Private Pilot License Air Law Practice Test 2025 – Complete Exam Prep

Mandatory instruction signs at an aerodrome are designed to communicate important instructions that must be followed by pilots and ground personnel. The correct color scheme for these signs is white on a red background. This specific color combination is used because it provides a clear and immediate visual indication of mandatory actions. The red color signifies caution and indicates that the instruction is critical for safety; for example, stopping, holding, or following specific taxiing paths.

Using a white symbol or text on a red background ensures that the sign stands out and is easily visible in various lighting conditions and weather. This is vital for safety, as pilots need to quickly and clearly understand their actions on the ground.

Other color combinations, while they may be used for different types of signs or instructions, do not convey the same level of required compliance and safety caution as the mandated white on red. Thus, this color scheme is standardized for clarity and effectiveness in aviation environments.