How thick must ice be to land on it?

[xrayalpha]

Just asking, there are some cracking lochs here in Scotland that have been subject to minus 0 for 24hrs a day for at least two weeks.

And, no, not asking: how thick must a pilot be to attempt to land on such a loch!

[blueandwhite]

Just a few variables spring to mind

Aircraft - microlight, 747, R22 for instance

[Maoraigh1]

I haven't a clue, but seem to remember being told about land rover racing on Loch Morlich in a hard winter 40 or so years. Anywhere a landrover has driven should be strong enough for a GENTLE light aircraft landing. It is possible to get thick snow covering very thin ice. It insulates, and prevents ice thickening. It also spreads its weight evenly. Skiing over a snow covered lochan, in the mid 60s, I pushed my ski stick down to see how deep the snow was. It broke through ice 2+ feet down. We quickly left the lochan. I assume you're thinking of a wheel landing.

My post refers to landrovers, but is changed to Trabant on posting.

[irish seaplane]

Ice ice baby - there is a mathematical relationship between ice thickness and its strength. River ice should not be trusted btw ;-)

Thickness = f x Square Root of aircraft weight/1000

The f value for ice formed above -9c in a Fresh Water Lake is 3.29 if you are working in lbs as per above. There are some other things to consider like radius of influence etc but generally I was hoping for 8" on the lake last year to try it. It only ever got to 5" :hmm:

Let us know if you try it.

Irish

[GGR]

If you are keen to plonk it on a large area with thick coating of ice try any major UK airport right now! Less likely to drown.......may get stuck with large bill for priviledge.

Happy landings and dry ones at that

GGR

[CanAmdelta1]

I'll take a shot at answering.

Please be aware that ice on lakes can be tricky due to many variables....snow insulation, springs underneath the ice, currents, has the water authority dropped the lake level?, ambient temps, etc.

Be extremely cautious, we had a grandfather and his 5 yr old granddaughter go through the ice on a snowmobile day before yesterday:ugh: Both survived.:D

Moose tracks on the ice usually means ice can support a Super Cub landing or 6" of good freshwater ice.

C206...C185 min of 8" of freshwater ice to land with skis or wheels

If staying(parking) overnight I would want 10" for the Cub and 12-13" for the Cessna.

Also cross pressure cracks at right angle.

Have a Merry Christmas!

[xrayalpha]

so:

3.something x square root of 1000 lbs (for a microlight/lsa) divided by1000 = 0.3 inches of ice!

Hmmm!

Think I will apply a safety factor of 10!

[Pilot DAR]

At least this thick....

http://i381.photobucket.com/albums/oo252/PilotDAR/Aircraft/IMG_2357.jpg

This was about 12".

You'd better be very sure of the thickness, and many other factors before you attempt it. Also be aware that your hull insurance may revert to the "moored" deductable (you are on the water after all), which can be considerably higher.

I have landed on the ice for more than 25 years, but have also had occasional problems. Be very careful, and may sure you are equipped and have a plan, for what might not work out well...

[IO540]

On my office wall I have a famous pic of what looks like a Cessna, sunk through the ice, with just the wings on top. I hope the occupants got out before it sunk...

Where I come from (former Czechoslovakia) they used to have go-cart races on frozen lakes. They used to drill holes in the ice to check the thickness, and also apparently to allow the fish to get some oxygen.

0.3 inches of ice!

I guarantee 0.3" won't be enough. I have a frozen pond right here next to my patio door, with about 1", and I can tell you what happens if I stand on it ;)

My guess (only a guess) would be 6" minimum.

