Tell me why it's impossible, I'll tell you how I did it.

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ubx

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May 13, 2022
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5
I don't know why, but I've always been attracted to things I'm told I can't do.
Maybe because I'm a middle child ?

I'm mildly educated in various unrelated subjects - Economics, medicine, IT...
Just one of those guys who "can't" get a diploma. Yet, I'm an engineer.

In my early twenties, I had a pretty bad motorcycle crash, involving backbone fractures.
Struggling for consciousness as my bike bled its oil on the roadside, taught me a few things :
- What's a 10 on the pain scale.
- It's not the machine's fault.
- Walking is a privilege. So is breathing. We, the living, are a minority.
- Life is short, death is forever. May I see a century, and still die young.

I breathed. I walked. I did so many other things - rebuilt myself, and the bike.
We rode up to the Arctic.
"You can't just move there on that thing !", they said. Now I live just above 65N.

I have more hobbies than I can give up. I have more plans than can fail.
The trick is not to be the genius who figures out how, but the fool who can't tell why not.

Before this introduction turns into a manifesto -- a word about airplanes.
I came here looking for Riblett airfoils - a polarizing subject, it seems.
A more uniting thing, is fascination for flight. I remember dreaming of airplanes as a child. I'd never be the Superman, a policeman, a fireman or anything-man. I would become a pilot.
Nothing but dreams.
Flight, you see, is a luxury for rich kids, they said. You can't make it to pilot school unless you're somebody's kid. "Don't be a child".
Maybe that's where I got my aversion for being told what I couldn't do : the acute, stinging feeling of injustice, from hearing grown-ups tell the child I was not to go for their dreams. Was it really so, that only the "right" wing could fly ?
But I'm not one to delve into politics, and soon I'll be the age they were then -- both too old, and too young, to dwell on mistakes past.
As time and tide wait for no man, I figured -- why wait for myself ?
A new generation has come.
I've got a kid of my own. They breathe, and soon they'll walk.
I feel like I owe it to them, as much as I do to myself, to write a better story - one where people get to do whatever the Foxtrot.
And if that's flying stuff heavier than air, then I say, whatever floats your rock.

Well...
I guess I did make it a manifesto after all ;)
Anyway, thanks for having me on board.

PS : Also, a buddy of mine bet me they'd jog around town naked if I fly a hundred yards in a machine of my own conception.
 

Victor Bravo

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Well, you may have to adjust your thinking a bit here, because most of us on this forum spend a lot of time telling folks that they CAN do something if you put your mind, and a little common sense, up to the task.

We get a little cranky when people are all tail-wagging enthusiastic about everything except the common sense, because the common sense is what usually prevents the part about lying there bleeding, struggling for consciousness.

So if you put up with our boring common sense lectures, we'll put up with pretty much anything else related to you flying.

We will be particularly interested in helping you enforce the victory of seeing your friend jogging naked, and we will put in the extra effort to make sure you remain conscious to see it.

Welcome :)
 

TFF

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Joined
Apr 28, 2010
Messages
17,323
Location
Memphis, TN
I have always had a problem trying to staple a piece of paper to a bowl of liquid water.

Learning to fly, building a plane are about doing it. Sometimes you have to do things painful to get to the other side. That is what a lot of people don’t like. There is a time to be independent but there are certain things in aviation, you can’t do different than everyone else. There are a lot of things you do get to do as you please. It’s a balance.
 

challenger_II

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Joined
Jul 15, 2009
Messages
1,086
Location
Fisher County, Tx. USA
A middle child, with a middle finger, and ain't afraid to use it! I admire your tenacity sir! :)


I don't know why, but I've always been attracted to things I'm told I can't do.
Maybe because I'm a middle child ?

I'm mildly educated in various unrelated subjects - Economics, medicine, IT...
Just one of those guys who "can't" get a diploma. Yet, I'm an engineer.

