1 mile vis -SN BLSN temp -09, do you deice on the turn?

wheelsup

Well-Known Member
Serious question - if it was snowing at night with 1 mile visibility, atis reporting (and you seeing) snow falling and blowing across the field akin to a nor'easter, with the temp at -09C, and wind 25G35 would you deice?

I can (kinda) see reasoning for not that's why I'm asking.
 

Alchemy

Well-Known Member
Yes, unless I'm absolutely sure that no snow is adhereing to my critical surfaces. I'd ensure that by doing a tactile check of the critical surfaces during the preflight, and perhaps an optional contamination check from the cabin windows at the hold short just prior to takeoff.

I don't subscribe to the "it'll blow off during the takeoff roll" theory that I read on the Internet form time to time. If it's adhering during preflight or taxi, I don't think you can just assume that it's going to blow off during the takeoff roll. In fact it's even written into our FOM "Pilots may not assume that snow will blow off during takeoff". If it's that cold (-9), I don't see how you wouldn't be accumulating some snow on the wings (although I guess it's possible), and if you're flying a jet without slats, you're especially susceptible to performance degradation.

So I have to say I'd probably de-ice with type I, assuming I could get out of there within the holdover time for -SN, otherwise I'll take some III, or I + IV. They only exception would be if the snow was falling in some way that it wasn't adhereing to the aircraft, or was melting on contact. I don't see how that could happen at -9 though.

Maybe that makes me overly conservative, but that's the way I interpret the rules.
 

Baronman

Well-Known Member
I would say it depends if it's adhering to the wing.

I've seen the conditions that you're talking about (like yesterday) where it was BLSN etc with a -15C temp and deice/antiice was not needed. It was so dry out (low temp/low dp) and the wind so strong that nothing was sticking, the wing looked like the day it came out of the factory. But just my observation is that when the temp starts getting below -10, many times light precip just doesn't stick with high winds.

I do agree that if there is any frozen moisture on the wing at the gate then you must deice, you can't assume it will blow off.

I feel that I'm conservative yet functional. I know some guys that know matter what they're asking for, "Full Body Type 1 and 4." I guess that's the conservative way to do things and that's how they justify it. I think that they're being overly conservative do to a lack of knowledge (most times) and this is a safe way to cover their butts. Fine. Better than being a yahoo.

But the short answer to your question is to go out, look at the wing, and see if it's adhering or just blowing away. Then ask yourself if you see the conditions being different on the taxi out.
 

dc3flyer

Well-Known Member
Does the airplane need de-iced????

It doesn't matter what the presip or the temp or the vis, or even if EVERYBODY else is getting dei-iced. If nothing is sticking to the plane I am not getting de-iced.
 

wheelsup

Well-Known Member
Yes I agree with the above. In addition putting wet fluid on the wing also seems to attract the snow that was really just blowing by the wing. No ice on the airplane at all. Just curious if others wouldn't deice as well.

Also it's sad but you have to wonder how the FAA thinks about it, would they be upset you didn't deice when its snowing like it was yesterday?
 

Baronman

Well-Known Member
This is out of our (XJT) FAA approved Flight Operations Manual .

"Under certain specific conditions, winter precipitation may be falling yet ground icing conditions might not exist. When the aircraft has not had deice and or anti-ice fluids applied and ice and or snow pellets are falling but are not adhering (and are not expected to adhere) to the aircraft's critical surfaces, the crew and or the winter ops coordinator may make a reasoned judgment that the aircraft critical surfaces may be free of contaminants. Crews are advised that refueling with fuel warmer than the wing skin temp may create a condition that previously non-adhering contaminates may adhere to the wing surfaces. "

Again, in no way am I saying be cavalier about ground icing. But the company and the FAA seem to agree with my personal observations that there are circumstances when there is precipitation falling but not adhering to the critical surfaces. I'll usually walk inside the cabin to the wing and check, then either myself or the FO will make another check and be 100% sure that it's not sticking. If I think I may have a lengthy taxi where conditions may deteriorate or lead to a contaminated wing, I deice/anti-ice. But if there is no contamination of the critical surfaces and I forsee us being off the ground in 15 minutes with no change in the conditions, I would go.
 

wheelsup

Well-Known Member
That certainly corresponds with what I was seeing out the window. It's hard for dry blowing snow to stick to anything unless it's outside for an extended time frame. Good find.
 

Nick

Well-Known Member
Serious question - if it was snowing at night with 1 mile visibility, atis reporting (and you seeing) snow falling and blowing across the field akin to a nor'easter, with the temp at -09C, and wind 25G35 would you deice?

I can (kinda) see reasoning for not that's why I'm asking.
I had a similar set of conditions a few days ago.

It was -24C outside and the wind was 26 gusting to 36. About six inches of snow had fallen and it was blowing across the ramp and on the walkaround it was quite obvious that absolutely none of it was adhering to anything because it was too cold and windy to even be able to fall onto anything let alone stick to it.

Additionally, the ATIS had no falling precipitation anyway. It was BLSN 6SM BKN022 OVC060.

Our FOM does go into distinguishing between contamination adhering to the wing and not adhering.

We did not de-ice.
 

Boris Badenov

Just running in to a burning house...
I'm a chicken and we get paid by the minute so yes.
I get paid by the mile, so no.

In all earnestness, though, I think the rules are probably different for 121, but in on-demand 135 stuff (as I understand it), if I conduct a tactile check 5 minutes before I roll, and there's nothing adhering, I'm good to go. If the feds want to get mad at me, it's up to them to prove that there was ice on the plane, which isn't going to happen because if there's ice on the plane I'm getting deiced, because I don't want my certificates growing a set of wings and flying back to OKC.

In your particular example, I'd walk around the airplane, paying special attention to the wing and tailplane. If I don't find any ice, I fire up in a burnin hurry and try to get out before I'm required to check again.
 

JDE

Well-Known Member
I'm a salaried employee, so I don't let pay become a factor in whether or not I'm going to de-ice (not that that should matter in the first place). But to answer the question, I would not de-ice if there was nothing sticking to the airplane. We were in LSE last week when the temps were well below 0 F. We opened the hangar door, let the airplane "cool down" before pulling it onto the ramp so the snow that was falling wouldn't melt on the warmer surface and then freeze. It was a dry snow, so we had zero problems. Started up, taxied out, and took off.
 

BE19Pilot

Well-Known Member
Put Type 4 on the thing and let's go! Just kidding (kinda). Too many variables to consider...But a good call would be to put the type 4 on launch. That decision is based on experience and operating in the Northeast for 5 winters running. Might not adhere at the gate, and it might not stay at-SN. It's an airline, so you do what you can to be safe FIRST, but the object is to attempt to mitigate delays when possible. "deicing" already implies ice adhering or present on critical surface. "deicing" implies that you have a "clean" airplane and want to keep it that way till you are ready for take-off.
 

Pilotforhire587

Lycra Man
After going to AK last year to fly I would agree that deicing will only attract the snow. If the snow is a dry snow and isn't sticking, Don't deice, I am not saying that deicing will make is going to attract snow, but im not taking chances.
 
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