Definition
A propeller blade angle in which the leading edge of the blade is rotated past flat (zero pitch) so that the blade bites into the air in the reverse direction, producing thrust that pushes the airplane backward or decelerates it during the landing roll.
Plain English
The propeller blades are twisted so far that instead of pulling the airplane forward, they push air forward — which slows the airplane down or moves it backward.
Context Anchor
Seen in turboprop and controllable-pitch propeller operations, especially when discussing beta range, reverse thrust, and landing rollout.
Derivation
‘Negative’ here means ‘below zero’ on the pitch scale. Flat pitch is zero; positive pitch pulls the airplane forward; negative pitch is the other side of zero, so the blades push air the opposite way.
Why Pilots Care
It provides additional deceleration on landing without sole reliance on wheel brakes and enables tighter ground handling in some turboprop aircraft.
Analogy
It is like turning a fan blade angle the other way so the air is pushed in the opposite direction.
Grounding Statement
With negative pitch, the propeller is no longer helping the airplane go forward; it is pushing air forward to help slow the airplane down.
Intuition Check
Negative pitch does not mean the airplane nose is pointed down. Here, pitch means the propeller blade angle, and negative means the blades are set past flat pitch into a reverse-thrust position.
Example Sentence 1
After touchdown, the pilot moved the power levers into the beta range, where the propeller blades shifted to negative pitch and slowed the airplane quickly.
Example Sentence 2
In beta range the crew used negative pitch to control speed while taxiing without heavy brake application.