In my early twenties, I had a pretty bad motorcycle crash, involving backbone fractures.
Struggling for consciousness as my bike bled its oil on the roadside, taught me a few things :
- What's a 10 on the pain scale.
- It's not the machine's fault.
- Walking is a privilege. So is breathing. We, the living, are a minority.
- Life is short, death is forever. May I see a century, and still die young.

I breathed. I walked. I did so many other things - rebuilt myself, and the bike.
We rode up to the Arctic.
"You can't just move there on that thing !", they said. Now I live just above 65N.

I have more hobbies than I can give up. I have more plans than can fail.
The trick is not to be the genius who figures out how, but the fool who can't tell why not.

Before this introduction turns into a manifesto -- a word about airplanes.
I came here looking for Riblett airfoils - a polarizing subject, it seems.
A more uniting thing, is fascination for flight. I remember dreaming of airplanes as a child. I'd never be the Superman, a policeman, a fireman or anything-man. I would become a pilot.
Nothing but dreams.
Flight, you see, is a luxury for rich kids, they said. You can't make it to pilot school unless you're somebody's kid. "Don't be a child".
Maybe that's where I got my aversion for being told what I couldn't do : the acute, stinging feeling of injustice, from hearing grown-ups tell the child I was not to go for their dreams. Was it really so, that only the "right" wing could fly ?
But I'm not one to delve into politics, and soon I'll be the age they were then -- both too old, and too young, to dwell on mistakes past.
As time and tide wait for no man, I figured -- why wait for myself ?
A new generation has come.
I've got a kid of my own. They breathe, and soon they'll walk.
I feel like I owe it to them, as much as I do to myself, to write a better story - one where people get to do whatever the Foxtrot.
And if that's flying stuff heavier than air, then I say, whatever floats your rock.

Well...
I guess I did make it a manifesto after all ;)
Anyway, thanks for having me on board.

PS : Also, a buddy of mine bet me they'd jog around town naked if I fly a hundred yards in a machine of my own conception.
 

ubx

Member
Joined
May 13, 2022
Messages
5
Well, you may have to adjust your thinking a bit here, because most of us on this forum spend a lot of time telling folks that they CAN do something if you put your mind, and a little common sense, up to the task.

We get a little cranky when people are all tail-wagging enthusiastic about everything except the common sense, because the common sense is what usually prevents the part about lying there bleeding, struggling for consciousness.

So if you put up with our boring common sense lectures, we'll put up with pretty much anything else related to you flying.

We will be particularly interested in helping you enforce the victory of seeing your friend jogging naked, and we will put in the extra effort to make sure you remain conscious to see it.

Welcome :)

Hello VB !

I too value sense, as well as my peer's time, and apologize for my lyricism.
Shyness makes me guilty of excessive verbosity -- I blabber when I blush.

That's a very legitimate reality check, and the crankyness is understandable.
Rest assured, the privilege of breathing isn't one I'm willing to relinquish, and no wings are worth trading my legs for.
The task of making a flying machine isn't one I take lightly, but I consider it feasible.

I'm here to get in touch with like-minded people, rather than be answered "witchcraft" by "muggles".
All I find hard to put up with, is being put down under cover of "common sense" by the very people who lack it.

Your "lectures" are welcome, though, and I'm confident we're on the same page here.

I see my enthusiasm hasn't gone unnoticed, though when it comes to tail-wagging, let's wait until my friend gets jogging ;)
 

ubx

Member
Joined
May 13, 2022
Messages
5
Whatever works, frankly. Lots of things work eventually.

I couldn't brook a winter anywhere near 65N. The few melanin producing cells I have would go on strike.
Sure can be tough, winters get long and dark. But the return of the sun is just glorious !
You get to love the summer like never before -- last year it was a Friday !
 

Victor Bravo

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Jul 30, 2014
Messages
10,869
Location
KWHP, Los Angeles CA, USA
Tell us more about exactly what you mean by "a machine of my own conception". Does this mean something you clean-sheet designed, or something you built from plans or even a kit?

