Definition
Wing-mounted panels that, when raised in flight, disrupt the smooth airflow over the upper wing surface to reduce lift and increase drag. Flight spoilers can be deployed symmetrically (both wings together) to steepen descents and slow the airplane, or asymmetrically (one wing only) to assist roll control by reducing lift on the wing that is rolling down.
Plain English
Panels on top of the wing that pop up during flight to spoil the lift the wing is making, so the airplane can come down faster, slow down, or roll into a turn more easily.
Context Anchor
Seen in discussions of drag devices, descent control, and aircraft systems for airplanes equipped with spoiler controls.
Derivation
Called 'spoilers' because they spoil the smooth airflow the wing depends on for lift. The word 'flight' is added to distinguish them from ground spoilers, which only deploy after touchdown.
Why Pilots Care
They enable a controlled descent rate without excessive airspeed buildup and help the aircraft settle firmly on the runway after touchdown.
Grounding Statement
Picture a flat panel lifting up on top of the wing and breaking the smooth airflow, making that part of the wing less effective at holding the airplane up.
Intuition Check
“Spoilers” are not something that spoils the flight; they spoil the smooth airflow over the wing. “Flight” means these spoilers are intended for use while airborne, not only after landing.
Example Sentence 1
Cleared for a steep descent into the airport, the pilot extended the flight spoilers to lose altitude quickly without gaining airspeed.
Example Sentence 2
After touchdown the flight spoilers deployed automatically to reduce lift and keep the wheels firmly on the runway.