1900D question.

[Guilden]

Anyone out there who fly D's experience a fog or mist shortly after departure coming from the floor outlets? Is been humid the last couple days, but this phenomenon should not be occurring.. Any suggestions? It's not the VCS because its coming from the floor outlets.... Thanks.

[frozen solid]

I've heard of that happening before, I'm not sure what causes it and I'm sure if you're patient someone will answer your question sensibly.

[Heliian]

sounds like she's full of water, dry it out. Is this happening just with cooling? Maybe slam the heat on and see if it clears out the moisture.

[GA MX Trainer Dude]

Pretty normal with very high humidity on the D.

Cooling turbine is dropping the temp below the dew point - water separator cannot keep up with the extraction and you get the leftover coming out the vents.

Can be a bit spooky the first few times as it can look like smoke.

I actually had it last week in the car - was so humid that the VCS couldn't cope and the visible vapor was coming out the vents - scared my wife as she had never seen it before.

Regards,

Mx

[Diadem]

I heard of this happening a month or two ago; shortly after take-off, 19 passengers started screaming and forced the pilots to return for landing because they saw "smoke". I also recently saw this in an A320 on a day with 95% humidity, so it's not confined to 1900s.

[pdw]

Pretty serious when pax start freaking out over it like that. Discussed this with a caravan pilot a while back who also got surprised over the close resemblance to smoke in a climbout at YYZ during high humidity. You'd almost think by now there'd be a way to avoid it ... to prevent the scaring of pax. I does look real; have seen it out of the car vents as well.

Its when the first real humid air moves (too slowly) through the AC system as the AC is started, ... maybe before the AC vent is opened or blower speed is increased ? It's that very humid air suddenly chilled across a very cold (frozen) evaporator just after it is turned on.

[Colonel Sanders]

Not sure if this is a troll or not, but I will answer it straight up ...

Doing a type rating a few years ago with a guy on a very
humid day, and after takeoff (N1 came up), he panicked
when it started to snow in the cockpit.

I told him the AC was starting to work, and that's what
happens to water when it gets cold.

[FlightSolutions]

I experienced it. Pax came up with a concern so I pull over to have the FO check it out. No smell so it obviously was just mist. Decided that in the interest of customer service to have mx look at it. We did a run up and turned up the heat and it disappeared. It was hot and humid with light rain.

[sidestick stirrer]

It gets even better: on some types of airplanes, during times of low ambient noise, one could hear this faint "tinkling" sound. It was ice crystals coming up the ducts, out of the air-cycle machines...

[pdw]

.... and somehow there the conditions become right to make the real dense ice fog that looks like smoke.

[icewa]

I've had it happen often. It's normal and fairly common, remember to alert your pax on subsequent flights.

[pelmet]

Have seen it on a freighter type where the entire cargo area is completely engulfed in fog with vis about 10 feet. However, on some types we have to take specific measures to prevent false cargo fire warnings.