Final Exam Review Flashcards
Who is credited for creating the gyro and the inner feedback loop?
Elmer Sperry
Who is credited for helping design the first AP system?
Lawrence Sperry
What is the purpose of the AP system?
Reduce pilot workload so the pilot does not have to fly the plane manually
Know the boxes
DO IT
What is another Autopilot element that allows the assembly to remain parallel to the earth’s surface regardless of attitude?
Spinning gyroscope and its gimbals
In an EI pickoff, what is the output voltage from the secondary coil proportional to?
Displacement of elements away from Null position
In the EI Pickoff Output signal, what does the Null represent?
Reference Position
In the EI Pickoff Output signal, what does the Magnitude represent?
Angular deviation from null
In the EI Pickoff Output signal, what does the Relative phasing represent?
Direction away from null
In the EI Pickoff Output signal, what does the Rate of Change of Magnitude represent?
Angular velocity which the aircraft is changing course
The RLG senses what type of measurement?
Angular measurement
What is an RLG and how does it detect motion?
Ring Laser Gyro, detects motion using rate sensors
If the RLG is in phase, what does this mean and how are the lasers acting?
Level flight and light is intense
If the RLG is out of phase, what does this mean and how are the lasers acting?
Different frequencies, not on course and has a fringe pattern (dark bands)
What is MEMS?
MicroElectroMechanicalSystems used to make accelerometers
How does the MEMS work?
The position of the small cantilever beams = capacitance = accelerating force on the sensor
What do we use to measure angular rates and accelerations?
Inertial Reference Systems
What are the inputs of an IRU?
Initial position, latitude, and longitude
The IRU position gives us what?
aircraft location, direction of travel and other nav data
What are the inputs of an ADC?
pitot, static, and outside air temp (OAT)
Inputs of an ADC determine what?
ASI, VSI, ALT, SAT and TAT
ADC outputs a signal to what?
AP comouter and EFIS
What is the servo feedback proportional to?
Proportional to movement of control surface (servo, actuator, control surface)
What are the 2 types of feedback servos?
AC synchro and Differential transducers
What are the 2 types of AP systems?
Position (attitude) and Rate based
On what axis do we roll and which direction is a positive roll?
Longitudinal axis, nose to tail, roll right is positive
On what axis do we pitch and which direction is a positive pitch?
Lateral axis, wingtip to wingtip, pitching up is positive
On what axis do we yaw and which direction is a positive yaw?
vertical axis, yaw right is positive
What is the cause of adverse yaw?
Drag of a lowered AILERON during a turn
What is the affect of adverse yaw?
Causes nose of the aircraft to point away or, outwards, from the direction of turn
what is the unwanted yaw due to asymmetric thrust by the descending blade in a climb?
P factor
The vertical gyro output signal range for a roll is?
3mV/degree of roll
The vertical gyro output signal for a pitch is?
6mV/degree to 200mV/degree
What is the autoflight primary axis?
Roll axis
Single axis AP controls the what?
Ailerons
Know the HDG mode steps for Lateral mode operation
- The HDG bug is moved from 12 o’clock position on the HSI.
- A voltage µ error from that position is sent to the computer.
- The roll attitude signal is summed with the error signal, amplified and drives the servo to move the ailerons.
- Aircraft then rolls until the attitude signal is equal and cancels the HDG error signal.
- A standard rate turn is continued until within 25-30˚ of selected HDG and the resultant error is gradually reduced until the attitude signal begins to dominate.
- ØThe summed lateral circuits will now reduce the roll servo drive to reduce the bank angle until the aircraft has settled on the selected HDG.
What is the number/degree of a VOR/LOC mode intercept?
45degrees (FSD 150mV)
What does the Turn-Coordinator and Accelerometer give the aircraft?
Position and rate sensing
In a rate based AP system, what components are used for altitude control and pitch rate?
Accelerometers and static pressure sensor
What is the output between the supply voltage and ground that is proportional to the absolute pressure sensed at the static port?
Ratiometric signal
What is the purpose of the PITCH LIMITING FUNCTION on a Rate gyro vertical mode operation?
protect the airframe from excessive g forces/turbulence
The pitch limiting function results in what?
Momentary disconnects from pitch/trim solenoids
What are the 2 categories of FGS modes?
Lateral and Vertical
Lateral modes control what?
Horizontal motion by rolling
Vertical modes control what?
Vertical motion by pitching
What are the 5 Lateral modes?
ROLL, APPR, GA, HDG, NAV
What are the 7 Vertical modes?
PTCH, ALT HOLD, ALT SELECT, APPR, FLC, GA, VS
The modes on the PFD are displayed on what?
Flight Mode Annunciator (FMA)
What is the function of the flight director?
To present steering instructions on the PFD
The selection and indication of the FD modes is a function of?
