Definition
A force applied to a bearing in a direction perpendicular to (at right angles to) the axis of the shaft it supports.
Plain English
A sideways push on a bearing — pressing in toward the shaft from the outside, rather than along the length of the shaft.
Context Anchor
Seen in aircraft engine and powerplant maintenance when discussing crankshaft, propeller shaft, gear, or accessory bearings.
Derivation
Radial' comes from the Latin radius, meaning the spoke of a wheel — a line running outward from the center. A radial load is one that pushes inward along that spoke direction, straight at the shaft.
Why Pilots Care
Bearings are designed to handle specific load types. A bearing built mainly for radial loads can fail prematurely if it is also asked to carry significant end-on (axial) loads. Recognizing the load type matters during inspection and when matching replacement parts.
Analogy
Think of a bicycle wheel: the rider's weight pushes down on the hub from the side, squeezing the bearings against the axle. That sideways squeeze is a radial load.
Intuition Check
Do not read bearing here as a compass direction. In this term, a bearing is a part that supports a rotating shaft, and radial means the force is sideways to that shaft, not along it.
Example Sentence 1
The propeller's weight on the crankshaft creates a radial bearing load that the main bearings must support.
Example Sentence 2
Technicians measure radial bearing loads to confirm the crankshaft is properly supported under normal engine operation.