May we make a few assumptions from your location, that:

1 You want something that is actually usable/practical up at that latitude, more than one week a year?
2 You are willing to at least get some amount of flight instruction instead of self-taught?
3 You are not needing anything to fly commercially, for hire, or rent out to other pilots?
4 You have access to 500 feet of level ground to operate whatever it is?
5 You can live with just flying yourself... or do you need to have a passenger seat?
 

J.L. Frusha

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Joined
Feb 17, 2006
Messages
982
Location
Luling, Texas
I had an $800 motorcycle that I did $1800 worth of damage to, as well as fractured ribs and a broken collar bone. In the process, I flew more than a few yards, watched the world spin around me and landed on my back, then walked several miles home..., but, the dog that came charging at me and my motorcycle lived another day and I avoided the steel pipe and mailbox that were fast approaching... Later that week, I was kicked by a mule, which finished breaking some of my ribs. I spent the next few months sleeping in a chair, across a pile of pillows and sipping air.

There is plenty of good advice to be had in this forum. Many think I have ignored much of it on my path to designing and building the plane I will be starting in a few weeks. Will it be an ultralight? If I can make it such, then, yes, it will.

Amatuer airplane designer, builder and pilot with limited experience flying.

Welcome to the nuthouse! Crayola Crayons to Port, Windex to Starboard.

1652767596066.png
 
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ubx

Member
Joined
May 13, 2022
Messages
5
Tell us more about exactly what you mean by "a machine of my own conception". Does this mean something you clean-sheet designed, or something you built from plans or even a kit?

May we make a few assumptions from your location, that:

1 You want something that is actually usable/practical up at that latitude, more than one week a year?
2 You are willing to at least get some amount of flight instruction instead of self-taught?
3 You are not needing anything to fly commercially, for hire, or rent out to other pilots?
4 You have access to 500 feet of level ground to operate whatever it is?
5 You can live with just flying yourself... or do you need to have a passenger seat?

You may assume. Those are all valid questions.
1/ June to October usually provide decent, nonfreezing weather, calm air and plenty of light (mid June usually provides 24h VFR).
Outside of those, I wouldn’t try my luck.
I see ATR72's landing at our local airstrip in winter and always find that confusing as heck —man, the braking…
Besides, climate control is hard enough on cars up here. Plane will have to do without. Summer only.
2/ Theres what I can teach myself, and then there’s the law. YouTube, MSFS and instruction manuals are all fine and dandy but nothing's worth cockpit hours. I have a couple of those and wouldn't mind getting more. I’m planning to run the whole process in a way that doesn’t put me in jail or worse.
3/ Heck no. If I go commercial it’ll be after logging hours, getting checked up with instructors and certified as one should be. Renting wasn't considered either. As dumb as that may sound, I'm in it for myself, and bragging rights. I don't have a business plan. If someone wants to rent it, and that's legally feasible, fine. If someone wants to get plans, fine, too, but that's not part of the goal.
4/ the whole landscape here is mostly level ground. We’ve got an airport that accommodates GA flying too. I’m pretty sure there’s abandoned airstrips accessible (with owner’s blessing), flat farmland, desert roads, all within a dozen kliks.
5/ I’m currently designing it to be a single seater, especially to accomodate myself (I'm 1.93m/6'3). Makes it easier for centering mass.
To be honest my current level of confidence means I wouldn’t promise to fly my neighbour’s dog if it begged me.


So, about the machine.
Long story short, I have no specific end goals in mind, just some objectives and constraints.
Usually, that makes designing processes a bit more fluent.

Let me grab my crayolas, and a sip of that Windex.

End idea :
- wingspan ~8m (26ft). Anything beyond that is hell to lug around even disassembled.
- low wing preferably
- Under 300kg (660lbs) if I can. Based on napkin calculus and wishful thinking, it seems I've got about 50kg margin. Calculations were probably wrong.
- Power plant TBD. 912’s offer plenty of power and reliability for the weight but come with a cost. 1/2 VW seems quite popular but I haven’t researched enough to make my own opinion. Depending on the weight and drag, I might just go with something small and cheap for unmanned tests until I’m confident it’s worth investing in. See below explanation of design / RD process.

