I'm sure someone will tell me why this wouldn't work, which is kind of the point in asking.

Has anyone ever played with "driving" conventional landing gear. Traction would be an issue to overcome but battery technology is getting good and the weight is coming down. I figure 0-take off speed would be near instantaneous in a 1400 lb plane. If the traction issue could be overcome. Maybe this has been done or maybe there is a great reason why it hasn't. But Google has nothing for me.

Thanks,
Mike

Edit: no bites so I will explain the purpose of the question. If possible I think it would be a neat "buffer" in case of wind shift, getting a steeper climb off the roll in a shorter distance for obstacle avoidance. If highly refined could correct a potential ground loop scenario. I, like most of the folks on here appreciate the simple, proven, bullet proof nature of a bush plane and pilot skill. But that doesn't stop the wheels from turning every now and then.

Come on, man...

Let's get back to the issue of getting your pilot certificate.

Not exactly the same concept as the whole treadmill deal haha but I appreciate the humor.....if it was humor. Pilot cert is in the works. Local club. Just killing time. Work and rain slowing the process considerably. If I'm not doing something related to a hobby I will quickly lose interest. In hyperfocus mode. If I've made an ass of myself in the process, well wouldn't be the first time.

The added weight and complexity would negate any benefit I think.

Zzz wrote:Come on, man...

Let's get back to the issue of getting your pilot certificate.

Then how about little Sea Doo jet pumps installed in some floats?

A1Skinner wrote:The added weight and complexity would negate any benefit I think.

Seems like everything ends up falling into that category. From assisted takeoff to adjustable wing geometry. It's all about the complexity. And cost vs reward. System redundancy and so on. I believe we have the ability to make a high lift, low stall wing that makes a transition after takeoff, be it camber or leading edge or both, to allow better cruise efficiency. But then we hit the complexity wall again. And the saftey wall. Then lastly the cost wall. Or maybe the cost wall comes first

The dream plane, in my limited experience, would be stol capable, 180mph cruise sipping fuel. Ahhh to dream. Need a transformer plane

It's not a motorized landing gear, but here is a video of how to do a 300 foot takeoff in an Ercoupe.

https://www.facebook.com/352ndFighterSq ... 391173634/

Ideas are great if you have the fortune and time to make them happen; just ask any EAB aircraft owner that has successfully integrated a one off automotive engine to an airplane like this: https://backcountrypilot.org/features/category/featured-bush-planes/moosemods-murphy-bull-moose. That's why most of us working stiffs accept the existing technology and put our hard earned cash into avgas, since that's the reason we got our certificates anyway. Don't let this reality discourage you from developing viable concepts; who knows, you may be the next Burt Rutan. But then again, it'll take gobs of money to make it happen.

Msmithabr wrote:I'm sure someone will tell me why this wouldn't work, which is kind of the point in asking.

It will absolutely work and could be a pretty meaningful improvement for a STOL competition plane. I'll look forward to seeing someone compete with Steve Henry!

It makes no sense to add weight, complexity and cost to a airplane without making it work better in the air...where it belongs. More horsepower and a better propeller will also shorten take off distance, plus they work when the tires aren't on the ground.

As for ground handling...the airfoils and brakes do that just fine. No need to add thrust to a wheel, IMO.

Hammer wrote:It makes no sense to add weight, complexity and cost to a airplane without making it work better in the air....

And yet people compromise cruise for STOL all the time. I took his question to be the same.

If you have the best engine and prop you can have at an airplane, being able to add another 50HP to the wheels would allow you to take of shorter. There is no question about that. Whether the complexity is a worthy trade-off is up to the OP. Wouldn't be for me. But neither would building a plane like Steve Henry's where everything is amazingly finely tuned to STOL competitions.

It's been thought of, tried, patented, funded, forgotten about, picked back up, re-thunk, dumped, patented again, ..........

https://patents.google.com/patent/US3762670
https://patents.google.com/patent/US4659039
https://ieeexplore.ieee.org/document/7748078/
http://www.freepatentsonline.com/y2017/0057624.html
https://patents.google.com/patent/EP0756556B1/en

....and forgotten about, dredged back up, used in physics class, laughed at, patented some more, and forgotten about.

The problems are significant and the weight is better put into more ponies up front. It adds up to hundreds of pounds to make a SE Cessna cut the ground roll in half.

I don't think getting power to the wheels is inherently mind boggling, or will involve hundreds of pounds of weight. The biggest issue I see is that you need friction to turn that power into movement. If you've ever tried to get on the brakes hard while the wings are producing any lift, you know this friction isn't really there until the plane is moving slow; this is compounded on a STOL plane. STOL also lends itself to reduced friction surfaces like dirt and gravel. Then you have the risk of tubed tires spinning the tire on the wheel and cutting the valve stem, especially if the tire slips and catches suddenly. So basically you're trying to rotate a tire on a loose surface attached to a machine that inherently reduces available friction until it lifts off, so it becomes less or ineffective relatively quickly.

