aircraft electrical systems - welcome to the instructional web

Aircraft Electrical Systems

Electromagnetic Induction was

•Electromagnetic Induction -movement of electrons through wires (or conductors) to create electric current.

•Magnets passed across a closed-loop of wire at right-angles create an electromotive force (ELF)

ELF – VOLTS – occurrwhen electrons move in the wire

•Vice Versa: Electricity produces magnetism

What is Electricity?

Vice Versa: Electricity produces magnetism

Aircraft Electrical System Power Sources

Battery

• Provides Electrical Power when Alternator or Generator is not available

• Several types of Batteries– Most Common – Lead-Acid Battery

• Lead and Acid produce electrical charge

Electrical battery

• Small, light, not a lot of power

• Simple and effective built to last

• Recharges during flight from Alternator or Generator

AlternatorConverts

• Alternating Current (AC) to

• Direct Current (DC)

• For electrical system uses

•DC is easier to use,

• Lower volts, Safer

•Also, provides Current to Battery

to maintain battery power at max

levels


GeneratorProduces Direct Current (DC)




•Like Alternator- provides Current

to Battery to maintain battery

power at max levels when Battery

is “off –line”


Aircraft Electrical System Controls

Master SwitchControls ALL aircraft electrical

power from Source to Use Points

•Left Side Switch controls

Alternator Power Source

•Right Side Switch controls

Battery Power Source


Circuit Breaker & Fuses•Protect individual electrical User

Systems from Electrical Overload

(too much power)

•Breakers and Fuses do Same Job

•Difference:

• Replace a Fuse

• Reset a Circuit breakers

•Technology Improvement

• Fuses- Older Technology

• Circuit Breakers – Newer

Technology


Airplane Electrical Systems

Ammeter

•Monitors electrical system

performance

Two types

•To/from battery

•Alternator load

Voltage Regulator• Volt is a measure of Electrical

Power

• Voltage regulator automatically maintains constant voltage level


Master Switch

Master Solenoid

Starter SolenoidElectrical Switch

• starter solenoid relays a large electrical current from origination source (Battery or Auxiliary Power Unit – APU) to rotate Starter Motor

Starter Switch

Starter

• Electric Motor connected by special gearing to Engine Crankshaft

• Rotates at very high speeds to rotate Engine Crankshaft

• Engine Crankshaft rotation Aircraft Engine Magnetos

• Magneto is a Field Generator– Rotating Magnet surrounded by

loops of conducting wires

• Rotating magnets generate electrical current flow through wires

• Aircraft engines have TWO Magnetos for Redundancy – Safety feature – two spark

sources are better than one

Magneto

Magneto Systems

AND, TWO Spark Plugs• Two plugs fire

simultaneously in Each Cylinder from Each Spark Source

• Efficiency – More even spark

– More even, steady burning

– More complete burning

– Spark improves burning in all areas of cylinder

– Plug fouling – A problem


Battery

•Stores Electricity

•Powers Engine

•Short-term Power

Magneto and Electrical System

By Cory and Amanda

Electrical System- 727 Simplified

Magneto and electrical systemJonathan Hord

Magnetoes are self-sufficient

Air, fuel and spark starts engine

http://www.aircraftspruce.ca/catalog/eppages/4300svcparts.php

Glass Cockpits • Electrical power is

essential for Glass Panel Cockpits

• Magneto Powered Engine can run without Battery power

• Glass Panels Can’t

Glass Cockpit Power - Critical

• Backup Battery – 30 Minutes??


The End – Fly Safe!

Basic Electrical/Magneto Aircraft System

A cylinder is a central working part of an engine. The space in which a piston travels. Multiple cylinders are arranged side by side by the engine block. The distance the piston travels in a cylinder is called the stroke. In the cylinder is where combustion occurs.

A busbar in electrical power in distributing refers to thick strips of copper and aluminum and conducts electricity within a switchboard, distributing board, or other electrical apparatus.

