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Experience and local knowledge go a long way towards mitigating risk, but if anyone is saying that 850's are a good tire for unknown sand conditions, which is what the OP is talking about, I call BS.

This reminds me of that "how much snow will my bushwheels handle?" thread. It's just impossible to give quantified advice...there are too many variables, and sand is damn near as complicated and unpredictable as snow. 850's aren't sand tires any more than bushwheels are skis.

If you opt to use regular tires instead of bushwheels for sand, or bushwheels instead of skis for snow, you'll do fine under some conditions. But since the surface conditions are completely unknown, you're really just flipping a coin. Heads: you landed somewhere you didn't need to be in the first place. Tails: airplane destroyed.

Why anyone would choose to accept those risks for simple kicks, when a few thousand dollars will vastly increase their safety margin, is beyond my comprehension. If bushwheels (or skis, or floats) aren't in the budget, don't land where you'll need them. It's not really that hard a choice...there are plenty of other places to go.

Of course everyone is entitled to equip and use their airplane as they see fit.

My 00.02 USD ramblings....

Local knowledge is paramount.

Reading "Nature" takes time and experience.

I spent several years driving/flying on beaches and rivers in Australia. 8.5 is not an ideal off-airport tire. It may work in many areas but, I would simply get bigger if I could. Riverbeds are (can) be dangerous for any vehicle. Don't let anyone convince you otherwise.

With local knowledge 8.5s can hold a loaded (over gross) C180 on a beach with solid sand (barley leaving tire tracks). But possibly, a mile down the beach it would sink and die.

I repeat (at the risk of beling offensive...)

Local knowledge is paramount.

Reading "Nature" takes time and experience. Get as much information as humanly possible before each flight. If there is a known safety void do not go!

Carry on men...

8GCBC wrote:My 00.02 USD ramblings....

Local knowledge is paramount.

Reading "Nature" takes time and experience.

I spent several years driving/flying on beaches and rivers in Australia. 8.5 is not an ideal off-airport tire. It may work in many areas but, I would simply get bigger if I could. Riverbeds are (can) be dangerous for any vehicle. Don't let anyone convince you otherwise.

With local knowledge 8.5s can hold a loaded (over gross) C180 on a beach with solid sand (barley leaving tire tracks). But possibly, a mile down the beach it would sink and die.

I repeat (at the risk of beling offensive...)

Local knowledge is paramount.

Reading "Nature" takes time and experience. Get as much information as humanly possible before each flight. If there is a known safety void do not go!

Carry on men...

Well, I wrote a long soliloquy about this in response to Hammer's post.....then dumped it. Can't figure out how to post a picture here, though I've done it a dozen times before, but it's an illustration of what 8GCBC notes here.

I would add that it's not just LOCAL knowledge. A pilot who's experienced at off airport landings can "read" most surfaces.....but knowledge of local conditions is in fact golden.

I think we're losing sight of the fact that the OP noted that he's planning on doing this with a Taylorcraft on 8.50 tires. That is a very light airplane, and a great airplane to learn off airport ops with. But, there's still a learning process that he's going to have to go through.

That's the key: Training and practice. Big tires are nice and indeed they do reduce the risk somewhat, but I've seen guys buy a set of big tires, bolt em on, and go break their airplanes, because they did't know how to read the landing surface.

Get some instruction, start slow and carefully, and work your way up. If you really want to spend 10% of the hull value of your airplane on tires, go for it, but with lots of experience you can do quite a lot on 8.50s.

But, understand that ALL off airport ops involve some additional level of risk. If you simply can't afford to lose your airplane, stick to airports.

MTV

glacier wrote:There is still a strong sense of adventure alive here. But nobody likes seeing a plane on its nose either.

Sand can vary from hard enough to roller skate on to soft enough to bury almost anything short of a light cub on 35's. The two ends of this spectrum can be present in the same vicinity on a beach or a bar. The advice given here also spans this spectrum, and is just really hard to give, let alone to give over the internet.

Good post - my sentiments exactly.

Also, yes - all the old guys down here used to do EVERYTHING in the backcountry on on 8.50s, but only because they were the largest tires readily available at the time. It doesn't mean it was the best way of getting it done, it was riskier. Its just the way things used to be.

Its analogous to building the Hoover dam or the Empire State building. Taking high risk and occasional loss of life used to be accepted. These days, not so much.

To the OP - I would say avoid SAND bars where you can, and stick with gravel and rock - particularly the high and dry stuff. You'll do fine there, better to accept a few rocks in the tailplane than to stand the plane on its nose. Sand is the nasty part of the whole equation, a gravel bar is a lot easier to read a more forgiving.

Battson wrote:

glacier wrote:There is still a strong sense of adventure alive here. But nobody likes seeing a plane on its nose either.