RD process:
The whole deal here is that I’m starting from scratch. I’ve been browsing for some profile and top views to get an idea of what I like, and basically threw a bunch of blueprints into my CAD soft. Because this kind of process usually takes a whole lot of adjustment as I learn along the way, I can’t just plop a fully fitted aircraft and jolly go a-flying. Trial and error works best with rapid prototyping, not so much with builds taking hundreds of hours and thousands of social-credit-bills.

I figured, I own a 3D printer. If I start with a small (1:16) scale model, I can prototype relatively fast. While the dynamics don't scale linearly, it can help build experience w/ the CAD software, and provide some guideline approximations.
An example, current wing design:
Root: 10cm (~4in) chord, clark Y 120%thickness, 1.5°AoA
Tip: ~5.6cm (~1.4in) chord clark Y 100% thickness, 0°AoA
2° dihedral, 3.7°/8.5° taper, single-spar, 12 ribs.
Takes about 160 metric minutes to print, 20 to clean up assemble.
Insights :
- Ribs have room for hollowing out at least 5% volume.
- Spar longitudinal resistance is potato. Any drag would send the wing flagging. Going with 2 spars could help. Shape and material isotropy may also be the issue.
- Not satisfied with rib/spar attachment. Spar notched under ribs is the wrong way to skin that cat. Only applies at this scale.
- Spar isn't attached properly at the tip.
- Weight : 18g. Napkin scaling -- span by 16, area by 256, volume by 4096, round to higher 5 => 75kg (~165lbs), without fairing, fasteners, etc.
Action points :
- Hollow out ribs leading edge. Can probably save a gram (4 kilos !) there. That's a quarter of the weight budget for a second spar.
- Add trailing spar. At this scale and with no choice on materials, that's the most reasonable way to make the wing structurally sound. Expect another 4g (16kg) off the weight budget.
- Install xfoil. Simulate foil behavior at 10-50m/s (~20-100kt). (Re 1:16 = 70-350, Re 1:1 = 1.1-5.5 M). Pray for lift.

Current progress:
- First draft of wings, rear fuselage, motor(for 1:16) mount. Specs, model, print. Control surfaces and cockpit missing.
- Analysis and take-away. Learned a lot. Most tedium unwarranted.
- Center of mass analysis rather hopeful, althouh too high. Incress dihedral to 5°
- Ordered RC stuff for miniature prototype.

Near-future TODO:
- Complete remodel / fix current known design flaws
- Maybe change scale to 1:8, this is "tiny"-ish. My fingers can't cope with anything thinner than 3mm and I feel there's no room to work. scaling the craft two-fold, 3mm thickness may still work but work room doubles.
- RC stuff (I have no idea what I'm doing):
-- Operator side : XBox controller -> laptop -> Atmega328 (arduino) -> NRF24L01 (2.4GHz radio)
-- Craft side : NRF24L01 -> 328 -> 30A ESC/BLDC, 4xSG90 servos (apparently, that's what everybody uses)
- Pray for lift.

Short-term plans :
- 1:4 scale (~2m span).
- UAS (Unmanned Aircraft Systems) license. Required to legally fly that thing.
-- V1: Minimal design changes, most parts fit the printer. Spars / spine / keel to use aeromodelism materials. Check control and thrust requirements. May get away with the same stuff. Hopefully to be completed this season.
-- V2: Scalable materials. Redesign to get as close as possible to target. Various budgets (weight, costs, thrust) and capabilities (lift, payload, stall, TO&L) start to take shape.
- Praying for lift ends.

Mid-term plans :
- Over the winter, redesign / rebuild as needed.
- In my wildest dreams, by then I'd be better trained / equipped to simulate and test aerodynamics, material stresses, etc.
- Final-ish designs ("Aircraft-final-final-definitive(2).cad")

Lont-term objective :
- 1:1 scale UAV, matching "end idea".
- Mission authorization for prototype flights.
- Unmanned test flights, with on-board diagnostics systems. Hoping to livestream engine temp, bank/climb angles, forces, airspeed, GPS location.
- Ballast flights, 100kg (220lbs) payload to simulate operator and instruments (Monkey, bananas, telephone).
- Prove and measure lift.

