On En Route Low Altitude Charts, prohibited, restricted, and warning areas are shown in which type of hatched boundary?

On En Route Low Altitude Charts, prohibited, restricted, and warning areas are indicated with light brown hatched boundaries. This visual representation helps pilots quickly identify areas where flight operations may be limited or prohibited due to safety or regulatory reasons. The use of light brown is consistent across various aeronautical charts, making it a standardized method for recognizing areas that require caution or avoidance during flight planning and navigation.

Understanding the color-coding system is essential for pilots and air traffic personnel, as it allows for effective situational awareness. Pilots rely on these charts to ensure compliance with airspace restrictions, contributing to overall flight safety. The specific use of the light brown color helps distinguish these areas from others, which may be designated using different colors for other types of information or airspace designations.