Lack of carb heat leads to crash landing - video from inside cabin

jbrinker

jbrinker

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Jbrinker

Saw this posted on another forum - so if a dupe here tell me and I'll delete the thread.

Most striking to me as a student approaching checkride and analyzing this for my (hopefully) own benefit are a few things:

1) the fact that they wound up in this situation in the first place - but we can leave that for now, as carb icing can sneak up on anyone and we can't know what led to this exactly - i.e. took off carb heat too soon? Failed to put it on until too late? We don't know.
2) The calmness of the passengers, and the seeming lack of any instruction from the pilot to them (maybe just not caught on video). I;d at least expect brace instructions and "brace brace" before landing. (And put the damn phone down, its a missile!!)
3) The landing itself -
- After we can see at the end, no flaps. Why? Did the pilot just forget to deploy flaps? Even if they were electric, you can see the radios are still working in the video, so he had power.
- The flare looks way too shallow (no flaps but still too shallow). Looks to me like he flew it on, landed nosewheel first and flipped it. I heard no stall horn at all.
- Look at the track in the snow, you can clearly see that the "dig" from the nosewheel is right at the start, which means it probably hit first or at best same time as the mains, and crumpled immediately.

I've been practicing soft field landings this past week, and seems to me landing in snow (Which was not that deep if you look at it) you'd want to basically start a stall with full flaps right above the ground just as the mains touch and hold full back elevator and hold it in a "Wheelie" as long as you possibly could, even dragging the tail if it came to it.

I can hardly believe they all walked away from it, the dude was still filming it, and the baby was ok! Lucky bunch for sure. Oh, and the cameraman to the girl at the end: "You gonna ever fly again" girl: "Yeah." Wow, there's a keeper!

Edit: Open the link in youtube and read the comments, cameraman explains more about the circumstances, including why the highway seen in the video was not a good choice at that time. Still wonder most about flaps and lack thereof.

Oh, and apparently the pilot let his insurance lapse - renewal date was the DAY BEFORE so he ate the cost by 13 hours... Man, that sucks.
 
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It had manual flaps. You can see them on the floor in the after crash shot.

You are correct in that full flaps should have been deployed & nose held off as long as possible. Classic soft-field landing.

On a clear day like it appears to be with relative low humidity carb ice is quite rare actually. It's the warmer days with high humidity you have to worry about. Also, another technique to clear a frozen carb is to pull the mixture back to the point the engine backfires. That has been know to clear the ice.

Was carb ice really the cause of engine failure?

Another observation. The flew over a lot of straight roads. Were there too many power lines or traffic?
 
Big Question.... How do you know when it is too cold to have carb ice?
 
Hope everyone is OK.

Not to take away or steal the thread, but it brought up a question. I have flown a Beech Sport with and O-320-E3D for the past 20 years. I have flown over a good part of the country winter and summer never encountered carburetor Icing. During my flight training many, many years ago flying a C-152 we had carb icing at 70F OAT. Was that due to the type engine, carb or both?
 
Wow, I fly a C175 with O-360, and have never experienced carb ice. I wonder what the differences are in the carb box heating arrangement with his STC? Good reminder to always pay attention.
Dave
 
Anyone else see issues with the carb ice diagnosis? The way it reads, the engine suddenly lost power, he immediately applied carb heat, saw a positive result momentarily, then lost power again and never got it back. It does not read like he removed carb heat after getting a positive reaction. Obviously "immediately" was likely a few moments due to the "oh crud" processing time (it was for me the first time I experienced it). I guess my question is, how possible would it be to apply carb heat promptly after experiencing ice, leaving it on, and still losing power anyway?
 
Omalley1537 said:
Anyone else see issues with the carb ice diagnosis? The way it reads, the engine suddenly lost power, he immediately applied carb heat, saw a positive result momentarily, then lost power again and never got it back. It does not read like he removed carb heat after getting a positive reaction. Obviously "immediately" was likely a few moments due to the "oh crud" processing time (it was for me the first time I experienced it). I guess my question is, how possible would it be to apply carb heat promptly after experiencing ice, leaving it on, and still losing power anyway?
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I agree that it sounds strange. I have had countless incidents of carb icing over many years of flying, and in each case the application of carb heat restored power within seconds. In this particular case, the engine did not quit (according to the NTSB report) but continued to produce "partial power", so there was definitely a continuous source of heat. My personal guess is that either the pilot did not lean the mixture properly for his (original) 8,500' altitude with carb heat on, or the carb heater was faulty/weak, or both.
 
