Everything Flashcards
How many milli amps is fatal
100 milli amps or more
During a shock the degree of interference depends on? [3]
Where the current flows in the body
Amount of current flowing
Duration of electric shock
Effects of electric shock
● burns
●unconsciousness
●respiration stops
●reduction of blood circulation
Immediate actions to take when discovering a shock victim [3]
●assess for dangers
●Isolate victim from power source
●render first aid and call for medical
When removing the current source for an electric shock victim what items do we use?
A DRY inulating material
Eg.
Wood
Plastics
Rubber
Outline voltage
The driving force in electric circuits
Explain EMF (electromotive force)
The force that tends to produce a current in an electric circuit
Symbol, V or E, units Volts
Outline PD (potential difference)
The voltage difference between two points in an electric circuit
Symbol V, units volts
Describe current
The flow of electrons in an electric circuit
Symbol I, units Ampere
Outline resistance
The materials property to resist the flow of electrons when a voltage is applied across the material.
It causes the electrical energy to be converted to heat energy
Symbol omega, units ohms
Factors effecting restistance
Length
Resistivity
Cross sectional area
Ohms law,
V=IR
Outline power
The rate at which electrical energy is converted into another form. Aka amount of work done
Measured in watts
P= VI
What are domains
Groups of atoms in a material that act like little magnets. If aligned the material will be a natural magnet. Domains in a un-magnetic material are aligned randomly.
2 types of magnets and explain each
Permanent- when field is removed domains do not return to original state
Temporary- when field removed domains revert back to original state
Magnetic force lines, Flux lines [8]
Do not cross
Elastic in nature
Acting in same direction repel
Acting in opposite direction attract
Form complete loops
Pass through all materials
Concentrate at poles
Travel from north to south
What’s left hand rule
To show which direction Flux lines travel in a moving current. As when a current moves through a conductor a magnetic field is set up
What direction do electrons flow
Negative to positive
Strength of solenoid depends on:[3]
● Number of turns of wire in coil
● Current flow in coil
● How concentrated the Flux lines are(increased by adding a core)
Solenoid is a…
Electromagnet
What properties does a solenoid have when current is flowing
Turns into an electromagnet and creates north and south poles
Define electromagnetic induction
Voltage is produced in a conductor when there is relative motion, between conductor and magnetic/electromagnetic field
3 methods of inducing EMF in a conductor
● relative motion of conductor in magnetic field (generator)
● self induction (inductors)
● mutual induction (transforming)
Define generator
A machine that converts mechanical energy into electrical energy using electromagnetic induction
Generators action
Single loop of wire rotated at a constant speed between poles of a magnet
Outline production of DC
Using a generator but slip rings are replaced by a commutator
2 types of voltage regulation
Carbon pile
Electronic
3 parts of a brushless generator
● permanent magnet gen
● excitation gen
● main gen
Define motor
A machine that converts electrical energy into mechanical enegery
How Operation of a motor in reference to Flux lines
Relies on the fact magnetic lines of force do not cross, therefore the motion is due to interaction between magnetic fields
Rwferncing motors, How does a conductor move in relation to the main field
At right angles
Outline Mutual inductance
Induction achieved when a changing magnetic Flux in one circuit induces an emf in another seperate circuit.
Noting: Flux must be changing so an emf can be induced
Purpose of tranfsormers
To step up or step down voltages to required levels.
Note: transformers are AC ONLY
In relation to transformers will the frequency change of the emf produced
No. The frequency will remain the same
Outline isolating transformers
A safety device to protect the operator when equipment developes a phase fault. It stops the power ground through the operator.
Define capacitors
A device to store energy in the form of an electrostatic field
A capacitor is a device that opposes the change of voltage in a circuit
3 factors effecting a capacitor
Area
Distance
Dielectric material
3 things impacting a solenoid
Number of turns in wire coil
Current flowing in coil
Concentration for Flux lines(increased by a core)
Define an open loop servomechanism
Is one system that the initiating action is independent of the result obtained
Requires operator to monitor the output and adjust as necessary
2 open loop servomech applications
Trim tabs
Search light
Define closed loop aervomechanicsm
Desired result is compared to actual result, in the loop
Applications:
Aircraft flaps
Define a relay
An electronic device, that unlike a solenoid, is used to open or close electrical connections remotely.