Target :
- See "end idea"
- Aircraft registration / airworthiness
- Whatever license will be necessary

Timeline :
- Optimistic ~2-5 years
- Pessimistic ~No.
 
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TFF

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So exactly where are you? It’s kind of hard to read. There are plenty of northern places, but it’s hard to know what type of advice is relevant. Alaskan to Canadian is slightly different answers. If you are in Norway or other, completely different answers. The rules to play by for government dictates different things.
 

J.L. Frusha

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Feb 17, 2006
Messages
982
Location
Luling, Texas
Sounds like a plan. FWIW, there are several small high-wing designs that should give a far better view. I'd think that and potential STOL capabilities would be important. I've seen pics of a mini 'Wilga' bush plane...
 

Pops

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USA.
I understand. Struggling to stay conscious, but when conscious the pain was a 10 where I didn't want the next heartbeat. But every heart beat is a precious gift. And when it's all over, the world looks new and fresh. Bolted together in two places with bone grafts and more bones broke than not. about 4 feet of scars. Makes you have a different outlook on life and realize how blessed we are to be alive. Enjoy every minute. Have fun.
Just trying to guess what it will look like when its built.
 

skip SMITH

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Joined
Nov 8, 2021
Messages
9
Location
pacifica cali
Well, you may have to adjust your thinking a bit here, because most of us on this forum spend a lot of time telling folks that they CAN do something if you put your mind, and a little common sense, up to the task.

We get a little cranky when people are all tail-wagging enthusiastic about everything except the common sense, because the common sense is what usually prevents the part about lying there bleeding, struggling for consciousness.

So if you put up with our boring common sense lectures, we'll put up with pretty much anything else related to you flying.

We will be particularly interested in helping you enforce the victory of seeing your friend jogging naked, and we will put in the extra effort to make sure you remain conscious to see it.

Welcome :)
Ah the joy of victory, but I wouldn't want to see any of my friends jog around naked.
 

ubx

Member
Joined
May 13, 2022
Messages
5
So exactly where are you? It’s kind of hard to read. There are plenty of northern places, but it’s hard to know what type of advice is relevant. Alaskan to Canadian is slightly different answers. If you are in Norway or other, completely different answers. The rules to play by for government dictates different things.
Northern Europe. I’m aware of the rules and intend to play by them, but don't want to get too specific about my location.

Most likely I'll have to take a pilot's license anyway.
 

TFF

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Memphis, TN
I never thought you were not going to play by them. My point is why suggest something that I can do in Alaska and you can never do into the conversation. Physics may be the same. Being allowed to use them is going to be different.
 
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Sonny Furman

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Feb 23, 2011
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Punta Gorda FL
The actual term for that kind of tenacity is called "counterdependence" I was told that by a shrink many years ago, 1971 to be exact after I had been shot down over Bien Hoa and later ended up at Walter Reed Medical, with a poor prognosis, even that I might not walk again with fractures of L-1, L3 and C-3 (upper neck) and shrapnel in my intenstine. The USAF was determined to kick me out with a medical discharge and "have a nice life" but I fought it tooth and nail with the caveat that I would be able to pass a physical after six months intensive rehab. Pass forward I retired from the USAF in 1998 and went on to teach for the navy at the academy in Annapolis. Never tell a pilot that he can't do something.
Irv "Sonny" Furman, Lt. Colonel, USAF ret.
PS. My SE5a is coming along nicely in my shop.
 

Victor Bravo

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KWHP, Los Angeles CA, USA
Never tell a pilot that he can't do something.
Irv "Sonny" Furman, Lt. Colonel, USAF ret.
PS. My SE5a is coming along nicely in my shop.

Nice to have you here with us Col. Thanks for walking (flying) in to harm's way, and we're glad you got to come back.

"Never tell a pilot that he can't do something"... that's the bumper sticker and T-shirt that needs to be available for our Young Eagles program.

Consider that catchphrase stolen in cold blood :)
 
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