Ron Lee

Ron Lee

Well Known Member
Yesterday a low wing aircraft (non-RV) landed short of our main runway and reportedly sustained major damage (the pilot was ok).

People on the scene reported beaucoup ice from the plane. Temps on the ground were near freezing and it was overcast.

We may see eventually from the NTSB report if it was avoidable but it made me wonder what I would do in a similar case.

Obviously, for that to happen to me I really screwed up somewhere prior to the landing. Since I am a guy, we will assume that I did screw up and I had no choice but to descend through freezing clouds.

What is my best option to not only survive but ideally save the plane?

Since I cannot quantify the ice buildup, I will assume that it is not so much that full power is inadequate to maintain level flight. I can at least stay level if not climb.

Since I have to get down due to low fuel, I have to assume a higher stall speed than normal. How much I do not know.

So I would make an approach at a high airspeed...120 MPH or higher at the airport ten miles away that has two longer runways (11,000+ feet and 13,500 feet). Flight it down to just over the runway and slowly reduce power until it settles...reducing airspeed if possible.

Thoughts and suggestions.
 
Icing

We definitely brief it as the weather gets cold. We have deice but not all required parts are always installed. Helicopters get it FAST (think about that "wing" flinging through the air making its own relative wind at 500+ MPH!

I have thought about the possibility of climbing through it (did it once, but knew the cloud was just 500 ft thick). Been stuck below the freezing layer before.

I wonder though if there is an accepted "icing penetration procedure"? If you are stuck above and need to go through it...speed of descent versus time in the goo??
 
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"climb to sublimate" was the answer in the -38. In an rv and you can get below the wx then I'd fly as fast as possible loading the wing as little as possible until it sublimates off. It will eventually. Finding a clearing line must be your first option.
 
That video is scary. Not as much with an RV because you can just look back and see if there is ice, but taking regional flights. Very good info on feeling the shake in the stick rather than the seat for a tail stall. Good info and a good video to watch as we get into winter. All 3 are about 25 minutes total - a good use of your time. Thanks for posting the link.
 
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I haven't been in ice - so feel free to toss my ramblings and tell me to shut up (but please educate me and others as well)...

Ice robs the aerodynamic lift from the wing and tail surfaces. It happens as time allows the ice to build up. Lift is a function of airspeed and angle of attack, as well as aerodynamic shape. Ice impacts you on all three by changing the basic shape of the airfoil and adding drag. Therefore, logically, you want to do two things where ice is a KNOWN property on descent to landing.

1 - minimize time in the realm of ice accumulation. This means stay above (or below) it as long as possible until above the intended landing point (or ANY good landing point in this ugly scenario) if possible, and descend through it as fast as reasonably possible to minimize time spent in the accumulation zone once you can't help but expose yourself. If in doubt on approach and given vectors into suspected icing conditions, an emergency declaration is on my short list. I prefer FAA paperwork over medical paperwork.

2 - Once you are committed and exposed to the ice accumulation, keep airspeed as high as possible as long as possible until immediately over the runway. Myself, personally, loaded up with ice I would be OK with 10' AGL and stall plus 50 knots as I cross the threshold and let it bleed it off in hopes of a smooth landing or force it on if I run out of runway. The insurance company owns all of the airplane except the spinner. I either make an "ugly normal" landing or I go off the end at slow speed, either is survivable. With exposure to ice the shape of the wing and the tailplane have changed, and you don't know where Vso is anymore - so you need to live at a survivable height anytime you are close to that speed. Corollary to that - once at 10' AGL, all drag devices are fair game because we are rapidly running out of runway. Bent metal is fair game but protect the spinner on the prop because anything that hits the spinner hurts you, so the spinner belongs to you. The insurance company owns the rest of the airplane.

The thing you absolutely don't want to do is put yourself in an icing position while in flight, with hopes it will get better. The pasture/highway/golf-course/county-road/etc below you is a better choice. The insurance company owns the airplane - they would rather pay hull than death benefits, don't worry about the airplane.

