IMC at destination - what would your decision be?

What would you do?

  • 1) Take the approach

    Votes: 10 30.3%
  • 2) Turn around, get fuel, continue VFR under the ceiling

    Votes: 9 27.3%
  • 3) Turn around, land and wait

    Votes: 9 27.3%
  • 4) Other

    Votes: 5 15.2%

  • Total voters
    33

skidoo

Line Up and Wait
Joined
Nov 13, 2009
Messages
987
Location
Montana
Display Name

Display name:
skidoo
Here is the scenerio - You are on a 600NM flight in a Turbo C-182m non-FIKI aircraft. You filed IFR and departed through clouds for less than the first 50 miles. You are in clear skies until the last 100NM of your destination, of which is over mountain terrain. There is an icing airmet over that last 100 mile area for between 10K to 15K. MEA for the area is 13K. Approach chart IAF begins at 8K. You are cruising at 17K and 100 miles out, you can clearly determine that you will be on top of any clouds. You are expecting scattered clouds in the destination valley and that is what was observed when you departed a couple hours prior. So, you continue on, expecting to cancel and drop down through the open areas when you reach the valley area. And, you expect to have enough fuel for an extra 2 hours.

But, when you get there, you find that all that scattered turned into an overcast with a 5k ceiling, freezing level at 10K. At this point, what decision would you make:

1) Take the approach, and coordinate with ATC to drop through 15K to 8K as quickly as practical., or
2) Turn around and go back the 100 miles cancel IFR, land and get fuel, then continue VFR under the ceiling through a valley route., or
3) Turn around land and wait for better conditions., or
4) Other
 
Any current PIREPS?

OAT?

How thick is are the layers?

Shy of a few folks saying negative ice, I'd just fly back, get some fuel, pee, stretch my legs and fly to my destination under the clouds.

BTW flying a 182 at 17k, you get nose bleeds up there? It's all about low level ;)
 
How thick is the layer? Any other PIREPS? ^^^oops - James beat me to it.
 
Land short of the destination,get fuel and a rest. Get the latest weather and see if the weather is going to go by you.
 
Icing in the mountains with a non-FIKI single? I'm not going there... I'm turning around and waiting.
 
I would land, get fuel and check to see if there has been any weather trend. (IE: Are forecast ceilings going up or down?)
If there is comfortable clearance to go under the 5k ceiling (IE not crossing mountains at 4500ft) then I would take this route.

This is typical flying IFR up in Michigan during the winter in non FIKI plane when coming back home from the south. When there is Icing, clouds and the ceilings are holding at 2000 or greater its not too bad. I always pickup flight following, go VFR, and never do this at night so I have good ground contact.
 
As others have noted, there is definitely not enough information in the question to make an intelligent decision.
 
As others have noted, there is definitely not enough information in the question to make an intelligent decision.

There's often not enough information in real life, either. But sometimes you have to make a decision anyway.
 
There's often not enough information in real life, either. But sometimes you have to make a decision anyway.

As a pilot, it is your duty to obtain as much information, both before and during the flight, as possible. The OP has failed to provide the minimum necessary that any prudent IFR pilot would and should obtain. Making decisions without information is a last resort, often followed by bad results.
 
As a pilot, it is your duty to obtain as much information, both before and during the flight, as possible. The OP has failed to provide the minimum necessary that any prudent IFR pilot would and should obtain. Making decisions without information is a last resort, often followed by bad results.

Sheesh, it was just a chat board post.

The OP was not regurgitating an entire weather briefing. That would make a tiresome post.

He said that at departure, the icy clouds were scattered at the destination and forecast to remain so. But sometimes forecasts are off, and that was the case here, when nearing the destination. So he has to make a decision.

Personally, given the equipment and terrain, I would not have chosen to launch, betting that (1) the icing airmet would be no factor due to scattered clouds remaining as forecast at destination, and (2) that the forecast 'out' would remain good. However, some pilot could do so, and then be forced to make a decision, just as the OP posed. I think it's a good OP.
 
Sheesh, it was just a chat board post.

The OP was not regurgitating an entire weather briefing. That would make a tiresome post.

He said that at departure, the icy clouds were scattered at the destination and forecast to remain so. But sometimes forecasts are off, and that was the case here, when nearing the destination. So he has to make a decision.

