Antilift

Antilift is a term used in aerodynamics to describe forces or configurations that oppose or reduce the lift generated by a body moving through a fluid. In practical terms, antilift can refer to deliberate downward forces or to conditions that decrease the net upward force on an object. It is particularly relevant to aircraft design and control, where balancing lift, weight, and moments is essential for safe operation during takeoff, cruise, and landing.

Common means of generating antilift include devices and surfaces that disrupt or reorient airflow over a wing. Spoilers and airbrakes reduce lift and typically increase drag, aiding rapid descent and speed control. The horizontal stabilizer or tailplane can produce downward lift (negative lift) to balance pitching moments, a form of antilift essential for trim and stability in many conventional aircraft. In some flight regimes, wing fences or differential control surface deflections contribute to lift redistribution, producing lower net lift on the wings.

In automotive engineering, downforce created by front or rear spoilers constitutes a form of antilift, helping tires maintain grip at high speeds. The term itself is not universally standardized and is often used interchangeably with negative lift or downforce in technical texts. See also lift, downforce, spoiler, airbrake.