Definition
Describes a wing flap design that incorporates two or more narrow gaps (slots) between the main wing and the flap segments, allowing high-pressure air from beneath the wing to flow through the slots and energize the airflow over the upper surface of the extended flap. This delays airflow separation at high flap deflection angles, producing greater lift and permitting steeper, slower approaches than a plain or single-slotted flap.
Plain English
A flap built with two or more small openings that let air pass through them when the flap is lowered. Those openings keep the air flowing smoothly over the flap, so the wing can produce more lift at slower speeds.
Context Anchor
Seen in discussions of flap effectiveness, high-lift wing designs, approach, landing, and aircraft-specific flap systems.
Derivation
Multi' comes from the Latin 'multus' meaning 'many,' and 'slotted' refers to having narrow openings. Together: 'having many slots.' The slots are the key feature, because they are what let high-pressure air pass through to keep the airflow attached to the flap.
Why Pilots Care
Multi-slotted flaps produce the highest lift coefficients of common flap types, allowing large aircraft to land at lower speeds and on shorter runways.
Intuition Check
Multi-slotted does not just mean the flap has several grooves cut into it. It means the wing and flap sections form multiple working air passages that improve airflow over the extended flaps.
Example Sentence 1
The airliner's multi-slotted flaps extended in stages, allowing a slow, stable approach to the short runway.
Example Sentence 2
During the preflight briefing the instructor explained how the multi-slotted flaps increase both lift and drag compared with simpler flap designs.