Definition
The average slope of a runway, expressed as a percentage representing the change in runway elevation divided by the runway length. A positive gradient indicates the runway slopes uphill in the direction of travel; a negative gradient indicates a downhill slope.
Plain English
How much a runway tilts up or down along its length, given as a percentage. A 1% gradient means the runway rises or falls one foot for every 100 feet of length.
Context Anchor
Seen in airport information and aircraft performance planning, especially when checking takeoff and landing distance.
Derivation
Gradient comes from the Latin gradus meaning step or degree. In engineering and aviation it describes the rate of rise or fall along a surface — the steepness of the slope.
Why Pilots Care
Affects how quickly the aircraft accelerates on takeoff or decelerates on landing, changing the runway length required for safe operations.
Analogy
It is the same basic idea as a hill on a road. A runway with a small uphill gradient gently climbs as the aircraft rolls forward.
Grounding Statement
A positive gradient means the far end of the runway is higher, so the airplane must climb slightly while accelerating.
Intuition Check
Do not assume a runway is flat just because it looks flat from the cockpit. Runway gradient is the measured rise or fall of the runway, not a visual impression.
Example Sentence 1
The runway has a 0.8% upslope gradient, so the pilot added extra margin to the takeoff distance calculation.
Example Sentence 2
A downhill gradient helped shorten the landing rollout on the wet runway.