forward vis in ice

…edited…Assuming that something went really, really wrong … with apologies to anyone it happened to… and coated the windshield of an SR20 with ice – and then had no choice but to land with it loaded, how would that person see outside to land?

I read in the POH that the door open procedure was not a big deal – it would remain open 1 to 3 inches. However, if you needed to push it open wide enough to look outside I would very strongly suspect that would have a major effect.

My one icing encounter in an SR20 leads me to believe that it wouldn’t matter. By the time the windshield was coated it wouldn’t be flying anyway (10KIAS drop with just a dusting of rime).

Thanks,
Robert

In reply to:


Assuming that somebody really, really screwed up and coated the windshield of an SR20 with ice – and then had no choice but to land with it loaded, how would that person see outside to land?

I read in the POH that the door open procedure was not a big deal – it would remain open 1 to 3 inches. However, if you needed to push it open wide enough to look outside I would very strongly suspect that would have a major effect.

My one icing encounter in an SR20 leads me to believe that it wouldn’t matter. By the time the windshield was coated it wouldn’t be flying anyway (10KIAS drop with just a dusting of rime).


Robert,
I can answer this one from experience. Unfortunate that I had the experience, and fortunate that I’m still here to talk about it.
It’s not necessary to have “really, really screwed up” to be in that situation – in my case, the temperature was thought to be too cold for icing at -17C… and the air too dry – so neither cloud nor ice was forecast (no airmet for icing). However, there WAS cloud, and in the brief time that I was in it, my windshield DID flash over with a layer of ice.
That points up the second thing that is actually a misconception: “By the time the windshield was coated it wouldn’t be flying anyway (10KIAS drop with just a dusting of rime.)”. The airplane was flying just fine. But I had no visibility with which to land.

I don’t have time at the moment, but I’ll come back and post the whole story (which I orignally post on the Members forum). For now, I’ll say this much: I don’t believe it’s possible to land with NO forward visibility. If it had come to it, I’d have asked for a vector to an open area, and used the CAPS.

  • Mike.

One technique would be to forward slip to the runway, looking out the side window to line up, and kick it out at the last second, using the view out the side to stay on the asphalt. Of course, this only works if your side windows are clear. I’d hate to have to do this without having practiced it.

-Mike

Robert,

I don’t have as much experience as Sir Michael has with windscreen icing, however, I’d use a technique used by taildraggers taxiing on the ground. In a conventional gear aircraft you can’t see what’s in front of you, but you can if you make gentle turns while on the ground back and forth. Using this technique and as long as the side windows are not iced over you could make a fairly decent visual approach even if your windscreen is completely iced over.

Landing is obviously the hardest part, but once you are doing S-turns you can adjust your descent rate and altitude until you are about 20-30 feet above the runway. At that point, keeping yourself over the runway is just a matter of seeing the edge of the runway now that you are just 20 feet above the runway. It is at that point you revert back to your student pilot days where you would look out the side of the aircraft to do your flare.

I’ve never tried it, but it seems doable.

What percentage of Cirrus are now being equipped with the TKS system?

To me, the TKS adds tremendously to the safety and utility of the aircraft. I can’t imagine ordering a new Cirrus without it. Hopefully, it can be approved for known ice in the future though it always makes the most sense to stay completely away from ice.

By the way, for those who have accidentally gotten into ice with a TKS system, how well does it work on the SR22? I’ve heard nothing but great reports on the system from people I know who have it on 210s, Mooneys and Bonanzas.

Mike:

Please accept my apology. I edited the original post. Please post the rest of the story. I am very interested to hear it!

At Simcom in the PC12 training, you practice a 0/0 ILS approach. Of course in that scenario you presume to be able to see enough to stay on the runway once you thump into it. And CAPS isn’t an option. But at least in the Sim an ILS can get you onto a big runway. I don’t know how that translates to the real world.

-Curt

_I posted the text below on the Members Forum on February 15th. Hard to believe it was less than 5 weeks ago. What a horrible winter this was!
To answer Mike Murdock… yes, a forward slip might make a landing possible; but at the time, I ruled it out because I was not sure how much ice I was carrying (more than I realized, as it later turned out); and I didn’t want to risk an aerodynamic upset close to the ground. The very time a forward slip might save the day, I felt I couldn’t use it.

