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ABW how is that snow? Hope to warn someone about this. Save the next guy.

Bump!! It is getting to be that time of year again. For all the new guys/gals that heard Bushwheels are fine in snow. Doug was good enough to show you what a few inches can do. DENNY
 
Bump!! It is getting to be that time of year again. For all the new guys/gals that heard Bushwheels are fine in snow. Doug was good enough to show you what a few inches can do. DENNY

I'm hoping he post pictures of his new skis ;- )

Glenn
 
Back on the Datum retracts myself, and I have to remind myself: MAKE SURE THE WHEELS ARE DOWN IF LANDING ASPHALT, OR SKIS IF LANDING SNOW, DUMMY."

One time I landed a remote canyon, and was surprised by how sticky the snow was. Before I came to a full stop, I thought "screw this place" and I made my turnaround to get out of there. But I ran out of canyon before reaching lift off speed. When I realized I was wheels down, it was equal parts chagrin and relief. Skis down, I was quickly back on my way. I have yet to land on asphalt on the skis, frozen grass yes, on purpose. I suppose it's a plus for the Datum's design that let me get away with this. There was no tendency at all of nosing over, it just felt real draggy, so controllable/normal otherwise, that it's a possible technique I could use for making a short as possible snow landing.
 
I think the higher your axle is the less chance is you'd flip over because you are effectively shifting the cg rearward the taller you sit. 35s would be better!
 
How ironic that this thread was revived yesterday. We've had a bit of snow here in north central MN and was busy deer hunting the last couple of weeks and have really wanted to go flying. I was thinking of flying yesterday and since the snow has been settling a bit I was thinking of 'trying' to go up. After reading this thread again, I mad the smart decision of postponing any attempts until the snow either melts further, or I get around to putting my skis on.
 
That U tube video on the tall gear cub noseing over was a case of tail too high when he landed and then he must have hit the brakes. Tall gear I don't think had anything to do with it. IF he'd been in a 3 point when he landed and hit the brakes; he probably wouldn't have gone over as his cg would have been way back. You can't land in a flat attitude and hit the brakes like he must have done. Landing is hard to do perfectly, especially every time, I have found out.
 
I did the bump because it usually starts about now that we see planes going over testing that Bushwheel thing. Doug was good enough to show how easy it is to go over so figured We could ride it another season. Kid, I think the big tires and tall gear do have a greater effect on the possibility of getting up on the nose. It creates a very long lever arm, once that tail starts coming up the elevator just does not have enough force to counteract the drag on the gear even with nose up trim like this pilot had. Talking with some fellow members of the bent prop group a few noted that the salvage point for tipping on the 35s seems too be a bit further back. Could just be the sight picture or whatever but they say once it starts to go it gos fast. I would agree that to avoid going over the lower the tail /aft CG the better.
DENNY
 
I launched in a C172 in 6” powder years ago. A couple hours later on my return everything looked the same but there was slush under the surface.

No damage but it felt like a carrier landing after snagging the hook.



Sent from my iPhone using SuperCub.Org
 
Think of a teeter totter. The further the one kid sits back the harder it is for the other kid to totter. When you add axle height you are shifting the CG back or moving the kid back. Back is better in a cub for keeping the tail down. The wheels are the fulcrum. Tire width probably does play a role in the wrong kind of snow and the bigger the tire the more width it has. Keep the power on big time to help keep the tail down. When I get the coinola I'm gunna try the 35s.
 
Think of a teeter totter. The further the one kid sits back the harder it is for the other kid to totter. When you add axle height you are shifting the CG back or moving the kid back. Back is better in a cub for keeping the tail down. The wheels are the fulcrum. Tire width probably does play a role in the wrong kind of snow and the bigger the tire the more width it has. Keep the power on big time to help keep the tail down. When I get the coinola I'm gunna try the 35s.
And don't use as much brake force, as the longer gear will be more easily be able to nose it over due to the extra leverage.
 
‘Tis the season. 172 trike on 29’s tried the the ski strip/gravel runway here yesterday and got the prop and wingtip. Seems we get at least one about this time every year…:banghead:
 
Sigh, there's probably a lot more of that which doesn't make the news. Thanks for the heads up as a reminder to folks to be extra cautious. "But it worked on YouTube!"...sorry, I couldn't help but throw that in.
 