Mode Logic
Mode logic and control laws are _______ that control the flight control systems
Software
What are the subsystems of a FGS?
FD, AP, AT
Computing FG steering commands is done by what?
Flight Control Laws
Controlling FD and AP is done by what?
Discrete logic and hardware
The correct selected and indicates modes on the FGS are based on what?
Selected = Input
Indicated = output
When turning on FGS, what modes are on by default?
Roll and Pitch
Control Systems can be classified as either?
Closed or Open loop
What is the purpose of the error signal?
Issues a correcting order that changes existing conditons to desired conditions
How do we eliminate overshooting?
Damping by introducing a voltage in opposition to signal voltage
Physical restraint on servo output
What type of servos do we use on Transport category aircraft and how does it work?
Hydraulic servos, works using a transfer valve and an LVDT feedback
Why is the Dutch Roll only dampened and not eliminated?
The signal to control it must come from the Dutch roll itself
In a rate gyro Dutch roll signal, when does the phase of the gyro signal reverse?
When direction of turn changes
What do the control laws do?
Prevent the aircraft from going into dangerous positions of flight
What is the B787 Autoflight system comprised of?
Autoflight Function
Thrust Management
Flight Management
In the B787, the AF system is capable of what phases of flight?
all
When the flight crew needs to input data into the FMS, how do they do that?
using the CCD and MFK which goes into the CDU
What are the flight crew entries?
Cost index
Cruise Altitude
Airplane gross weight
What are the preflight introduction pages?
IDENT
POS INIT
RTE
DEP/ARR
PERF INIT
THUST LIM
TAKEOFF REF
This page in the preflight intro is used to verify the FMF operational program and data base info
IDENT
This page in the preflight intro is used to set the reference airplane initial position
POS INIT
This page in the preflight intro is used to generate a flight plan or set a company route from the nav data base
RTE
This page in the preflight intro is used to select departe runway and standard instrument departure (SID) data. Destination and approach also selected here
DEP/ARR
This page in the preflight intro is used to enter aircraft and atmospheric data that is necessary for the FMF to calculate the flight vertical profile performance data
PERF INIT
This page in the preflight intro is used to select the engine thrust limits for the thrust TMF
THRUST LIM
This page in the preflight intro is used to select takeoff flap, cofg and takeoff V speeds
TAKEOFF REF
What is the purpose of the TMF?
controls engine thrust levers from takeoff to touchdown, gives max fuel conservation
How are the thrust levers moved by the TMF?
2 independent servo motors
What TMF controls are available in the flight compartment?
Arm switch on MCP,
TO/GA or thrust lever,
Disconnect on thrust lever,
Mode select (thrust or speed) on MCP
Which function is used to calculate the thurst control settings?
FMF
What are normal AF modes in cruise?
LNAV and VNAV
How would the pilot initiate take off and what modes are on?
AT armed, then TOGA switch
FD and AT
Study this diagram
Study it
Study this diagram
Study it
The thrust management system indications show on which displays?
PFD, HUD, EICAS
During a ground inspection external check, what are you checking for?
- Control surfaces for looseness, bushings tight
- NO movement on hor/vert stabilizers
- trim tabs for unusal placement/settings
- pitot and static ports for debris and deformations
On a turn coordinator/rate based AP where should the flag be when the gauge is powered?
Out of view
When performing an AP ground test, when youn turn on the AP what are the default modes?
HDG hold and Attitude hold
During a trim operation ground test, the autotrim will trim in which direction if the yoke is applying a downward pressure?
Opposite, it will trim up
After monitoring the heading for long term drift, adjust the roll null trim pot for ________ heading change
minimum
When overpowering the roll clutch, what will you do and what are you checking?
forcing the aircraft into a 30degree bank and seeing if the clutch can bring the aircraft back to level flight
After repeating the overpowering procedure, if there is a difference in performance in the clutch, what is the issue?
P factor and weak clutch
An AP response after pitching the nose 5-7degrees must be damped such that the aircraft returns to level attitude within _______ cycle in converging manner
ONE CYCLE
How many degrees must you adjust the HDG bug of the current HDG to check roll gain?
10 degrees
The difference betwen the left and right turn bank angles should not be more than what? If the tolerance is exceeded what is at fault?
+-2degrees, gyro at fault
The forces needed to move the control yoke through its neutral position and the rudder pedals from their center position describes what?
Cable Friction
An oscillation lasting roughly one second is caused by what?
AP malfunction or cable friction too low
An AP malfunction or cable friction that is too high can cause what?
10-30s oscillations
The key to knowing there is a GAIN problem is that the oscillations are what?
periodic
Which function has vertical and lateral guidance for all phases of flight except the takeoff roll and final approach and touchdown?
FMF
The FMF autotunes which nav radios?
DME, VOR, ILS, GPS/GLS
