Definition
In fire protection systems, the period between the moment a fire-extinguishing agent (such as foam concentrate) is mixed with water or air and the moment the resulting mixture is fully formed and ready to be discharged onto the fire.
Plain English
The short delay between starting to mix a fire-extinguishing agent with water or air and the mixture being ready to use.
Context Anchor
Seen in aircraft maintenance instructions for bonding, sealing, priming, and painting work.
Derivation
From the Latin 'inducere,' meaning 'to lead in' or 'bring in.' Induction here refers to drawing one substance into another (the agent into the water or air stream). The 'time' is simply how long that drawing-in and mixing process takes.
Why Pilots Care
Proper induction timing directly affects engine power, efficiency, and smoothness.
Analogy
It is like letting dough rest after mixing before shaping it. The waiting time is part of getting the material ready, not wasted time.
Intuition Check
Induction time is not engine induction time and it is not the full drying or cure time. It is the wait after mixing and before applying the material.
Example Sentence 1
The crew accounted for the foam system's induction time when planning their approach to the fire.
Example Sentence 2
Changes in induction time altered the engine's power output at cruise RPM.