Definition
A small, sturdy structural component mounted under the rear of an airplane's fuselage, designed to protect the tail from damage if it strikes the ground during takeoff, landing, or other ground operations. On tailwheel airplanes without a steerable tailwheel, an actual skid (rather than a wheel) may serve as the rear ground contact point.
Plain English
A small bumper or skid under the back of the airplane that takes the hit if the tail touches the runway, so the fuselage itself isn't damaged.
Context Anchor
Seen in discussions of older airplanes and tailwheel-type landing gear, especially when comparing early designs with later airplanes that use a tailwheel.
Derivation
From 'tail' (the rear of the airplane) and 'skid' (something that slides along a surface rather than rolls). The name describes its job: a sliding contact point at the tail, rather than a wheel.
Why Pilots Care
A worn or damaged tailskid can allow the tail to strike the ground, risking control-surface or structural damage on every landing rollout.
Analogy
It is like the small plastic or metal glide on the bottom of a chair leg: it is not a wheel, but it protects the object and lets it slide without wearing away the main structure.
Intuition Check
Do not picture a tailskid as a tailwheel. A tailskid does not roll; it is a fixed support or protective piece that slides if it contacts the ground.
Example Sentence 1
The pilot rotated smoothly to avoid scraping the tailskid on the runway.
Example Sentence 2
Before flight the student checked the tailskid for cracks and excessive wear as part of the preflight inspection.