The three types of crown fires are passive crown, active crown, and _____.

• A. Secondary crown
• B. Independent crown
• C. Isolated crown
• D. Remnant crown

Answer: (B)

When a fire involves the canopy, how the heat moves and fuels crown flames determines the type of crown fire. The three types describe how dependent the crown fire is on heat from the surface fire to keep burning.

A passive crown fire stays tied to the ground fire’s heat—the crown ignites because the surface fire heats it, so the main drive comes from the ground-level fire as it continues to feed the canopy flames.

An active crown fire, by contrast, has the canopy fire become the dominant front. The flames are burning through the crowns with their own energy and support, often growing due to wind and convection in the canopy, even as surface heat contributes.

An independent crown fire is a canopy fire that propagates on its own, without needing heat from the surface fire to sustain it. Once the crowns are ignited, the fire can continue to spread through the canopy even if the ground fire’s heat input diminishes.

So, the three crown-fire types are passive crown, active crown, and independent crown.