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.

Understood, and will do. At the same time if we are operating an airport only plane there is no purpose in building anything. The bush pilots, recreational or commercial, would be the only group to benefit from a higher weight/seat capacity plane having the ability to get down in more places safely. Unless an engine out scenario of course. Draco is not a light plane. He gets down. But even with all that engine out front his cruise is limited by the wing structure required to get that big plane on the creep. 300hp reverse thrust doesn't hurt either. It's not a problem. But something that would be fun to make better. Best of both worlds. Or close.

But Zzz is right here. Lack of first hand experience is a problem. Which is why I posted it in a place with a wealth of practical stol knowledge. And I've gotten many answers and I appreciate everyone who took the time. I'll go see if I can get those boys fired up on the home built forum.
Thanks for the link,
Mike

ya know...they do make 2WD motorcycles, and they are pretty amazing what they do...i think the idea is way valid...go drop your heavy airplane into lower loon and tell me that a little quicker departure wouldnt be nice...!? Just there today and man were there some density altitude issues....

I agree, there is some merit. My biggest question is what do you do with it on landing? Does it speed your tires up to try to match ground speed? Just stay disengaged? What if it fails and stays engaged?
The landing part to m is more technical then the takeoff part. But maybe I'm not seeing it right.

If you are looking for vertical take off and landing maybe Bell or Enstrom might have the solution for your quandary .

A1Skinner wrote:I agree, there is some merit. My biggest question is what do you do with it on landing? Does it speed your tires up to try to match ground speed? Just stay disengaged? What if it fails and stays engaged?
The landing part to m is more technical then the takeoff part. But maybe I'm not seeing it right.

Keep it engaged? Use the regenerative braking to make the tires oppose motion a bit, recover the energy to a point, now you have a Bush Prius and the hipsters will love you too.

Despite potentially no practical benefit when you consider alternatives, I do like the "engineering it because we can" mindset here. I really dig that kind of stuff. A lot of cool things have happened in aviation simply because someone ignored the commercial viability of something, and just did it because it seemed like a neat idea at the time. A lot of commercialized ideas flopped in the real world too, but that's how innovation works.

I also meant what I said about methods other than electricity as well. What about compressed air? You don't need a lot of it. Calidus uses that idea in their gyrocopters to spin up the main rotor early (rotors aren't spun by the engine in a gyro, just forward movement). Or hydraulics? A small engine driven pump spinning a turbine on the axle (though will reduce power to the prop, so probably not worth it). My point is, think outside the box. Electrics are cool but you also aren't building a Tesla here; you do not need huge batteries or motors. You need a brief peak torque falling off with velocity as a form of traction control. We're talking for a matter of seconds, and it just supplements the thrust from the prop anyway. You have the contact patch of a go kart, so size the wheel torque accordingly unless you can solve that issue too unless you want to do burnouts in your plane.

Maybe I should go follow the impending thread on homebuilts.

There is a jet powered glider (self launching) that uses electric drive on the mail wheel to shorten takeoff so, it has been done.
The jet engine doesnt provide enough thrust at the get-go to take of in a respectable distance so the electric wheel gets it up to speed.
Pretty sure they use regenerative braking as well instead of adding a disc and caliper.

https://www.planeandpilotmag.com/articl ... 2xvD9hKjBI


You wouldn't need a bajillion amps of power with 0000000 gauge wire unless you were trying to take off in 200 feet solely based on electric wheels (we still have a prop). You only need as much as you could reasonably get to assist takeoff and maybe shave 25 feet off the distance.

There could be a weight tradeoff if the drive motor could also act as your brakes. Battery packs for limited takeoff use could be attached to the gear legs.

lesuther wrote: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.

Remember, that you don't have to halve the roll to go from fourth to first in many STOL competitions. Just a few feet can make a difference.

Rather than power the wheels, which gives you no thrust in the air, why not go with a tried-and-true JATO system? Just don't start any wildfires, OK?

I'm always impressed by how clearly put together these wartime training films were. You almost feel like you could safely operate a JATO/assisted wildcat after watching this:

Oregon180 wrote:Rather than power the wheels, which gives you no thrust in the air, why not go with a tried-and-true JATO system? Just don't start any wildfires, OK?

I'm always impressed by how clearly put together these wartime training films were. You almost feel like you could safely operate a JATO/assisted wildcat after watching this:

1,000 pounds of thrust for 8 seconds from a 150 pound canister... why was an STC never made for this?

