I'm new to floats so I've been trying to get out as often as possible to keep from losing the sight picture and muscle memory. I've been doing pretty good, considering it is December, because there are a few lakes nearby that don't typically freeze up during winter.

Weather locally has been beautiful lately, around 27-36F with clear skies and stable air so I went down to my closest lake planning to do a few circuits. Water looked like glass at first, then I started to see a few rippled patches. I was puzzling over the fact that the rippled patches didn't seem to move as they would if they were driven by gusts when I realized I was looking at newly formed ice.

I decided not to land, even though at least 80% of the water appeared to be free of ice.

Am I being too cautious? I've read a fair bit about cold weather operations, but there isn't much I've found written about the risks of landing on a lake with a bit of ice here and there. I obviously couldn't tell from the air how thick that ice was but logic would dictate it isn't very thick. I am certain that there isn't a solid layer of ice under what appears to be open water. It isn't that cold around here.

What say the voices of experience?

I appreciate this isn't exactly the input you're looking for, but when the consequence of failure is immersion in freezing water, it's hard to be too cautious. Unless you're flying in a dry suit, it's unlikely you'd survive any cold water immersion, even if you did make it to shore or back on top of the airplane.

I'm interested to hear from the experts how ice and floats interact.

One winter in Kodiak, a construction outfit was working to extend the runway at Karluk Village.
They were working all winter there, and the airport was mostly closed. The construction outfit had leased a Beaver from Kenmore on 4930 straight floats, and the pilot kept it in Lilly Lake (fresh water) in Kodiak, and flew supplies and personnel to and from Karluk, landing the Beaver in the Karluk River, just below the village.

It was a pretty cold winter by Kodiak standards, and after a few pretty cool nights, I went up to Municipal Airport (just off the end of Lilly Lake) to check on planes. I got out of my truck and heard the Beaver engine, and some terrible crunching sounds. I walked over to the lake, and there was the Beaver, breaking up the ice on the lake, and warming up the 985 in preparation for takeoff. The ice there was probably a couple inches thick at least.

After he'd broken up a takeoff channel through the ice, he lined up and took off. I think he made two or three trips that day.

Next morning, I could hear him breaking ice from my house, which was a couple hundred yards from the lake.

This pretty much went on all winter. And, he pretty much kept Lilly Lake open (sorta) all winter with the floats on that Beaver. I wondered what sort of damage he was doing to those floats.

Next spring, I was in Seattle, and drove over to Kenmore, and there, sitting high and dry on one of their overhead racks, was that very Beaver. I wandered over there, and carefully examined the bottoms and sides of the floats. The bottoms were perfect, nary a scratch. The sides of the floats had a few gouges, which could have been dock rash or ice damage, but not ugly in any case. I was impressed.

I have landed an amphib on thick ice, and I used to fly our Super Cub to Anchorage from Kodiak and land on Lake Hood after it'd frozen up for gear change to wheels. In the spring, I'd take it back to ANC and get the floats installed, fly it off the ice on Lake Hood, and land in Lilly Lake. Once or twice, Lilly Lake had frozen partially before I got back so I had to break a little ice.

The biggest threat to working a seaplane in new ice is the possibility of a crosswind pushing the side of the floats into some really tough new ice, and cutting a big hole in the sides of the floats. The side metal doesn't have the protection of keels like the bottoms have, to protect the sheet metal. I've put a few creases in the sides of floats in new ice, but never done any significant damage. But.....how much more they would have taken??? Dunno. And, I was being paid to fly those airplanes.

The other issue you need to concern yourself with is the temperatures at which you're playing this game. I've operated in salt water in air temperatures as cold as 26 degrees. That was just one landing, and one takeoff. I wouldn't want to do several although the air taxi folks in Kodiak often did. I always stayed away from landings in fresh water when air temps were colder than 30 degrees and even then, I'd keep landings and takeoffs minimal.

On takeoff, you'll put a lot of ice on the tail surfaces of the plane if it's below freezing, and remember, that sheet metal is probably colder than the water, so it'll stick.

Also, water rudders tend to freeze in position, which is typically up in flight. So, you land in fresh water, then takeoff, with water rudders up. Get to your next stop and the water rudders are frozen in the "Up" position.....ie: No steering after landing. Things can get exciting quick. So, you shut down, leap out onto a float, and dance back to give one water rudder a kick to get it down, and forget that the float deck is likely covered in.....you got it....ice.

Reference Hammer's comment above. I can testify that it is in fact possible to yard oneself back up onto a float and proceed to the dock after cold water immersion. I would not call it fun, by even the most die hard Polar Bear participant, however.

Straight home, very hot shower, and some coffee laced with Kahlua helped.

Frankly, I was working airplanes at the time. I never even gave doing that sort of stuff a thought in my personal 90 hp J-3 on floats. As soon as the weather dropped below freezing occasionally, that little plane went on big tires, and it was beach combing time. I always looked forward to getting airplanes off floats, and on tires in the fall, and greeted the next float season just as enthusiastically when the floats went back on.

One winter, I was flying our amphibious Beaver up to Anchorage from Kodiak for some maintenance work. That trip was always a little nerve wracking, because you were crossing about forty miles of some of the nastiest open water in the North Pacific: Shelikof Strait. And, this was often accomplished at very low heights due to weather.

