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Windscreen Freezing /Frosting

Posted: Fri Jun 05, 2020 6:09 pm
by ctmcewan
Hi

Am having a weird thing happening on ground East Midlands Airport Temp +12 Centigrade IE TODAYS WEATHER

it was lashing with rain and the flight deck fwd windscreen went as though it had frosted over ie opak where is the windscreen heat control which I assume will be electrical elements with in the screen, clearly it should not have iced up or if condensation (fog) the cockpit aircond /blower should have cleared it?, I could not see directly front out of the windscreens side windows were fine and also DV Window that opens was fine.

Any Ideas Please

Best Regards
Charlie McEwan

Re: Windscreen Freezing /Frosting

Posted: Fri Jun 05, 2020 7:05 pm
by Taguilo
Hi,

What you experienced is typical windshield fogging due to cockpit moist condensation.
Always turn your WINDSHIELD ANTI ICE switches to normal (full up) when there is rain or snow in ambient and cockpit/cabin temperature is higher than OAT:

WshHeat.jpg
WshHeat.jpg (143.22 KiB) Viewed 687 times

If you haven't done that and you end with your windshield fogged, just put anti ice switches in HI position (full down) to allow for a fast defog. This is particular important if happening in flight, when descending from cold into warmer OAT (here e a fogged windshield might become a dangerous situation)

Both side windows (the 'D" ones) can be deffoged turning WINDOWS DEFOG switch to ON; this only works in flight, not when on the ground.
To defog vent windows, just adjust cockpit blower to max and select manual heat:

WndDefog.jpg
WndDefog.jpg (142.1 KiB) Viewed 687 times

Hope this helps.

Tomas