Definition 1 of 2
Definition
An ignition system fault in which one or more cylinders of a reciprocating engine intermittently fail to fire, producing irregular combustion and rough engine operation. Skipping is typically caused by fouled spark plugs, defective ignition leads, faulty magneto components, or improper fuel/air mixture reaching a cylinder.
Plain English
When an engine is skipping, some of its cylinders are not firing every time they should, so the engine runs roughly instead of smoothly.
Context Anchor
A pilot may notice skipping during engine start, run-up, climb, cruise, or any time the engine begins to run rough instead of smoothly.
Derivation
From the everyday sense of 'skip' -- to pass over or miss something. The engine is 'skipping' a firing event that should have happened.
Why Pilots Care
Indicates possible ignition, spark plug, or fuel issues that can reduce power and must be diagnosed before flight.
Analogy
It is like a steady drumbeat that occasionally misses a beat. The rhythm is still there, but it is no longer smooth or reliable.
Intuition Check
Skipping does not mean the aircraft is bouncing or jumping. Here it means the engine is intermittently missing normal firing events.
Example Sentence 1
During the magneto check, the engine started skipping on the right mag, suggesting a fouled spark plug.
Example Sentence 2
After takeoff the pilot felt the engine skipping and immediately reduced power for a precautionary landing.