Sand can vary from hard enough to roller skate on to soft enough to bury almost anything short of a light cub on 35's. The two ends of this spectrum can be present in the same vicinity on a beach or a bar. The advice given here also spans this spectrum, and is just really hard to give, let alone to give over the internet.

Good post - my sentiments exactly.

Also, yes - all the old guys down here used to do EVERYTHING in the backcountry on on 8.50s, but only because they were the largest tires readily available at the time. It doesn't mean it was the best way of getting it done, it was riskier. Its just the way things used to be.

Its analogous to building the Hoover dam or the Empire State building. Taking high risk and occasional loss of life used to be accepted. These days, not so much.

To the OP - I would say avoid SAND bars where you can, and stick with gravel and rock - particularly the high and dry stuff. You'll do fine there, better to accept a few rocks in the tailplane than to stand the plane on its nose. Sand is the nasty part of the whole equation, a gravel bar is a lot easier to read a more forgiving.

Problem is I doubt there are many if any gravel bars where he's at, but this is indeed good advice otherwise.

MTV

I flew the Mississippi on floats and never saw a gravel bar just sand bars. It was around Saint Paul, MN in August, 2009.

ok maybe this will make it easier. A buddy has a Just SS with 29's, he lands all over the place. I plan to follow him the first few times. What kind of tracks from him should i be looking for to know if it will handle my 8.50s? I have landed the SS on the sand bars and made noticeable tracks but they didn't appear to have any real depth to them were the mains hit the tailwheel did make a larger mark.

cstolaircraft wrote:ok maybe this will make it easier. A buddy has a Just SS with 29's, he lands all over the place. I plan to follow him the first few times. What kind of tracks from him should i be looking for to know if it will handle my 8.50s? I have landed the SS on the sand bars and made noticeable tracks but they didn't appear to have any real depth to them were the mains hit the tailwheel did make a larger mark.

Have your escort walk the area and relay the conditions (radio, hand signals, etc). You need a lot more information than just tire tracks. But, you will start learning with less risk. Any tire tracking with 29s should be evaluated thoroughly at your stage in the game, if they sink at all! The tailwheel may provide the most information for you, if it sinks, just say no!

Also, practice your technique in a benign environment before heading to the bush.

cstolaircraft wrote:ok maybe this will make it easier. A buddy has a Just SS with 29's, he lands all over the place. I plan to follow him the first few times. What kind of tracks from him should i be looking for to know if it will handle my 8.50s? I have landed the SS on the sand bars and made noticeable tracks but they didn't appear to have any real depth to them were the mains hit the tailwheel did make a larger mark.

I think you're firmly in test pilot country with this one. Given the enormous difference in flotation between the two tires, I don't believe that what his tire does provides any meaningful indication of what your tire will do. Even if you factually knew that 1/4th of an inch depression was OK but 1/2 of an inch was too much, there's no way to figure that out from the air.

The only way you're going to know if 850's will float you is by trying it. I wouldn't...but then I'm pretty cautious with my airplane. The consequences of failure are so out of proportion to the rewards for success.

With my PA-22 on 850's with a 600 on the nose, if I am walking around and my footprints are less than 1 inch deep, I can make it work for the airplane. If my footprints are deeper, I mark it off as a place I don't want to go. When I look at somebody else's tracks to see whether I want to land, if they have bushwheels, I am looking for virtually no vertical impression. So if there is any sand squeezed up at the edge of the track, that is pretty much a no-go for me.

But seriously...download the FAA's Alaska off-airport brochure and memorize it...they did a pretty good job of laying out the site evaluation process...fewer bent planes when people follow it.


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I hope it is coming through that 8.50's present a great deal of uncertainty on soft surfaces and should only be used if there is sound objective knowledge to confirm conditions. I learned initially on 8.50's but quickly saw the limitations. I have a light plane with 26's. It is a huge difference. I wouldn't consider trying to confirm 8.50's are suitable for various sites like I used to do anymore. It is a lot safer and more fun not having to worry about it. I would recommend getting larger tires.

Additionally, the discussion so far has talked about varying densities of sand and gravel. Depending on where in the country you are flying you can also encounter mud on river banks and bars (or elsewhere). This is a whole new world of risk. For starters make sure you avoid this peril until you really have knowledge of what you are getting into. Sometimes it is hard to differentiate from sand. Some mud will eat any tire. Mike

Due to search and rescue flying decades ago, the majority of my landings over the last 50 years have been on the sandbars of the Mississippi and White Rivers, using a J3 with stock 8.00x4 tires (which have been entirely adequate for my purposes - your mileage may vary).
Some general thoughts that apply to the Mississippi and White only:
1) Always land on dry sand, the wet stuff may be quick.
2) When possible, walk the site first
3) If you haven't walked it, always land downriver rather than into the wind. The ripples and dunes have a sawtooth shape in cross section and may rip your gear off if you land upriver.
4) Watch out for partially buried snags and logs
5) Never use the brakes
6) If you sink in after stopping, you can 'walk' your way back up to the surface by applying full throttle and enough down elevator to blow the tail off the surface while slowly walking the rudder in full excursions from side to side. Two caveats - this is hard on the tubing and may result in a noseover if not careful. It helps if you scoop some sand out from the front and rear of the tires first
7) Although I never did, you can damage an airplane doing this.