Again - I've not been in a life-threatening ice situation - please critique if I'm wrong, but educate me as to why, and what you would do different.
 
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Greg,
I thought the same thing as you, then I watched the video. If you have heavy buildup on your vertical stabilizer, you risk a tail stall. The chance of the tail stall increases with speed and flaps are your worst enemy. Check out the video. It is freaky.

I haven't flown in ice either, so Im only saying what was on the video, but they looked pretty smart!
 
It hapen in an instant

Happened to me in a C-150. I was flying along VFR under some clouds on a cold February day and the ceiling started to come down. As I was evaluating things in a snap my windscreen, (entire plane) was covered in ice. I could not see out the front. I descended as low as I could (500' AGL) and flew looking out the side window. I was within minutes of my fuel stop so I continued. I felt better once I was over a road I knew I could land on.

As I approached the airfield I knew I was now a test pilot testing a new wing. I flew the approach at 20 knot over normal, set it down and got on the brakes. Ice was still sliding off the wings when I got out of the plane.

I think the plane was super cool and I flew through a light shower which instantly froze to the plane. Needless to say I learned a lot that day! I have not put myself into that situation since.

If you can still fly with the weight of the ice, you still do not know what characteristics you wing will have since the ice has change things.

Be careful out there!
 
rockwoodrv9 said:
Greg,
I thought the same thing as you, then I watched the video. If you have heavy buildup on your vertical stabilizer, you risk a tail stall. The chance of the tail stall increases with speed and flaps are your worst enemy. Check out the video. It is freaky.

I haven't flown in ice either, so Im only saying what was on the video, but they looked pretty smart!
Click to expand...

Granted - and that's why I said that 10' AGL with some question marks still outstanding is where I want to be. If things go from all-good to I-don't-understand, I want to be at a survivable fall distance.

Guys - I'm an engineer with a physics and a chemistry degree - I speak numbers. Give me evidence and I'll be in your camp. I freely admit at this point that I know enough to know that I don't know. If you disagree with me, this is your chance to educate me.
 
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Icing

Ice can surely get you unexpectedly:eek:. Once, going into Boise in a C182 from a very cold (17F) 14,000 ft. we descended through a cloud layer (IFR flight). The cold-soaked airframe immediately accumulated a goodly layer of ice on all leading edges, struts included. Fortunately, the cloud layer was thin and warm temps were below. That ice came off with some pretty loud "bangs" but no damage.

Recently, flying to OSH in my buddies Bonanza we got ice starting to accumulate while trying to stay between layers between 16,000 and 18,000 feet over Nevada. A turbocharger sure helps at those altitudes (O2 also) but RVs can get there as well. Fortunately, his plane has the TKS weeping leading edges on wings and tail and the glycol slinger for the prop. The ice really grew on the unprotected tip tanks, however, and didn't melt (sublime maybe) for quite some time. Flying that thing is like driving a truck compared to an RV, but what a stable IFR platform.:)
 
Ron I think you have it right

I have been in ice several/many times and I haven't lost control or fallen out of the sky. I try with all my being to avoid icing conditions and thunderstorms. Clouds are visible moisture and if I am above the freezing level I expect ice accumulation - I don't go there. If you have the unfortunate bad luck to fly into freezing rain I believe your corrective action opportunity window is very small - I've only had that thrilling experience in a car. Robert Buck's book "Weather Flying" (I think that is the title) is a very good and informative read. After reading it I once on an IFR flight in our Piper Archer II remained in a slowly accumulating ice cloud to gain the experience as he discussed about various weather conditions. I'm sure I wrote that test up before in the forum so I will not repeat it here. My approach to ice is avoid it (in my personal test I climbed out of it with significant difficulty); if I get in it I try to get out quickly; if I can't get out don't do anything to reduce the performance of the airplane and use the power to keep flying to the point of contact with the ground - hopefully a survivable landing at the nearest airport.