  • M._

Well, yesterday was another one of those aviation experiences that qualifies as “no big deal” now that it’s over – but if I’d be lying if I suggested that I wasn’t seriously concerned at the time.
I was to do an Angel Flight, taking a patient from Allentown, PA (ABE) to Pittsburgh (AGC). I did much more weather prep than usual the night before - this time, in addition to all my normal sources (COPA CPPP Weather, various other sites, FSS briefing, Weather Channel, etc.), I decided to take advantage of Scott Dennstaedt’s generous offer of a personal tutorial-briefing – something that I found to be very helpful, because it helped a lot of theory come together in my mind (since it was for a real trip).
Scott reviewed various sources with me, and helped me to interpret them. One of the sources was the Skew-T forecast graphs for points along my route at the planned flight times. Among the things I took away from my session with Scott were that (a) the air was going to be pretty dry, and that any cloud would likely be only a thin layer, and (b) that the temps were very cold, certainly below -15C at 6,000’ (my intended altitude). Scott confirmed what I thought, which is that it’s rare (but not impossible) for icing to be a problem at temps south of -15C. I’m sure Scott can/will fill in more detail.
At about 6 a.m. yesterday morning, before launch from home (Allaire/Belmar/Farmingdale/Monmouth / BLM), I checked in with FSS and asked for another briefing. No airmet for icing, VFR weather most of the way, although some mountain obscuration over the Alleghenies, and light snow at Altoona and Johnstown. There was, however, an Airmet for occasional moderate turbulence below 10,000’, and a SIGMET for occasional severe turbulence below 10,000’ (I think) that the briefer advised was for areas south and west of Pittsburgh. I wasn’t too concerned, since I’d be approaching from the east and landing at AGC. Cloud cover was supposed to be thin at various levels, but seemed to average around 5,000’. The wind would be awful for the westbound trip - 45-55 knots in our face the whole way.
My friend Geoff Price and I departed for ABE. Other than the advertised occasional moderate turbulence, our flight was uneventful. On arrival I checked the radar, but not the textual weather reports, where I would have found that the SIGMET for severe turbulence had now moved east of Pittsburgh; although that did not directly affect me later. I also did not turn on my cell phone; if I had, I would may have received a message from Scott, warning me about the SIGMET.
Geoff and I picked up our passenger and our clearance, and launched for AGC. We soon found life very uncomfortable at 6,000’ - more like constant moderate turbulence. We’d heard a commuter report that the turbulence was pretty persistent up to 7,000, but smoother above. I requested 8,000, which was approved. Things were indeed much calmer, although the wind was worse - no surprise there. Mr. Garmin said we’d land at AGC at 1:30 p.m.
At about 1 p.m. I entered cloud, but the OAT was -17C, and so I was fairly sure I wouldn’t find ice; but after perhaps 10 minutes in the cloud, I started wondering whether the milky white I was seeing out the windshield was cloud… or was it frost? Geoff and I discussed it… From my CVR:
M - Mike
G - Geoff
CC - Cleveland Center
Dialog between me and ATC is in italics.
M: I think we’re getting some ice.
G: Minus seventeen?
M: Minus seventeen. It’s unusual.
… (I turned heat to defrost)
M: It’s hard for this to heat the window up when it’s that cold, eh!
… (ATC tells One Charlie Mike that people are getting into Latrobe with no ice on the descent).
M: Problem is, I can’t tell whether I can see out the window or not. I guess I can see only a little bit out the front there. Rest of it’s iced over.
G: Is that ice, or cloud?
M: Ice!
G: Oh, I see it, yes.
G: I wonder we got any on the leading edge?
M: Say again?
G: I wonder we got any on the leading edge?
M: We got some - guaranteed.
G: That’s what I was thinking… if we got it there, we also (drowned out by radio).

M: This could be a real problem. If it doesn’t sublimate off, we won’t be able to land with it.
G: I appreciate that. You’re unreasonable - you want to see where you’re going. It’s definitely ice!
M: Oh yeah.
… (Challenger Five Seven Mike reports that they’re picking up some light rime in the hold at six thousand, requests lower).
M: I don’t know that lower’s going to be better, though. That’s the problem.
G: The only advantage of lower is that you get the outside temperature increase.
M: Ya, but we’ll pick up less ice at minus seventeen than at minus twelve.
G: But I thought you’d have more chance of heating it.
M: Can’t see $$## out the window, eh.

