A pilot flying an airplane equipped with a TKS "weeping wing" ice protection system notices during a preflight briefing that the system is described as anti-ice rather than de-ice. Which statement best explains this distinction as it applies to the TKS system?
- AThe system uses inflatable boots that break ice accumulation off the leading edges after it forms
- BThe system heats the leading edges electrically to melt ice after a layer has accumulated
- CThe system pumps a glycol-based fluid through porous panels on the leading edges before ice can form or bond to the surface
- DThe system relies on bleed air routed through the wing leading edge to remove ice once detected
Show answer & explanationAnswer & explanation
Correct answer: C. The system pumps a glycol-based fluid through porous panels on the leading edges before ice can form or bond to the surface
The TKS system is a fluid freezing-point-depressant system that continuously weeps glycol-based fluid through tiny holes in titanium or stainless-steel panels on the leading edges, preventing ice from bonding in the first place, which is why it is classified as anti-ice rather than de-ice. Pneumatic boots (choice A) and cyclic removal systems are de-ice systems that remove ice after accumulation.
Why the other options are wrong
- A. Describes pneumatic deicing boots, a de-ice system, not the fluid-based TKS system
- B. Describes electrothermal deicing, which removes ice after it forms rather than preventing it
- D. Describes bleed-air thermal deicing used on some turbine aircraft leading edges, not TKS
TKS Weeping Wing Ice Protection
An anti-ice system that continuously exudes a glycol-based freezing-point-depressant fluid through porous titanium panels on the leading edges to prevent ice from bonding to the airframe.
- Classified as anti-ice because it prevents ice formation/adhesion rather than removing it after buildup
- Fluid is metered from a reservoir by a pump through proportioning units to leading-edge panels, propeller slinger rings, and windshield
- Differs from pneumatic boots (mechanical de-ice) and electrothermal panels (thermal de-ice), which remove ice after it forms
Memory trick: TKS 'weeps' fluid before ice can even think about sticking