Which form of ignition does not require a pilot?

• A. Piloted ignition
• B. Auto ignition
• C. Electrical ignition
• D. Chemical ignition

Answer: (B)

Auto ignition is when a material catches fire on its own, without any flame, spark, or external ignition source. This happens when the surrounding heat raises the material to its auto-ignition temperature, a specific threshold at which ignition occurs spontaneously. Because no pilot or external energy input is needed, this form of ignition can start simply from enough heat in the environment, such as a hot surface or hot airflow heating the fuel to that critical temperature.

Piloted ignition requires a flame or heat source to start burning, electrical ignition uses a spark or electrical heat, and chemical ignition involves heat from a chemical reaction that may or may not require an explicit ignition source. The defining feature of auto ignition is the absence of any external ignition pilot.