Definition
The shape and outline of an aircraft's wing as viewed from directly above or below. Planform includes the wing's overall shape (rectangular, tapered, elliptical, swept, or delta), its span, its chord, and the relationship between them. Different planforms produce different lift, drag, stall, and handling characteristics.
Plain English
What the wing looks like when you look straight down at it from above. The outline you'd trace if you drew around the wing on a flat piece of paper.
Context Anchor
Seen in aerodynamics discussions when comparing how different wing shapes affect lift, drag, stall behavior, and handling.
Derivation
From 'plan' (a view from above, as in a floor plan) and 'form' (shape). A planform is literally the shape seen in plan view — looking straight down.
Why Pilots Care
Different planforms change how the wing produces lift, how it stalls, and how much drag it creates, directly affecting climb performance, cruise efficiency, and low-speed handling.
Analogy
A wing planform is like a floor plan for a room: it shows the shape from above, not the height or side view.
Intuition Check
Do not read “planform” as the airplane’s flight plan or a design plan. Here it means the physical shape of the wing when viewed from above.
Example Sentence 1
The trainer's rectangular wing planform gives it gentle, predictable stall behavior at the wing root before the tips.
Example Sentence 2
The tapered wing planform on many light aircraft reduces structural weight while keeping lift distributed evenly across the span.