Is there a cheapest/lightest/simplest wing structure other than aluminium tube and fabric?

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AeroER

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In rough order of altitude expected...

Human tow. Get some young strong folk, use a speed changing pully/block arrangement, and tow to the limit of the field and crew endurance. Fairly short altitudes, but a marginal powered craft can cruise away once airborne.

Bungee tow, restrain craft and have humans run with multiple tow ropes with elastic sections. Release craft before you drag the crew backwards in a cartoonish way. Very typical system for hill launch popular in 1920-30s.

Tow by fixed location pull winch. These run from mini trailer mounted scooter tow, for hang gliders and paragliders, to big sailplane rigs.

Truck/car/boat tow with fixed length lines. I rate this as most dangerous, ymmv.

Truck/car/boat tow with payout winch. The safest and best way, IF you have the ground room.

I've used every one of these, you may argue that "catapult" doesn't apply to truck/car /boat tow, it's a question of definition.

things I have not personally tried, but know exist.

Explosive launch catapult. Most famously used in CAM ships to launch Hurricane fighters one way to defend the convoy. Explosive charge piston linear.

Rocket launch catapult. Most famous in the second generation of CAM ships, and Zero Length launch systems for jets in the Cold War.

Steam catapults. Aircraft carriers from pre WW2 to today.

Linear motor electric. Latest Carrier system.

You missed gravity launch down a short runway on a mountain top.



Horse tows, too -



 

AeroER

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Maybe the Kiceniuk Icarus II is worthy of consideration. A 25kg empty weight leaves a bit for an engine and pilot pod. Modern materials might even lower the empty weight.

What in the world would you propose are "modern materials"?
 

Aesquire

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Go for the more refined Easy Riser version.


It's the next generation, has been static tested and flies very nicely, weight shift for pitch and rudders for coupled yaw/roll. The vertical tubes behind the pilot made a good place to mount an engine in pushed configuration.

Iirc, the UMF guys traded a new kit for a well abused older glider for load testing, bent a couple tubes in the testing and flattened cable thimbles, rebuilt it and kept flying it.

Paul Yarnell designed a spine saving skid system that evolved into landing gear. I've lost my contact info. He did load testing too, hanging it from a tripod of drill pipe. Fun & scary with heavy leather jackets and helmets in case a cable whipped free. Ran out of sandbags @ 3 am. So had to empty a local 7/11 of gallon ziplocks. They thought we were druggies.

A marginal flyer with a big guy with 10 hp. One with a paramotor @25+ available today would climb like an angel.

As one of the original "ultralights" it was flown foot launched when the FAA ( pre pt103 ) decided "if you can pick it up and run for takeoff, it's a powered hang glider and not an airplane, so WE have NOTHING to do with you! Stay out of the way of Real Aircraft!" Landing on wheels was ok.

Yes, you could run & take off. I could, before knees. ( crippled at work and replaced with Ti & plastic ) Landing gear came later. Do some research and steal ideas.
 

GeeZee

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Yes, that sort of Dunne tailless biplane is a very efficient design for its weight, though most people would, I think, prefer landing gear that didn't require good sneakers. ;-p
At Osh 2019 (or maybe 18) there was an older gentleman that had an Icarus II with an aluminum tube enclosure and power pod with 3 plastic wheels. I could be wrong but I think he was trying resurrect the design and the seat/power unit could be detached to return it to foot launch hang glider configuration.
Edit: It could have been an easy riser as Aesquire has shown above. All those tailless ultralight gliders look alike to me….
 

oriol

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Barcelona, Spain.
A source of inspiration for me is the Utopia, or the Millenium flying wings. They both seem to be an older version, with tube and fabric, of the modern Swift Aerianne.

I think that something along those lines can fit in the sub 70kgs class with a small parafan engine.

I am still on the conceptual design phase. I have to learn a bit more aerodynamics before I can tell, if the specs can meet the requirements.

Oriol
 

henryk

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with tube and fabric,

"D"-tube longeron is very popular,but not cheap...

f.e.=the best today PHANTOM (light,strong,conical shape)=but many work=big price !

but it exist simple technology in carbon tubes production =

WHY not to involve them into D-spar production ??? (+INFUSION technology...)
 

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AeroER

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I was thinking of the carbon fiber that most everyone is so fond of these days.

I had a different glider in mind when I wrote that. I would not be surprised if a Icarus II with carbon tubes substituted for the aluminum tubes was heavier in the end.
 

AeroER

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???
CF =1.5 g /cm^3

Al= ?



=17 + 6 kg

old,Al prototype=





Aluminum is 0.01/0.068 = 1.47 times more dense on a good day.

It also has a higher Young's Modulus after producing a practical laminate, especially a tube.

The pin bearing strength is the factor that will ruin the weight of the carbon part if everything else works out. A C/E part not will be thicker at the joint, larger fasteners will be required to reduce fastener bending in the joint.
 

AeroER

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=1.5 g /cm^3 (65 % C arbon +35% Epoxy)

f.e,= Fi=42 x 1 mm, 5m long = 1.2 kg

What you're implying is that a tube is a tube and the details don't matter.

Please consider posting with fewer arcane, mysterious abbreviations. Most of your posts are barely decipherable. In this case f.e, and Fi. We'll assume the outer diameter of the tube is 42 mm.
 

Aesquire

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Carbon fiber is great! You can tailor wall thickness and other details.

The problem is your minimum weight/thickness isn't determined by load carrying, but by damage resistance to impact. It's too easy to make it strong enough to fly yet thin enough to break when some idiot raps it with a knuckle, or you hit a bush.

Nothing is proof against heavy pipe fence posts. Landing in mature corn? Aluminum tubing may need leading edge replacement. A Carbon D tube is totalled.
 

henryk

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jeśli potrafię przetłumaczyć to zdanie na polski w pięć sekund

-так может лучше буду писать цирилицей,а уж потом переводить на английский ?
ЗЫ=LOLITA= русский писатель Набоков писал на английском,а после перевёл на русский !

подобно и польский писатель Юозиф Конрад (Кorzeniowski)...

reaa.ru

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