Brian Bates, Baron Gould, & Richard LynchELECTRICAL & MAGNETO SYSTEMS FOR SMALL AIRCRAFT

• A magneto operates on the principle of electromagnetic induction, is self-contained and engine driven

• A magneto provides the electrical power for the ignition system to keep the engine running once the engine has been started.

• A magneto is a combination of a low voltage alternating current generator and a high voltage coil and distributor.

• The distributor in the magneto picks up the high voltage current from the coil and delivers it through the coil to the spark plugs.

The Magnetos

• Timing of magnetos is determined in the development phase. It is important to prevent pre-ignition and/or detonation.

• Small, general aviation aircraft are usually equipped with two magnetos for efficiency, smoother operation of the engine, and redundancy, to prevent the loss of the system if one magneto were to fail (L & R)

• Most small aircraft are equipped with a 28-volt direct current (DC) electrical system, because an alternator produces more output for less weight compared to a generator and can produce a specific amount of power at a much lower rotational speed.

• An alternator drives the electrical devices and stores energy in the battery.

• The battery provides the power to crank the starter.

Alternator or Generator?

OR

• The second electrical system connects the electrical buses and the devices to the battery through a switch, the master switch.

• The battery provides the power to crank the starter which will start the engine. Now, since the engine is running, the engine will supply power to the alternator and recharge the battery.

• The magnetos continually work to create spark, ignite fuel and crank the engine.

Electrical System,(in a nutshell)

• Inside the cockpit, you will find an ammeter

• Some instruments require electricity to function

• Read the pilot’s operating manual (POH) and aircraft flight manual (AFM) to learn how to identify and possibly handle any electrical problem in flight.

• In the event of a power failure, you should know whether or not an emergency landing is necessary.

• Evaluate Conditions

•VFR or IFR = Nav equipment?•Retractable Gear = extended?•Flaps retracted or extended?•Transponder/Comms avail?

Know Your Systems

• ER Procedures 101

• Aviate

• Best Landing Site

• Communicate

References

Glenn Research Center, http://www.grc.nasa.gov/WWW/K-12/airplane/icengine.html, 1-11-2008

Glenn Research Center, http://www.grc.nasa.gov/WWW/K-12/airplane/elecsys.html, 1-11-2008

Pilot Friend, http://pilotfriend.com/training/flight_training/tech/elec.htm, 1-11-2008

http://selair.selkirk.bc.ca/systems1/Engines/Aircraft%20Magneto%20systems.html, 1-11-2008

http://www.grc.nasa.gov/WWW/K-12/airplane/icengine.html



http://www.grc.nasa.gov/WWW/K-12/airplane/elecsys.html



http://pilotfriend.com/training/flight_training/tech/elec.htm

http://selair.selkirk.bc.ca/systems1/Engines/Aircraft Magneto systems.html

Electrical&

Magneto Systems

Mark Kinder

Nathan Williamson

Richard Douglas

AVIA 112

Outline

•Electrical Systems•Alternator

•Battery

•Ammeter

•Master Switch

•Circuit Breakers & Fuses

•Magnetos


Battery

•Stores Electricity

•Powers Engine

•Short-term Power

Magnetos

• Supplies current to plugs

• Changes mechanical

energy to electrical

•Each A/C has 2 magnetos

•Provides redundancy

•Improves combustion

•Magneto is engine-driven

Summary

•Electrical Systems•Alternator

•Battery

•Ammeter

•Master Switch

•Circuit Breakers & Fuses

•Magnetos

Electrical System

Magneto Systems

Typical Ignition System

aircraft electrical systems generate, regulate and distribute electrical power throughout the aircraft.Many aircraft flight instrument systems use electricity

•Aircraft electrical components operate on many different voltages both AC and DC•Most aircraft systems use :

•115 Volt Alternating Current (AC) @ 400 Hz•28 Volt Direct Current (DC)

Most aircraft engines provide power to generate AC generator (alternator) power.

