Definition
An aircraft turbine-engine ignition system designed to operate continuously throughout flight rather than only during engine start. It supplies a steady spark to the igniter plugs so that if the flame in the combustion section is disturbed or extinguished — by heavy precipitation, turbulence, icing, or unusual attitudes — combustion is immediately re-established without pilot action.
Plain English
An ignition system on a turbine engine that can be left switched on for the whole flight, ready to instantly relight the engine if the flame goes out.
Context Anchor
You may see this term in turbine engine systems, especially in discussions of engine starting, takeoff, landing, heavy rain, icing, or turbulent air.
Derivation
Continuous-duty' means built to run all the time without overheating or wearing out, in contrast to an 'intermittent-duty' system that only operates briefly for engine start.
Why Pilots Care
Ensures reliable spark during long climbs, high-power cruise, or any flight where ignition must stay active without duty-cycle restrictions.
Analogy
It is like the difference between a tool made for quick short bursts and a device made to stay on all day. A continuous-duty ignition system is built for extended use.
Intuition Check
“Continuous-duty” does not mean the ignition system is always required for normal engine operation. It means the system is built so it can be left on continuously when conditions call for it.
Example Sentence 1
Before entering the heavy rain shower on approach, the captain selected continuous-duty ignition to guard against a flame-out.
Example Sentence 2
Maintenance records showed the magnetos were continuous-duty units approved for the aircraft's long-range missions.