Snow, as you can see, doesn't take much to stop the wheels dead.
Also, they had 4 adults and an infant in that plane? Heavily loaded as well.
 
UngaWunga said:
Snow, as you can see, doesn't take much to stop the wheels dead.
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I was thinking the opposite...unless there were different snow conditions at touchdown than where the airplane came to rest, it should be very landable.
 
From what I could see in the video, there was a definite point maybe thirty or forty feet after touchdown where the nose gear dug in and snapped off. Snow can hide ditches and rocks.
 
Looking at the video again, you can see them postholing occasionally almost up to their knees. Uneven ground under the snow, and its deeper than it looks.

read through some of the comments. I still don't know why they didn't go for the road.
 
I had another thought about the landing. Disclaimer: I'm home taking care of my wife who's recovering from foot surgery - so I have lots of time on my hands.

With the straight tail Cessnas the elevator isn't quite as large & powerful as the swept tails. In my 182 (with STOL kit) when the tanks are full & two large people occupy the front seats - there's not much to the flare. I carry two cases of water (80#) in my baggage compartment when there just two aboard. He may have run our of elevator. Especially with no flaps.
 
3-4 inches if hard snow is enough to flip the bird when the nose digs in. You'll notice that the plane flipped almost instantly on touch down. The mains dig in, instant drag, slams the nose down, digs in and still enough inertia to flip the bird.
 
All you need is a little bit of drag on that nosewheel on a softer surface. That will cause the nose to pull down, placing even more weight on the nosewheel and making it drag harder, and this feeds on itself and flips the airplane onto its back. The whole thing doesn't even need the nose to slam down hard. There is a bigger risk of noseover on soft surfaces with a trike than with a taildragger; the taildragger's mains are much closer to its CG and it doesn't tend to dig them in hard. No pole-vaulting effect, see?

Carb ice wrecks a lot of airplanes. Many pilots seldom encounter it, some maybe never, but if the conditions are just right, even on an ice-resistant carb setup, you can get it and then not recognize it. It's all temperature and dewpoint spread, something too many folks just don't understand.
 
Omalley1537 said:
Anyone else see issues with the carb ice diagnosis? The way it reads, the engine suddenly lost power, he immediately applied carb heat, saw a positive result momentarily, then lost power again and never got it back. It does not read like he removed carb heat after getting a positive reaction. Obviously "immediately" was likely a few moments due to the "oh crud" processing time (it was for me the first time I experienced it). I guess my question is, how possible would it be to apply carb heat promptly after experiencing ice, leaving it on, and still losing power anyway?
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FWIW, the NTSB has been on a roll recently with taking the easy way to explaining away some GA accidents. Unless it was a high visibility accident that made the news and they put a big team on it, I don't have a ton of confidence in the level of effort they put into most of the GA accidents today.
 
BillTIZ said:
3-4 inches if hard snow is enough to flip the bird when the nose digs in. You'll notice that the plane flipped almost instantly on touch down. The mains dig in, instant drag, slams the nose down, digs in and still enough inertia to flip the bird.
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Exactly. They had a pretty good nose-up attitude going in, but as soon as the mains dug in that was it.
 
Stick all the way back and land as slow as possible but when snow builds up under the wheels over you go and there is usually nothing that can be done to prevent it.
 
I do wonder if the slower touchdown speed of landing with full flaps would have been enough to prevent them from flipping over.
 
Probably not in snow that deep.

When I did it, putting power in helped hold the tail down. I didnt flip. But it was close. It was old crusty snow about 4" deep on a grass strip in an Aviat Husky. I need the power to get to the cleared taxiway. I got stuck in the plow drift from the taxiway. Had to dig out by hand.

I landed on a frozen lake in 12" of fresh snow and did a power out go around before I stopped and breathed a sigh of relief once. "Get me outa here!" as I climbed out. That was TOO DEEP!

A few inches of fresh powder, 6" is ok if LIGHT, is not problem though. Done that a lot.
 
