Ignition System

[Ref. Pilot’s Handbook of Aeronautical Knowledge, FAA-H-8083-25B Page 7-15, 7-16]

Function of the Ignition System?

In a spark ignition engine, the ignition system provides a high voltage spark that ignites the fuel-air mixture in the cylinders at a predetermined time.

Composition of Ignition System?
it is made up of :

  1. spark plugs
  2. magnetos (x2)
  3. high-tension leads
  4. an ignition switch


Read More:

2 magnetos – WHY?

dual ignition system with two individual magnetos, spark plugs and separate sets of wires to increase reliability of the ignition system.

Each magneto operates independently to fire one of the two spark plugs in each cylinder – if one of the magnetos fails, the other is unaffected, provided that is operating normally.

Then, 2 spark plugs in each cylinder – WHY?

Multi-Spark plugs System

  1. The firing of two spark plugs improves combustion of the fuel-air mixture and results in a
    slightly higher power output.
  2. Redundancy and Safety reason – either one of the magnetos OR one of the two spark plugs in a cylinder fails, the other is unaffected. The engine continues to operate normally, although a slight decrease in engine power can be expected.

Indeed, there is “fuel injection like reciprocating engine”, so what’s the differences? – Spark ignition v.s Compression ignition?

Also reference # Engine System

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