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 take it that forum has a lot of dreamers?

Nothing wrong with dreaming; it's the fuel that makes ideas comes to life, and can produce something really innovative, if one isn't constrained and boxed-in by having the knowledge and experience of flying actual STOL airplanes.

Nobody's mentioned the hazards of differential thrust yet. If the unit produces enough energy to be of any use, it's also going to provide enough energy to ground-loop the airplane on take-off if the thrust isn't equal.

Even in an marginal STOL airplane I've found there's more than enough to keep me busy without managing power to the wheels, especially in bush conditions. If attention is taken away from all the other nuances of a short take off to manage wheel energy, I really doubt the take off is going to be one iota shorter.

It's fun to think up better ways to do things, but it's not like aviation has ever been cursed with a lack of funding or innovation or intelligence. There's usually a few dozen good reasons why things like powered wheels are not in use.

Hammer wrote:Nobody's mentioned the hazards of differential thrust yet. If the unit produces enough energy to be of any use, it's also going to provide enough energy to ground-loop the airplane on take-off if the thrust isn't equal.

It would be pretty easy to have the electric motors linked to the rudder peddles such that corrections in steering resulted in changes in energy being delivered to either side.

Hammer wrote:Nobody's mentioned the hazards of differential thrust yet. If the unit produces enough energy to be of any use, it's also going to provide enough energy to ground-loop the airplane on take-off if the thrust isn't equal.

Even in an marginal STOL airplane I've found there's more than enough to keep me busy without managing power to the wheels, especially in bush conditions. If attention is taken away from all the other nuances of a short take off to manage wheel energy, I really doubt the take off is going to be one iota shorter.

It's fun to think up better ways to do things, but it's not like aviation has ever been cursed with a lack of funding or innovation or intelligence. There's usually a few dozen good reasons why things like powered wheels are not in use.

Interesting concern. With dual speed controllers (which you'd need anyway) some inertia sensors (the size of a dime) and a few lines of code (far simpler than a Segway), that problem could easily be solved. Tie it into the rudder pedals and it could also aide directional stability.

Speaking of ground loops, an idea like this could actually minimize the risk by helping to keep the airplane straight.

But yeah, since it doesn't exist now there is probably good reason why it shouldn't ever. I think Orville and Wilber said that same thing about powered flight in the first place.

Zzz wrote:

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 take it that forum has a lot of dreamers?

Nothing wrong with dreaming; it's the fuel that makes ideas comes to life, and can produce something really innovative, if one isn't constrained and boxed-in by having the knowledge and experience of flying actual STOL airplanes.

It does

There are a number of very talented engineers and experienced pilots in a number of flying "genre" over there. But there are also plenty of keyboard commandos who have a lot to say with little else backing it up. Everyone makes the world go 'round.

I've really enjoyed learning from a lot of those folks, though. But this is where I come to when I want to learn about really flying stuff.

Zzz wrote:

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 take it that forum has a lot of dreamers?

Nothing wrong with dreaming; it's the fuel that makes ideas comes to life, and can produce something really innovative, if one isn't constrained and boxed-in by having the knowledge and experience of flying actual STOL airplanes.

Yes... amongst actual pilots, avid homebuilders, prepubescent teens, and contrarians looking for an endless debate.

A long since retired fighter pilot once said to me, "Some people dream while others do".
Be a doer, looking back on your unrealised dreams sounds unfulfilling. Nothing wrong with dreaming provided you have the guts to follow through.

Military doesn't need it. They have vtol jets and very fast helicopters we can't afford. Quadcopters just aren't the same, which is where the dollars are being spent. Commercial aviation doesn't need it. Cheaper to build more runways/longer runways and increase speed and economy to maximize profit margins. Technology has gotten better and lighter since any of those sectors have needed a single prop airplane for most anything. The recreational bush pilots and small companies will be responsible for any significant increase in single engine stol performance. Much the way it is now.

Just like the xdadeveloper community for cell phones. They put a bounty on a project that the community wants completed and then everyone starts working on it until someone gets it done. The bounty is payed out. Love that concept. And they are doing things that apple and samsung and such will never touch. Magic lantern for Canon cameras is sort of similar. Of course much less risk in software design than plane design. Still a fun environment to witness.

Battson wrote: "Some people dream while others do".

No truer words.

rw2 wrote:Remember, that you don't have to halve the roll to go from fourth to first in many STOL competitions. Just a few feet can make a difference.

