What is the daytime minimum altitude under 14 CFR 135.203, excluding takeoff or landing?

• A. 1000 feet above the surface
• B. 500 feet above the surface
• C. 2000 feet above the surface
• D. 300 feet above the surface

Answer: (B)

In Part 135 daylight operations (excluding takeoff or landing), there is a minimum altitude floor to provide a safety margin over terrain and obstacles during en route flight. The required minimum is 500 feet above the surface. This level gives pilots a practical buffer to maintain obstacle clearance while still allowing efficient routing in daylight.

Flying any lower would reduce the margin above ground hazards, which is why the other options aren’t correct for this rule. Optional context: higher minimums appear in other regulatory contexts (for example, different rules apply over open water or mountainous terrain), but the specific daytime en route minimum under 14 CFR 135.203 is 500 feet AGL.