IFR Go-NoGo, Non FIKI and Icing forcast

[skidoo]

So, here is a scenario I am wondering how many IFR pilots with a non-FIKI aircraft would choose to make a GO decision and get the most utility out the plane, and how many would not. But, more importantly, why you would make your decision.

Say you have a 300nm trip planned

Departure airport is overcast, perhaps 4K, visibility >10.
Destination airport is clear below 12K, visibility >10.
Destination forecast is broken 15K, visibility >6.

There are No valid icing AIRMETS even close to the route of flight.
But, the icing forcast shows that in the departure area, there is up to 25% probability if a trace to light icing between 9K and 12K MSL.
Due to surrounding terrain and the departure overcast, you decide that VFR is not on option. So, you would plan to climb to 13K or higher where the forecast is no icing for the entire route. Also, there are MEA's at 13K. Departure temp is about +3C and 3K MSL.

Would you choose to GO or Not Go, and what is the main reason for your decision?

If you chose to Go, would your decision be any different if the forecast probability was up to 50% instead of 25%?

 

[flyingron]

You have a forecast of icing in the departure area.
You have freezing levels in the clouds at altitudes you'll be flying (at least transiently) in.
No go in a non-FIKI ship to me.

I'm not sure I understand NO vote options, but for me the flight is ill-advised (and illegal) for the above reasons.

At 4000 AGL and improving ceilings, I'd be inclined to remain VFR unless there's some intervening terrain.

 

[jordane93]

if there is icing in the forecast there is no way im going in a non fiki airplane. i never try to force a flight. its cliche but definitely the phrase better safe than sorry applies here.

 

[poadeleted20]

If there's icing forecast at the altitudes at which I'll be flying, it's a "no go", and it sounds like you're saying such is forecast. I'm certainly not going to try climbing through 3000 feet of icing in a non-FIKI airplane.

 

[Immelman]

Need more info. You can't go VFR? A 4K ceiling will let you do an awful lot except in a few key mountainous areas.

 

[skidoo]

If there's icing forecast at the altitudes at which I'll be flying, it's a "no go", and it sounds like you're saying such is forecast. I'm certainly not going to try climbing through 3000 feet of icing in a non-FIKI airplane.

What I am saying is that the "forecast" is less than 25% probability of encountering a trace or light icing in that 3k feet levels. It is not "Known" there is icing, and there are no Pireps of icing anywhere along the route. The only Known, is there are clouds to go through and temps are below freezing. This applies only about 50 miles in the departure area. Destination has forecast no icing probability. I would expect to be in the clear for cruise...

I also forgot to add, that the airplane is turbo, can climb at 1000 fpm at those levels. So, the potential exposure would be 3 minutes or less. Should it be worse than expected, one should be able to come back down and return the the departure airport with relatively high ceilings...

 

[skidoo]

Need more info. You can't go VFR? A 4K ceiling will let you do an awful lot except in a few key mountainous areas.

Yes, I am dealing with mountainous areas, and trying to determine my limits of utility...

 

[poadeleted20]

What I am saying is that the "forecast" is less than 25% probability of encountering a trace or light icing in that 3k feet levels. It is not "Known" there is icing, and there are no Pireps of icing anywhere along the route.

It is not "known icing," but it is a forecast of known icing conditions, and that triggers the regulations. See the Bell letter for more on the difference. The question is not whether icing is known to be occurring, but rather whether "a reasonable pilot would expect a substantial likelihood of formation of ice on the aircraft based on all information available to the pilot." I think the forecast of a 25% probability of icing constitutes a "substantial likelihood of formation of ice on the aircraft," and would not launch without more information suggesting otherwise. Lacking that information, I'm not going.

The only Known, is there are clouds to go through and temps are below freezing.

You also know of a forecast of icing to be occurring during climb -- for quite a while, in fact, as you're not going to be climbing that fast from 9000 to 12000.

This applies only about 50 miles in the departure area. Destination has forecast no icing probability. I would expect to be in the clear for cruise...

