What do the numbers next to an obstacle on a sectional chart represent?

The numbers next to an obstacle on a sectional chart indicate the height of the obstacle in feet above sea level and often provide additional information regarding the height above ground level in certain contexts. This information is crucial for pilots to avoid obstacles during flight, especially during takeoff and landing phases. Knowing the altitude of an obstacle allows pilots to plan their approaches and departures, ensuring safe clearances above any structures.

The specific height above sea level is often used in aviation navigation because it provides a standardized reference that pilots can use regardless of the local terrain. This kind of information enhances situational awareness and is vital for maintaining safe vertical separation from obstacles during all phases of flight.

Other options, while relevant to aviation, do not accurately describe the role of the numbers associated with obstacles on sectional charts. For instance, distance to the nearest airport, altitude of surrounding terrain, or height relative to airport elevation does not convey the specific obstacle information intended by the numbers on sectional charts. Understanding the precise height of obstacles helps pilots make informed decisions and maintain safety in the airspace.