Definition 1 of 2
Definition
A coil spring wound in a tapered, conical shape resembling an old-fashioned beehive, with each successive coil smaller in diameter than the one below it. The tapered shape allows the coils to nest inside one another when fully compressed, giving a shorter solid height and a progressive (variable) spring rate.
Plain English
A spring shaped like a cone instead of a straight cylinder. Because each loop is a different size, the loops can collapse into each other when squeezed, and the spring gets stiffer the more it is pressed.
Context Anchor
Seen in aircraft engine maintenance, especially in discussions of valve springs in piston engines.
Derivation
Named for its visual resemblance to a traditional straw beehive (a 'skep'), which has the same tapered, stacked-ring shape. The name is purely descriptive of the form.
Why Pilots Care
Pilots usually do not handle this part directly, but a weak, broken, or incorrectly installed beehive spring can affect how an engine valve closes, which can affect engine smoothness and power.
Analogy
It is like a cone-shaped stack of coils instead of a straight stack. Because the coils get smaller toward one end, the spring can take up less room when it is squeezed.
Intuition Check
Do not read “beehive” as meaning it has anything to do with bees or honey. Here, it describes the spring’s tapered shape.
Example Sentence 1
The mechanic replaced the worn beehive spring inside the pressure relief valve during the annual inspection.
Example Sentence 2
A weak beehive spring can cause hard starting and occasional kickback on a cold engine.