None of this is to say it can't be done. You don't need massive batteries for 30 seconds of use and might get away with smaller motors that can handle a brief peak load. Who is to say you even need batteries at all? Electricity isn't the only way to move things or store potential energy. But I do agree it's a lot of complexity with many pitfalls for this use case, and there are other ways to shorten the roll that benefit other phases of flight too.

...However, if you show up at a STOL competition and take off in 3.5 feet because the airplane's tires yanked the thing forward like a Ferrari, I will be suitably impressed.

I honestly just like the conversations and building/trying different things. Grew up building custom cars. With a plane I feel like I would be unwise to take a course of action before having an open conversation with folks like the ones on here. And maybe a couple engineers. It all starts in a notepad and computers are not my thing. So limiting. Speaking of Steve is he still running the yammie in his Highlander? I've got a few of those engines in boat projects. They have been incredibly reliable even with the addition of boost. Cements my choice in aircraft engine seeing his success. Wishing there was a airworthy belt to retain the cvt setup. Just so simple.

Thanks for all of the responses. Seems like the current day Howard Hughes is busy sending rockets into space and building electric cars. Someone needs to pull him over this way and watch him go

DeltaRomeo wrote:Ideas are great if you have the fortune and time to make them happen; just ask any EAB aircraft owner that has successfully integrated a one off automotive engine to an airplane like this: https://backcountrypilot.org/features/category/featured-bush-planes/moosemods-murphy-bull-moose. That's why most of us working stiffs accept the existing technology and put our hard earned cash into avgas, since that's the reason we got our certificates anyway. Don't let this reality discourage you from developing viable concepts; who knows, you may be the next Burt Rutan. But then again, it'll take gobs of money to make it happen.

Maybe an adjustable wing geometry is the answer to the efficient stol plane. If someone came up with 2 wings equal in width and length. One that would allow super stol capabilities. And another that would allow for efficient/fast cruise. And these wings were identical in leading edge and top profile. With the only differences being the bottom wing profile then I feel like that would be an obtainable transition with the use of some form of "spring" alloy and a cam-like rod that could be controlled by lever in the cockpit. Staggered expasion joints. Take the bottom running surface from concave to a more neutral "speed wing" shape. Mechanical failure would default the wing back to stol mode because of the leafspring type material. You could vary the cam profile at each intersection based on.....well whatever they base it on. I know jack diddly about wing design. Just spit balling. If someone came up with those 2 profiles I believe I could build a wing that could accomplish both of them with the pull off a lever. A very long lever. Maybe this has been done also.

Fun talk nonetheless,
Mike

Edit: late to the party. People patent things hoping to collect when someone comes along and does it? Not that I have any commercial interest in aviation, just seems like patent laws hold back viable designs. Bummer

Well, it does seem to add up to hundreds of pounds for something that would double the thrust (and halve the ground roll) of, say, a 172. Using data for motors used in electric planes (light weight) for max peak loads, you are left with around 40 pounds on each main gear leg (unsprung, so you'd have to add damping and weight to the gear), plus enough cable to support 600 amps or so to each motor at 48V (less if higher voltage rails are used), and enough battery capacity to provide that current for 10-15 seconds (not limited by energy, but by the current draw). Using rosy numbers, it adds up to over 150 pounds of Li ion batteries, plus controller (or whatever electric system you have), plus sme astoundingly large, heavy cables, plus the motors and hardware, plus the heavier landing gear...

It is not really a "Hey, that looks easy. Why hasn't anyone done that?" sort of problem.

If you add the same weight to the engine and prop, you'd be far ahead. Nothing is for free.

Before getting too hung up on the illusion of there being a problem, perhaps go fly some of the more notable STOL planes. Take them off short, and LAND them short. The key to short landings, in addition to aerodynamics, is weight, or lack thereof.

Dream if you enjoy it, but learn what actually goes into operating short, from your own doing, and I think you'll move onto the next problem.

All theory and speculation until sound engineering principles are factored in:[url]www.youtube.com/watch?v=WKCl3lfAx1Q/url]
Been thinking of RATO for the 206 for awhile now......

You want to take these questions to the Homebuilt forum, you will get encouragement there. This isn't the right forum, too many bush pilots.

Battson wrote:You want to take these questions to the Homebuilt forum, you will get encouragement there. This isn't the right forum, too many bush pilots.

I respectfully concur. Visit http://www.homebuiltairplanes.com/ and post the same question there. Folks will come out of the woodwork to argue this for weeks over 30 ridiculous pages. But you’ll get well-thought-out over-engineered solutions to the problem. Trust me, you’ll either be glad you did or regret the decision in the worst way. [emoji3]

~Chris