Definition
An ice protection system that pumps a glycol-based fluid through laser-drilled porous metal panels along the leading edges of the wings, tail, and other critical surfaces. The fluid seeps out through tiny holes and flows back over the surface, lowering the freezing point of any water present so ice cannot bond to the airframe. It can be used both to prevent ice from forming (anti-ice) and to shed ice that has already accumulated (deice).
Plain English
A system that bleeds a special freezing-point-lowering fluid out through tiny holes in the leading edges of the wings and tail, so ice either never forms or breaks loose and washes away.
Context Anchor
You will see this term in discussions of aircraft ice protection, preflight checks for fluid quantity, and pilot decisions about flying near freezing clouds or precipitation.
Derivation
TKS comes from Tecalemit-Kilfrost-Sheepbridge Stokes, the British companies that originally developed the system. "Weeping wing" describes how the fluid seeps slowly out of the porous panels, like a wing that is gently weeping.
Why Pilots Care
Ice on wings destroys lift and increases drag; this system lets pilots operate safely in known icing conditions without the weight or complexity of boots or heated surfaces.
Analogy
Think of a surface that is kept slightly wet on purpose so ice has trouble grabbing onto it. The fluid is not a leak; it is being released in a controlled way.
Grounding Statement
In flight, the system makes a thin film of protective fluid flow back over the wing surface as air moves across it.
Intuition Check
“Weeping” does not mean the wing is damaged or leaking water. Here it means the system is intentionally letting approved ice-protection fluid seep out through tiny openings.
Example Sentence 1
Before departing into forecast icing, the pilot checked the TKS weeping wing anti-ice/deicing system fluid level and confirmed the pumps were operating normally.
Example Sentence 2
During the preflight the instructor pointed out the porous panels that allow the TKS weeping wing anti-ice/deicing system to function.