The trim lift coefficient () is the lift coefficient at which an aircraft is in a balanced or trimmed condition during level flight, meaning there is no net pitching moment and the aircraft remains stable without requiring continuous control inputs from the pilot to maintain its attitude. When an aircraft is in trim, the lift generated by the wings is equal to the aircraft’s weight, allowing it to maintain a constant altitude. Achieving trim involves adjusting control surfaces, such as elevators or stabilizers, to balance the aerodynamic forces acting on the aircraft.
Where:
- is the pitching moment coefficient at zero lift.
- is the slope of the pitching moment coefficient versus lift coefficient curve.
- CLtrim is Trim Lift coefficient