How high can an airplane glide if its engines fail?

Today is January 15, 2009. US Airways Flight 1549 is boarding at New York’s La Guardia Airport. If all goes as planned, the plane will land in Charlotte, North Carolina later tonight.

Not everything goes as planned.

At 3:24 p.m. Eastern Standard Time, the plane—now loaded with 150 passengers and five crew members—takes off. Within minutes, disaster strikes. The plane is unexpectedly bombarded by a flock of Canada geese, causing both engines to shut down 2,800 feet (853 meters) above one of the world’s largest cities.

Without engines, the airliner loses almost all of its thrust. This is a serious problem because thrust is the physical force that moves flying planes (and birds) in the direction of motion.

Unable to restart the engines, Captain Chesley “Sully” Sullenberger and First Officer Jeffrey Skiles must act quickly. Time is running out and they are losing altitude.

If you watched the news on that winter day in 2009, you probably know what happened next.

Miracle on the Hudson

After considering detours to La Guardia and Teterboro Airport in New Jersey, Sullenberger and Skiles made an emergency landing on the freezing Hudson River. Although some passengers were seriously injured, everyone aboard this plane lived to tell the tale. New York Governor David Paterson called it a “miracle on the Hudson”.

The landing was both dramatic and unusual. But it was not the first time that passing birds had caused problems for a large plane. When gulls or geese are sucked into the engine(s) of an aircraft, they can cause serious damage to machinery. These “bird strikes” are the most common cause of twin-engine failure on twin-engine aircraft (like the one Sullenberger flew).

However, if all of an aircraft’s engines stop working in the middle of a flight, it may have nothing to do with our feathered friends. Perhaps ice is forming in the carburetor – a problem that caused 212 airline crashes between 1998 and 2007, according to the Federal Aviation Administration (FAA).

Or maybe the vehicle just doesn’t have enough fuel. In 1983, a perfect storm of technical problems and unit conversion errors left an Air Canada Boeing 767 out of fuel some 41,000 feet (12,496 meters) above central Canada. Before long, he lost power from both engines.

After descending at a speed of 2,500 feet (762 meters) per minute, pilots Bob Pearson and Maurice Quintal were able to glide their Boeing to a safe, if bumpy, landing on a Manitoba race track. The pilots were hailed as heroes and the plane was nicknamed the Gimli Glider after the city where it landed.

How far can a Jetliner glide?

So basically any plane can hover if the need arises. And in situations where all engines have failed, pilots should expect the plane to slide. Without the thrust for which these engines are designed, the aircraft can only lose altitude. But how far can an airplane glide when it’s not designed to be a glider?

Aircraft whose engines fail at higher altitudes can hover for longer periods. This is one of the reasons Sullenberger and Skiles’ landing on the Hudson River was so impressive; they had to fight their way to safety in minutes from a fairly low altitude. (It all happened very quickly on US Airways Flight 4951. The plane hit the birds within two minutes of takeoff and just three minutes later the plane was in the Hudson River.)

Obviously, airplanes come in all shapes and sizes. So if you’re flying one, it’s important to know the “best glide speed” of your vehicle. In a nutshell, it’s the speed that will allow your aircraft to travel the greatest distance while sacrificing the least amount of altitude.

A related concept is minimum fall speed, the rate of movement that will maximize the time you can spend sliding. Depending on your situation, you can choose to prioritize time over distance or vice versa.

Writing for USA Today in 2013, veteran pilot John Cox said an airliner could likely glide about 100 miles (161 kilometers) if all of its engines failed 30,000 feet (9,144 meters) above. of the ground. That’s roughly the distance between Los Angeles and Palm Springs or New York and Atlantic City. In other words, not very far.

“All-engine shutdown in a modern aircraft is extremely rare,” Cox also noted. It’s reassuring.

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