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Yesterday's IFR flight with questions
What a flight I experienced yesterday! Got to do more things I never did
which made for such a wonderful learning experiences and also raised questions in my mind (surprise, surprise!). Really worked over my decision on to launch or not to launch today to fly from 2G2 (Steubenville, OH) to BWG (Bowling Green, KY) to MBO (Madison MS). Was closely watching the weather in Ohio, winds on the ground, winds aloft, clouds and ceilings, freezing level and everything else weather could throw a kink. Called FSS yesterday and this morning, no reports of icing, only airmets for moderate turbulence 10K and below. No TFRs in my route. Cloud tops were forecasted to be 6000. The further south I go, the better the conditions. Headwinds of 40 knots for the first leg, and tail winds of 15 knots for the second leg. The upper winds forecast were just about spot on. 2G2 is an uncontrolled airport. Weather was suppose to be IFR this morning, and I have never left an uncontrolled airport in IFR conditions. This of course required that I call FSS and get an ATC clearance. Every other time I have left an uncontrolled airport, I got my clearance in the air, but today, too much scud floating above my head. Temperature on departure was 43 degrees, with light sleet and rain falling. Figured the decision to leave was good, as somewhere above my head would be warmer weather then freezing temperatures due to the sleet falling. Also, based on radar trends, I knew I would be out of the precipitation within 10 miles. Question 1 at the bottom of this post regarding this situation. Got my ATC clearance from FSS and had to be off the ground in 13 minutes or my clearance was void. Not a problem, as I was the only one in the traffic pattern *smile*. Off I go, entering IMC at 2000 feet (900 feet AGL). I turn on my Pitot tube heat. Rain and sleet was falling, temperature held at 43 degrees entering the clouds. Break out on top at 5500. Final cruise altitude was 6000 (so I thought). Air was silk smooth! The further south I go, the clouds start to slope up hill, and I am more in IMC the further I go. Amazingly, the further south I go, the lower the temperature goes too. About 1 hour into my flight, center calls me and says, Sundowner 1943L, I have a reroute for you, are you ready to copy. I had filed direct, but I still am old fashioned by tuning each VOR in my path to help with my situational awareness. I replied standby, and grab my pen and erasable paper. Center says, you are now cleared direct to York VOR then direct to BWG due to MOA activities. Look on my maps, could not find YRK. Punched NRST on Garmin 296, and York was not listed. Sheepishly, I key up the mike and ask center for the frequency of York VOR. Center graciously gave me the frequency, and I dial it in and start tracking toward the VOR. Since I was in IMC, didn't want to mess around with the GPS, since it did not show on the list of nearest. What concerned me even more, was my DME was not reading a distance. I then called back into center and asked for the distance to the York VOR. They said I had 90 miles to go! Well crap, no wonder I couldn't locate it on the maps, I wasn't looking far enough down the road! This made me feel a little better, as I started wondering if I had lost situational awareness. I was then able to quickly find the YRK VOR on the en route map, and then decided to program my 2 GPS's for the YRK VOR for distance until my DME picked up the signal. I used my NAV1 and NAV2 for tracking, which really was fun to do, since I have not really tracked a VOR en route for some time . Get to the YRK VOR, turn direct to BWG. At this point, I am skimming the tops of the clouds more in then out. In a matter of 10 miles the temperature went from 35 to 25 degrees around this VOR. Watching my wings, see no ice, watching my windscreen, no beads of water or ice so I figured all was well (so I thought). I am still skimming the tops of the clouds, in visible moisture, but not your typical "hard" IMC. A few minutes later, I noticed that I had to sneak in a little more power then normal, which I thought was odd, so I decided lean a little forward to take a peek at the temperature probe. Sure enough there is a small coating of rime ice! I call into center and request to climb to 6,500 due to ice, and center quickly approved giving me a block altitude from 6000 to 7000. Center asked me to report when I climbed out of the clouds and to report when the icing has shedded. Cool I thought, I would stay 500 feet above the clouds and climb when needed. Turned out the clouds were reasonably level, so I was able to maintain level flight at 6,500. When the sun hit the wings, I could clearly see the ice on the leading edges as well as the leading edge of the stabilator. This really alarmed me as I could not see it while