M: I would say we need to do something about this.
G: I’m trying to think WHAT.
M: Let’s see if I can go higher and get it to sublimate off.
M: Angel Flight Four Mike Romeo, our windshield just flash-froze over, and er, what I’d like to do is to climb up and see if we can get this stuff to sublimate off otherwise we won’t be able to land.
CC: Angel Flight Four Mike Romeo, roger, you said you want to climb, sir?
M: That’s affirmative
CC: Angel Flight Four Mike Romeo, climb and maintain niner thousand, let me know if that’s high enough.
M: Roger, will do, we’re out of eight for nine.

G: What we don’t know is what the top of the cloud is.
M: Actually, I don’t even know if we’re in cloud, eh.
G: From the side vision, I reckon we are. The side windows haven’t frozen.
M: Otherwise the other thing we do is turn round and go back that way, uhm, pick up some clear air, and it will sublimate off eventually. I won’t be able to land if I can’t see out the window.
G: I appreciate that.
M: The other thing we can do is to shoot the ILS, and if we don’t see…
G: … overshoot…
M: … head back… only thing is it doesn’t make sense going that way if I’m then going to have a fuel problem going that way. 'Cos I’ve got twenty four gallons - going in that direction we’ll go very far.
(Note: The above made sense if you saw my gestures. Translation: It doesn’t make sense continuing West if I’m then going to have a fuel problem going East. With twenty four gallons (and a strong tailwind), I can go very far East.)
M: I think we need to make another plan, sir. Let’s go back to Harrisburg.

M: And er, Angel Flight Four Mike Romeo, we’re at nine, and it doesn’t look like anything’s happening on our windshield. We’d probably better turn around and head back towards Harrisburg, get a tailwind going, and er, try and land there.
CC: Angel Flight Four Mike Romeo, roger, descend and maintain, er, tell you what, do you want to climb up to ten thousand, sir?
M: Yes, sir, I do.
CC: OK, Angel Flight Four Mike Romeo, climb and maintain ten thousand, and on reaching, oh no, you can turn, right turn, direct Harrisburg, you say you want to land at Middletown?
M: Right turn direct Harrisburg, say again the rest?
CC: And er, you want to land Middletown, is that correct?
M: Haven’t decided that, sir, but sounds like a plan to me.
CC: OK, Angel Flight Four Mike Romeo, cleared direct Middletown via direct, right turn direct Harrisburg direct Middletown, climb and maintain one zero thousand.
M: Right turn direct Harrisburg direct Middletown and we’re out of nine thousand, slowly, for one zero thousand, Four Mike Romeo.
CC: Roger

G: If this doesn’t clear, we’re going to be up here forever!
M: We could have an emergency - a real emergency.
G: I know. I’m well aware of that. There’s no point in me getting upset about it though.
… (One Bravo Papa tells CC: We’re picking up quite a bit of ice at this altitude, so either get us down or get us up. CC tells them they’ll get descent in about 10 seconds, and they do.)
M: I’d say we’re definitely on top now.
M: Do you think the ice is moving forward? (i.e. on the windshield)
G: I think so, but I can’t guarantee it.
… ( I got MDT weather. 5,500 broken, unrestricted viz. )
G: Look at the front.
M: Yeah, it’s starting to clear. But he’s going to need to take me down, and that’s not going to help.
G: I realize that.

