- Airplane crabbing is usually needed because of high crosswinds.
- Those strong winds can also prevent planes from taking off and landing at the airport.
- A perfect crosswind landing is when the upwind wheel touches down first, the aircraft is straight down the runway, and then the second wheel comes down after.
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Following is a transcript of the video.
Alex Appolonia: It’s not always a smooth and pleasant landing for airplanes. Intense strong winds can affect the position of how planes land on the runway, making it look like the plane is literally landing sideways. Here’s how planes land sideways in high winds. Landings like this actually have a name, crabbing. The name comes from the way crabs walk sideways across the beach. That’s kind of what the airplane looks like when it’s landing this way. Crabbing is usually needed because of high crosswinds.
Les: The wind can either be blowing straight down the runway or 90 degrees to the runway or somewhere in between. And usually it’s somewhere in between there.
Alex Appolonia: That’s Les Westbrooks. He teaches aeronautical science at Embry-Riddle Aeronautical University, and is a retired airline pilot.
Les: Landing in a crosswind situation requires a couple of different maneuvers. When we’re at altitude, the aircraft just flies in a crab, and we just go across, kinda sideways. Once we get down to the ground, we can’t land with the aircraft in a crab, because that’s gonna put a lot of stress on the outside of the landing gear, and could actually cause the landing gear to collapse if we put too much stress on it.
Alex Appolonia: Whenever there is a crosswind, there’s a lot of turbulence, so it’s not like the pilots are flying through a slight summer breeze. Of course the ultimate goal is for the aircraft to land straight, where the nose of the plane is in alignment with the stripe that’s down the runway. Those crosswinds sure make it challenging!
Les: There is an angle to that. You know, as a forced vector, so the direction and the intensity that it’s coming at will determine how much input we have to put into the aircraft’s flight controls.
Alex Appolonia: As the plane comes in, the pilots are actively controlling it, so that it’s in the perfect landing position. But, when a gust of wind comes at the wrong time, it will cause the pilot to execute a go-around instead of landing. If the crosswinds are severe enough, around 72km per hour or so, the pilot does not have enough control to straighten the airplane out and land. If this happens, the pilot will abandon the approach and divert the plane to another airport. These strong winds can prevent the planes from taking off at an airport. That’s sometimes where those flight delays come in, and we all love those!
So, exactly how do the aircrafts land in these conditions?
Les: So, at the last minute, we want to move the nose of the aircraft parallel with the runway, but soon as we do that, the aircraft’s gonna start blowing off to the side of the runway with the wind. So in order to counteract that, we’d lower the wing, the upwind wing, we lower the wing, and straighten the nose out, and a perfect crosswind landing will be when the upwind wheel touches down first, the aircraft is straight down the runway, and then the second wheel will come down after that.
Alex Appolonia: Finally, the plane is on the runway and heading to the terminal.
Les: Some of your best landings are actually made when it is in challenging conditions, ’cause you are on your A-game when you’re doing this. All right, and you’re completely engaged, and actively controlling the airplane so, actually some of our best landings are made when we are in these crosswind landing situations.
Narrator: So, if you’re ever on a plane that feels like it’s landing sideways, feel safe knowing the pilots have the situation totally under control.
EDITOR’S NOTE: This video was originally published in April 2019.