in "semi" IMC. I also was shocked how much accumulated in "semi IMC" as it was like wisps of clouds zinging by with some hard IMC interjected. I never really did shed the ice, it kinda evaporated on it's own, as the outside temperature was now down to 18 degrees. I reported to Center that I was out of the clouds and the ice was slowly disappearing. So now here I am on top, solid overcast and wondering just how safe will it be to descend through the cloud deck! (Question 3) Luckily, this never had to be answered as within 10 miles of BWG, the clouds broke up and I was cleared for a visual approach into BWG. I was monitoring any AWOS, ASOS and ATIS en route and found the closer to BWG I got the thinner the clouds got. Question 1 on Sleet. In my case, it was 43 on the ground, and on my climb to my altitude, the temperature remained well above 32 while I was in IMC. I climbed to 6000 which was my designated altitude. I broke out at 5,500. How far up can sleet be created and not melt before hitting the ground? There was a layer of clouds above me. Seems that from the ground to 6000 feet, I came across some hardy sleet pellets to survive that long in above freezing temperatures? Question 2 on icing. Had I not climbed up like I did, I would have never seen the ice on the wings or stabilator. I now know to look on that temperature probe for first signs of icing as I did today, but will it readily show up in IMC without reflections of the sun? Especially clear icing? Where else should I look besides the temperature probem? I have a white plane with blue strips in the wing tips, but I never saw the ice! It truly scared the bejeebers out of me to see the ice on the leading edges, and luckily, I am intimately aware of my plane and it's idiosycrosies that I knew that adding power was not a normal thing for straight and level flight. Question 3 on icing. knowing that flying into known icing is a big no no, (no kidding!). So, here I am on top, evaluating the cloud thickness, and finding that the clouds were generally 1,500 feet thick. Temperatures were dropping, which made me even more nervous about descending. Obviously every situation is different, but what would be a reasonable amount of time for descending into clouds that the temperature appears to be below freezing when the cloud deck is NOT thick. Figuring on 500 feet per minute descent, for me, 1500 feet is rather thick for 3 minutes. I would naturally descend quickly and as safely as possible, but is there a reasonable gauge for getting below a potentially THIN icy cloud deck? Clouds today were widespread all the way down to BWG. When I left, ceilings at BWG were 4200 which would have been a 1800 thick layer of clouds. As forecasted, the clouds broke up, but what if the forecast had busted? It's not like I could dip my wings to see if I get ice or not. Thanks for answering my questions! Allen |
#2
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Yesterday's IFR flight with questions
Was there an airmet for icing? I use this as a guide. If there is an
airmet for icing, and I will be in IMC, I don't go. The airmets are a good guide. That and PIREPS. AS for question 1. Ice can form anytime there is visible moisture and temperatures are at or below freezing. So your question can't be answered. It all depends. You know how the weather is, it is always DIFFERENT! Question 2 seems to be about seeing ice. Well, look. If you can see it, you've got it! If you can't see it and you are in the clouds and its below freezing you MIGHT have it. Clear ice can be smooth or rough. If it looks clear it is clear. If it looks white, it is rime. Rime can be smooth or rough too. And if some is clear and some is rime, then its mixed. Question 3. Cant really answer in a general way. If there is ice in those clouds it will probably accumulate on your airplane. And without deice, there isn't much you can do except fly out of it. Sure you can fly with a little bit of ice. But what if you have to go missed and go back into it? There really isn't any safe way to fly a small GA airplane around in icing conditions without having deice system. Good thing you didn't have a thick layer on decent and approach. You would have really scared yourself then. Sorry to be so negative. We've all gotten ice from time to time. Maybe you should follow me. You won't get any ice, cause it will ALL BE ON MY AIRPLANE!!! Except I don't do that anymore. I'd be back at 2G2 having a soda. No ice. |
#3
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Yesterday's IFR flight with questions
Doug wrote:
: Was there an airmet for icing? I use this as a guide. If there is an : airmet for icing, and I will be in IMC, I don't go. The airmets are a : good guide. That and PIREPS. I would like to add that MEAs have something to do it it in my opinion. I don't have a problem climbing into potentially icing conditions, so long as I know I can get below icing and stay above MEA. Of course that precludes the nastiest of icing (clear, freezing rain), but in a GA spamcan you've gotta have a deathwish to even consider a flight in conditions like that. With a freezing level a few thousand feed above MEA, it's still a possibility. With a known-thin layer and clear above into improving weather, it still a possibility. For the most part, though, I'll agree. Good chance of solid IMC + below freezing temps at MEA or below = no-go. : AS for question 1. Ice can form anytime there is visible moisture and : temperatures are at or below freezing. So your question can't be : answered. It all depends. You know how the weather is, it is always : DIFFERENT! I got icing in VMC at 2000' AGL last Christmas. I thought the tower was kidding when he told me to "let me know if I picked up any ice" while overflying his airport. -Cory -- ************************************************** *********************** * Cory Papenfuss * * Electrical Engineering candidate Ph.D. graduate student * * Virginia Polytechnic Institute and State University * ************************************************** *********************** |
#4
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Yesterday's IFR flight with questions
On Fri, 18 Nov 2005 12:38:32 +0000 (UTC),
Cory I got icing in VMC at 2000' AGL last Christmas. I thought the tower was kidding when he told me to "let me know if I picked up any ice" while overflying his airport. But you must have been flying through visible moisture to pick up ice? I was taught you cannot pick up ice without visible moisture. The wisps of clouds I was flying through would have been considered VMC above the cloud deck. I could see blue skies through the wisps with the occasional IMC encounter before my climb request to Center Allen |
#5
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Yesterday's IFR flight with questions
: But you must have been flying through visible moisture to pick up ice? I
: was taught you cannot pick up ice without visible moisture. Yes, I suppose. It was more like "think air." Visibility about 4 miles, and I was under a heavy overcast. Within 15 minutes it was snowing (and I was just about ready to land at my destination). -Cory -- ************************************************** *********************** * Cory Papenfuss * * Electrical Engineering candidate Ph.D. graduate student * * Virginia Polytechnic Institute and State University * ************************************************** *********************** |
#6
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Yesterday's IFR flight with questions
On 17 Nov 2005 19:54:53 -0800, Doug wrote:
Hi Doug, Was there an airmet for icing? I use this as a guide. If there is an airmet for icing, and I will be in IMC, I don't go. The airmets are a good guide. That and PIREPS. No icing airmets or pireps just departure. I had called FSS 15 minutes before leaving for the airport. If there would have been an airmet for icing in my proposed route, that is an automatic no go for me. AS for question 1. Ice can form anytime there is visible moisture and temperatures are at or below freezing. So your question can't be answered. It all depends. You know how the weather is, it is always DIFFERENT! To clarify my question, on my climb to 6000, the air temp was well above freezing. It was still sleeting on the ground, and I was wondering just how high above my head was the freezing level. I thought it was pretty hardy sleet to remain in ice pellet form for over a 5000 feet fall. Question 2 seems to be about seeing ice. Well, look. If you can see it, you've got it! If you can't see it and you are in the clouds and its below freezing you MIGHT have it. Clear ice can be smooth or rough. If it looks clear it is clear. If it looks white, it is rime. Rime can be smooth or rough too. And if some is clear and some is rime, then its mixed. I think with my plane being white, and nothing "reflective" to see the ice like it was in the sun, it was harder to spot? It was on the temperature probe that I clearly saw the white rime ice. I had looked on the wings for the ice and didn't see it. There really isn't any safe way to fly a small GA airplane around in icing conditions without having deice system. Absolutely agree with this. The weather forecast for my deciding to leave did not have icing, the precip was to end within 10 miles and improving ceilings en route. With the ground temp at 43 degrees, the cold front had passed about 6 hours earlier, I did not expect the temperature to drop above my head, which turned out to be a correct thought. you should follow me. You won't get any ice, cause it will ALL BE ON MY AIRPLANE!!! Except I don't do that anymore. I'd be back at 2G2 having a soda. No ice. I think for me, as cold and windy as it was, it would have been a hot cup of coffee *smile*. Allen |
#7