The problem is getting to cruise altitude. Essentially, you're saying it's OK to risk a 25% chance of picking up ice in the climb. Based on the Bell letter, I don't think the FAA agrees.

I also forgot to add, that the airplane is turbo, can climb at 1000 fpm at those levels. So, the potential exposure would be 3 minutes or less. Should it be worse than expected, one should be able to come back down and return the the departure airport with relatively high ceilings...

Well, you can certainly make that argument. It might even hold up. I'd also be looking to see how solid the layer was, and whether I could dodge the clouds in the climb -- that might be something I'd do, especially if it was only around 50% coverage. But do not confuse "known icing" with the rules regarding "known icing conditions," which is another term with a different definition. The regulations prohibit non-FIKI airplanes from flying into known icing conditions, not just known icing.

 

[Henning]

Sure you can't make it out VFR? If I had to go IFR and had surrounding bad terrain, I would ask for a climb in a hold near the airport until I got above. That way I have an 'out' below me until in safe air.

 

[rbridges]

You have a forecast of icing in the departure area.
You have freezing levels in the clouds at altitudes you'll be flying (at least transiently) in.
No go in a non-FIKI ship to me.

it's better to drive to your destination and ***** about not flying than be dead and not able to *****.

 

[comanchepilot]

belaboring for a moment the fact that there are icing forecasts up in clear conditions, icing forecasts for post frontal clouds which rarely have icing, and icing forecast essentially from about now until April in most of the country north of 36N . . . how are you going to get any flying done?

The Go No-Go is alot more complex - if I absolutely positively need to be someplace in the morning and there is a decent shot at ice at an altitude I'll be at and no place I can go to get out of it - I'll drive.

If I have schedule flexibility and an out - taking a look and turning around at the first sign - sure.

What about a situation where tops are gonna be around 9-10, bases at 5-6, [rocks to 6 and 7 k preventing VFR underneath] ZR level at the base of the clouds - they are all enroute - with CLR forecast and actually present at both ends - so you go above them - and there are a few areas of build-ups higher than 10k that have light rime in them - you go around most of them but catch one or two and pick up some very light rime - punch out into the clear and fly the next 30 min with light rime cause it takes a while to sublimate.

Is that illegal? You have forecast and likely ice under you - but unless something bad happens - you will never enter those clouds and only inadvertently pick some up - do you go then?

 

[midlifeflyer]

I can appreciate Comanche Pilots' comment. Kind of like "moderate turbulence" airmets in the mountain west that show up in the most benign conditions. At the same time, in a non-FIKI, the potential for a climb through 3,000' of even light icing conditions gives me a lot of pause. So my initial reaction, like others, is "No way; not today."

But...

Especially given the relatively small stated percentage of trace to light icing probability, I would like to drill down a bit more before making a decision. What are the forecast depressions in the climb? Where are the forecast cloud layers? Are there temperature inversions and if so, where? Are there options to depart earlier or later in the day or in a direction a bit out of my way for the climb that will mitigate or eliminate exposure?

I care much less about the technical regulatory issues of whether this is "known icing conditions" than I am in attempting to understand the real risk involved as best I can and keeping it acceptable parameters.

 

[Jeff K]

The regulations prohibit non-FIKI airplanes from flying into known icing conditions, not just known icing.

Is "FIKI" just a shorthand here? I'm flying an airplane that isn't certified for flight into known icing, yet if I have particular equipment (I do) the POH/AFM allows flight into icing conditions. I think the language got changed sometime in the early 70's (mines a 1965 Piper Aztec with boots, hotplate, heated props/pitot and dual alternator/vacuum).

However, even with FIKI you only should use it to go through layers... never cruise in layers.

 

[Henning]

Is "FIKI" just a shorthand here? I'm flying an airplane that isn't certified for flight into known icing, yet if I have particular equipment (I do) the POH/AFM allows flight into icing conditions. I think the language got changed sometime in the early 70's (mines a 1965 Piper Aztec with boots, hotplate, heated props/pitot and dual alternator/vacuum).

