Glide Distance Calculator: Engine-Out Range, Glide Time and Wind Effect
How far can you glide from a given height? Turn your glide ratio (or best-glide speed and sink rate) and height above the ground into the distance you can reach, with headwind or tailwind, time aloft, glide angle, a pattern-altitude reserve and a reach table by altitude.
How it works
Glide distance (still air) = height above ground × glide ratio · Glide ratio = true airspeed ÷ sink rate (1 kt = 101.27 ft/min) · With wind: ground distance = still-air distance × (airspeed − headwind) ÷ airspeed · Time = height ÷ sink rate · Glide angle = arctan(1 ÷ glide ratio) · 1 nm = 6,076.12 ft
The glide ratio is how far an aircraft travels forward for each unit of height it loses at its best-glide speed. In still air it equals the lift-to-drag ratio, so multiplying it by the height above the ground gives the furthest you can reach with the engine out. If you know the best-glide speed and the sink rate instead, the glide ratio is simply the speed divided by the sink rate in the same units. Wind changes the answer a lot. The time you can stay airborne is fixed by your height and sink rate, but the wind changes your groundspeed: a headwind cuts the distance covered in that time and a tailwind adds to it, in proportion to groundspeed ÷ airspeed. Use the wind component along your glide path and your best-glide true airspeed. You can also keep a reserve height, for example to arrive over a field at pattern altitude. The result is a planning figure. The published ratio holds only at best-glide speed, in a clean configuration and with the propeller as the POH assumes; turns, flaps, landing gear, sinking air and a heavier or dirtier aircraft all steepen the glide.
Worked example
At 5,000 ft above the terrain with a 9:1 glide ratio, the still-air reach is 5,000 × 9 = 45,000 ft, which is 45,000 ÷ 6,076.12 = 7.41 nm (8.52 statute miles or 13.72 km). At a 65 kt best-glide speed the sink rate is 65 × 101.27 ÷ 9 = 731 ft/min, so the glide lasts about 6.8 minutes. A 15 kt headwind cuts the reach to 7.41 × 50 ÷ 65 = 5.70 nm.
Sources: Gliding flight (glide ratio = L/D = airspeed ÷ sink speed; typical ratios) · Gimli Glider (5,000 ft lost in 10 nm, about 12:1) · FAA Airplane Flying Handbook, Chapter 18: Emergency Procedures (65 kt glide, about 1,000 fpm descent) · Glide ratio
Frequently asked questions
How far can a plane glide from 10,000 feet?
Multiply the height by the glide ratio. A light single at about 9:1 covers 90,000 ft, about 14.8 nm (17 statute miles) in still air, from 10,000 ft above the ground. The Boeing 747 of British Airways Flight 9 glided at about 15:1, which from the same height would reach roughly 1.7 times as far. Wind and turns change the real figure.
What glide ratio should I use?
Use your aircraft’s published best-glide figure from the POH. Many light singles are around 8:1 to 10:1, the Boeing 767 of the Gimli Glider managed about 12:1, hang gliders about 15:1 and sailplanes 30:1 to 60:1 or more. The ratio only holds at the best-glide airspeed.
How do I work out glide ratio from speed and sink rate?
Convert both to the same units and divide: 1 knot is 101.27 ft/min. A glide at 65 kt with a 1,000 ft/min descent is 6,582 ÷ 1,000 = 6.6:1; at 65 kt and 731 ft/min it is 9:1. Choose Speed and sink rate above to enter them directly.
How does wind change glide distance?
Your time aloft stays the same, but the distance covered over the ground scales with groundspeed. With a 65 kt glide, a 15 kt headwind cuts the reach by 15 ÷ 65 = 23% and a 15 kt tailwind adds 23%. In a headwind, fly slightly faster than best-glide speed for the best result.
Does weight change the glide distance?
Hardly at all: a heavier aircraft has the same best glide ratio but a higher best-glide speed, so it covers the same distance faster and with a higher sink rate. Configuration matters far more: flaps, landing gear and a windmilling propeller steepen the glide considerably.
What is a glide ratio of 12:1 in feet per nautical mile?
One nautical mile is 6,076 ft, so at 12:1 you lose 6,076 ÷ 12 = 506 ft per nautical mile. The Gimli Glider crew measured about 5,000 ft lost over 10 nm, which is roughly 12:1.
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For planning and training only. Always use the aircraft’s POH/AFM figures and current conditions; this is not a substitute for flight instruction or approved performance data.