Common Core 2 Flashcards
Electricity
the physical phenomena arising from the existence and interaction of an electrical charge
Voltage, or EMF(Electromotive Force)
the amount of force being applied to a circuit to produce an electron flow
Amperage, or current flow
quantity of electricity flowing through the circuit
Resistance
opposition to the flow of electrons offered by a device or material
OHM(Omega)
the measurement of resistance to current flow
Watt
measurement of electrical work done
Forms of Electricity?
Static and Dynamic
Static Electricity
is electricity at rest, produced by friction and not easily measured nor controllable or useable
Dynamic Electricity
practical form of current flow, easily produced, measured, and controlled
Methods of Producing Electricity?
Mechanical, Chemical, Thermal, and Pressure
Mechanical produced electricity
by rotating a magnetic field through another magnetic field
Chemical produced electricity
surrounding two or more metallic plates with a chemical electrolyte
Thermal produced electricity
joining two dissimilar metals and applying heat
Pressure produced electricity
applying pressure to quartz, which will produce an electron flow
Types of Electricity?
DC(direct current) and AC(alternating current)
DC
is a steady current flow in one direction only, produced by a DC generator, or chemically by a battery
AC
flow that reverses direction at specific intervals, HERTZ/CYCLES. produced mechanically by an AC generator
SAFETY AROUND ELECTRICAL EQUIPMENT
determine power requirements before testing, inspect test equipment for calibration date
Multimeter
measures voltage, current, and resistance
Before making a resistance measurement??
remove all power to the circuit under test and discharge all residual voltage from storage capacitors
Multimeter Low Battery indicator
100 hours of life remain, standby mode kicks in after 1 hour of no use
AIRCRAFT ELECTRICAL SYSTEM
provides electrical power to the various aircraft systems
COMPONENTS OF THE Aircraft Electrical System
- Generator
- Control Switches
- Generator Advisory Lights
- AC/DC Transformer Rectifiers
- Power Distribution(AC/DC BUSES)
- Emergency Generator
- External Electrical Power Receptable
Aircraft Electrical System: Generator
produced AC power of three phase, 115/200VAC, 400Hertz. Driven by a constant speed drive(CSD) unit that regulates the generator at a constant speed
Aircraft Electrical System: Control Switches
located in the flight station/cockpit. Used to select electrical power
Aircraft Electrical System: Generator Advisory Lights
located in the flight station/cockpit. Indicates if the generator is supplying power
Aircraft Electrical System: AC/DC Transformer Rectifiers
convert AC power to DC power
Aircraft Electrical System: Power Distribution(AC/DC Buses)
a number of circuits may be connected, protected by circuit breakers.
Aircraft Electrical System: Emergency Generator
three phase 115/200VAC, 400Hertz generator that will provide electrical power to both essential AC and DC buses in the even of main generator failure. NOT ALL AIRCRAFT HAS EMERGENCY GENERATORS
Aircraft Electrical System: External Electrical Power Receptacle
Provides a means of connecting an electrical source of external electrical power for ground maintenance and servicing
Pictorial Diagram
simplest of all diagrams. provides readily component identification
Block Diagram
Arrangement of blocks that are labeled with the name of each component, presents a general description
Schematic Diagram
most useful of all diagrams, provides overall aid to system operation. Illustrates various components that make up the system
Series circuit
a circuit with only one path for current flow
Parallel circuit
circuit with two or more paths for current flow known as branches
Series-Parallel circuit
circuit which is part series and part parallel
Engine Electrical System
provides electrical power to the engine performance indicators.
Engine Electrical System Components
- Engine Speed Indicating System
- Engine Temperature Indicating System
- Fuel Flow Indicating System
- Oil Pressure Indicating System
- Engine Fire Detection System
Tachometer Indicator
indicates compressor rotor RPM in %.
