Definition
The rate of change of a quantity over distance or time, expressed as a ratio, percentage, or angle. In aviation, gradient most often refers to the slope of a climb, descent, or runway, or to the rate at which pressure, temperature, or wind changes across a region.
Plain English
How steeply something rises, falls, or changes as you move from one point to another.
Context Anchor
Seen in climb performance, departure procedures, approach planning, runway slope discussions, and weather explanations such as pressure gradient.
Derivation
From the Latin gradus, meaning 'step' or 'degree.' A gradient is literally the rate at which you step up or down — how much change happens per unit of distance or time.
Why Pilots Care
Determines whether an aircraft can clear obstacles on takeoff or meet required climb performance in instrument procedures.
Analogy
A road sign that shows a steep uphill grade is describing a kind of gradient: how much the road rises over the distance you drive forward.
Grounding Statement
If an airplane gains 300 feet while traveling one nautical mile forward, that climb has a gradient of 300 feet per nautical mile.
Intuition Check
Gradient does not just mean a steep hill or a color fade. In aviation, it means a measured amount of change over a measured distance.
Example Sentence 1
The departure procedure required a minimum climb gradient of 250 feet per nautical mile until reaching 3,000 feet.
Example Sentence 2
A steep pressure gradient produced strong winds across the route.