M: I think I’m going to ask for lower now. Let’s ask for six, initially.
G: Give me your reasoning?
M: Uhm, well, we’ve gotta get down in order to get there, we’re only twenty five minutes away, we gotta descend anyway, and my hope is that we’ll be below the clouds, they’re reporting five thousand five hundred, maybe I’ll get down to four.
[Just then, we experience a strong engine vibration. I pulled the throttle back immediately, and the vibration stopped. I increased power again slowly, and everything remained smooth.]
M: I think we just shed some ice on the prop.
M: Angel Flight Four Mike Romeo, we’re getting prop icing, we need a descent now, down to initially six thousand.
CC: Angel Flight Four Mike Romeo, descend pilot’s discretion, maintain seven thousand, if you get a clear altitude let me know.
M: OK, down to seven initially, Four Mike Romeo.
G: Is our passenger asleep?
M: Ya. I don’t see any reason to wake her up yet, either, eh?
G: I could give you a couple of reasons not to!
CC: Angel Flight Four Mike Romeo, what kind of icing did you have, sir, and what was the outside temperature?
M: The outside temperature was minus one nine, er, I don’t know that we had icing, we had a vibration, reducing RPM got rid of the vibration, and it seems like a good idea to descend.
CC: Roger.
M: And, er, Four Mike Romeo, we have a different problem, which is that our windshield is all frozen over, we do need to get that sublimated off so that we can land.
CC: You’re just passing Altoona airport there, sir, would you like to land at Altoona?
M: Er, what’s their weather?
CC: Altoona eighteen zero two observation, wind two seven zero at one seven gusting two eight, four miles visibility light snow, two thousand scattered, two thousand seven hundred broken, three thousand five hundred overcast, temperature minus seven, dew point minus one two, altimeter two nine nine four.
M: No, we’ll take Middletown, thank you.
CC: Roger.
… (Geoff notices that the cloud deck below us is patchy, and we can see the ground in the gaps.)
M: Four Mike Romeo, I’d like to descend through the cloud layer as quickly as I can, any chance you can give me four thousand?
CC: Angel Flight Four Mike Romeo, you can descend and maintain er, four thousand six hundred.
M: Four thousand six hundred, Four Mike Romeo, will do.

G: Seems to be improving, Mike.
M: What?
G: Seems to be improving.
M: Yup. Four thousand six hundred, he gave me.

(CC tells Northwest 600, “Be advised there’s sporadic icing, whole lot of altitudes right now, all the way up to ten to eleven thousand… seems to be in the moderate range”.)

M: I’ve almost got enough to land with, eh.
(Referring to clear windshield area).
G: We’re just under the cloud, we need to get down a bit more, eh.
M: Yup.
M: Four Mike Romeo is in and out of the bottoms here at four thousand six hundred, any chance of lower?
CC: I’m going to have lower for you here in… actually, I may have it now, stand by one second… and er, Four Mike Romeo, you can descend and maintain four thousand.
M: Thank you very much, down to four thousand, Four Mike Romeo.

CC: Angel Flight Four Mike Romeo, contact Harrisburg Approach, one two four point one.
M: Twenty four one, Four Mike Romeo

Harrisburg told me to expect a visual landing on RWY 31; I asked for the ILS, because my view out the front was still pretty restricted. However, as time went by at the lower altitudes, the heating very slowly overcame the ice, and soon enough I felt that I could do the visual with no problem. At that point, I decided that a landing at nearby Capital City would make more sense, so I changed destinations and landed there - a completely uneventful visual landing.
After the landing, I told the passenger, “I have good news and bad news”.
She said, “What’s the bad news?”
I said, “You’re not at your destination.”
“Well, where are we?”
“Harrisburg”.
"Harrisburg???"

“Yes.”

She wasn’t asking, so I added… “The good news is, you’re safe.”


After landing (no flap, extra speed), I was amazed at the amount of ice I’d collected. The spinner was almost totally white, there was still some ice on the windshield, and what looked like a thin layer on the leading edge of the wings and tailplane.

The FBO was outstanding - they helped our grumpy passenger to find transportation she was willing to use, and offered to de-ice my airplane gratis. However (and this surprised me), the fellow who did it came back to tell me that the ice was too thick to remove with glycol solution. The manager offered to put the airplane into a heated hangar, and we did that. It didn’t take too long before we were able to slide the ice off the leading edges. At that point, it was about 1/4" thick. The ice on the top (black) portion of the pitot tube was easily 3/4" thick, but there was no ice on the pitot tube itself. I’d switched pitot heat on immediately after takeoff.

I filed for the trip back to BLM, which was fast and uneventful. But when I put the airplane away in my hangar, I found some ice I’d overlooked at Cap City… on the main wheel pants. White on white - difficult to spot.


I can think of lots of things I coulda/shoulda/woulda done differently, starting with taking the opportunity to get a PROPER weather update at Allentown. One other regret is that I didn’t turn my situation into a PIREP, since the stuff was not forecast; I hope that someone else, who was thinking more clearly, did do that.

I filed a NASA ASRS form today.

  • Mike.

Mike:

You never know about that -20 thing. We were at FL180 today (in our Cessna 414) and it was exactly -20 and suddenly we loaded up with rime. Later, on the same trip, we hit IMC that looked much wetter and the temps were just below 0 and we didn’t get any ice. Go figure. [:)]

Robert,
No apology needed!
In fact, now that I’ve “been there, done that”, hopefully I’ve learned a bit more about where/when ice might hide, regardless of what forecasts indicated SHOULD happen. So if I ever did that again, I will really have screwed up. You know - bite me once, and so on.