Tachometer Generator
mounted and splined to the accessory gearbox, creates an electrical signal representing rotational speed of engine compressor
Thermocouple Assembly
mounted in the turbine or exhaust section, they are 2 dissimilar metals Alumel and Chromel, creating voltage signal of engine exhaust temp
Fuel Flow indicating system
indicates the amount of fiel being consumed by the engine in PPH
Fuel Flow Transmitter
mounted on the engine, provides an electrical signal that is proportional to the mass rate of fuel flow
Oil Pressure Indicating System
provides indication of engine oil pressure in PSI
Engine Fire Detection System
alerts pilot of an engine bay fire or overheat
Fire Detection Element
senses an overheat condition or fire and transmits the signal
Starting System
provides initial rotation to accelerate the engine to the point where ignition can be accomplished and sustained
Ignition System
provides a high energy spark at the engine ignitor plugs
Type of ignition system….
a high energy capacitor discharge type
Ignition System Components
Input leads
Transformer
Ignitor Leads
Ignitor Plugs
Types of Engine Lubrication Systems
Wet Sump and Dry Sump
Wet Sump—-
stores oil within the gearbox, used primarily on centrifugal flow engines
Dry Sump—-
stores oil in a separate oil tank, used on axial flow engines, allows a larger supply of oil
OIL pressure relief valve
limits maximum system pressure, and returns excess oil to the inlet side
Lubrication System Pumps
Pressure element pump
Scavenge element pump
Types of Pumps
Gear type–may be dual or multi element
GErotor type–may be single dual or multi element
Lubrication System Filters
Cartridge Filter–periodically removed and replaced
Screen Filter–can be cleaned and reused
Screen Disk Filter–can be cleaned and reused
Lubrication Heat Exchangers
Transmits heat from the oil to Air or Fuel
Air/Oil and Fuel/Oil
Lubrication Jets(Nozzles)
direct oil onto the bearings and or gears, can be mist or solid spray
Oil Pressure Transmitter
senses oil in the lube system, sends signal to indicator displaying pressure in PSI
Types of Lubricating Oils
Petroleum based and Synthetic based
Oil used in most gas turbine engines is?
MIL-L-23699 or NATO O-156
Main Engine Bearings
support compressor and turbine rotors to allow free rotation
What determines the Number of bearings?
Length, Weight, and the number of rotors
Accessory bearings
allow accessory shafts and gears to move freely
Types of Bearings
Ball bearings–absorbs axial and radial loads
Roller bearings–used in high centrifugal force areas, absorbs radial loads only
Oil Seals
Labyrinth, Thread, and Carbon
Labyrinth seal
controlled by engine bleed air
Thread seal
seal that uses reverse threading and centrifugal force to retain oil
Carbon seal
a spring loaded seal mated with a machined surface
Aircraft Fuel Systems purpose
to provide a controlled means of receiving fuel from external sources and supply fuel to the engine
Jet Propellant is a type of?
highly refined kerosene and is clear or light straw in color, classified into grades
Volatility
ability to evaporate
AVGFE
aviation gas free engineering, must be performed prior to entering any type of fuel cell
Aircraft Fuel Pumps
delivers a continuous supply of fuel to the engines UNDER ALL OPERATING CONDITIONS
Types of Aircraft fuel pumps
Transfer Pump and Boost Pump
What must be performed prior to entering any type of Fuel Cell for Maintenance
AVGFE (Aviation Gas Free Engineering)
Electrically operated shut-off valves are commonly referred to as?
Gate valves
Why are Manually operated shut-off valves important?
they may be closed to stop fuel flow in case of fire
Fuel Drains purpose
drain condensation, excess fuel, and samples of fuel.
External tank capacity
150, 300, 400 gallons, mounted on pylons on the underside of the wings and fuselage
do not conduct _________ within _____ feet of operating aircraft
fueling operations, 100 feet
how many people is required for fueling
minimum of 3
Engine-Driven Fuel Pump
provides a continuous supply of fuel AT THE PROPER PRESSURES under all operating conditions
Aircraft Fuel Pumps
provides a continuous supply of fuel to the engines under all operating conditions
