Engine failure in flight sounds like a nightmare scenario, but for modern airliners it is not an automatic death sentence. Commercial jets are designed to keep flying, and even to reach a safe landing, when an engine quits. In fact, twin-engine airliners are certified to complete flights on a single functioning engine, with the remaining powerplant carrying the load while crews manage the emergency and divert to an appropriate airport.
Gliding on Wings, Not Thrust
Most passengers do not realize they have already “glided” on many flights. Airline pilots often descend at what they call “flight idle,” pulling the throttles back so the engines provide near-zero thrust while still powering vital systems. As pilot and writer Patrick Smith notes, jets routinely ride long descents with engines producing no push, relying instead on altitude, airspeed, and wing design to carry them forward.
The reason this works is fundamental aerodynamics. Airplane wings are shaped to make air move faster over the top surface than beneath it. That difference in airflow creates a drop in pressure above the wing and higher pressure below, generating lift. As long as the aircraft maintains enough speed and the wings keep interacting with the air at the right angle, it will stay aloft-even with engines producing no usable thrust.
Engineers continue to refine that basic principle. NASA, for example, has explored new wing concepts, including pivoting configurations designed to maximize lift and control in different phases of flight. These innovations all work toward the same goal: preserving safe performance across a wide range of conditions, including rare emergencies.
When Both Engines Go Quiet
If both engines fail, the aircraft effectively becomes a large glider. The pilot’s first priority is to prevent a stall. That usually means lowering the nose to trade altitude for speed, then adjusting the descent rate to hold a safe glide. The plane’s glide ratio-how far it can travel forward for every unit of altitude lost-depends on its design, weight, configuration, and the surrounding weather.
Real-world incidents show how far a powerless airliner can go. In 1983, an Air Canada Boeing 767 now known as the “Gimli Glider” lost fuel at about 41,000 feet and still managed to glide around 45 miles to a decommissioned airfield, thanks to precise energy management by the crew. In 2001, Air Transat Flight 236, an Airbus A330, suffered fuel exhaustion at roughly 33,000 feet over the Atlantic, then glided nearly 75 miles in about 19 minutes to reach a runway in the Azores.
Another dramatic case came when British Airways Flight 009 flew into a dense cloud of volcanic ash over Mount Galunggung. All four engines flamed out, leaving Captain Eric Moody and the crew to calculate how long the aircraft could remain airborne and how far it could travel without thrust. At 37,000 feet, they estimated roughly 23 minutes of glide time and about 91 nautical miles (around 105 statute miles) of potential range, enough to steer toward clearer air and eventually restart the engines.
How Safe Is Air Travel When Engines Fail?
The key takeaway is that a multi-engine jet losing power is not destined to fall straight down. With altitude to work with and a crew trained in glide procedures, the aircraft can cover surprisingly long distances. Crews are taught how to optimize glide speed, configure flaps and gear, and set up for a power-off landing if necessary.
Crucially, these scenarios are exceedingly rare. Modern engines are incredibly reliable, and layered maintenance, monitoring, and redundancy keep in-flight failures uncommon. Even when problems arise, the design margin built into airframes, wings, and control systems provides pilots with options. For all the dramatic stories of engine failures and emergency descents, the underlying record still supports a simple conclusion: commercial aviation remains one of the safest ways to travel, precisely because aircraft are designed to keep flying even when things go wrong.