It used to be called K-Ice.

 

[poadeleted20]

Is "FIKI" just a shorthand here?

Yes. It is generally used to mean an airplane which is certified for Flight Into Known Icing conditions. See your AFM or other limitations documents for whether your plane is or is not, including what conditions are attached to that certification.

I'm flying an airplane that isn't certified for flight into known icing, yet if I have particular equipment (I do) the POH/AFM allows flight into icing conditions. I think the language got changed sometime in the early 70's (mines a 1965 Piper Aztec with boots, hotplate, heated props/pitot and dual alternator/vacuum).

If the AFM allows that with that equipment installed, then the aircraft is certified for flight into known icing conditions when that equipment is installed and operating. Otherwise, it is not.

However, even with FIKI you only should use it to go through layers... never cruise in layers.

Good, prudent thinking. Of course, if you're flying something with turbine engines and hot wings/etc, you're a lot better off than a piston-powered plane with boots. Know the capabilities and limitations of your equipment, and remember that even FIKI covers only up to moderate icing (the definition of severe icing being "The rate of accumulation is such that deicing/anti-icing equipment fails to reduce or control the hazard. Immediate flight diversion is necessary.")

 

[skidoo]

belaboring for a moment the fact that there are icing forecasts up in clear conditions, icing forecasts for post frontal clouds which rarely have icing, and icing forecast essentially from about now until April in most of the country north of 36N . . . how are you going to get any flying done?

The Go No-Go is alot more complex - if I absolutely positively need to be someplace in the morning and there is a decent shot at ice at an altitude I'll be at and no place I can go to get out of it - I'll drive.

If I have schedule flexibility and an out - taking a look and turning around at the first sign - sure.

What about a situation where tops are gonna be around 9-10, bases at 5-6, [rocks to 6 and 7 k preventing VFR underneath] ZR level at the base of the clouds - they are all enroute - with CLR forecast and actually present at both ends - so you go above them - and there are a few areas of build-ups higher than 10k that have light rime in them - you go around most of them but catch one or two and pick up some very light rime - punch out into the clear and fly the next 30 min with light rime cause it takes a while to sublimate.

Is that illegal? You have forecast and likely ice under you - but unless something bad happens - you will never enter those clouds and only inadvertently pick some up - do you go then?

Yes... I was looking at the weather and forecast issued this morning, looking at Kalispell to Bozeman. I should have copied the images to post. It has changed now... of course. An as you mention, it seems to at least have some probability of trace or light icing a lot of the time here...

 

[comanchepilot]

I think you misunderstood me - I was not talking about climbing through 3000' of frozen clouds - I said CLR at both ends and ice in the middle . . . .

But there are icing airmets all the time even on days with forecast clear skies becasue somewhere - there is a cloud. . . ..

 

[Bill Watson]

I think Commanche Pilot got it right; go no-go decisions can be a lot more complex.

Here's a flight from earlier this year that I wrote up that has a lot real world stuff in it. The thread was started by Bryon - Aztec Driver and the subject was the stationary front on 3/17/13.

The biggest decision involved going a full day early which not only gave me a weather window, but also gave me the option to drive the next day to attend a must attend event. Was the flight well advised? It worked out.

Late to the party, and the great thread, but have to share.

I flew on the 17th - Home (near KRDU) to KIPT for Lycoming engine school.
http://flightaware.com/live/flight/N215TG/history/20130317/1500Z/8NC8/KIPT
Back story is that I need to be there for an 8am class on the 19th. Plan was to arrive on the 18th. The weather was clearly going to be no-go on the 18th but the 17th looked possible. I really didn't want to drive my 1985 mini-van up there and screw up several side trips so I was motivated.

Even though I used to look at skew-Ts back in my glider days I can't decipher them now. But the icing airmet was for for 8,000 and above even though freezing temps reached lower. It also mentioned ice associated with any convective areas. Ceilings along the route were in the 800' and up range. My plan was to try it around midday but when I looked carefully at all the weather resources, an early start looked like it would match up with a weak spot in the stationary front. I was prepared to turn around and go home knowing I could time to drive up on the 18th. It was worth a go and a look.

