What does it mean when a plane hits an air pocket?

My first flight was when I was 8. I once thought flying was fun as I had flown domestically and overseas to Germany with never an issue. I had started working for a new company and needed to fly to Chicago for training. I remember it was a non-stop from Dallas to Chicago.

On the way there, the pilot told us they had storms coming in and that it could be a little rough during our approach.

As we got closer to O’Hare, the turbulence became stronger and less predictable. I am guessing that it was really bad down below because we started circling the airport and often hitting some pretty rough patches where the plane would pitch, roll or drop. At one point this went on for a good 5 minutes and all of us started to come unnerved. Finally, after about 45 minutes, the pilot said the tower had approved a short window for some of the planes to land.

As we made our approach from the north, the pilot was executing the standard rolls as we declined. And yes there was a high amount of pitching and rolling and drops. Many women and men were voicing their displeasure and anger as we had been shaken and jolted for well over 2 hours.

What made this distinctive was when we broke through the lower level clouds. I remember I could see the lights on the ground and that there were rain droplets hitting the window. As we turned for another angling descent, the plane literally dropped like a rock and I honestly thought we were flipping all the way over. It appears we had hit an air pocket (that’s what one of the flight crew said after we landed) and dropped a good 600-800 feet. When we dropped, the woman sitting next to me grabbed my leg and screamed. This of course scared the bejesus out of me and I screamed. Then it seemed like many people started screaming, crying and yelling.

After that drop, it was rough the rest of the way in but nothing like that big drop.

Since then I don’t like to fly but I will.

Tagged as: weather

IF YOU’VE flown before it’s highly likely that you’ve experienced an “air pocket,” or what feels like a quick drop in the air.

You might feel as if you’re falling from the sky, but rest assured, if you flying commercially, you rarely gain or lose more than about 20 feet (6 metres), especially if the plane is on autopilot.

The term “air pocket” comes from early aviation, a time when pilots flying open-cockpit biplanes took adventurous locals on a rides in their “flying machines”.

These planes, with two wings one above the other, flew at relatively slow speeds. When the plane entered air that, instead of simply sitting there, was flowing slightly upward or slightly downward, the plane’s path was altered slightly upward or slightly downward.

Air pockets do not technically exist, yet it’s an expression that has caught on and is still misused today. Really, what you’re experiencing is turbulence.

So what happens when you experience a bumpy ride that rattles glasses and turns some knuckles white? The first thing you need to understand is a basic rule of flying: the Earth has different surface temperatures that impacts flight as the aircraft passes through.

For example, the surface of a lake is cooler than the surrounding earth, or ploughed fields have a different surface temperature than those that are unploughed. Warm air is lighter than cool air. Warmed air rises. Cooled air descends. When a plane encounters varying airflow, we can feel what we call an “air pocket” today.

The idea of an “air pocket” might seem reassuring from a pilot’s point of view, for a pocket is something you slip your hand into. When you do, your hand can only go so far. But, over the years, the phrase has come to be thought of as an area where there is no air.

With no air, what is going to hold the plane up?

The term, if misunderstood, can lead to fear that an “air pocket” — a place devoid of air — could be big enough to cause a plane to plunge to the ground or go out of control. But it doesn’t exist.

It may be helpful to try to imagine a “water pocket,” an area in a lake where there is no water. You can’t, right? Since you can see water, it is hard to conceive of such a thing as a water pocket.

One analogy that is helpful to some people is picturing the sky as one large bowl of jelly. Imagine that large bowl of chilled jelly with a small, plastic aeroplane in the middle. Now, pick up the bowl and shake it. The aeroplane certainly moves and jiggles, but it is impossible for the small plastic toy to fall out of the bowl (the sky).

Flying through an “air pocket” isn’t much different from driving your car over a pothole or steering a boat over waves. It may be bumpy, but you’re rarely in danger — that is unless you’re not wearing a seat belt.

