What exactly is a landing gear side load?

Hi everyone,
I've come to know that during crosswind landings, touching down in a crab is not recommended as this may imposes side loads on the landing wheels. However i've got no idea what a side load is.
Is it a force imposed on the wheels by the runway? In what direction does it act? A detailed

Hi everyone,
I've come to know that during crosswind landings, touching down in a crab is not recommended as this may imposes side loads on the landing wheels. However i've got no idea what a side load is.
Is it a force imposed on the wheels by the runway? In what direction does it act? A detailed explanation is highly appreciated.

Best Answer:

alex: JetDoc pretty much has it.

When you land in a crosswind, your airplane and your wheels are pointed in a slightly different direction than your direction of travel. As your wheels contact theground, the wheels want to go in the direction they are pointed, and the inertia of the airplane keeps it going in the same direction it was travelling in. The difference in the direction of travel, and the direction the wheels are pointed, causes the tires and wheels and landing gear struts to be pulled sideways. If the difference is extreme, the tires can pull away from the rims. Landing gear struts are designed to take a straight on load as you land, and the side force could make the strut fail, or pull away from its mount.

Other answer:

alex:
Just what it sounds like. Think of it in car terms. When you go around a corner at high speed you're putting a side load on the bearings. Landing gear on a plane is designed to be strong when the weight of the plane rests on it and strong when forces are applied when the plane is going in a straight line. Watch a plane land in a high crosswind. As soon as the plane is touching down the pilot applies control input to straighten the plane.
AlCapone:
Side load forces are perpendicular to the plane of the wheel — from the *side* of the landing gear and wheel. Imagine the extreme — landing a plane with the wheels turned completely sideways. They wouldn't turn but would simply scrape on the pavement, putting extreme pressure forces on the mechanism which would break off the gear under the worse circumstances. So these forces exist even when the wheels are only a bit sideways.
mitchell:
to land in crosswinds u can do something where the rudder and ailerons are balanced and makes the plane balance and the plane is easier to land on landing gear