Windscreen Fogging
Looking for advice and information share about problems with windscreen fogging in a tropical environment:
Mainly occurs after night IFR descent (7000'/20 deg C/high humidity) to MDA and landing. Usually the night ambient range at landing is around 24-30 deg C and 85-100% humidity, and we are getting fogging on the inside and/or outside. Our frame arrived with plastics after the problems with the heated glass fit.
We have had varying success with the following:
1. Leaving cabin door closed - a problem with outfield landings.
2. A/C off in cruise, and then heater on low during descent. Problem is the cockpit can get pretty warn, the aft cabin v.hot, and there is also the ambient temp limit to consider. Some times, just vents with high fan on produces adequate results.
3. Some variations on the theme above have also produced different results. If you leave the heater too late on descent, the moist ambient produces instant IMC on the inside, which can then be cleared by full A/C, but if you time that wrong, the windscreen cools and you get fogging on the outside!
The obvious answer is warm/dry air onto the screen to clear the inside (if required) and heated windscreen to keep the fogging off the outside during descent. We are still coming to grips with heater and A/C and can't seem to find ideal settings, and there may be a considerable time to wait for a heated windscreen fit.
Any operators out there having the same problems?
Do/did you have the heated glass and was it any good? What is the range of view - the wipers are useless and only good for forward viewing, ie no good for steep approaches/winching.
Any advice about the heater and A/C?
Appreciate any help/advice.
SNED