Which of the following water application techniques is considered improper?

The use of a straight stream to penetrate is considered improper in the context of fighting wildland fires because it can lead to several issues. Straight streams can be less effective in areas where fire behavior is aggressive, as they do not provide sufficient cooling or smothering effect on the flames. Instead, a fog or spray stream is often preferred for its ability to provide better coverage and to effectively cool the fire area while minimizing the risk of causing flare-ups.

Moreover, applying water from outside of the hot area inward is a strategic approach to manage fire intensity and can help protect firefighters while controlling the fire. Similarly, applying a fog/spray stream is beneficial as it maximizes the surface area of water, allowing better absorption and cooling of the hot gases and surfaces. Lastly, standing in the blackened areas to spray perpendicular to the control line is a tactical move that helps ensure that unburned fuel is protected from potential spotting or resurgent fire behavior.

In wildland firefighting, effective application techniques help to mitigate risks and improve overall safety and firefighting efficacy, making the choice of water spray important.