I too wonder about the diagnosis of carb ice - if you read the report on that other link that got posted, they say that the "water detecting putty" was positive for the presence of water in the fuel bowl. Now, the way I understand it carb ice forms in the throat of the carb, downstream from the throttle plate, due to the drop in pressure(temp) and moisture content in the air. Thoughts here? Maybe water in the fuel (or ice crystals)?

This was a lycoming O-360 from what I read, which has the intake plumbed through the oil pan. Temps (according to the report) were 20F and dew point of 19F. Thats mighty close, and makes carb ice a possibility. But according to the chart I saw, at temps that low it's unusual.

I'm trying to learn from this - so the landing: Why not pull flaps? I can see that winds are not strong, and you can definitely see that they were not after landing. It just seems like a water landing, you want to slow down as much as humanly possible. Definitely sobering though - around here there is a lot of snow covered fields 1/3 of the year. If it really only takes 4" of crusty snow to flip, I'd just have to plan on it like a water landing and be happy if it did not happen.

I was not aware of the limited elevator authority on a C175, especially loaded up, that may have been a factor, especially as you say with no flaps. Personally I'd have gone for the road, there were several. Although I wasnt there, and they all lived without a scratch... so maybe I'd have landed head on into a plow truck :(
 
jbrinker said:
I'm trying to learn from this - so the landing: Why not pull flaps? I can see that winds are not strong, and you can definitely see that they were not after landing. It just seems like a water landing, you want to slow down as much as humanly possible. Definitely sobering though - around here there is a lot of snow covered fields 1/3 of the year. If it really only takes 4" of crusty snow to flip, I'd just have to plan on it like a water landing and be happy if it did not happen.

I was not aware of the limited elevator authority on a C175, especially loaded up, that may have been a factor, especially as you say with no flaps. Personally I'd have gone for the road, there were several. Although I wasnt there, and they all lived without a scratch... so maybe I'd have landed head on into a plow truck :(
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By all means, he shoulda used full flaps. He was probably overwhelmed by the situation and wasn't thinking straight. Whatever you can do to reduce speed/kinetic energy before touchdown, do it!! Just don't stall/spin before you get into the flare. At just above stall speed, I don't think many planes have the ability to be so nose-high they can scrape the tail, but as soon as the mains touch, the nose wheel is going to instantly plant itself into the snow from the drag.

coloradobluesky said:
Stick all the way back and land as slow as possible but when snow builds up under the wheels over you go and there is usually nothing that can be done to prevent it.
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Yep. If I ever have an off-airport landing in a soft field, I fully expect to flip. My plane's tiny wheels/tires don't help matters much. Cinch the belts tight, full flaps, slow it to a stall 2 feet off the deck, into the wind if possible, and hold on for the Tilt-o-Whirl ride. Kick out the plexi canopy, if it's not already shattered from the flip, or use the fire extinguisher to break it. If I had a passenger, I'd tell him to pull out the seatback cushion (held on with Velcro in my plane) or the canopy cover from the baggage area, and put it between his face and the instrument panel. If you don't have one already, get a nice padded edge for the glare shield...it can help reduce facial lacerations.

In the original scenario, if the traffic was light, I'd take the road option in a heartbeat.
 
jbrinker said:
I too wonder about the diagnosis of carb ice - if you read the report on that other link that got posted, they say that the "water detecting putty" was positive for the presence of water in the fuel bowl. Now, the way I understand it carb ice forms in the throat of the carb, downstream from the throttle plate, due to the drop in pressure(temp) and moisture content in the air. Thoughts here? Maybe water in the fuel (or ice crystals)?
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Wonder what the odds are that snow got in there when it nose over.

jbrinker said:
I was not aware of the limited elevator authority on a C175, especially loaded up, that may have been a factor, especially as you say with no flaps. Personally I'd have gone for the road, there were several. Although I wasnt there, and they all lived without a scratch... so maybe I'd have landed head on into a plow truck :(
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I have noticed some diminished elevator authority in 172s with 40 degrees flaps. In other words, the nose felt a little heavier and if you get too slow, it can limit your ability to flare. But, I have only noticed that with the full 40 degrees flaps. Not a reason to avoid putting at least 30 degrees out.
 