Electrical Systems• The function of the aircraft electrical system is to

generate, regulate and distribute electrical power throughout the aircraft.

• It is essential for the flight instrument systems.

• Aircraft electrical components operate on many different voltages both AC and DC

• However, most of the systems use:– 115 VAC @ 400 Hz

– 28 VDC

• Each of the engines on an aircraft

drives an AC generator (alternator).

Electrical Power System Components

• AC Generator or Alternator

• Constant Speed Drive: in this case would be the belt driven by the engine.

• Today's modern small aircraft contain all of this inside the alternator:– Integrated Drive Generator

– Transformer Rectifier Unit

– Generator Control Unit

Basic Functions

• The basic functions of the electrical system’s components are to:

–Generate Power

– Control Electrical Power

– Protect the Electrical System

– Distribute Electrical Power

Throughout the Aircraft

Magneto

How they WoRk!• The ignition magneto combines

the functions of a dynamo, contact breaker points, "condenser", and ignition coil.

• The engine spins a magnet inside a coil, and also operates a contact breaker, interrupting the current and causing the voltage to be increased sufficiently to jump a small gap. The spark plugs are connected directly from the magneto output.

All pilots are…

Aircraft Electrical and Magneto Systems

Corey Hjalseth

Ali Spirggs

Fernando Rodriguez

Aircraft Magneto Systems

• A magneto is a combination of low and high voltage current generator and distributor.

• The magnetos ignition coil transforms low voltage to high voltage.

• The distributor picks up the high voltage from the coils and delivers it to the spark plugs for ignition.

Magneto Diagram


• The purpose of an aircraft electrical system is to generate, regulate, and distribute electrical power through the entire aircraft.

• It consists of a battery, an alternator, and regulators for these devices.

• The alternator charges the battery just like in a car.

Electrical System Run Through

• The master switch turns on the battery.

• The battery turns on all of your aircraft lights.

• The Alternator is activated along with the radio and instrument lighting.

• The alternator continues to work and recharge the battery and thus light the aircraft.

Aircraft Electrical System Diagram

General Aviation Aircraft Electrical and Magneto Systems

By: Silvia Fresnedo, Mark Tison and Karen Fisher

Electrical System

• The airplanes electrical system consists of a battery and a generator or alternator with associated voltage regulators, current limiters, or other protective devices.

• The primary function of the battery is to provide power to the starter motor.

• After the engine starts, the magnetos provide ignition,

– generator or alternator takes on the tasks of powering:

• Radios

• Instruments lights

• Electrical landing gear

• Flaps

• Recharging the battery

• Individual circuits are protected by circuit breakers or fuses.

Electrical System

Magneto SystemMagneto-equipped aircraft engines

are typically dual-plugged, that is, each cylinder has two spark plugs, with each plug having its own separate magneto; This arrangement provides: – redundancy in the event of a

failure of one of the magnetos.

– more complete and efficient burn of the fuel mixture, and

– if placed far apart in the combustion chamber, decreases burn time, allowing higher engine speeds.

For this reason, double plugging is also used in high performance automobiles and motorcycles.

Magneto System

Magneto Internals

Magneto Components

Questions?

Electrical and Magneto Systems

Mark, Godfrey, Shane

996 835

MAGNETO GENERATOR P12W150

1996 821

1 MAGNETO FLYWHEEL P12W150 1 From serial# 4084219 & above

996 820

MAGNETO FLYWHEEL 1 Up to serial# 4084218

2 996 849

COIL KIT P12W150 1 2-5 996-840 STATOR PLATE ASSY.

How the Electrical system works

AlternatorConverts

• Alternating Current (AC) to

• Direct Current (DC)




•Also, provides Current to Battery

to maintain battery power at max

levels


aircraft electrical systems - welcome to the instructional web

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