Definition
The ratio of altitude gained to horizontal distance traveled during a climb, usually expressed as a percentage or in feet per nautical mile. For example, a 200-foot-per-nautical-mile climb gradient equals roughly 3.3 percent.
Plain English
How steeply the airplane rises compared to how far it moves forward across the ground. A higher number means a steeper climb over the same distance.
Context Anchor
Used in takeoff and initial climb planning, especially when checking whether the airplane can clear trees, towers, terrain, or other obstacles after liftoff.
Derivation
From the Latin gradus, meaning 'step' or 'slope.' A gradient is simply the slope of something — here, the slope of the climb path through the air relative to the ground.
Why Pilots Care
It determines whether the aircraft can clear obstacles on departure, especially in high terrain or after an engine failure.
Analogy
Climb gradient is like the steepness of a ramp. A steeper ramp gains more height over the same forward distance; a shallower ramp gains less height over that distance.
Grounding Statement
If an airplane gains 300 feet while moving one nautical mile forward, its climb gradient is 300 feet per nautical mile.
Intuition Check
Do not read climb gradient as simply “climb rate.” Climb rate is height gained over time; climb gradient is height gained over forward 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 lighter takeoff weight improves the climb gradient and helps clear nearby terrain on departure.