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Just because the calendar says spring doesn’t mean in-flight icing is no longer a concern—especially around your home base in Chicago. That means today’s proposed flight home from Detroit (PTK) to Gary, Indiana (GYY), might be a challenge. You are instrument rated and current, so you’re planning on an IFR flight for the 1+20 trip. Your Cirrus SR22 has a TKS deice system but not a “known ice” system, so it’s mostly useful for escaping ice and not plowing through it.

Read the weather forecast below and tell us if you would go or cancel. Proposed departure time is 1530Z.


The Map view in ForeFlight looks mostly clear, with just a few scattered showers to the south of your route. But there are definitely some IFR conditions at most airports, and a few icing PIREPs.


The surface analysis shows that your route is in between two fronts, with a weak cold front to the southeast and another front moving in from the west.

The prog charts show that conditions won’t get much better tonight or tomorrow as that next front moves in, so delay isn’t a great option. Here’s the 00Z chart.

The satellite image shows there are widespread clouds ahead of this front, but they might have fairly low tops.


This appears to be the main threat today, so it’s time to dive into all the details. First, a look at the AIRMETs for icing—sure enough, there’s one right across your route.

The visual icing forecast offers a lot more precision than an AIRMET, including a more three dimensional view of the atmosphere. At 3000 ft, there is plenty of icing along your route, but most of it looks light:

At 4000 ft the icing appears to be more significant.

You might choose 6000 ft as a cruising altitude, but it seems like that might be in the tops of the clouds.

By 8000 ft it looks like you would be out of the ice.

The visual cloud forecast backs up this last icing layer, suggesting tops are somewhere between 5000 and 7000 feet across southern Michigan and the Lake Michigan area.


Now that you have a good overview of potential icing, it’s always important to back it up with real observations from pilots. There are plenty of PIREPs to read today. The first one, just northwest of your departure airport, shows two thin layers with tops at 6400 feet and just a trace of rime ice in the upper layer.

Further down the road, over South Bend, tops are reported at 7000 ft and clear above.

Another report near South Bend shows tops at 6100 feet and light rime during the climb through the 2100 ft thick layer.

Closer to Chicago, there are conflicting reports. First, a 737 PIREP shows negative ice, a smooth ride, and tops at 5400 ft.

Another one, a little further west, reported moderate mixed icing between 4000 and 6000 ft.

Finally, even further to the west a Cessna 414 reported moderate rime ice at 5000 ft.

Text weather

So much for the icing forecasts and PIREPs. You also need to know about conditions on the ground, both for a potential escape from icing and for making a landing at Gary. Your departure airport is reporting marginal VFR conditions, and it’s forecast to stay that way through the afternoon.

En route, weather conditions seem to vary between marginal VFR and IFR. Two airports along your route report the same lower cloud layer, with bases around 800 to 900 ft.

Weather at your destination is marginal VFR and forecast to stay that way, but with gusty winds and occasional rain showers.

Decision time

This is a classic IFR conundrum in the northern parts of the US. Overall weather is pretty benign, with reasonably high ceilings and good visibility, but there are enough cold clouds to make icing a legitimate concern. On the one hand, you can probably get on top today and cruise to Chicago ice-free at 6000 or 8000 ft. On the other hand, you’ll most likely have to climb and descend through a layer with some ice. Your airplane is equipped to handle some ice, but how much?

Add a comment below and tell us what you think: is it a go or a no go?

Air Facts Staff
10 replies
  1. Ron Backnick
    Ron Backnick says:

    I fly a TKS (not FIKI) SR22 based in the Cleveland area and this scenario is all too familiar. For me, this is a no go. Yes, I could get above the layer(s) and avoid prolonging time in the clouds on departure. I’ve found ATC to be very accommodating with clearances to help stay out of the clouds when icing is a threat. But, arrival into KGYY would require an approach that may result in extended time in the clouds. The ILS RWY 30 approach shows initial at 2400′ and FAF intercept at 2100′. So it could work out that you’re between the layers, per the KGYY TAF for 1700Z. But the icing PIREPs west of KGYY could mean that icing has moved over the destination field or route of flight by the arrival time. And the ground temps are low enough to suggest a freezing level at 2000′, more or less. At the very least I’d be thinking about the speed of the cold front to the west. The TAF also calls for winds gusting over 30 kts, although pretty well aligned with RWY 30. I think this flight could “probably” be executed safely if a lot of things went right. But, a TKS Cirrus is prohibited from flight into known icing. It would be hard to defend a decision to make this flight given the airmet for icing and the PIREPs that make the icing conditions “known” along the route of flight. All things considered, I’ll stay on the ground.

  2. Larry Brock
    Larry Brock says:

    Isn’t this the definition of flight into know icing? With this aircraft, I wouldn’t go, but I am generally very conservative in my flying decisions. If I had to be there, I’d drive.

  3. JR
    JR says:

    Like Ron B says… If all the cards line up, then the flight is doable. It’s just that there are so many cards. Any one of which could make this a bit of a messy situation. The biggest being the possibility of the ice to the west moving in. That makes this a no go.

  4. Jack Morey
    Jack Morey says:

    After 39 years as an airline pilot I now fly for fun. Picking up ice in a General Aviation airplane is NOT fun. No go for me, if I have to be there I’ll drive.

  5. José Serra
    José Serra says:

    For me is a definitely no go. Risk of ice encounter in a no Fiki airplane is something that isn’t adequate for me.

  6. Jack Ellis
    Jack Ellis says:

    This trip would be a no-go for me. There’s the potential for icing on climb, icing on descent, and like others have said, the potential for an extended stay in icing near the destination. I would point out that in addition to the weight and lift penalties imposed by icing, a pilot would also be fighting engine temperatures as more power was used to keep an airplane aloft at slower and slower air speeds.

    At least over the Midwest there are plenty of airports. At this point most of my instrument time has been accumulated over British Columbia and the Yukon Territory flying between Northern California and Anchorage. Airports along the preferred route are about two hours apart once you get halfway into BC and there’s a section between Fort St. John and Fort Nelson where the last place you want to be is over the Alaska Highway, which runs through some pretty rough mountains and based on my experience is infamous for bad weather on summer afternoons.


    Would like to know the ceiling between departure and destination. Would like to know MEA. Recent flight from Rochester Minnesota to Asheville North Carolina in similar conditions. Flew at MEA, always able to see ground below me. Plan B, VFR under the ceiling, was never needed. But it was there.

  8. Scott Winick
    Scott Winick says:

    I really enjoyed the setup and analysis for this all-too-frequent situation. Home base on the border with Canada in VT.
    “No Go” for me. In my M20E, I’d worry about 3 factors:
    1. Picking up too much ice during the time in the climb through potentially 3K’ of icing cloud layers,
    2. The length of time I might have to be in a layer during an IFR approach to any airport along the route, and finally,
    3. The temp on the ground is just barely above freezing, so the ice may not shed quickly enough or with enough visual margin to see-avoid-land on the way down.


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