Flashcards
5. Autopilot
Cards in this deck (70)
- 1define a single axis Autopilotattitude control about the roll axis - using the ailerons
simplest type - 2what can a single loop axis autopilot also be known aswing levelling system
- 3what systems are able to inject information into the single looppilot - change a heading
nav equipment - tracking capabilities - 4define a two axis autopilotauthority in roll and pitch
system can use external loops to hold different conditions - 5what is an example of a two axis autopilot and an external loop2 autopilots and a yaw damper
- 6define a three axis systemhas authority in all axis
- 7what are the two types of autopilot classificationsstandard autopilots
operational autopilots - 8define standard autopilotsis one where if it were to fail, the manoeuvre would have to be carried out manually.
- 9are standard autopilots certified to fly an autolandno
- 10define operational autopilotsperform a number of manoeuvres.
built in redundancy so that if a failure of an autopilot or part of it will not affect the continuation of an approach - 11how can the classification also be definedby how many autopilots are installed
- 12what are the two methods of controlling runwaycomparators
rate trigger systems - 13how do comparators worksensors and actuators are monitored and compared so that so that if the sensors feel movement in a particular direction whilst the actuators are demanding a control in the other direction, the system will disconnect
- 14define rate trigger systemsif an A/P was to runaway then the rate of change of aircraft attitude will be high, sensors monitor this rate, and if the exceed the design thresholds of the aircraft they will be disconnected
- 15what has to be ensured for rate trigger systemsthat there is enough sensitivity so that it will not be triggered during a turbulent flight
- 16what is the main disadvantage of the both systemsthat the systems are REACTIONARY
the movement has to be sensed and then responded to before turning off the autopilot - 17which configuration can be used on the different types of autopilot systemsboth methods can be used on any of the autopilot systems
- 18what does a duplex system consist of2 complete A/Ps
2 sensors
2 actuators
2 hydraulic system lines
2 electrical systems
2 switches - 19how is a duplex system usually configuredso that any output is averaged before the signal is sent out
- 20how can a duplex system prevent runawayif there is a failure in one of the AP lines, then the other AP will command a corrective signal of its own, that should average out the movement and result in an average of approximately 0
- 21define cross couplingfeedback that works on the ability of a sytem to self monitor and monitor the other lines actuators, and therefore any error can be detected quickly and the system in that axis can be disconnected
- 22what is the main disadvantage associated with the duplex systemif one of the systems is supplying incorrect information there is no way of telling which system it is, and to tell you would need to switch off each one individually and compare to standby instruments
- 23define a triplex systemworks on the same idea as duplex system, but you can easily identify when a single autopilot is correct via a voting system
- 24what is one of the disadvantages of a triplex systemyou need to have triplicate of all parts of the system, and that has a cost and weight implication
- 25define psuedo triplexessentially a triplex system, but instead of the third complete autopilot, there is a computer that participates in the voting system
the "brain" predicts outputs and with the predicted outcomes can partake in the voting system - 26define servo mechanismsclosed loop control systems in which a small power input controls a much larger power output - STRICTLY PROPORTIONAL
- 27what do servomechanisms have the ability to doerror detection
amplify error signals
close the loop by providing feedback - 28what are the two classes of servo-mechanical feedbackposition control
speed and rate control - 29how do position control servomechanisms workthe position of the pilots flight controls (control column) is sensed by potentiometers attached to it. these are sent to an amplifier. the same is done with the positions of the actual control surfaces.
in normal flight they are the same, but when the pilot moves his control column it creates an error between the signals. the control surface will be moved until the signals are again equal - 30what type of actuators are speed or rate control servomechanisms used onspeed sensitive or rotary actuators
- 31describe the idea behind the speed or rate control servomechanismsspeed control looks for a difference in voltage between the input control speed and the load speed. difference is amplified and fed to the servomotor.