Personally, given the equipment and terrain, I would not have chosen to launch, betting that (1) the icing airmet would be no factor due to scattered clouds remaining as forecast at destination, and (2) that the forecast 'out' would remain good. However, some pilot could do so, and then be forced to make a decision, just as the OP posed. I think it's a good OP.

If you bet it's no factor, then why not launch?
And perhaps you are missing my point.
I don't expect the OP to provide us with reams of weather data. What is needed in flying, and even more so in IFR flying, is learning to select and focus on the critical information. In this case, we don't have it. For example, what is the alternate? How far? What weather? Terrain?
And by "alternate" I don't necessarily mean the filed one, but the one that is your "plan B" (which may get updated throughout the flight).
Also, as others mentioned, how thick is this overcast layer? Descending through a thin (<1000') layer with possible ice with good shedding expected below is not a big deal (unless it's freezing rain, but then you'd know if that's even possible based on your preflight preparation and inflight updates).
And also as others mentioned, get PIREPs. Are others experiencing icing? If so, what type aircraft, how much and what kind?
Bottom line: keep yourself fully and constantly informed, before and during the flight. Don't gloss over details, esp. critical ones. If that attitude is not etched into your personality, you might want to stick to VFR.
 
If terrain were no factor, I would probably turn around, land, get fuel, and continue VFR under the deck. But given that this is a mountainous area, no way. I'm in the land and wait for the weather to clear camp.

It's good to see though, that so far, no one has chosen to take the approach. If I'm above the freezing level, no way am I going to take an approach through the clouds. If it's a thin layer, maybe I'll take a quick letdown to VFR conditions underneath. But 5000 feet worth of potential icing?* And with the MEA in the soup? Nope, no way.

*I'm assuming that the layer extends from 15k down to 10k, coinciding with the icing airmet. This is not necessarily the case, of course, but without that assumption, there really isn't enough information to answer the question (as others have said as well).
 
Sheesh, it was just a chat board post.

The OP was not regurgitating an entire weather briefing. That would make a tiresome post.

He said that at departure, the icy clouds were scattered at the destination and forecast to remain so. But sometimes forecasts are off, and that was the case here, when nearing the destination. So he has to make a decision.

Personally, given the equipment and terrain, I would not have chosen to launch, betting that (1) the icing airmet would be no factor due to scattered clouds remaining as forecast at destination, and (2) that the forecast 'out' would remain good. However, some pilot could do so, and then be forced to make a decision, just as the OP posed. I think it's a good OP.

OP Here:
Yes, that is sort of my point - things change after hours into a flight. I'm just imagining such a scenario what others have done or would do based on their experience. To add to the scenario, ground level is about 3K in a relatively wide valley surrounded by mountains. A 5K ceiling would mean that the base of the clouds would be near 8K, and the freezing level beginning at 10K. With tops at 15K, that should make a 7K thickness, with 5K possible icing. Once cleared for the approach, one could drop to below the icing level in under 5 minutes and into clear air in 7 minutes. The scenario is not just forecast, but actual you would observe at the 100 mile out point, clear air turning to clouds under you. At that point, you decide to either land, or cancel and drop down and go underneath and add another 50 miles, or continue on expecting scattered over the valley. If you decided to continue on, and it turned out different than expected, then that is what this decision is about.

It would not be an emergency because one would have enough fuel to turn back to clear conditions. So, this would be more of a get-there-itis condition, which we all know to watch out for. Just wondering how many would choose the get-there-itis route rather than go back and delay a couple or more hours. I'm not trying to promote one way or the other, just looking for others decision rationale.
 
I would not descend though 5K's worth of possible ice in non-FIKI, unless I had very good reason to believe there is no ice in it, e.g. PIREP (fresh, same path, similar aircraft), and even then I'd be extra alert.
In general I won't launch if my destination would require going through possible ice. With modern tools, I like to see all white along my route on this site (on the SLD lines): http://www.aviationweather.gov/adds/icing/icingnav
 
Last edited:
Mountains, ice, IMC, single, non-FIKI...

And an MEA 5K higher than the bases?

You're already past my normal limits right at the start.

But to add to the chorus of information people are adding, I'll say, "What happens if something stupid closes the valley airport and you've already descended through the ice?"

Now you're in a lovely big fat valley with an overcast above full of ice, and nowhere to go, and an hour or so from declaring an emergency and landing wherever on the airport -- grass, partially fouled runway, whatever depending on what closed it...

Big fat NOPE for me.
 
snip...