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Yesterday's IFR flight with questions
A Lieberman wrote: I think with my plane being white, and nothing "reflective" to see the ice like it was in the sun, it was harder to spot? It was on the temperature probe that I clearly saw the white rime ice. I had looked on the wings for the ice and didn't see it. This is an important point. I think one of the online "learn about icing" courses advises you to take a small strip of some black tape and wrap it around the leading edge of the wing or the strut---by looking at the tape you can see more easily if things have started to ice up. (I've been to Steubenville! Greetings from Pittsburgh. I'm a pretty new instrument pilot, but I've heard that this area is a great place for icing.) --Tom |
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Yesterday's IFR flight with questions
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#9
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Yesterday's IFR flight with questions
The standard lapse rate is 3.5F per 1000'. So it you are going to fly
at 5000' above the ground, the temp up there will be 17.5 degrees colder. Giving 5 degrees for variation, that is 22 degrees colder. So in this case it would have to be 44 degrees or higher on the ground to not have ice 5000' higher. (I've done some rounding). Of course you COULD have inversion. But inversion means it is warmer above. You could also have a non-standard lapse rate. But this is a calculation worth doing. Usually people have a place on the airplane where ice forms first. It will usually be something thin, like an antennae or strut. You can use that as a guage. Thin frontal surfaces ice up first and worse. Some sort of physics thing about the air in front deflecting the moisture. More deflection with fatter curves. But usually my first indication of ice has been decreased aircraft performance (if I am in level flight). Descending or climbing is a little harder to tell. As for decending. if it is rime, I think 1500' of undercast is usually fairly safe. If it is freezing rain then no-go. Someone mentioned 1500' per minute. But the most important thing is keeping the airplane upright and not overspeed. You may want to use your standard decent rate and not go around doing something different. The word is that horizontal stablizer icing is the worst thing on decent. Don't use flaps for landing if you have ice when you land and land a little faster. Do everything at higher airspeed if you have ice. This will keep you above stall speed (hopefully). See that is the problem. Due to different shape of the wing due to ice the plane will stall at a higher airspeed. Another item. We all know to stay out of thunderstorms, but you should stay out of towering cumulus too, even if they aren't thundering and lighting. It is icy in there. I think the abreviation for these is CB. Don't fly in CB's. A lot of times there is just a thin layer of clouds, like 1000' thick that you have to climb and decend through. And there is ice in them. That one is a close call. If you have a PIREP or other good info and know it is clear on top, it is tempting to try and climb on up. The lower the ceiling is below, the riskier this is. You will have to evaluate and make your own judgement. Talking to a pilot who has just landed is very valuable. Hang out at the fuel desk. Maybe someone will come in who just flew through it. Sometimes airmets are wrong. Ice tends to be worse at the initial part of the front, and an old icing airmet MAY be invalid, just hasn't been cancelled yet. All depends. But if someone comes down through it and he says he didn't pick up any ice and he doesnt think anyone would, that can be helpful information. Like someone else mentioned. you can venture fairly safely into icy clouds if you have warm VFR conditions under you, above the MEA, no mountains and flat terrain. If you ice up, just descend. If you tell ATC you have ice, be prepared to answer their questions about it. Rime or clean? What is the temperature etc. They usually want a full report. After all, if you have ice, YOU'RE the expert. Having a turbocharged and high power to weight ratio is a godsend in ice. Just climb up through it to clear above. Thats what the airlines do. Sometimes they dont even turn on their deice cause it takes away power. They'd just rather climb like a homesick angel and get out of it. All depends. But the point is, being able to CLIMB is a godsend. They need their deice mostly on decent. If you cant outclimb it, and you have low ceilings below you, my suggestion would be TURN AROUND, unless you know that you have VMC in front of you SOON. Presumbably, you didn't get ice back there and if you go back there you wont accumulate it. Whatever you do , don't just try and hold altitude while you go slower and slower. That's how you stall and spin. Even a decent below