Definition
A standard descent gradient used in non-precision approaches, expressing how many feet of altitude the aircraft should lose for every nautical mile flown along the final approach course. A 300-foot-per-mile gradient corresponds to roughly a 2.86-degree descent angle, which closely matches the standard 3-degree glidepath used on most precision approaches.
Plain English
A descent rate measured by distance: for every mile you fly toward the runway, you come down 300 feet. It's the slope the approach is designed around.
Context Anchor
Seen in radar approach procedures, especially when describing the descent path used during an Airport Surveillance Radar approach.
Why Pilots Care
Confirms the aircraft has enough performance to clear obstacles during the published procedure.
Grounding Statement
Picture the airplane moving one mile closer to the runway and being about 300 feet lower than it was one mile earlier.
Intuition Check
Do not read “per mile” as a speed or a time limit. It means altitude lost for each mile of forward travel.
Example Sentence 1
The approach was designed to a 300 feet per mile gradient, so at 90 knots groundspeed the pilot planned a descent rate of about 450 feet per minute.
Example Sentence 2
Before accepting the clearance the pilot confirmed the aircraft could sustain at least 300 feet per mile.