Last night I flew my first AP flight in the C172 G1000 on Xbox, and it went well - for a while. It made all the correct turns, pointed in the right direction, all by itself. Pretty cool. I was flying north in Michigan at 3800 feet, around 3:00 am, well on my way to Mackinac Island from Chicago. I took out my phone to rewatch a video about using OBS to line up with a runway - and looked up just in time to see a lot of red on the PFD and then the crash dialog with the somber music. Bummer.
I didn’t know what happened. I have all the crash and damage safeguards turned off. After some research, I’ve come to the conclusion it was icing. The OAT was about -10C and I’d flown through some precipitation and clouds. I read the C172 has no anti-icing capabilities, and the only thing to do is to avoid icing situations.
So my question is - once I’m up there, how can I tell that icing is happening, or likely to happen? Are there early warning signs, like outside air temperature, frosting on the windows? Can you see ice on the wings (in the sim)? Can any hints be gleaned from the instruments or from performance oddities?
You’ll notice ice slowly start to build on the wings and glass if you are paying attention. It can also happen quick tho
But really you shouldn’t have to use that as a warning sign - a good check of the weather before departure will tell you if icing is a concern or not. If it is, you have options: pick a different route, don’t fly, switch off real world weather or disable icing in the menu
When OAT is between +2 and -20C, your chances of icing up are decent. Add that to flying through precipitation (rain/snow)or moisture (reasonably thick clouds), your chances increase even more. Thus, change altitude if you can to stay out of precip.
Unfortunately, the sim doesn’t model sophisticated visual representation of icing yet. So if you don’t want to compromise realism by constantly switching to an outside camera view, use VFR landing view which will let you see more of the aircraft nose. If it’s iced up, you’ll see it.
IRL sharp objects accumulate ice first, so often a probe is fitted that is visible from the cockpit, which is monitored by the pilots when icing is predicted, usually in cloud with TAT of 10C and below, which is the point where jet engine anti-ice is typically turned on for prevention.
I think the challenge here is that MSFS seems (not 100% on this but by appearances) to treat a cloud layer as a cloud.
So you can pick up ice in the clear even if you are avoiding clouds because you are at the cloud layer.
It would be difficult I think for MSFS to equate the drawing of clouds with the accumulation of ice, so you may just have to accept that cloud layers in the icing temperature zone (10C TAT to -40C SAT in the planes I’ve flown) are likely to produce ice in the sim and avoid them.
FWIW, I’ve been pretty iced up in the sim and not had any appreciable loss of performance. I’m curious as to whether your mishap was from ice in the first place.
I would agree this must be the case. I have picked up clear air icing on the ground in MSFS. (Clear blue skies.) It seems in the game that visible moisture is not a requirement for ice accretion. Cold air and high enough humidity seem all it takes for the infamous invisible ice fog to get you.
And remember that water vapour condenses out of the air at or below the dew point temperature. So if its 1 degree C and the dew point is higher than that, in clear skies you will still get dew, which will freeze into frost… that why you get icing at ground level.
Icing is best avoided by checking the weather forecast for temperature and potential for precipitation. Even if it isn’t raining, if there are clouds in the sky there is a possibility of icing in flight near clouds, if temps are below 5C. There is also a meteorological condition called virga which you should avoid: it is rain at altitude that does not reach the ground. (From the ground, it looks like wispy streaks of cloud.)
Flying a C172, the best place to observe ice accumulation is to check the wing struts. At night, you can use the flashlight.
That said - in the real world - I would not be inclined to fly a C172 at 03:00 in weather conditions other than CAVOK and above 10C at altitude. Following those rules you’ll be certain to avoid icing!
There are old pilots, and there are bold pilots, but there are very few old, bold pilots.
-anon-
How can dewpoint be higher than temperature? Equal maybe, not higher. In your situation the relative humidity is 100% which will cause mist / fog and below 1 mile visibility this is considered as icing conditions. You could of course have “cold soaking” due too low fuel temperature or low airframe temperature which will cause frost.
Hey look at that…
From Wiki: The temperature can never go below the dew point. The dew point is the temperature that 100% relative humidity is reached, based on the amount of water vapour in the air. That means that once the temperature drops to that point, the air cannot hold any more water vapour so condensation occurs.
Exactly, thats why this standard 10C dewpoint in the ATIS makes no sense when temperature is below 10C … Dewpoint could be reached locally of course when the airframe is colder than the surrounding air, causing condensation which might freeze.
Not much of a concern during flight, but could happen on the ground. The icing visuals they are using now look exactly like that. That’s how I would expect to find my car in the morning, for in-flight icing they have it completely wrong.
… Dewpoint could be reached locally of course when the airframe is colder than the surrounding air, causing condensation which might freeze.