I filed for 5,000 and got in the soup at 2,000. It was 34F and all was good until reaching the front. I was nicely lined up with what looked like it's thinnest part per Nexrad but there looked like there was a weak but discernible convective area embedded in it more or less on my course. I also noticed that outside the Nexrad green/yellow areas, the moisture was sparse enough to occasionally see around. There even seemed to be a clearer layer just above my altitude. I talked to FSS, made a Pirep but didn't get any help.

On one hand, I could plunge ahead at 5,000 and 34F counting on the temp to stay above freezing. But glimpses of a clear layer above along with the "ice in convective areas" forecast gave me a plan. I requested a climb to 7,000 and a 20 degree deviation to the west for weather. The controller seemed puzzled because he probably wasn't seeing anything meaningful and he was aware that there was ice above. Maybe he was just wondering why an experimental RV was droning around in a stationary front in the first place.

As I climbed, the temperature dropped to below freezing as expected and I started picking up some very light rime. But as I approached 7,000, there was a 'clear' layer, or at least a dry layer with a solid overcast and a lumpy undercast. Even though it was below freezing, I could see that I didn't want to be lower (no visibility at all) and I certainly didn't want to be higher - solid icing there for sure.

I could now see out the window and on Nexrad where the small but distinct convective lump was and I requested deviations to skirt it. When I got close, I started picking up rime again but I could already 'see' that in 10 minutes or so I would be past it. In 15 minutes I broke out into clear with a scattered layer below.

Was making the flight a good decision? Well, it was fun as hell. While I fly with my wife 95% of the time, she didn't fly this particular leg and that was a good thing. She's a great passenger (soloed in gliders) in all conditions but I enjoyed playing the lone strategizer on this one. The best part was making the turn and climb decision based on conditions in the air, and having them work out so well.

I had to hang around Williamsport PA for an extra day but this was a place my Dad used to take us camping and fishing as a kid, so that was nostalgically enjoyable.

To my perverse pleasure, a fellow student in the class arrived late on the 19th. He had traveled from Paris to Williamsport via Phillie. On the 18th, he boarded a plane for the last 20 minute leg from Phillie to Williamsport. They apparently flew a miss at Williamsport and had to return to Phillie to await a flight on the 19th. I think it took him 4 days to make the whole trip!

So, the 18th would not have been possible and the 17th worked like a charm. As a result, I was able to leave the first week of class on Friday and fly down to Pittsburgh to visit my Mom. I flew back on Sunday in time to not see Tiger win the Bayhill because of a rain delay.

After 3 more days of a great class, I flew down to Phillie's KPNE to meet my wife who took the train from NYC. There we hooked up with an elderly but spry cousin and my wife's soon to graduate nephew for lunch. After congratulations and a graduation gift, we had cookies and coffee in Atlantic's FBO before some screwed up clearances and rapid fire vectors over Phillie on the way home to a night grass landing in Durham. (take a close look at the Phillie portion of this plot)
http://flightaware.com/live/flight/N215TG/history/20130327/2300Z/KPNE/8NC8

It could not have been more fun or as productive a couple of weeks done any other way than in our RV10.

 

[skidoo]

I archive some weather data on my website. Which "forecasts" were you using? The Forecast Icing Product or Current Icing Product? Which time were these charts valid?

I was using this one
http://aviationweather.gov/adds/icing/icingnav

and this one
http://aviationweather.gov/products/gairmet/

But valid for Oct 9, I believe 1200 zulu... Today 02:37 PM

 

[skidoo]

What about a situation where tops are gonna be around 9-10, bases at 5-6, [rocks to 6 and 7 k preventing VFR underneath] ZR level at the base of the clouds - they are all enroute - with CLR forecast and actually present at both ends - so you go above them - and there are a few areas of build-ups higher than 10k that have light rime in them - you go around most of them but catch one or two and pick up some very light rime - punch out into the clear and fly the next 30 min with light rime cause it takes a while to sublimate.

