Recip Ignition Starting Sys. Flashcards
Name the different circuits of a magneto:
1) Magnetic circuit
2) Primary circuit
3) Secondary circuit
The magneto primary circuit consists of:
1) Coil
2) Breaker Points
3) Ignition Switch
4) Capacitor
The magneto magnetic circuit consists of:
1) Magnet
2) Pole shoes
3) Coil core
The magneto secondary circuit consists of:
1) Secondary coils
2) Distributor (rotor & housing)
3) Harness & plugs
Benefit of magnetos over battery ignition systems:
1) Magnetos are lighter weight.
2) Has its own source of electrical energy.
To turn on a battery ignition system the circuit must be ______.
Closed.
To turn on a magneto system the circuit must be ______.
Opened.
Purpose of the capacitor in the magneto:
To prevent arcing at the breaking points.
Ignition switch positions:
Off - Left - Right - Both
Produces the highest amount of voltage in the rotation of the magneto magnet:
Efficiency gap (E-Gap)
These components of a magneto must be timed together:
1) Magnet
2) Cam
3) Distributor Finger
Magneto manufacturers:
1) Bendix
2) Slick
Used to reduce chance of arcing in magnetos:
Upper deck air
Arcing from distributor finger to the wrong distributor terminal is called:
Flash over
Numbers on the magneto indicate what?
Firing order of plugs.
The coupling on a base mount magneto:
Vernier coupling.
Retards the timing of the spark to increase intensity at start up:
Impulse coupling
A result of breaker point erosion and cam wear:
Magneto drift
Types of magneto mounts:
Flange mount
Base mount
Causes of spark plug fouling:
Carbon
Dirt
Fuel lead
Over priming
Rich mixture at idle/takeoff
Stopped by plug resistor:
Capacitance after firing
Problem with spark plug reach being too long:
Preignition of incandescent threads.
Carbon build up on threads
Problem with plug reach being too short:
Reduced exposure to fuel/air charge.
Plug fouls faster in the recessed area around plug.
Drawback of magnetos:
Does not produce a hot enough spark at low RPM during startup.
Name the two types of engine magneto systems:
1) High tension
2) Low tension
The wire from the breaker points to the ignition switch is called:
P-lead (primary lead)
When is flash over most likely to occur?
During high altitude operation, due to low dielectric strength of low air pressure.
What is the safety gap of a magneto?
A location inside a magneto that allows a spark to jump to ground from the secondary circuit before the voltage rises high enough to damage the secondary insulation.
Purpose of impulse couplings on magnetos:
To produce a hot, late spark for starting the engine.
Another name for the vibrator ignition system:
Shower of sparks ignition system
T/F
The spark used for starting an aircraft must occur earlier than the normal spark.
False.
Later.
The _______ breaker points open last in a vibrator ignition system.
Retard.
14 CFR 33.37 requires that each spark ignition engine must have what?
1) Dual ignition system with at least two spark plugs for each cylinder.
2) Two separate electrical circuits with separate sources of electrical energy.
Three ways of mounting a magneto to an engine:
1) Base mount
2) Flange mount
3) Clamp mount
When should magnetos be checked?
On each annual or 100 hour inspection.
Things to look for when inspecting magnetos:
1) Oil in the housing.
2) Evidence of burning or pitting of the points.
3) Carbon tracks in the distributor block.
Erosion of the breaker points will cause the magneto to engine timing to drift ______.
Early
Wear of the cam follower will cause the magneto to engine timing to drift ______.
Late.
The two components in a magneto distributor are the:
1) Block
2) Rotor
What is a hot spark plug?
A plug with a long insulator tip which is slow to dissipate the heat.
What is a cold spark plug?
A plug with a short tip which rapidly dissipates heat.
Two types of electrodes used on aircraft spark plugs:
1) Massive electrodes
2) Fine-wire electrodes
Why are dual magnetos used?
Improve combustion efficiency and provide redundancy for safety.
Magneto internal timing consists of:
Adjusting breaker points to open at E-gap and ensuring that the distributor rotor is in position to send voltage to cylinder one.
What malfunction in the ignition system would cause a recip engine to continue to run after the ignition switch is placed in the off position?
The ignition switch is not grounding the magneto primary circuit.