I’m going to go dig up that post now.

  • Mike.

In reply to:


One technique would be to forward slip to the runway, looking out the side window to line up, and kick it out at the last second, using the view out the side to stay on the asphalt. Of course, this only works if your side windows are clear.


What about using the hammer? Might get breezy, but the window would be very clear!

In reply to:


What about using the hammer? Might get breezy, but the window would be very clear!


Gordon,

There were two good ideas that didn’t occur to me at the time - the hammer was one.

The other was to use a rolled-up jacket/coat/blanket to trap the hot air between the glareshield and the windshield. Since one can’t see out the front anyway with ice there, there’s no loss of visibility, and it might in fact help to hasten the melting. Not sure if it would work when it’s extremely cold, but worth a shot.

If I were to use the hammer, I’d try to make a hole low, just to the right of the center of the windshield. That way I wouldn’t have wind blowing in my face, which might actually make it impossible to see without goggles. I’d try and put a gloved hand through the hole to scrape a saucer-sized area clean in front of me.

  • Mike.

Those are very interesting ideas. I’d be scared, though, that any break in the windshield or side window could lead to the whole window shattering.

You make an excellent point about the forward slip. If there’s any time when airspeed is critical, it’s when you’re carrying ice. Depending on the direction and degree of slip, I believe your indicated airspeed could be way off.

Based on all this, I’d try the jacket over the window first. If that didn’t work, I’d try the slip, keeping the nose well down. Only as a very last resort would I use the hammer.

-Mike

In reply to:


Based on all this, I’d try the jacket over the window first. If that didn’t work, I’d try the slip, keeping the nose well down. Only as a very last resort would I use the hammer.


Mike,
I agree. Assuming I’m not suffering additional ice accretion, I’d try the slip at altitude first, knowing that if anything bad happened I have the CAPS. That would give me a good idea of what speeds work, etc. And if I get to the hammer, and it doesn’t work, my real last resort would be the CAPS anyway.

One interesting aspect of all of this: When this really did happen, I was feeling very calm, and I had the good fortune to have a level-headed, competent friend with me - so we could bounce ideas off each other. Yet the notion of trying out the slip at altitude, or using the hammer, or the coat… none of those occurred to us. This really does underscore the idea that if one doesn’t deal with emergencies in one’s head before leaving the ground, dealing with a real emergency properly is not very likely.

It also underscores how insidious an enemy ice is, and how lucky we really were.

  • Mike.

I just hope I could remain as calm as you and your buddy did in a similar situation. Like they say, a single mistake doesn’t usually kill you. The trick is to break the chain by not making the second and third and … mistake.

I’m a SCUBA diving instructor. We teach people to control incipient panic with these steps:

  1. STOP – quit thrashing around, or trying to fix whatever you are fiddling with.

  2. BREATHE – just getting your breathing under control (slow inhalations and even slower exhalations are the best way) will have a calming effect.

  3. THINK – formulate a plan of action.

  4. ACT – execute the plan.

I think these are pretty good rules for a lot of situations, and you provided a shining example in your handling of a sticky situation.

-Mike

In reply to:


I’ve never tried it, but it seems doable.


Ok who volunteers to be a check pilot for Scott’s first landings under a hood?!

-Curt

Mike,

Thank you so much for posting. I look to your example as Pilot in Command of that situation. It is clear that you made correct decisions for the flight. I hope I have your cool if it ever happens to me.

This brings to mind another question which I will post in a separate thread.

Curt,

I’ve done an approach down to 50 ft under the hood and it is extremely challenging. 100 ft isn’t too bad after you’ve done a few. It’s that transition from 100 to 50 ft that is tough to do consistently.

Scott,

Can you practice the low descents at any ILS airport or do you need a CAT II or CAT III location?

-Curt

Curt,

I normally practice them at an airport with a Cat II approach. The one I normally use is the ILS 10 Cat II approach at Baltimore. However, the real value is being able to do this even with a simple category I approach. In the event of a need to go down to 100 or 50 ft, you may not have the option of a cat II or III ILS. In this case, you can’t trust the glide slope below the DH, so you have to learn to dead reckon the descent once you are below the effective height of the glideslope. This takes some practice (although it is lots of fun).