Bob Axsom
 
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Scary video

Geico266 said:
Icing usually results in loss of control. The is not due to the added weight of the ice, but from loss of aerodynamic qualities of the flying surfaces. Usually, the tail adds way more ice than the wings resulting is loss of control.

https://www.youtube.com/watch?v=w1c4-aDB4k8&feature=youtube_gdata_player
Click to expand...
Wow - I hope this is a standard training video for all those regional pilots. Hopefully the chief pilots at these regional airlines are drilling this into their heads about this time of year.
 
Most important thing is to always have a "sure thing" way out. I trapped myself one day in an LJ35 flying into Omaha and didn't have much extra fuel. The icing was so bad that the bleed air anti ice and alcohol windshield systems were not keeping us clear. Finally got the runway on the second try with about 2" of windshield to see through. The ground crew had never seen an airplane so iced up. Chalk that one up to dumb luck.

Not too long after that one of my friends was taking care of some currency items on the way back from a trip. Same airplane. He had penetrated some deck on the way back in during winter. He went to do a go around at simulated RNAV approach minimums and as he executed the textbook go around procedure, the aircraft departed sharply to the right. Apparently the air ducts that carry the bleed air out to the leading edge of the right wing had begun leaking and had left a little bit of accumulation on the bottom side of the right wing. They got it back just in time to miss an FBO hangar by about 200'. If they were on any other approach at that airport they'd be dead.

Visible moisture in the temperature range of -10 to 50 is nothing to mess with.
 
In the mid-70s when I was working on my IFR rating, one of my instructors was from Norway. He believed that anyone who was going to fly IFR needed to have some experience flying in icing conditions. Maybe in Norway if you don't fly in ice, you don't fly.

We went out one night in the fbo's Cardinal RG looking for ice, and found it. Not hard to do in CO. As I recall, we accumulated about 1/2" of ice on the leading edge, and the Cardinal became a real slug. After we left the clouds and moved into warmer air, there were terrible noises as we shed ice and it hit the tail surfaces. It was an interesting experience that I hope not to repeat. I don't know if the instructor survived his flying career or not.

Jim Berry
RV-10
 
Jim,

I bet your instructor either "got a brain" or is no longer with us. Looking for ice to learn how the plane flys is nuts and taking a student with you is even worse! Those NASA guys in the video used everything they had to control the plane they were testing in. Of course the type of equipment you are in makes a difference. In Colorado it is easy to get into situations that can be harry enough without looking for them as you know.

Next time I am in Denver, I would like to see your plane. I may be coming over the hill around the 14th. Maybe we can work out a time. thanks.

N15JB said:
In the mid-70s when I was working on my IFR rating, one of my instructors was from Norway. He believed that anyone who was going to fly IFR needed to have some experience flying in icing conditions. Maybe in Norway if you don't fly in ice, you don't fly.

We went out one night in the fbo's Cardinal RG looking for ice, and found it. Not hard to do in CO. As I recall, we accumulated about 1/2" of ice on the leading edge, and the Cardinal became a real slug. After we left the clouds and moved into warmer air, there were terrible noises as we shed ice and it hit the tail surfaces. It was an interesting experience that I hope not to repeat. I don't know if the instructor survived his flying career or not.

Jim Berry
RV-10
Click to expand...
 
Landing With The Wings Iced Over?