Captain Tom Bunn, retired airline pilot and licensed therapist, is the founder of SOAR, a program designed to help those with fear of flying and flight-related anxieties. This story originally appeared on Fox News.

It's not uncommon for airline passengers to feel a sudden jolt during a flight. Often, this shaking and juddering will come without much prior warning; even when the weather conditions appear calm, the plane may get shaken around to some extent, or could even briefly lose altitude before normal service is resumed.

Such effects are sometimes attributed to a plane encountering an "air pocket," but is this accurate? 

Well, as it turns out, it's not at all correct — because air pockets don't actually exist.

"Basically, there's no such thing. It seems to be a layman's term to describe certain forms of turbulence or windshear," Guy Gratton, an aeronautical engineer, test pilot and professor of aviation and the environment at Cranfield University in the U.K., told Live Science in an email. "I don't personally ever use the term. I don't think it's useful."

Related: Why does the Earth rotate?

Turbulence is, according to the National Weather Service (opens in new tab), "one of the most unpredictable of all the weather phenomena that are of significance to pilots." Planes are most likely to experience turbulence when they come into contact with a "relatively random large magnitude current, or a rising or descending column of air," Gratton added. 

The term "windshear," meanwhile, is used to describe a "sudden change" in wind velocity. This immediate change in wind speed or wind direction happens over a relatively short distance in the atmosphere, and can occur at both high and low altitude, according to the Federal Aviation Administration (opens in new tab).

"If a plane is flying along at a constant speed and height, then suddenly the headwind reduces, or it enters a descending column of air, this can cause the aircraft to suddenly descend," Gratton explained. "Conversely, if the headwind rapidly increases, or the plane enters a rising column of air, this can cause it to suddenly climb." 

So, where is a plane most likely to encounter such conditions?

"There are two main places," Gratton said. "Either around a cumulonimbus cloud, which routinely has high magnitude air currents around it, or around the edges of one of the jet streams." Jet streams are essentially rivers of wind high above in the atmosphere, and have a huge influence on climate, as they can push air masses around and affect weather patterns.

Cumulonimbus clouds are commonly referred to as "thunderclouds," because they are, according to the U.K.'s Met Office, "the only cloud type that can produce hail, thunder and lightning." They are born from convection — warm air rising due to it being less dense than the surrounding atmosphere — and "exist through the entire height of the troposphere," the lowest layer of Earth's atmosphere, which extends to about 33,000 feet (opens in new tab) (10,000 m) above sea level.

Turbulence is relatively common around these clouds when updrafts and downdrafts converge. According to the Airplane Academy (opens in new tab), an aviation resource website, "microbursts," a term used to describe particularly hazardous extreme winds, can see planes experience "downdrafts in excess of 2,000 feet per minute [610 m/minute] and surface winds in excess of 100 knots [115 mph or 185 km/h]."

It can certainly come as a shock to be shaken around when on a plane, and the experience can range from rather uncomfortable to extremely scary. But can turbulence damage a craft? And, if so, could it potentially cause a plane to crash or require a pilot to make an emergency landing?

"In extremis, turbulence can damage an aircraft," Gratton confirmed. "If the plane transitions suddenly to climbing or descending, and is flying too fast for the conditions, the plane can potentially become overstressed. In simplistic terms, this could pull the wings off, with inevitably serious consequences."

Gratton noted that windshear can impact planes in different, but no less serious, ways.

"An encounter with windshear, if close to the ground, can cause the airplane to descend out of control into the ground, also with very serious consequences," he said. "This has happened."

However, Gratton is keen to note that these are worst-case scenarios, and are very unlikely to happen. "Any kind of turbulence or shear-caused accident is very rare. In fact, it should be almost impossible, as airports and aircraft have windshear detection systems, and pilots know to slow aircraft below critical speeds if severe turbulence is predicted or experienced. 

"In reality, the greatest risk may be items flying around the cabin that weren't secured properly, which can happen even when the aircrew does its job properly."

Originally published on Live Science on May 13, 2010 and rewritten on July 19, 2022.