I meant yes, that is the type of situation I am looking at/referring to...

 

[bbchien]

I was just in your area. The amount of ice in those pacific overcast clouds is incredible. At one point my boots could barely keep up with it.

Do as you wish, please don't make us read....

 

[skidoo]

Were you looking at the forecast valid at 12Z or the analysis valid at 12Z? If it was the forecast, what hour?

I don't recall the exact time, but it was the current one that was there at about 9 am MST, just before I started this thread... I recall a small blob area in the NW Montana area that had a trace to light icing, 25% between about 9 and 12Kft. It showed no probability of icing above that.

 

[skidoo]

I was just in your area. The amount of ice in those pacific overcast clouds is incredible. At one point my boots could barely keep up with it.

Do as you wish, please don't make us read....

Just curious, was that cruising in the clouds or climbing through? Also, was it in an area where precipitation was occurring? Or are you talking about incredible icing just being in clouds that otherwise doesn't show precipitation? What altitudes, temps did you observe the worst? I am trying to learn as much real world experiences in my area without actually making a serious mistake.

 

[azure]

I voted for the last choice, avoid subfreezing clouds, because it's what I would do in THIS situation though I'm not always that doctrinaire about it. My choice would depend on the type of clouds as well as thickness and the forecast. But with a 3kft layer all below 0C, there's no way I would try to climb through it regardless of the forecast (unless soundings showed it was glaciated).

C-177RG NA, not turbo, and not great climb performance even on the best of days, especially at the altitudes in the OP.

 

[Alexb2000]

I face this exact decision many times a year. I fly out of Taos year round with a lot of icing potential and high MEA's. I almost always go.

First if I didn't fly in those conditions then I wouldn't fly for a lot of the year so dealing with it is just part of the territory. The most important thing is experience dealing with the weather in your area IMO.

I don't know about your exact location but in the Southern Rockies the mountains often disrupt the air enough that a perfect solid wet stratus layer with icing conditions is rare. On those rare days I don't go.

I spend a lot of time physically looking at the conditions more than looking at the computer on those days:

Can I get a glimpse of the tops or get a solid pirep from a departing aircraft? If not it's no go. I never ever trust the forecast in the mountains. I never want to find out the forecasted 3K cloud layer is actually 6K.

Is the cloud layer consistent with a consistent amount of moisture, or are there thin lighter areas or perhaps a small hole? If I look in all directions is one place better than another. I don't care about the DP path as much in these cases because in my area that often puts you into the worst icing in the valley. If I can see a good spot with good VFR underneath then I will chose that place for my climb with a descent back into VFR underneath as my escape plan.

My bird in winter can climb at 1000 FPM at the altitudes you described, only important because knowing your performance in those conditions is critical IMO. Even with that I always level just underneath, let the airspeed build as high as it will go and then start the climb. I often get in excess of 2,000 FPM initially, falling off as I slow. So 3K' of possible icing would take about 2 min to climb through. It's going to take a lot of icing to create a problem in 2 min.

Also, I always have my escape plan worked out. I never plan to fly an approach in icing conditions. I don't go on those days, too much exposure. Instead I want a nice forgiving layer of VFR underneath where I can easily return to the airport visually.

I also 100% make sure ATC knows my plan before I get in the clouds. I often have to climb into class A airspace to top and I pre-negociate an unrestricted climb. In my area ATC can't help you when you are in the valley since they can't see you (or hear you) so everything just takes some more coordination.

Like I said above, there isn't one answer for every place in the country, it takes knowing your local conditions IMO.

 

[bbchien]

Just curious, was that cruising in the clouds or climbing through? Also, was it in an area where precipitation was occurring? Or are you talking about incredible icing just being in clouds that otherwise doesn't show precipitation? What altitudes, temps did you observe the worst? I am trying to learn as much real world experiences in my area without actually making a serious mistake.