[Grabbers]

Try it. Please do. :ugh:

[Whopity]

I recall bringing back the remnants of two Gloster Gladiators that had landed on the Fjord at Trondheim and then the ice melted
http://www.fleetairarmarchive.net/aircraft/Gladiator_MkII_N5628_preserved_recoveredNorway_RAFMuseum.jpg

[Pilot DAR]

You'll see all kinds of information about doing anything on ice. As they say, "good judgement comes from bad experience". It is impossible for someone to tell you that is completly safe to land on any given piece of ice, unless they have just done it ahead of you, and you are similarly skilled and equipped. Conditions vary too much for definate answers for broad circumstances.

I have purposefully landed a C 180 floatplane on the ice, to break it through in the spring - it went through happily about 5 inches of ice, and floated among the chunks. I watched a friend taxi a ski equipped 180 (actually, the same plane, come to think of it!) across the ice toward shore. The Ice gave way under the plane, and it started to go through. His use of full power with the speed he had was just enough to water ski it onto shore. There was zero leftover margin of safety on that one!

With great care, I can move like an alligator on just over 1" thick of "good" ice. If I'm going to stand (and concentrate my weight) It's going to take more than 2" to hold me. I train Fire Department personnel to do this....

If you are contemplating landing on the ice, get really good advice from someone who understands airplanes, and has stood where you plan to land, within the last 24 hours. If it's you, because you walked the ice first, excellent. May I recommend a suit such as that which my daughter and I are wearing in this photo, and some training, just for your safety....

http://i381.photobucket.com/albums/oo252/PilotDAR/IMG_0339.jpg

[seat 0A]

Interesting hobbies DAR! :ok:
Cheers

[irish seaplane]

You said:

so:

3.something x square root of 1000 lbs (for a microlight/lsa) divided by1000 = 0.3 inches of ice!

Hmmm!

Think I will apply a safety factor of 10!

Basic maths says:
3.29 * Square Root of 1000/1000 = 3.29" :D

I tried it, how did you get on?

Irish

[RatherBeFlying]

Here in Canada the ice fishers drive up to their huts in cars and trucks; so, after the huts are out as long as you see road vehicles (not snowmobiles), your odds are pretty good.

Some communities put in short cuts to save a long drive around the lake, which is used until the first car goes in:uhoh:

As PDAR has observed, nothing substitutes for walking on it yourself.

In certain places up North they put in ice roads to reach remote communities and run semi-trailers along the ice. But just about every year, somebody goes in:uhoh: Roof exits are commonly installed;)

Once temperatures get above freezing, candle ice can develop. It can be six feet thick and you can fall through it:(

One fine summer, I was canoeing down the Spanish River where it was a number of ponds with sandbars and riffles in between. As we came over one sandbar, we passed over a moose skeleton that seemed as big as the canoe. Most likely that moose had fallen because the current below had thinned the ice and it got trapped by the current between the ice and the sandbar. Snowmobilers do this too, perhaps even more than the moose do:ugh:

[Pilot DAR]

Yup!

I flew my local lake (Simcoe) this afternoon. The ice was so clear in places, I could see all the details of the bottom clear as could be. Zero sense of how thick the ice was, I would have not imagined that a view so clear could exist with ice of any thickness. Open water is two miles away for where I'm looking....

I flew home and drove back to walk it. With the ice suit on, I went out with the drill. To my amazement, the ice was 8 inches thick! I stood and looked at the bottom between my toes, and watched a fish.

Ice landings tomorrow!

[MR.X99]

In Northern Canada we liked the ice to I think about 12 inch,s sounds like a good starting point.Scotland would not get safe ice. In the North its -20,-30 for a good few weeks before Ice Roads Open.Wouldn,t want to try it unless professionally surveyed as usually roads and runways are made on the most shallow part if possible.:ok:

[twentygrand]

Landed a Starlifter on 9ft of sea ice in a former life!

[xrayalpha]

Irish,

My apologies, I understood:

3.29 muliplied by (square root of 1,000) divided by 1000.

Even then I got it wrong since the square root of 1,000 is not 100!

So if you are taking the square root of (1000 divided by 1000), yes, you get 3.29.

