Definition
A descent path with a slope of approximately one foot of altitude lost for every 300 feet of horizontal distance traveled, used as a planning standard for some nonprecision instrument approaches. It corresponds to a glidepath angle of about 0.19 degrees per 100 feet, or roughly 318 feet per nautical mile of horizontal distance.
Plain English
A gentle descent rule of thumb: for every 300 feet you move forward across the ground, you come down 1 foot. It gives pilots a simple way to plan how steeply to descend on certain approaches.
Context Anchor
Seen when planning descent rates for a nonprecision instrument approach, especially when deciding what vertical speed will keep the airplane on a stable path toward the runway.
Derivation
The name describes the ratio itself: 300 units forward for every 1 unit down. It is a shorthand label, not an etymology — the number is the meaning.
Why Pilots Care
Provides a standardized shallow descent rate that maintains obstacle clearance while allowing a stabilized approach to the runway.
Grounding Statement
At 3 miles from the runway, this path would put the airplane roughly 900 feet above the landing area.
Intuition Check
Do not read 300-to-1 as a glider performance ratio or as 300 feet forward for 1 foot down. In this context, it means about 300 feet down for each nautical mile forward.
Example Sentence 1
The chart shows a 300-to-1 glide path from the final approach fix down to the runway threshold.
Example Sentence 2
A 300-to-1 glide path is used to calculate the required descent rate during the final segment of a nonprecision approach.