SoCal RV Flyer said:
If I had a passenger, I'd tell him to pull out the seatback cushion (held on with Velcro in my plane) or the canopy cover from the baggage area, and put it between his face and the instrument panel. If you don't have one already, get a nice padded edge for the glare shield...it can help reduce facial lacerations.
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Shoulder belts, man.
Doors unlatched before crashing if you can.

In the original scenario, if the traffic was light, I'd take the road option in a heartbeat.
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Yup.
 
seeing videos like that make me want to get a plane with 4 point harness and wear a helmet when I am not at cruise.
 
jbrinker said:
I too wonder about the diagnosis of carb ice - if you read the report on that other link that got posted, they say that the "water detecting putty" was positive for the presence of water in the fuel bowl. Now, the way I understand it carb ice forms in the throat of the carb, downstream from the throttle plate, due to the drop in pressure(temp) and moisture content in the air. Thoughts here? Maybe water in the fuel (or ice crystals)?
Click to expand...

Water in the carb float bowl is pretty much guaranteed to stop the engine. The main jet that meters the fuel can be blocked by a drop of water, since the water's surface tension makes it reluctant to pass through the jet. If the water does get through, it can freeze at the fuel nozzle and start restricting the fuel flow. That might have been why he lost power and temporarily recovered some when he pulled the carb heat. The usual conditions in the carb,in the venturi where the nozzle is located, involve a pressure drop due to increased velocity and therefore a temperature drop, and evaporating fuel, which absorbs heat from the airstream to convert the liquid to a gas, further lowering the temperature.

Water in fuel is found in three forms: free water, the stuff we're familiar with when we sump the tanks or drain the strainer. There's entrained water, tiny suspended droplets that sometimes appear as "snow" in the fuel at low temperatures. And then there's dissolved water, completely invisible in the fuel, and all fuel has a little of it. The free water is the most dangerous. The entrained water can clog filters at low temperatures. Not much one can do with dissolved water besides adding alcohol to the fuel, and we can't do that. Cars in the frozen north often get a bit of methyl hydrate in the form of "gas-line antifreeze" and the refineries here also add a bit of alcohol to winter gasolines. Less than 1%, I was told.
 
Fearless Tower said:
Wonder what the odds are that snow got in there when it nose over.
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Very unlikely. It would have to get into the carb airbox and find its way into the bowl vent inlet, often buried behind the venturi sleeve where the air is still and close to ambient pressure.
 
jbrinker said:
Saw this posted on another forum - so if a dupe here tell me and I'll delete the thread.
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Yeah, it's a dupe. One of many over the years. :) This is a pretty (in)famous video that has circled them Ynterwebs several times already.
It is always good to watch these to see learn what we could do differently for hopefully a better outcome (without judgement). These kids got dang lucky. I could not believe that they just climbed out like nothing happened. The first time I saw this video, I thought it was maybe a fake due to the 0 injuries.

So anyway, to be a typical PoA-er, I better point out some flaws, right? :D
I noticed (besides the obvious no flaps) that the mags were hot, mixture full in and so was the throttle. I hope I'd remember to secure my airplane before landing out. It is easy to forget in the situation.

Definitely a good video to show to students and have them pick it apart at what could have been improved. Putting them in the cockpit is a little different than just teaching theory from a book.
 
BillTIZ said:
3-4 inches if hard snow is enough to flip the bird when the nose digs in. You'll notice that the plane flipped almost instantly on touch down. The mains dig in, instant drag, slams the nose down, digs in and still enough inertia to flip the bird.
Click to expand...

Flying SE Alaska as I do, I fly over a lot of water. I often wonder about ditching in water, would you hold it off as long as possible and stall it? I know once the mains touch it's going upside down...:( Maybe, I should post in a thread of it's own. What do you think.
 
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AKBill said:
Flying SE Alaska as I do, I fly over a lot of water. I often wonder about ditching in water, would you hold it off as long as possible and stall it? I know once the mains touch it's going upside down...:( Babe, I should post in a thread of it's own. What do you think.
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There are some YouTube videos of planes landing in water. Some do nose down, not all totally flip. Yes, as slow as possible, and if you stall, be at 2ft AWL (Above Water Level).
 
I would have likely secured the engine before landing... also pop the doors.

That said, it's hard to criticize when everyone walked away.
 
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