Descending for approach, entering a layer from the top. Out of 6,500 for CIPUT (KCOE). I didn't even look at the temp. I was in a hurry to get through, and hurry we did.

When we broke out, I had the "tank commander's view" of the planet.

 

[skidoo]

It's hard to say for sure what specific charts you were viewing. Kind of matters if it was a forecast valid at 15Z or an analysis valid at 15Z. In this particular scenario, timing is also quite important as I'll explain below. If I assume it was the CIP analysis you were viewing at 15Z, the latest analysis would have been valid at 14Z (the 15Z analysis doesn't hit the wire until around 1520Z).

Appears the icing threat began right around 6 to 7,000 feet and ended around 13 to 14,000 feet. Probabilities were generally less than 30 percent around the Kalispell area through that entire layer. Here's the 8,000 ft. analysis that's the "worst" of the altitudes in terms of overall probability.

And the highest intensity of ice was at about 12,000 feet based on the image below.

There were no "official" icing forecasts in the area as shown below by this G-AIRMET snapshot valid at 15Z.



But the real decision maker for me was the infrared satellite image loop which showed a trend that this area of ice was dissipating rather quickly and the reason there wasn't an AIRMET along that route. In the end, I would have flown this route with a high confidence that structural icing would not have been an issue, but may have waited an hour or two before departing (maybe departing at 16Z) to allow the area to completely dissipate.

Thanks Scott... Those charts are close to what I was seeing, but even less area than this one shows. I was thinking of climbing southward and being at 13 or 15 or 17Kft before crossing that high intensity area (where it dissappears at those altitudes) and then turning SouthEast.

 

[skidoo]

Descending for approach, entering a layer from the top. Out of 6,500 for CIPUT (KCOE). I didn't even look at the temp. I was in a hurry to get through, and hurry we did.

When we broke out, I had the "tank commander's view" of the planet.

Wat this on Oct 9th? How did this turn out relative to the forecast? In other words, at the time of your flight, were you expecting a high probability or high intensity of ice?

 

[skidoo]

Well, I was planning a trip for today (10/11) and return on Sunday. The icing forecast was more widespread than a few days ago when I started the thread. And, I still thought I could find a way to make it today. But, I decided to drive because it wasn't looking good for Sunday's return trip. So, the whole driving trip, what do I see in the sky except for blue and less than 5% clouds. Wow, an easy VFR or IFR trip. It is things like this that make me want to push the limits more. But, I worry about sometime being wrong the other way...

So, how about when there are no icing airmets, and the forecast shows no icing probabilities, but there are some clouds to fly through that is below freezing. Do you consider flying though it? Say you get 1500 ft climbing through a layer, see some blueness above and notice a trace of ice. Do you continue climbing expecting clear above, or immediately request a return and decent?

 

[comanchepilot]

If its VFR you are not pushing your limits at all

 

[ChitDisturber]

Played the non-FIKI in ice game (non-forecast on a x-country), I would never knowingly put myself into that!

 

[comanchepilot]

There are two kinds of Non-Fiki IFR pilots- those who have gotten ice, expected or not, and those who lie about it.

 

[0luke1]

I'm curious tot hear some opinions: What if you have non-FIKI TKS and it's a 25% forecast?

 

[Computerjim]

Descending for approach, entering a layer from the top. Out of 6,500 for CIPUT (KCOE). I didn't even look at the temp. I was in a hurry to get through, and hurry we did.

When we broke out, I had the "tank commander's view" of the planet.

I based at KCOE for about 10 years in the 80's. At that time I was traveling the Northwest in a 250 Comanche. One of my most interesting approaches there was an ILS into a 300'/3/4 mile under cast one winter day. At the outer market it was severe clear, but about 30 seconds after entering the cloud (fog) it was obvious that we were committed to the approach because the ice came on so quickly that a climb was probably not possible. Lots of power, no flaps and got the ground at 400'. It was cold enough (-10F) that nothing should have stuck. My car windshield iced up on the short dive home.

 

[kgruber]

No wonder you moved to Florida.