Top of wing ice

[TheFirstDohrnPilot]

Hi everyone.

I thought this would be the best section of the forum to post this on, since it's not strictly a flying question.

We all know that airliners have wing anti-ice, in the form of hot bleed air running across the leading edges of the wings. I was wondering though, how do they stop ice forming further downstream - nearer the trailing edge??

If freezing rain, or just normal rain, hits the wing when it's at -40c it will do nothing to the leading edges because they're piping hot, but can it not run back and re-freeze, causing obvious problems?

Thanks, just curious :)

[TURIN]

Short answer. Yes it can. Which is why takeoff with a contaminated (ice covered) wing is prohibited.

Long answer. The aircraft is only likely to encounter precipitation at lower flight levels after a cruise has cold soaked the wing for some hours. EG when flying through cloud on descent.
By this time the aircraft is lower weight. The Wing produces plenty of lift at max TOW so at lower weights there is plenty to spare even on a contaminated wing.
At high altitudes its not a problem due to the effects of sublimation. IE. the ice boils off at lower atmospheric pressure.

Flight testing during certification determines the procedures required if ice does build up. No doubt someone will point that out. :ok: