Spark Plugs and Ignition Leads: A Dynamic Duo

Engine ignition leads are used to power spark plugs for prominent commercial assemblies— the Rolls Royce Trent 1000 utilized by Boeing B787’s, Rolls-Royce Trent 900 engine integrated on the Airbus A380, and Pratt & Whitney PW2000 engines all incorporate some type of ignition leads. Spark plugs allow combustion within the ignition system but transferring current across a spark plug gap wouldn’t be possible without ignition leads.

In a piston engine assembly, a spark plug is attached to the magneto through means of ignition leads. The actuator component sends positive voltage across one lead, and negative voltage down the next lead. Current from the ignition leads form a conductive path between the ground and center electrodes of a spark plug. At this time, the plug is able to fire. 

The more capacitance a lead has, the more current it can generate across the spark plugs’ gap between its ground electrodes and its core. The distance between the core and electrodes is engineered to build up to a specified voltage before firing and discharge.

In a gas turbine engine, standard ignition leads, or high-tension ignition leads are utilized to provide voltage to ignitor plugs within a capacitor-type system. The functioning of leads in this capacity is similar in concept, but on a bigger scale. An igniter plug must handle higher energy current than a spark plug. Because an igniter plug also operates in an environment that has lower operating pressure but a higher voltage emission upon firing, it features a wider electrode gap than a spark plug.

For both piston engine and gas turbine engine applications, dual ignition systems are required by the Federal Aviation Association. This ensures that if the ignition system has a problem, the other components can act as a continuous ignition system until the issue can be resolved.

At Aviation Sourcing Solutions, owned and operated by ASAP Semiconductor, we can help you find ignition leads, spark plugs, and more. For a quick and competitive quote, email us at sales@aviationsourcingsolutions.com or call us at +1-714-705-4780.