In an Emergency, Where Will You Land Your Aircraft?
Geometry & Trigonometry
If an aircraft loses all engine power mid-flight, how far can it glide, and which airports fall within reach?
Introduction
A powered aircraft that loses all engine thrust becomes a glider: it can still cover a large horizontal distance for every metre of altitude it loses, determined by its glide ratio. From a chosen cruise altitude and glide ratio, the reachable area on the ground forms a circle (or, accounting for wind, an ellipse) around the aircraft's position. This exploration uses that reachable-area calculation to check, at each point along a real flight route, which airports are within gliding distance, and to find the single worst point on the route, where the nearest runway is furthest away.
Guiding Questions
- A plane loses power mid-flight. What determines how far it can glide?
- From cruise altitude and a glide ratio, calculate the reachable region on the map.
- For a real route, plot which airports are reachable at each point of the flight.
- Find the point of the route furthest from any runway. How bad is the worst case?