Outline microswitches
A switch that has no internal adjustment and can only be done by moving the switch body
Aircraft tradespers are responsible for what with microswitches
Fitting, setting, adjustments, and functional checks.
Avionics do: servicing switch, connecting and disconnecting, continuity checks
In relation to HERP, most subspecialty organs are:
Eyes
Testes
HERP stand for
Hazards of electromagnetic radiation of personnel
HERF stands for..
Hazards of electromagnetic radiation to fuels
HERO effects can be cured by
Restricting radio transmissions during handling ordances
Avoid aircraft in HIF
Hardening EEDs
What does HERO stand for
Hazards of electromagnetic radiation to ordances
Lightning effects can be mitigated by; [3]
● diverter strips
● arresters
●correct bonding
P-static can be mitigated by… [3]
●static wicks/dischargers
●static wicks are connected to rest of aircraft through low impedence bonds
●observing good bonding practises
HIRF stand for?
High intensity radiated field
EMI stands for
Electromagnetic interference
Symptoms of EMI, [5]
●degraded comms, radar and navigation
●nav errors, false readings
●warning light activation
●spontaneous movement of control surfaces
●interfers with engine controls
E^3 Stands for
Electromagnetic environmental effects
2 effects of EMI are:
And where is it found nzap…
Natural phenomena (esd, p-static, lightning)
Man made effects (radios)
Nzap6000 pt2, Lf B9.2
2 sources of EMI
Intentional emitters
Unintentional emitters
Outline Static dischargers
Develops charge when flies, aka p-static. Uses static wicks to discharge and reduce this effect
Bonding vs earthing
Bonding is electrically connecting all conductive parts together to complete a electrical circuit, ensuring no PD between parts.
Earthling - process of physically connecting item to earth
2 precautions when operating HEIU
● never touch output lead or ignitor plug when in op.
● safety man must be positioned where can warn others away during HEIU ops
Hazards of Lox
When oxygen is exposed to oils and greases under pressure will spontaneously combust
Expansion rate of Lox
862:1
Procedure of major Lox spill [4]
● call fire
● clear area
●keep unauthed pers away
● extinguish fire properly
Pitot static safety, safety precautions [6]
● never blow into pitotstatic
●always blank pipes when disconnected
●always fit protective blanks when on ground
●ensure heaters are off at all times
●ensure drain holes not blocked
●Carey out sense and leak test when required
Pitot static safety, hazards to aircraft [4]
● water contamination
● blockage
● crossed pipelines
● loose pipelines
EWIS inspection safety!
Prevent electric shock, ensure power is turned off before inspecting.
Fibre optics safety question
Never look into Fibre optical light source or cable connected to light source. Cause damage to sight
Fibre optical cable precuation
Ensure minimum bend radii is observed
Connector, tradesman responsibility
Connection and disconnection of plugs when equipment is of mechanical nature
Nzap 6001-1, Lf D1
Avionics wiring sys. Types of wiring diagrams
● location
● schematic
● routing (wiring)
Automatic flight control system
AFCS purposes… [2]
● releive stress from pilot and mental fatigue
● automatic pilot will fly aircraft more stable than human
Regarding AFCS, what are the 2 ACFT trade responsibilities…
● Rev, inst, serv, engine accessories
● Rev, inst, serv, pilot servos and connections to aircraft controls
Problem with direct/wet reading compass
Become unreliable at high magnetic latitudes
Gyro magnetic compass [direct indicating] 2 main errors are…
● magnetic field of aircraft structures
● acceleration errors
Gyroscope handling during aircraft movement [2]
● do not move unless gyro at full speed or stopped
● cage gyro if applicable
Gyroscope handling precautions, transportation [3]
● handle with care
● lift gyro base, 2 hands,
● secure in appropriate transit case
Horizontal gyro is used where
Directional
What gyro in artifical horizon
Verticle gryo
Outline capacitive fuel sys
Probes, in tank connected in parallel to provide an average value regardless of aircraft attitude
Tachometer consists of 2 main units
Transimtter - Tachometer gen
Indicator - rpm guage
Landing gear indicated posisitons
● up and locked
● in transit
● down and locked
Landing gear, types of indicators
● red and green light assy
● dolls eyes
● mechanical indicator
Advantages of remote indicating sys [2]
No hazardous fluids in cockpit
Weight saving