True enough. I would hope for something more practical, though.

Hammer wrote:Nobody's mentioned the hazards of differential thrust yet.

I assumed traction control was implemented, which is not an astoundingly difficult thing, really. But yes, critical, especially on bouncy terrain. As mentioned above, it could be used to be corrective as well, something I hadn't thought of.

Bagarre wrote:You wouldn't need a bajillion amps of power with 0000000 gauge wire unless you were trying to take off in 200 feet solely based on electric wheels (we still have a prop). You only need as much as you could reasonably get to assist takeoff and maybe shave 25 feet off the distance.

The basics of the approach are pretty straightforward to calculate and ball park the weight and cost. I can't really see it as a game changer unless it can cut 1/2 or 1/2 of a ground roll off personally, and by the numbers, it does require several dozen kilowatts of power for a brief period for a 172 or 182 sized plane. That takes a lot of weight in electrical management and control.

The idea of a compressed air source came up as well. The very best compressed air storage systems have power to weight ratios close to lead acid batteries.

In any case, it has been yakked about a lot before. It is fun to run the numbers on these sorts of things, and to not get too attached to disbelieving the results if they are flat, and to go and try them in some fashion if they actually pan out. I always admire those who "do" over those who pan something they may not quite understand fully.

They say that a bumble bee can't fly but she don't know that so off she goes, keep right on with your ideas, technology is getting better and better and at some point lots of these impossible ideas will be practical.

Lots of talk of "dreamers and doers". I was simply asking about the validity of some concepts. Namely engineering problems that can not be overcome or failures of either concept in reality. The internet gives us this amazing tool to learn not only from those around us but from those the world over. Too far into life to head to college to aquire the knowledge required to call all of the shots myself. But on the subject of "doers", And without being boastful we will just say I have been involved with many different industries so long as they held my interest. From custom cars, boats, piping systems, kiln construction for concrete and paper production, home building, designed a automated system to de-fluid scrap autos before the chipper when I was still in high school. I like solving problems. Even ones that don't exist. I love making things more efficient, faster, and with more longevity. And I've just fell in love with stol plane design and operation and the recreational joys that it could bring me and my family......of 4. Thanks alot YouTube. So I will make a thread on homebuilt if anyone would like to follow I will link it when it's rolling. Thanks for the wisdom and the realism. I'll be back when I have something to contribute to the community. And maybe when I'm officially a pilot

Stay safe,
Mike

colopilot wrote:

A1Skinner wrote:I agree, there is some merit. My biggest question is what do you do with it on landing? Does it speed your tires up to try to match ground speed? Just stay disengaged? What if it fails and stays engaged?
The landing part to m is more technical then the takeoff part. But maybe I'm not seeing it right.

Keep it engaged? Use the regenerative braking to make the tires oppose motion a bit, recover the energy to a point, now you have a Bush Prius and the hipsters will love you too.

Despite potentially no practical benefit when you consider alternatives, I do like the "engineering it because we can" mindset here. I really dig that kind of stuff. A lot of cool things have happened in aviation simply because someone ignored the commercial viability of something, and just did it because it seemed like a neat idea at the time. A lot of commercialized ideas flopped in the real world too, but that's how innovation works.

I also meant what I said about methods other than electricity as well. What about compressed air? You don't need a lot of it. Calidus uses that idea in their gyrocopters to spin up the main rotor early (rotors aren't spun by the engine in a gyro, just forward movement). Or hydraulics? A small engine driven pump spinning a turbine on the axle (though will reduce power to the prop, so probably not worth it). My point is, think outside the box. Electrics are cool but you also aren't building a Tesla here; you do not need huge batteries or motors. You need a brief peak torque falling off with velocity as a form of traction control. We're talking for a matter of seconds, and it just supplements the thrust from the prop anyway. You have the contact patch of a go kart, so size the wheel torque accordingly unless you can solve that issue too unless you want to do burnouts in your plane.

Maybe I should go follow the impending thread on homebuilts.

Hell ya I wanna do burnouts!
I like the idea of keeping it engaged, I have just seen to many planes nose over trying to land super short or land with the brakes on. I'm sure there's a way to control ho much pressure there is when you land, it's just over my head.
My other concern would be rocks thrown at the tail surfaces. Our tires already throw lots, and now you add torque to them I think they'd throw even worse. But strictly used for STOL competitions it would be fun to try!