the MEA is safer than that strategy. And ATC will be telling you he cant give you any lower. Just declare an emergency if you have to. MEA's have at least 1000' cushion, usually more. It would be a desperate crap shoot to be accumulating ice, unable to hold altitude, and have to decend below the MEA. Good way to run into something. This is the reason why I don't do this kind of stuff. Like I said, we all get ice now and then if we fly in the clouds below freezing. But don't get yourself boxed in. If you don't have an out, fly to where you do have an out. And don't fly into a trap where you can't outclimb the ice, and you can't decend because of low ceilings. That is where the icing accidents occur. That and on landing with a load of ice. I hope that helps. Bottom line, you can't really do much about ice except stay out of it, or get out of it if you are in it. |
#10
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Yesterday's IFR flight with questions
On 18 Nov 2005 11:39:06 -0800, Doug wrote:
Hey Doug The standard lapse rate is 3.5F per 1000'. So it you are going to fly at 5000' above the ground, the temp up there will be 17.5 degrees colder. Giving 5 degrees for variation, that is 22 degrees colder. So in this case it would have to be 44 degrees or higher on the ground to not have ice 5000' higher. (I've done some rounding). Of course you COULD have inversion. But inversion means it is warmer above. You could also have a non-standard lapse rate. But this is a calculation worth doing. My thoughts b4 launching was that most of the flight was going to be between 3500 and 4500 AGL on the first portion of the flight. Since sleet was falling, I honestly expected the temperature to remain or rise a little. More deflection with fatter curves. But usually my first indication of ice has been decreased aircraft performance (if I am in level flight). Descending or climbing is a little harder to tell. Yep, exactly right, I had to add power, and I knew that was not normal, thus no longer depending on the wings for icing but looking at the temperature probe. No wing strut for my Sundowner *smile*. As for decending. if it is rime, I think 1500' of undercast is usually fairly safe. If it is freezing rain then no-go. Someone mentioned 1500' per minute. But the most important thing is keeping the airplane upright and not overspeed. You may want to use your standard decent rate and not go around doing something different. Which was my initial thought, to maintain as "normal" as possible. I don't want to stick around in the clouds any longer then necessary, but I don't want do something reckless either by descending too quickly.. I wasn't even going to think about deploying flaps. Figured the less metal hanging out, the less that ice could collect. A lot of times there is just a thin layer of clouds, like 1000' thick that you have to climb and decend through. And there is ice in them. That one is a close call. For me, won't take a chance if there is known icing. Not worth it. Just like anything else we do, there is a risk of the unknown, but for me, if there is ice reported I simply won't go. If you tell ATC you have ice, be prepared to answer their questions about it. Rime or clean? What is the temperature etc. They usually want a full report. After all, if you have ice, YOU'RE the expert. Which I did when asked by Center. I was surprised that they gave me a block altitude. Maybe I was a little more pro-active and insuring I get out of the situation. Just glad it did not become an event. it. All depends. But the point is, being able to CLIMB is a godsend. They need their deice mostly on decent. If you cant outclimb it, and you have low ceilings below you, my suggestion would be TURN AROUND, Good advice, and in my case, I was right at the tops, so climbing was my only option. unless you know that you have VMC in front of you SOON. And this was my quandry. I was on top, BWG was VMC but from my view, it was solid overcast, yet ASOS reported broken 4300. So, I knew that the clouds were about 1700 feet thick based on my current conditions I was experiencing. Like I said, we all get ice now and then if we fly in the clouds below freezing. I truly hope I never get myself in this situation. Thankfully, I am down south where icing is an unusual event. I have been flying in the winter for two seasons, and only once did I come close to freezing temperatures in the clouds. It was a local flight, doing IFR training, and I had plenty of outs since it was local. But don't get yourself boxed in. If you don't have an out, fly to where you do have an out. And don't fly into a trap where you can't outclimb the ice, and you can't decend because of low ceilings. That is where the icing accidents occur. That and on landing with a load of ice. Bottom line, good advice above and well appreciated. Allen |
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