Some background: I spent a the better part of twenty years regularly flying a T-210 around the Great Lakes, where you can always find ice pretty much from October thru April. The 210 was equipped for known ice, but that only creates more options-it's not a total solution.
Very seldom had the wings ice over, as the circumstances for clear ice flowing back are fairly unique. Most often, it was rime or mixed on the leading edges. As far as handling ice, the first part is knowing your equipment: what have you got and is it anti ice or de-ice. After equipment is conditions: where's the freezing level, what's the OAT, where are the tops, what's the lapse rate, how fast am I accumulating, and what are plans A,B, and C?
While I try hard to avoid ice in the RV, my limited encounters have lead me to conclude that excess lift quickly becomes a problem, and my intake starts to get plugged (I have a carb) pretty much as soon as I see any traces on the windscreen or wings. So... When I'm flying IMC in icing conditions, I pay very close attention to the OAT gage and apply carb heat (close off the air box) before I reach the possible ice range. Of course, choking the intake leads to further leaning and loss of power-not a good combo if the plan is to climb thru the clag. Dealing with these issues generally results in shedding any ice accumulation before landing. On the other hand, if the ice were still with me at that time, carrying an extra 10 to 15 knots on a no-flap final and down to about 10 inches above the pavement might be the only choice left.
My $.02 as far as ice and RVs - avoid it, and if you do encounter it, get out as quickly as possible. While these planes can get us out of a jam rather quickly, they can also put us deep into trouble in a short time as well.
Terry, CFI
RV9A N323TP
 
Training

When I was the Chief Pilot at a Charter Company I used to work at I made all of my pilots go through two training courses that NASA developed. Good stuff and I thing should be mandatory to all pilots. I can highly recommend it and I testify to its accuracy with my own experience. I am dealing with icing a lot in my everyday flying.

http://aircrafticing.grc.nasa.gov/courses.html

By safe
 
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My lesson....

Ron Lee said:
Yesterday a low wing aircraft (non-RV) landed short of our main runway and reportedly sustained major damage (the pilot was ok).

What is my best option to not only survive but ideally save the plane?
Click to expand...

Depends, and I can only speak about my personal experience. On my very first IFR flight after getting my ticket I screwed up in exactly that way. Then I spent way to long in the approach environment. Droning along at 3,000 right in the middle of the ice to pick up the ILS 20L into LUK I had so much ice accumulate that I was at full throttle, doing 80 kias on the edge of a stall. I was having to shove the elevator forward every minute or so as it was freezing up.

Luckily I did one smart thing before my flight that saved my bacon. I made sure the ceilings were fairly high, in this case around 1,500'. If not for this I would have been back in the arms of his noodley goodness sooner than I would have liked. Once established on the localizer I knew the area intimately and was able to descend enough safely that I could get out of the soup. The ice immediately began to ablate.

So, my answers would be:

0) INFORM THE CONTROLLER OF YOUR ISSUE, DECLARE AN EMERGENCY

In my case I was asked several times what I wanted to do after I mentioned ice. I could have had priority and gotten vectored in on the approach before other traffic. In the event I was slowed down behind another aircraft, who interestingly enough picked up no ice.

1) Stay high, above the ice, as long as possible (if possible). Plan on a steep descent into the approach.

2) If you have a choice between approaches and the ceiling is high enough that it will let you, pick a non-precision approach and drop like a rock when you pass the fix, get to your MDA asap if its below the soup.

3) Keep the speed up

4) Its a bad choice, but if it comes to it and you are comfortable with the area and its hazards you may have to descend below the clouds if the ceiling is high enough. If you are out of clouds and precip hopefully it will start to come off, or at least stop accumulating.

Don't know about RV's, and don't want to find out, but I found out that Grummans will carry a way more ice than I could have imagined and still fly.
 
Thought provoking video...

Really interesting video as a safety officer, Aero engr and mil pilot. What follows is speculation on my part, however some flags were raised in my mind as I wastched as to how this training would be received and implemented with pilots. The video did address that diagnosing and correcting for a tail stall did vary aircraft to aircraft, but I think it would be pertinent to address which aircraft are more or less susceptible to this failure mode. This would undoubtedly require more time, money, and other resources to be included with the study. While watching the video, I had to picture myself on final/at glideslope intercept with full flaps and experiencing some of these symptoms knowing I had penetrated say moderate icing on the descent. Prior to watching the video, I would increase power and speed (for extra weight of ice and degraded aero interactions) to initiate a go around. Now, however, I would give consideration to tail icing. Balancing the information from the video while knowing the possibility of misdiagnosing the symptoms, I'm concerned pilots could ineffectively recover from a wing stall bc of over consideration for tail stall that may have a small likelyhood of developing. I think the Colgan air Buffalo incident would be a good case study.