But to add to the chorus of information people are adding, I'll say, "What happens if something stupid closes the valley airport and you've already descended through the ice?"

I guess what I didn't include in the information is that within the 70 mile long 20 mile wide valley, there are 4 paved airports, plus one class D airport, plus a few grass strip airports. They are spread out enough that the weather is not the same at each, but close enough, that any one is a suitable alternate. That said, I understand all the concerns you raised. Thank you...
 
I guess what I didn't include in the information is that within the 70 mile long 20 mile wide valley, there are 4 paved airports, plus one class D airport, plus a few grass strip airports. They are spread out enough that the weather is not the same at each, but close enough, that any one is a suitable alternate. That said, I understand all the concerns you raised. Thank you...
If you've ever been single engine above a cloud layer over the mountains then you've already thought about this and made your decision.
 
'Destination valley, 5k' ceilings'? If it truly is a valley without higher terrain to the destination how about getting under that ceiling and pressing on?

Maybe you have to backtrack a bit or find a hole. Just keep an airport in your back pocket on the way to your ultimate destination. There is plenty of room under that ceiling, providing you don't try to squeeze through a mountain pass.

Once you land, and all was safe, minimum of 3 beers.
 
I voted "Other" because there are always more than a couple options :). What about your alternate? Ask ATC where there's VFR weather around you. Check your in-flight weather if you have it, or call up FSS.

Doing the approach through icing and "hoping" it will be a success is just silly in a non-FIKI plane. There's an accident study on AOPA where a guy "hoped for the best" inbound to a field, tried climbing out the icing, etc and ended up killing himself.

Ice is no joke. As a last option if I can't make my alternate or get anywhere close to the field without going through icing, yeah I'd turn around.
 
Decending into icy clouds at high altitudes in mountains? NO
Scud running under low clouds in mountain valleys? NO
Turning around and landing at a VFR airport? YES
 
I certainly wouldn't descend through a 5000' thick overcast in icing conditions. If I were familiar with the valley and comfortable with the width, other obstructions, and confident the ceiling/visibility wasn't going to get any worse, I don't see why VFR underneath would be a problem. 5000' is a pretty high overcast.
 
IF the destination is in a valley and IF there is no terrain between the nearest VFR behind me and there, and IF I'm comfortable with the width of the valley to allow a 180 in case the weather changes, then my decision might be different, I have to admit that. But those are a lot of IFs, and the second one was not satisfied by the conditions in the OP.
 
I would avoid descending through visible moisture until you temps are above 0. If there is an iced layer between you and 10k I would divert or if my equipment allows, find a place to descend below 10k out free of moisture. If you are seeing clouds up ahead in the freezing levels, you should probably descend before getting to them, tell ATC what you need. They will accommodate you even if that means putting you in a hold. If the terrain doesn't let you go below the freezing level, you need to divert. Under no circumstance should you descend through an icing layer.
 
... non-FIKI aircraft. ... icing airmet ... between 10K to 15K. MEA for the area is 13K.

Possible icing at the MEA in a non-FIKI aircraft. Land short without questioning it IF I even left home.

Maybe I could make it, but "maybe" implies a guess about the successful outcome of the flight. I'm not into guessing about living longer.
 
Here is the scenerio - You are on a 600NM flight in a Turbo C-182m non-FIKI aircraft. You filed IFR and departed through clouds for less than the first 50 miles. You are in clear skies until the last 100NM of your destination, of which is over mountain terrain. There is an icing airmet over that last 100 mile area for between 10K to 15K. MEA for the area is 13K. Approach chart IAF begins at 8K. You are cruising at 17K and 100 miles out, you can clearly determine that you will be on top of any clouds. You are expecting scattered clouds in the destination valley and that is what was observed when you departed a couple hours prior. So, you continue on, expecting to cancel and drop down through the open areas when you reach the valley area. And, you expect to have enough fuel for an extra 2 hours.

But, when you get there, you find that all that scattered turned into an overcast with a 5k ceiling, freezing level at 10K. At this point, what decision would you make:

1) Take the approach, and coordinate with ATC to drop through 15K to 8K as quickly as practical., or
2) Turn around and go back the 100 miles cancel IFR, land and get fuel, then continue VFR under the ceiling through a valley route., or
3) Turn around land and wait for better conditions., or
4) Other

So I'm 100 miles out, destination is worse than expected, I have fuel for an extra two hours (from decision point, or beyond destination?), but I'll need to pass through potential icing and hope that the 5k ceiling doesn't become a .5k ceiling that I have to climb back into?

