Definition
Small, near-vertical extensions fitted to the tips of an aircraft's wings that reduce induced drag by limiting the spanwise airflow and weakening the wingtip vortices generated in flight.
Plain English
The little upturned fins you see on the ends of airliner wings. They reduce the swirling air at the wingtip, which makes the wing more efficient and saves fuel.
Context Anchor
Seen in discussions of aircraft design, performance, fuel efficiency, and during preflight inspection of the wingtips.
Derivation
From 'wing' plus the diminutive suffix '-let,' meaning 'a small wing.' The name fits because a winglet behaves like a tiny wing standing at the tip of the main one, redirecting airflow rather than just blocking it.
Why Pilots Care
They improve fuel efficiency, range, and climb performance without requiring longer or heavier wings.
Intuition Check
Winglets are not just decorative tips on the wing. They are shaped surfaces that help control the airflow at the wingtips.
Example Sentence 1
The new model added winglets to the wingtips, giving the aircraft a small but measurable improvement in cruise fuel burn.
Example Sentence 2
Winglets on the new trainer helped reduce fuel burn during the cross-country flight.