What Is Turbulence? A Pilot Explains How It Happens, Even in Clear Skies | WSJ

a lot of times people think of turbulence as the wind hitting the nose this is captain stuart walker after more than 30 years of flying he knows a lot about turbulence and there's more than one type we've actually got the winds coming from all different directions of the airplane he's here to explain the main types of turbulence how they impact your flight and what he and you can do to get the smoothest ride there's many types of turbulence that you can find out when we're flying but the four main types are clear turbulence thermal turbulence mechanical turbulence and wake turbulence clear turbines is exactly that it's clear its air is turbulent meaning it may look clear outside your window then the plane starts to shake ideally if we're traveling we've got a nice tailwind and if we've got the jet on our tail we might have 150 knots of extra ground speed just because of that tailwind but if the jet stream veers off i'm going to lose some of that tailwind and as i do i change the dynamics of the airplane and basically i can get a rocking motion or i can get a large pitch up if it's a sheer from another crossing wind so what's happening here has a lot to do with jet streams those invisible rivers of air that encircle the globe and when they are bent and turned they create shears in the air and those pockets of shear are where we're finding that clear turbulence we've got 150 knots off the left wing and all of a sudden it's shifting to a tail when we're expecting that it's probably going to have a little bit of a shear but clear air turbulence is tough to predict walker says pilots rely on modeling graphical displays on board and information from dispatchers to try to avoid turbulent areas the good news about clear turbulence though is it typically does not last but a couple thousand feet so if we just descend a couple thousand or climb a couple thousand we can usually fly out of some of that rough air [Music] thermal turbulence is just the opposite of clear air turbulence we can see it that's because it's caused by rising warm air or thermals which can create clouds cumulonimbus clouds the kind that carry thunderstorms are the biggest concern typically planes fly over most of the weather but clouds can sometimes tower up into a plane's cruising altitude so if our aircraft encountered for some reason flew into an area that had those those towering clouds what we would expect is we've got a lot of those vertical shafts either coming up or down and so we're going to get some pretty violent movement on our aircraft not only that but we might have those hailstones that might damage the aircraft or our engines so for that reason it's always best to turn around and fly around the weather but dispatchers try to stop the scenario before it even happens by giving pilots a detailed flight plan which contains in at a route that should avoid these weather systems when i get the flight plan i've got some of the same tools in my cockpit when the weather changes and moves and shifts i get the real-time information when i get that i'm able to make much better decisions about my route of flight or my altitude but don't worry if you fly through clouds on your next flight i get a lot of people sometimes ask do you just avoid all the clouds and the answer is no when we have nice strata clouds those clouds if we fly through those you probably wouldn't even notice mechanical turbulence has kind of a funny name but it's exactly that there's something mechanically in the way of that wind that's blowing down the lower altitudes it might be trees it might be buildings might be hills up at higher altitudes it could be something a lot more than just the trees and the hills it could be the rocky mountains the rockies can create what's called mountain wave it happens when air blows over the mountains and falls down the other side creating rotors of air that are then carried up into the jet stream sometimes hundreds of miles from the mountains if we're flying and we've got the rockies over here and we've got that strong wind with those rotors as they come up and they impact my aircraft sometimes i'm going to see an increasing performance and then a decreasing performance of the aircraft it might cause my aircraft to pitch up slightly and then back down typically they're not as violent if i'm hitting them head-on but if i'm hitting them from the side sometimes it can give you a good rocking motion to try to avoid these situations walker says he communicates with air traffic control to learn of any reports of mountain wave before entering mountainous airspace as a pilot we're always concerned about mountain wave because just like clear air turbulence it can just all of a sudden be there and not there but if we can fly at a lower altitude we can avoid some of those rotors or we can sometimes fly above those out that altitude avoid them as well wake turbulence is something that we encounter when we come in for landing is something that comes naturally off of our wings is a byproduct of the lift on the wings as that uh airflow directs the wind over and around off the wingtip we get these vortices that come off the wing on both wings and so you can actually see them trailing off at times think of it like the wake off of a boat the vortices of air coming off the plane's wings tend to dissipate out from the aircraft if we're following too closely behind another aircraft that wake instead of falling and dissipating down here it stays active for a couple minutes and it can be blown back into our course so if we're the aircraft following we might encounter that wake turbulence and we get basically a little bit of a rocking how much rocking depends on the plane in front typically larger aircraft produce more weight still this doesn't worry walker much the good news about wake turbulence is that all we have to do is adjust a couple you know 50 feet a little bit left or right and we're out of it though pilots are working to keep the plane flying smoothly walker does have a few tips for flyers looking for the calmness ride first where you sit if you are one of those that are fearful of turbulence you know that actually sitting over the wing maybe further to the forward part of the cabin is going to be a slightly better ride than the back of the bus second when you fly maybe book it in the morning typically in the morning you don't have quite the heating and you don't have that thermal turbulence that we were talking about and as every pre-flight announcement says keep your seat belt fastened you never know when you may experience rough air [Music]

Channel: Wall Street Journal

Views: 823,904

Rating: 4.9499898 out of 5

Keywords: pilot, aviation, turbulence, airplane, flight, flying, jet stream, airplane turbulence, clear air turbulence, what is turbulence, what causes turbulence?, what causes turbulence, turbulence explained, aviation explained, wsj, the wall street journal, wsj aviation, airplanes, planes, air travel, travel, pilot explains, pilots explain, airplane pilot, aviation pilot, wsj pilot, pilot interview, pilot explains turbulence, explained, wsj explans, wsj explained, wsj explainer

Id: 5wQ9nAlO12E

Length: 7min 14sec (434 seconds)

Published: Fri Jun 18 2021