On this particular trip, something was really bugging me, and I couldn't figure out what it was. I kept studying the engine gauges, the floats, etc, and I just couldn't shake the feeling that something was terribly wrong.

I landed at the Homer airport for a short break, and it dawned on me: I wasn't wearing hip boots. It was the first flight in months that I'd done without wearing hip boots.

MTV

Mike covered most. Here's a few obs.

My lowest air temp was +15F with ice floes running with the river current and thin ice/slush on lakes.
Below freezing ice forms on the prop, floats, and tail. Unless you find warm air it's stuck. Performance suffers and controls get stiff.
A couple of options after takeoff..leave the water rudders down so they thaw quicker on landing. Or work the retract and rudder cables after takeoff to free them. Maybe works. No turns immediately after takeoff so they don't freeze offset and create a turn in flight. Rudder springs need to be flexible. On landing and off step apply full up elevator to submerge the rudders so they thaw and keep the prop dry.
I've fallen off an ice covered plane twice fueling and there's a problem with crawling back onto a frozen float deck. Bystanders wonder why the Polar Club swim was necessary.
Go slow breaking ice and it gets thicker close to shore. Let the weight of the plane do the work not the forward speed.
Carry cans of spray windshield defroster to deice parts between trips.
On one plane I installed O-rings for seals on the water rudder hinges and greased them to exclude water. Seemed to work for awhile.
Don't fly on floats when it's freezing unless someone's paying you well.

Gary

Thanks Gary and Mike, yours were the responses I was looking for most.

My question was more about the safety of inadvertently landing on a thin skim coat of ice but your answers indicate that isn't my biggest worry.

It has been sunny and 35-37F when I've been flying so I wasn't too worried about stuff freezing but I hadn't given consideration to the fact that the metal is likely colder than the ambient air.

I'm paying for the privilege of flying, not the other way around, so I'll give it a pass unless it is a warm day.

Thanks, Allan

I really enjoy when the old experienced dudes here lay it out like that. Good responses!

One comment on thin ice and landing is to make a short test run first on open water patches if possible. Let the created waves break up (or not) the nearby frozen portions. Then land if necessary if it looks like takeoff is possible. I've had to do that after getting caught out in early October but I'm far from experienced and now by choice no ice expert. Frozen ice chunks are abrasive and can damage the plane when thrown up to the belly and tail.

Here's one of a good series of recently published reads about pilots that dealt with this routinely: http://www.hardscrabblelodge.com/gary-d ... lots-book/ The series offers a great perspective of flying in Maine and some of the routine operations they were involved with. Lots of learning skills described there.

Edit: I did observe a late season post-freeze landing once in Fairbanks. Local doctor and wife in Cessna floatplane came back from the bush. The pond was covered and ice 2-3" (guesstimate) thick. He landed and slid ok at first then broke through when slowing in a turn towards the shore. Next was a full power run at ice breaking until the plane rested half out of the water. Both jumped out and ran around pretty excited. The noise was incredible with all the banging and prop pitch but I guess it ended well. I knew others that simply waited out in the bush until the ice got thick enough to support the plane (4-6" probably) then came home and landed on the ice in town. Rivers freeze last so that's another option.

Gary

One winter in Kodiak, we had a fellow who worked seasonally for another agency asked us if we needed a winter watchman at our camp on Karluk Lake. This gent had spent a lot of time there in any case, so we agreed that he could spend the winter in our cabin there. We used the cabin only occasionally in winter.

Well, it turned out that he got a message to the effect that his sister was getting married in New York City in February, and he asked if I could pick him up and take him to town. My boss agreed, so I asked the camper about the thickness of the ice on the lake..... He got back to me that it was about six or seven inches, maybe more in places.

On the appointed day, I opted to take the amphibious Beaver, because, while the weather was severe clear, it was pretty cold....for Kodiak. I figured that much ice would hold the Beaver, and if it didn't, it'd fall through, and we'd deal with it that way.

When I arrived over the lake, there wasn't a stitch of snow anywhere on the lake ice....just glare ice. I started thinking about steering and brakes. So, I opted to put the gear down, to hopefully give me at least a smidgen of brake and steering. I landed a ways off shore, and the airplane came to a stop smoothly on the glare ice. So far so good.

Peter came out with his gear, which we loaded in the (very lightly loaded) Beaver, and we saddled up. I warmed the engine up a bit, then started the takeoff run.....sorta. As I increased the power, the airplane swung to the left, even with full right rudder. I backed off the power. Now we were pointed toward the island where the cabin was located.

I pushed up some power again, and the airplane swung around more. Finally, I smoothly applied power, increasing the power as the airplane literally rotated in place. Finally, the thrust gave the rudder enough authority to steer, and fortunately, we were pointed toward open lake ice when that happened. I applied takeoff power, and we were airborne in no time.

I had not considered the possibility that the ice was so slick that I would not be able to control left turning tendency, which the Beaver possesses in spades. Fortunately, I'd opted to land well out on the lake ice, rather than close to shore. Had I landed close to shore, we might not have been able to escape the shore.

Serendipity, rather than skill or knowledge.

Ten days later, Peter returned, and I flew him down there in the Super Cub on wheels.

MTV