In my experience in the tanker/707, I have operated frequently in ice producing conditions and have descended through icing bad enough to lose 1 air data system. Most locations the freezing level is below 0 AGL over half the yr with frequent IMC so icing is a common topic. In the tanker, the controls are all manual/ cable & pulley actuated anti servo tab with aero balancing but we do have vortex generators on the horiz stab to help with any seperation issues. We have to always keep the aero balance bays clear of icing. Because we don't have a T tail, I beleive the flap downwash would be a factor as well. Having an understanding of the RV control system and the performance envelope of the elevator along with CG factors and the predicted degradation due to ice would be pertinent, I wonder if we can get some feedback from Van's on this? Obviously the best answer to avoid icing completely.
 
RVG8tor said:
Happened to me in a C-150. I was flying along VFR under some clouds on a cold February day and the ceiling started to come down. As I was evaluating things in a snap my windscreen, (entire plane) was covered in ice. I could not see out the front. I descended as low as I could (500' AGL) and flew looking out the side window. I was within minutes of my fuel stop so I continued. I felt better once I was over a road I knew I could land on.

As I approached the airfield I knew I was now a test pilot testing a new wing. I flew the approach at 20 knot over normal, set it down and got on the brakes. Ice was still sliding off the wings when I got out of the plane.

I think the plane was super cool and I flew through a light shower which instantly froze to the plane. Needless to say I learned a lot that day! I have not put myself into that situation since.

If you can still fly with the weight of the ice, you still do not know what characteristics you wing will have since the ice has change things.

Be careful out there!
Click to expand...

Your third paragraph is a good point that I would like to try to shed some light on.

In the airline world +10c or less in visible moisture is considered icing conditions.

While flying in cold temperatures flying in visible moisture, especially rain,even light rain is very risky. This kind of has to come back to basics to properly explain. Airspeed across a wing creates a low pressure above it in order to create lift. A by product of creating a low pressure area above the wing surface is reducing the temperature. (reducing pressure reduces temp and visa versa) Flying through rain, cloud, etc. the moisture hits the wing and the reduced temp caused by the reduction of pressure (lift) causes the moisture to freeze and attach to the wing as it thins out and flows back even-though the OAT is above freezing.

Flying around fronts in the winter can be fraught with risks, warm air with moisture above cold air can set up the worst icing conditions. Warm rain falling into freezing temps can load up a wing in seconds. It takes less thickness of clear ice to bring down an airplane than rime ice. Think weight here.

Some Things I try to live by.
1. Never fly through rain in freezing temps without deicing/anti-icing equipment (edit to add: and even with de-icing equip be extremely vigilant) and if it is close to freezing seriously consider other options.
2. Pireps are pilots best friends in icing conditions.
3. Know the tops and bottom heights and if it is safe or possible to get there (Pireps)
4. Know OAT's all around you. (Pireps, awos, atis, etc)
5. If there is no warm air below you be afraid of ice. (get down there to melt it off with room/time to get it done)
6. If your de-icing equipment consists of boots test them before entering and expect them not to work.
7. A 180 immediately after entering ice is a good escape option. Don't wait too long to exercise this option.
8. Never be so concerned about the ice on the airplane that you neglect to fly the airplane.

I have more but these are the bigger ones.

TerryKohler, and Walkman have very good points as well.

