Definition
In a magneto, the position of the rotating magnet at which its poles are aligned with the pole shoes of the magneto frame so that maximum magnetic flux is passing through the iron core, and no flux is linking the primary coil. From this position, a small rotation produces the most rapid change in flux, which is why the breaker points are timed to open just past neutral to generate the spark.
Plain English
The exact spot in a magneto's rotation where the magnet's poles line up with the iron frame and the magnetic field through the coil is at its strongest. Spinning slightly past this point causes the field to collapse fastest, which is when the spark is made.
Context Anchor
Seen in constant-speed propeller and propeller governor discussions, especially when describing how the system holds a selected engine speed.
Derivation
Neutral' comes from the Latin neuter, meaning 'neither one nor the other.' In the magneto, this name fits because at this position the magnet is producing no useful change in flux through the coil — it is between the two active states where the field is collapsing in one direction or the other.
Why Pilots Care
Ensures predictable aircraft response to pilot inputs and prevents unintended attitude changes during flight.
Analogy
It is like holding a faucet handle in the closed position: water is not being added or drained, so the level stays where it is.
Intuition Check
Neutral does not mean “unimportant” or “disconnected” here. It means the control valve is balanced in the middle, with no oil being commanded either direction.
Example Sentence 1
The technician rotated the magnet to the neutral position before setting the E-gap angle.
Example Sentence 2
During the control rigging inspection the mechanic confirmed both ailerons were in the neutral position before tightening the turnbuckles.