Broke through crust and got pulled to the side. Tipped up on one tip and prop then came down. Nose gear structure looks ok. 172XP
 
I think the higher your axle is the less chance is you'd flip over because you are effectively shifting the cg rearward the taller you sit. 35s would be better![/QUOT

One could think so but -- that is exactly the opposite to how it works the loner the arm the easier it is to flip if you have a stock gear and go to extended you will notice how much easier it is to lift the tail while braking. There is a great video on you tube of a guy with what looks like 12 inch extended gear at Hood strip flipping over as he applied brake. It's like the aircraft is the end of the Whip.
To push the large tire through the snow can sometimes be more drag than a small one, like pushing a bigger snow shovel I found that out the hard way. The application of full power saved me from flipping over while just dragging the strip that had grass sticking through the snow - it sucked me in and it stoped in about 50 some feet underI full power and full aft stick in a Maule M7, there I was and could not get enough speed for take of or control the plane to go straight in almost 18" of wet snow.
I did let most of the air out so the 31s so they were halve flat this makes a big flat spot on the bottom of the Tire and after taxiing back and forth a couple times it waddled itself to take of speed on top of the snow instead of digging in (an old timer told me that trick years ago) still works.
 
I would suggest that, for an aircraft being rapidly decelerated by deep snow, the height of the CG above the point of rotation may be of at least as much interest as the position of the CG behind the point of rotation.

The influence of gear position on nose over tendency will vary with pitch attitude. Taller gear may be an advantage when the tail is low but that advantage may go away as pitch attitude reduces.
 
I always felt that the longer the gear, the longer the tell before going over center after starting from a tail low attitude. A cub on standard gear and small tires will go over center quick when on the brakes. A long gear cub on bushwheels takes a long time before getting to that over center attitude. More time for your brain to compute what needs to be done.
 
I always felt that the longer the gear, the longer the tell before going over center after starting from a tail low attitude.

Ah, but you are describing the gear as longer not taller. The advantage comes from moving the axles forward not from moving the airplane higher above the axles. The forward advantage remains in level flight attitude. The taller part is a disadvantage in level flight attitude.
 
If you operate in a handful of inches of snow, the taller the tires the easier it is to move the plane through it. 3-4” of crusty snow is no big deal on 31s and is no cause for concern on 35s. Like with any soft or sticky surface you need to be ready to add power. Taller gear isn’t much of a factor in that. Brakes are a total non factor since they’re completely ineffective. The drag of the snow will stop you faster than you want. Power counters the deceleration.
 
Rapid deceleration is the problem. Controlling deceleration is the solution.

Take a tall object with a small base. Make it move horizontally toward an obstruction that impacts the object at its base. The base of the tall object decelerates but the CG of the tall object wants to keep going forward so the tall object rotates about its base.

You suggest that pulling forward on the tall object above its base will reduce it's tendency to tip over. Clearly that does not stand up to any scrutiny. A force pulling forward is only useful if it acts in the same plane as the obstruction causing the deceleration. Only then does the forward force counter the deceleration without producing a rotational couple.

Power only helps if the downforce on the tail produces a couple that is greater than the thrust couple.
 
You don’t fly on soft surfaces much, right? When you do try it? The proper response to uncommanded rapid deceleration is to apply power and control the deceleration. It’s the only tool you’ll have.

The 172 pilot should have been using classic soft field technique that all of us were taught in nose draggers. Maintain power to keep the nose wheel up. The more the plane decelerates the more power it takes to make it work.
 
The proper response to uncommanded rapid deceleration is to apply power and control the deceleration.


Is it the uncommanded rapid acceleration you want to oppose or is it the resulting nose over tendency?

How much would you expect adding power to help in an aircraft with a high thrust line and/or the elevator out of the propwash?
 
I could be wrong, but. The attitude of aircraft should not matter when it comes to prop wash over the wing/tail. If it did aerobatic flight might be difficult. The downforce should be the same tail low/level flight/tail high. You can hold a tail down, or pick it up with power and elevator. Wing AOA, CG, Stabilizer position and flap position also matters. The problem with landing in snow/mud/water/sand/ect is overcoming the drag created on the tires. Forcibly holding the tail down in snow/mud/water/sand is going to drive the mains deeper into whatever stuff stuff have. Once you reach the drag point to overcome the tail downforce that forward force the prop is creating will become a huge problem. If you fly the tail and keep it from digging in you have now removed some of the downforce. The force momentum created by sudden drag is another issue if you are unprepared. Bottom line is I think the power helps until it doesn't, then it hurts. The smart guys should be able to do some of that triangle math to help figure out at what point the long gear hurts vs helps. I put my skis on this weekend.
DENNY
 
Air pressure?? With my very limited experience flying Bushwheels on snow, I did notice that when I had low tire pressure, 6psi, the snow would build in front of the tires like a tire chalk and the tires did not like to roll. When I ran higher pressure they penetrated the snow and rolled better. Can anyone with more experience speak to this? Thanks
 
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