What is the maximum runway slope?

• A. +-2%
• B. +-1%
• C. +-3%
• D. +-4%

Answer: (A)

Runway slope is the incline or decline of a runway, expressed as a percent grade. It shows how much vertical change occurs for a given horizontal distance. A 2% slope means the runway rises or falls by 2 meters for every 100 meters of runway length. The maximum slope used in standard aviation practice is two percent in either direction. This limit keeps takeoff and landing performance predictable, maintains effective drainage and surface friction, and keeps aircraft performance charts valid across a wide range of aircraft. If the slope were steeper, uphill sections would require longer takeoff distances and could worsen climb performance, while downhill sections would affect braking and deceleration on landing and also stress drainage and surface integrity. So the greatest permissible slope is ±2%.