By the way, where did you get the formula from? What is the significance of square root of 1000/1000? and where did the constant come from?

Basic maths says:
3.29 * Square Root of 1000/1000 = 3.29"

I tried it, how did you get on?

Irish

[Jan Olieslagers]

As I read the original post, the first 1000 is max gross weight, in pounds; the second apparently a constant. Make it 452 if gross weight is in kilograms.

[Pilot DAR]

Today's ice flying...

http://i381.photobucket.com/albums/oo252/PilotDAR/IMG_2185.jpg

By the bouy....

http://i381.photobucket.com/albums/oo252/PilotDAR/IMG_2187.jpg

You can see the lake bottom throught the ice, though it is now 9 inches thick....

C 150 Ice takeoff video by PilotDAR - Photobucket (http://s381.photobucket.com/albums/oo252/PilotDAR/?action=view&current=MVI_2193.mp4)

Video clip of takeoff from the ice...

[irish seaplane]

Chapter and verse are available from the book: Seaplane Operations by Dale de Remer chapter 16 section 8. Original formula from RG Weber, later studied by a russian called Moskatov.

I'd would be inclined to build in a fudge factor into it, there seems to be alot more to it than just the theory.

Irish

[India Four Two]

Back in the 70s, I jump-seated in a 748 (CF-CSE) that landed on an ice runway by a drilling rig in the Mackenzie Delta. This was a regular operation throughout the winter. I don't know if they used ice-road techniques to thicken the ice.

[ChrisVJ]

I have flown onto ice in both Beaver and Otter on skis with our local floatplane operator. He says rule of thumb is 6" plus 1" per thousand pounds.

[Pilot DAR]

rule of thumb is 6" plus 1" per thousand pounds.

Good rule, though I'm not sure the math still works for Twentygrand's Starlifter landing!

[Finn47]

We have a fly-in on the ice of Lake Nummijarvi, near Kauhajoki, Finland on March 11 & 12. For the 9th year now, in fact. Dozens of aircraft taking part. The largest is an Antonov 2. Great fun. Lots of pictures from last year here:

Nummijärvi Fly In 2010 (http://airpilot.pp.fi/kuvat/nummijarvi2010/)

[Pilot DAR]

Some video clips of fun on the ice...

(I'm not quite sure how to make Photobucket do this, but there are videos there somewhere...)

http://i381.photobucket.com/albums/oo252/PilotDAR/th_MVI_2219.jpg (http://s381.photobucket.com/albums/oo252/PilotDAR/?action=view&current=MVI_2219.mp4)

http://i381.photobucket.com/albums/oo252/PilotDAR/th_MVI_2213.jpg (http://s381.photobucket.com/albums/oo252/PilotDAR/?action=view&current=MVI_2213.mp4)

http://i381.photobucket.com/albums/oo252/PilotDAR/th_MVI_2210.jpg (http://s381.photobucket.com/albums/oo252/PilotDAR/?action=view&current=MVI_2210.mp4)

http://i381.photobucket.com/albums/oo252/PilotDAR/th_MVI_2207.jpg (http://s381.photobucket.com/albums/oo252/PilotDAR/?action=view&current=MVI_2207.mp4)

http://i381.photobucket.com/albums/oo252/PilotDAR/th_MVI_2206-1.jpg (http://s381.photobucket.com/albums/oo252/PilotDAR/?action=view&current=MVI_2206-1.mp4)

[Hank195]

In the US, a seasonal ice runway has been operated for many years (with FAA approval) at Alton Bay in New Hampshire. I understand they look for 12 to 14 inches of ice to open but that's more to support the plow trucks than the aircraft. When I was flying on skis with a 7ECA we use to look for cars/trucks driving on the ice or more than 6". Comments above are correct, local conditions and knowledge matter more that a single minimum number of inches.

AOPA Online: Alton Bay ice runway opens (http://www.aopa.org/aircraft/articles/2010/100114altonbay.html)