How Far Can An Airplane Glide If It Loses Its Engines?

Engine failure does not automatically spell disaster — airplanes are designed to be able to glide and won't plummet straight down to earth if an engine fails. Planes are required by law to be able to fly to their destination with just one working engine. The second engine is often a backup and planes can fly if they lose one engine, although the performance will suffer a bit. Said pilot Patrick Smith: "While it may surprise you, it's not the least bit uncommon for jets to descend at what a pilot calls 'flight idle,' with the engines run back to a zero-thrust condition. They're still operating and powering crucial systems, but providing no push. You've been gliding many times without knowing it. It happens on just about every flight."

But what happens if both engines go out? If there's no engines left to propel a plane forward, they will still remain in the air for a duration of time due to their design. Airplanes use their wings to manipulate the air to stay gliding, with the shape forcing air to move faster over the top. When the air moves faster, the air pressure will then decrease, making the pressure above the wing less than the pressure below it, lifting the wing upward into the air. Various wing designs continue to be explored by NASA, including a pivoting wing for max lift and control.

So if the engines fail, pilots will descend the plane to increase airspeed and avoid stalling. They will keep adjusting the height in this situation in an attempt to maintain a speed that keeps the plane in the air, using the wings to interact with the air around them. Luckily engine failures mid-flight are very rare and planes remain one of the safest forms of travel.

"This is your captain speaking. We have a small problem and all four engines have stopped. We are all doing our damnedest to get them working again." Those words were heard over the speaker by Captain Eric Moody when British Airways Flight 009 encountered an immense amount of volcanic ash while flying over Mount Galunggung. While the cabin was full of panicked passengers, Moody calculated exactly how he could possibly attempt to land the plane without engines. The crew calculated that at their height of 37,000 feet, the aircraft was capable of gliding for 23 minutes, covering 91 nautical miles (about 105 miles).

The distance an airplane can glide without engines varies significantly based on the plane itself, the height it's at, the wind, and weather. Back in 1983, American Airlines Flight 143 ran out of fuel at 41,000 feet while flying from Montreal to Edmonton. The plane ended up gliding 45 miles before landing at an airport thanks to the pilot's gliding skills. In 2001, Air Transat Flight 236 from Toronto to Lisbon lost its engines at 33,000 feet. The aircraft ended up gliding without power for nearly 75 miles in the course of 19 minutes.