Definition
An upward bending of helicopter rotor blades caused by the combined effect of lift pulling them up and centrifugal force pulling them outward. The result is that the spinning rotor disc takes on a slight cone shape rather than remaining perfectly flat.
Plain English
When a helicopter's rotor blades are spinning and lifting the aircraft, they bend slightly upward at the tips, making the spinning disc look a bit like a shallow cone instead of a flat disc.
Context Anchor
Seen in helicopter aerodynamics, rotor system discussions, and explanations of how rotor blades carry the aircraft’s weight.
Derivation
From 'cone,' the geometric shape with a flat base and a point at the top. The blades flexing upward form a shape resembling a very shallow cone, hence 'coning.'
Why Pilots Care
Coning affects rotor efficiency, blade stress, and the amount of lift available; excessive coning can reduce performance or indicate an overloaded rotor system.
Analogy
Picture holding the center of a spinning umbrella shape while the outer ribs lift upward. The whole spinning shape is no longer flat; it forms a shallow cone.
Grounding Statement
In flight, each rotor blade is being pulled upward by lift and outward by its own spinning motion, so the blade settles at an upward angle between those forces.
Intuition Check
Do not read “coning” as damage or a permanent bend in the blade. Here it means the normal cone-like shape made by rotor blades under load while they are turning.
Example Sentence 1
When the helicopter lifted off with a heavy load, the increased blade coning was clearly visible from the side.
Example Sentence 2
The pilot monitored blade coning angle during the hover check to confirm the rotor system was operating within limits.