Mark
 
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Ice Avoidance Tools

NOAA has been working hard to improve aviation weather icing forecasts. I've used these features for a few years now for all my flight planning in the colder months. The Supplemental Icing Product is really cool. You can pick your altitude and pick your time frame and it gives you a visual picture of the risk for icing conditions. It adds a greater dimension to the old standby of reading winds/temps aloft forecasts.
http://aviationweather.gov/adds/icing/
 
I took my instrument check ride last year and the FAA has gotten serious with icing to the point there are a few questions on the written and the checkride included some verbal questions.
Mostly I remember tail stalls from icing and they recommend no flaps and high speed landings.
The DPE had me do a no flap landing at 110 kts visual approach and landing.
I thought he was crazy but it wasn't that hard and something that should be practiced.
 
icing

Almost all of my icing experience is from light twins on thru twin turbopops etc. Each airplane type is different. I started out in Pipers in the Twin Commanche/Aztec era. The Aztec is very forgiving but the Twin Commanche actually carries ice better IF you can keep the speed up. Never saw a tail stall problem with either. The most ice I have ever had on an airplane was in the Aztec and Navajo. Both fully deiced but that doesn't mean you can sit in ice for long periods of time. Light twins are certified for light icing only. The Aztec event was an experiment with warm air and good vfr below the clouds. The ice buildup was such that the engines were starting to get hot with cowl flaps full open and full power. The buildups on the unprotected areas-wingtips, cowl and inboard wing brought the speed down to about 120 knots. I won't say how much ice, but when the ice on the inboard wing section broke off it put a dent about a foot long in the side of the fuselage.
The Navajo will carry ice better than any piston twin I have flown. I flew the Navajo 1000 hours in one year in the Chicago area. Never saw any ice that challenged the airplane. I think we only canceled two times in one year for ice.

The Baron and the Twin Cessnas are the worst for tail ice. I had the Baron stall on landing at 125 knots with just a little ice. There was a Baron accident years ago where the airplane stalled and spun from around 10,000' due to ice.
One thing I have not seen discussed on here is flap useage. The Piper Seneca will pitch out of control when the flaps are moved beyond approach setting. I have no Caravan experience, but accident reports indicate the Caravan does the same thing as the Seneca. So the safe bet is no more than approach flaps.

The best descent profile in ice is the steepest possible descent. Most twin turboprops have a minimum target speed for ice of 140 knots. This is not always feasable, but is a good goal. The reason for this is to avoid angle of attack that will allow ice buildup on the bottom of the wing behind the deice boots. Even in airplanes with no wing deice, 140 knots will, in most cases, keep the ice from building on the aft bottom portion of the wing.
 
icing

Almost all of my icing experience is from light twins on thru twin turbopops etc. Each airplane type is different. I started out in Pipers in the Twin Commanche/Aztec era. The Aztec is very forgiving but the Twin Commanche actually carries ice better IF you can keep the speed up. Never saw a tail stall problem with either. The most ice I have ever had on an airplane was in the Aztec and Navajo. Both fully deiced but that doesn't mean you can sit in ice for long periods of time. Light twins are certified for light icing only. The Aztec event was an experiment with warm air and good vfr below the clouds. The ice buildup was such that the engines were starting to get hot with cowl flaps full open and full power. The buildups on the unprotected areas-wingtips, cowl and inboard wing brought the speed down to about 120 knots. I won't say how much ice, but when the ice on the inboard wing section broke off it put a dent about a foot long in the side of the fuselage.
The Navajo will carry ice better than any piston twin I have flown. I flew the Navajo 1000 hours in one year in the Chicago area. Never saw any ice that challenged the airplane. I think we only canceled two times in one year for ice.

The Baron and the Twin Cessnas are the worst for tail ice. I had the Baron stall on landing at 125 knots with just a little ice. There was a Baron accident years ago where the airplane stalled and spun from around 10,000' due to ice.
One thing I have not seen discussed on here is flap useage. The Piper Seneca will pitch out of control when the flaps are moved beyond approach setting. I have no Caravan experience, but accident reports indicate the Caravan does the same thing as the Seneca. So the safe bet is no more than approach flaps.

The best descent profile in ice is the steepest possible descent. Most twin turboprops have a minimum target speed for ice of 140 knots. This is not always feasable, but is a good goal. The reason for this is to avoid angle of attack that will allow ice buildup on the bottom of the wing behind the deice boots. Even in airplanes with no wing deice, 140 knots will, in most cases, keep the ice from building on the aft bottom portion of the wing.
 
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