will speed it up or slow it down, this is done by a tacho-generator - 32what does the rate of response of the servomechanism depend onaltitude
speed
aircraft load
configuration
rate of manoeuvre - 33what is the number of servo-actuators required dependant onthe number of control loops in the system
- 34what is the primary purpose of servo actuatorsto move the control surfaces
- 35what are the different types of actuatorselectro-pneumatic
electro-mechanical (fly by wire)
electro-hydraulic - 36what is the basic operating principle of the electro-pneumatic actuatorsuses engine compressor bleed air or air fro an engine driven pump
normally A/P authority will not exceed 50% of the range of the aircrafts flight control system - 37define a series servo actuatorone that does not move the pilots control column
- 38what is a parallel servo-actuatormoves the pilots controls when surfaces are moved
- 39define the disengaged state of servo-actuatorsthe actuators are disconnected from the flying control system
OFF POSITION - 40define the engaged state of servo-actuatorsActuators are moving the flying control surfaces, and are engaged with the aircraft controls
- 41define the override state of servo-actuatorsthe crew would need to override the control of the autopilot if the servo actuators were to fail.
- 42what can be said about the axis that are trimmedthe trim of a commercial aircraft is only available in pitch
roll and yaw are manipulated manually - 43what happens if a auto trim failure is detectedthe autopilot will automatically disengage
- 44what is important to remember about the mach trim systemit is an independant system
- 45what does the AP need to do before the AP can be engagedit has to run a BITE (build in test equipment)
to self check its own systems - 46what is the modern method used to do thislogic gate system
- 47what are the two main conditions for the autopilot to be engaged- no force to be applied to control column
- the STAB TRIM AUTOPILOT cut-out switch set to normal - 48what will happen if you try to engage another A/P when not in APPthe new autopilot will engage but it will disengage the first one
- 49is no mode has been selected on MCP, what mode will the AP automatically engage inCWS R
CWS P - 50what does a flashing red warning light indicatethe AP is disengaged, the warning can be reset by pressing disengage light or either A/P disengage switch
- 51what does a steady red warning light indicate- stabiliser out of trim below 800 ft RA on a dual channel approach
- ALT ACQ mode is inhibited during A/P go around if the stabiliser is not trimmed for a single AP operation
-automatic ground system test fails - 52how can the steady red warning light be switched offthe conditions must be rectified
- 53what does an amber light indicateAP has automatically reverted to CWS pitch or roll whilst in CMD mode
an amber annunciation will occur on the PFD if this occurs - 54how can the amber light be turned offeither light is pressed or another mode is engaged
- 55what will happen when the autopilot is engaged or disengageda tone will sound
- 56how is the tone turned offmust be manually turned off by pressing the disengage switch
- 57what is the purpose of autopilot synchronisationto prevent the controls being snatched when the autopilot engages
- 58what is the purpose of auto trimto prevent a snatchy disengagement of the autopilot
- 59what will happen in CWS mode, if the bank angle is set within 6 degreesit will assume you wish to fly straight and level and will roll the wings level
- 60when is CWS inhibitedbelow 1500 ft with gear down
after LOC capture in APP mode
after VOR capture with less than 250 kts TAS - 61when will CWS P engagewhen there is no pitch mode selected
- 62when will CWS R engagewhen there is no roll mode selected
- 63define the purpose of TCSit allows the pilot to manoeuvre the aircraft when the TCS button is held (on control column)
motors and the automatic control channels are disengaged during this time - 64what limits must the aircraft be in to disengage the AP in regards to pitch and rollpitch +/- 10 ˚
roll +/- 30˚ - 65what are torque limiters used forto prevent control surface runaway
- 66define Control Surface Runawayexcessive control inputs that could cause the load factor to be exceeded
- 67what is important to remember in regard to the authority that the Autopilot hasit does not have authority for full control deflection
- 68what must STAB TRIM indicate for take offgreen
- 69what are the three types of mach trim-fuel transfer
-trimming of the elevator
-trimming of the horizontal stabiliser - 70in a duplex system what can be said about the Radalt and each APthe Caps RA feeds Autopilot A
the FOs RA feeds autopilot B
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- INST (Advanced Instruments) Flashcards on 5. Autopilot, created by Ella Davies on 23/05/2018.
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