term positive feedback refers to signals which are
of the same sense as the demand signal
the autopilot may capture a new altitude with
IAS or VS speed lock engaged
active stability
may be used in conjunction with a passively stable aircraft
when the clutch is energised the servomotor
connected to the control surface
electrically operated torque limiting is achieved by a resistor connected in
series with the control phase
when operated any torque pedal micro switches will
disengage heading hold
a position servo tachogenerator feedback signal is required to
damp out oscillations of a control movement
when reverse thrust is selected
AT disconnects
mach lock mode can be operated with
altitude hold mode disengaged
a versine signal is generated when the aircraft is
rolling
dutch roll is an oscillatory motion about the
yaw and roll axis
go around mode can be initiated
at and time after auto approach has been engaged
on an autopilot check loss of control surface psioiton feedback will cause
the control surface to move to its maximum position
a servomechanism having a tachogenerator only as a feedback device will
vary its speed with the input error voltage
a compatible mode in turbulence penetration is
heading
for an aircraft to be certified for a cat 2 autoland an AT system is
dependent on flight crew work load
in a helicopter AP
barometric capsules control altitude hold rad alt controls height hold
a servo motor has torque limiting for the purpose of limiting the
AP authority
in a yaw channel with heading hold the yaw synchroniser circuit operates when the
pilot puts his feet on the pedals
a radio coupled approach is
loc first followed by the glide slope
when a helicopter has AP engaged in alt hold and during the low speed regime range what used to maintain the altitude
longitudinal control
a radio coupled AP in pitch uses
glideslope
a rate servo tachogenerator feedback signal is required to
ensure proportional control movement for a given command signal
a triplex system loses one channel
pilot can continue with autoland
a triplex system loses one channel the system becomes a duplex system
duplex system
a triplex system loses one channel the system is now
fail passive
a yaw damper adds to its signal chain aileron and spoiler inputs
to help counteract adverse yaw
a yaw damper gain
decreases with speed
aileron signal is fed to the rudder channel
for turn coordination
aileron to rudder crossfeed is applied in autopilot system to
prevent aircraft yawing in the opposite direction to the turn
airspeed hold is a
pitch mode
alert height is when
a decision of whether to land is made
alpha range is applicable to
auto throttle
altitude hold mode what signal is washed out
pitch angle