Due to the limitation of the equipment, I'm not going to try to complete the flight as planned. I'll consider the VFR option if I have an updated weather briefing, good daylight, and airports or landing areas that I can divert to if the weather gets worse.
 
I've had a similar choice over the flatlands. I went to a VFR airport. The cloud deck was thinner and another pilot reported picking up ice on the approach. The ceiling was about 700' as I recall. Anyway, I my choice worked for me.

Anyway, I've always avoided flying in clouds in the mountains. Over them or under them or even beside them. One time I flew to New Mexico to avoid the clouds on a trip from Denver, CO to Alamosa, CO.

Perhaps a more realistic scenario is scattered rain showers and sub-freezing air temperatures. Would you fly through the shower that is near the approach end of the runway? You can see through the shower and it appears to have snow mixed with the rain.
 
OP Here... Well, yesterday, I came close to just about the scenario I described. IFR flight plan, clear skies most of the way, and as I got to within 150 miles or so, I started running into scattered clouds. My foreflight weather at the class D airport in the destination valley showed clear skies, but 65 minutes old. But, my NexRad weather showed non-precipitating clouds in the area. So, I called FSS to double check. The class D airport now showed overcast 7K with icing airmets. That was enough, and I diverted to my plan B which was to cancel, descend and continue VFR underneath... Interesting responses.:)
 
OP Here... Well, yesterday, I came close to just about the scenario I described. IFR flight plan, clear skies most of the way, and as I got to within 150 miles or so, I started running into scattered clouds. My foreflight weather at the class D airport in the destination valley showed clear skies, but 65 minutes old. But, my NexRad weather showed non-precipitating clouds in the area. So, I called FSS to double check. The class D airport now showed overcast 7K with icing airmets. That was enough, and I diverted to my plan B which was to cancel, descend and continue VFR underneath... Interesting responses.:)

What you did here seems quite reasonable.
 
As a pilot, it is your duty to obtain as much information, both before and during the flight, as possible. The OP has failed to provide the minimum necessary that any prudent IFR pilot would and should obtain. Making decisions without information is a last resort, often followed by bad results.

You must not fly much if you'll only consider flying with perfect knowledge of what's in front of you. This is not to say that one shouldn't seek as much info upon which to base a decision, but sometimes you got what you got, not what you would want. Circumstances, equipment, experience, available outs, etc. all go into risk management. If my info is less than perfect, it affects my go/no decision but it doesn't automatically ground me.
 
OP Here... Well, yesterday, I came close to just about the scenario I described. IFR flight plan, clear skies most of the way, and as I got to within 150 miles or so, I started running into scattered clouds. My foreflight weather at the class D airport in the destination valley showed clear skies, but 65 minutes old. But, my NexRad weather showed non-precipitating clouds in the area. So, I called FSS to double check. The class D airport now showed overcast 7K with icing airmets. That was enough, and I diverted to my plan B which was to cancel, descend and continue VFR underneath... Interesting responses.:)

Textbook example of risk management. Good on ya.
 
You must not fly much if you'll only consider flying with perfect knowledge of what's in front of you. This is not to say that one shouldn't seek as much info upon which to base a decision, but sometimes you got what you got, not what you would want. Circumstances, equipment, experience, available outs, etc. all go into risk management. If my info is less than perfect, it affects my go/no decision but it doesn't automatically ground me.

I am not sure about you, but I do fly a lot, much of it IFR/IMC, with more icing encounters (in non-FIKI single engine) than I'd like to remember. And I am not sure where I said that we have or need "perfect knowledge". We never do, of course, but we strive to get as much as we can, constantly, and that's what flying is all about, especially IFR/IMC.
In this case in point, the context was that OP told us something vague about needing to descend through possible icing, without providing any details. In real life in that situation you'd try to get from ATC and other pilots in the area, as well as on-board tools such as ADS-B, the cloud layers, thickness of the icing band (if any), etc. You'd also have a fair idea about these things from before launch. None of that was in the OP's scenario, so to me that indicated a lack of experience.
Sure, in a pinch, you might lose all electricals and/or radios and whatnot and need to make an emergency descent, but if you keep updating yourself, you'd at least have some general idea of what's ahead when that happens. But OP didn't mention emergency, only a normal situation, and for that you want normal data points.
 
Last edited:
Back
Top