IMHO, as someone with a little bit of T-craft time (but zero big tire experience):

You have one advantage with the Taylorcraft, you can keep the weight lower than most other airplanes. Use that advantage. The first time you go testing any off-airport location, go in at the lightest weight. Leave the gun rack, the roll-away tool chest, and the ice cooler back home.

The amount of weight per square inches of tire contact patch (tire loading) is what will determine whether the airplane floats or sinks in the surface. 8.50 x 6 on a light Taylorcraft may be less likely to sink than larger tires on a loaded 185.

I've tried larger tires on the J3. Didn't like the increased takeoff roll and reduced rate of climb. Since they weren't necessary on sandbars (my surface of choice) I took em off after a weekend and went back to the more satisfactory and entirely sufficient stock 8.00x4's.

JS170B wrote:8.50s on sandbars? No way. 29s have excellent float on sand. 26" Goodyears are doable but not ideal on soft sand, much less float than the 29s. Landing soft sand on 8.50s and you may expect to leave the plane there.
Jim

What Landed on many sand bars and beaches on 8:50s on everything from pipers to C206 and C207 without leaving anything behind. Yes 26" goodyears were better. Spent way more time on 25x11x4 then I wanted. Finally could afford 29s and way better. If we would have had those Air Streaks back in the day would be a lot less trophy animals available Best advice is what MTV suggests here:

"Right after first landing on a bar, STOP. Get out and walk around, looking for ugly spots, obstacles, etc. only after you've explored the bar, get in and taxi."

There is one pretty sure fire way to land on a potentially iffy surface, if need be, otherwise if it looks questionable and you don't need to, do don't do it.
I use a similar technique for snow and Ice, except when it comes to soft ground, instead of using a wet log, I use a rock the size of a cantaloupe.
Determine the point where you want to be stopped at, and drop the rock, if the surface is soft or marginally hard crusted the rock will carry enough energy to punch through it. If it looks good use your finely honed skills to make your approach so you will be stopped over the rock.
The rolling drag method is unpredictable and I would not risk a 60k+ machine on it. It is surprising how slow you can roll over a shit surface and not make any significant impression. If you can stop on a confirmed solid surface, for the most part the surrounding area is of little consequence with reasonably sized tires. If you don't get out for some reason to determine the integrity of the departure run out, then use an expedited take off procedure, once your up to some rolling speed you should be safe.

This is where flour bombing and pumpkin dropping practice can come to practical use.

Sidewinder wrote:There is one pretty sure fire way to land on a potentially iffy surface, if need be, otherwise if it looks questionable and you don't need to, do don't do it.
I use a similar technique for snow and Ice, except when it comes to soft ground, instead of using a wet log, I use a rock the size of a cantaloupe.
Determine the point where you want to be stopped at, and drop the rock, if the surface is soft or marginally hard crusted the rock will carry enough energy to punch through it. If it looks good use your finely honed skills to make your approach so you will be stopped over the rock.
The rolling drag method is unpredictable and I would not risk a 60k+ machine on it. It is surprising how slow you can roll over a shit surface and not make any significant impression. If you can stop on a confirmed solid surface, for the most part the surrounding area is of little consequence with reasonably sized tires. If you don't get out for some reason to determine the integrity of the departure run out, then use an expedited take off procedure, once your up to some rolling speed you should be safe.

This is where flour bombing and pumpkin dropping practice can come to practical use.

So you pack around a load of cantaloupe size rocks to evaluate landing sites? Seriously? Boy, has this conversation gone sideways.

Glad I didn't read this thread before I started flying off airport......

MTV

Yes I do. If there is a particular site I'm interested in that is questionable, but attracts my interest, I will invest time and effort into extensive reconnaissance of that site, so there are no surprises,If I really want to land there. I will use remote methods to probe the surface, and using objects and gravity are the simplest and effective Id hardly say that a couple of cantaloupe sized rocks are going to tax space and weight in the interest of a safe and assured landing. Again this only applies to surfaces that are questionable. and no I do not make a habit of carting rocks for the run of the mill vanilla sand and gravel sites. I got enough in my head thanks.

I surprised by your response MTV, Your one of the more experience pilots on here. You do not take risks foolishly at least I assume.