The key measure of performance in gliding is the glide ratio which is related to the lift-to-drag ratio of the aircraft. The glide ratio of a clean A320 is 17:1 which means it can travel 17 units of distance forwards for every 1 unit of distance downward at best glide speed.

The typical glide ratio of an Airbus A320 (and similar modern jet airliners) in a clean configuration (engines idle, landing gear up, flaps up) is approximately 17:1 to 18:1.

This means that from an altitude of 1 mile (or 1 kilometer), the aircraft can glide about 17 to 18 miles (or kilometers) horizontally in still air.

Important Context and Nuances:

1. Speed for Best Glide: This ratio is achieved at a specific speed, which for the A320 is around 210–220 knots Indicated Airspeed (IAS). This is the speed pilots aim for during a complete loss of engine thrust (a “dead-stick” scenario).
2. Configuration is Critical: The glide ratio degrades significantly if the aircraft is not clean:
   • Landing Gear Down: Creates massive drag, severely reducing the glide distance.
   • Flaps/Slats Extended: Also increases drag and reduces the ratio.
3. Real-World Factors: The actual glide distance in a real emergency is affected by:
   • Wind: A headwind reduces distance over the ground; a tailwind increases it.
   • Altitude: Higher altitude provides more potential energy and more time to select a landing site, but the ratio remains roughly constant.
   • Aircraft Weight: Heavier weight requires a higher optimum glide speed but does not significantly change the glide ratio in jet aircraft.
   • Pilot Technique: Precise speed management is crucial to achieve the best performance.

Comparison and “Miracle on the Hudson” Reference:

• The A