Design a plane?

[Yenn]

How many of the forum members are interested in design of an ultralight?

 

A few years ago there was an interactive design series of articles in Kit Planes magazine.

 

The articles started off by questioning what people wanted from their aircraft, such as number of seats, baggage capacity, range, speed, etc.

 

I am not an aeronautical engineer but have an interest in learning about design, so if others are interested we could find out what the majority are looking for in an ultralight, and do some preliminary design.

 

My preference is for a low wing occasional 2 seater which can seat 2 with a small fuel load or replace the 2nd seat with a removable fuel tank and baggage, to use a tractor configured Jabiru 2.2 engine, minimal equipment ie. no DG. ASI etc. Cruise at 90kts, safely use 600m strip, tailwheel configuration and of course be RAAus registerable.

 

If anyone is interested give me your thoughts or contact me.

 

 

[hiperlight]

Ian,

 

Like you I have an interest in ultralight design.

 

My preference is for a single seat biplane, taildragger, tractor four stroke engine, lightly turbocharged to overcome power drop with altitude (below 5000'). Wet top wings with gravity feed to the motor. Enough luggage space for a cut lunch and a sleeping bag. STOL performance for short field operation if necessary.

 

Bruce

 

 

[Galpin]

Ian,Like you I have an interest in ultralight design.

Bruce

2 seats, retractible and a blended wing body have kept my brain cells going round. In my radio aircraft days, I often tweaked designs and played around, but never get to the blended wing body.

The Manthos will be interesting when it comes, but it is still no blended wing body. Thoughts and designs on this type of aircraft will drive you crazy.;)

 

 

[TechMan]

Bill Whitney sells a DVD set on aircraft design. I don't have the details on me at the moment, though it is around $115 for the set of 4 DVD's and advertised in pacific flyer I think.

 

Chris

 

 

[pylon500]

while not trying to drive people away from our great forum, there is a really good forum in the states with lots of design work discussions going on.

 

Have a look at, homebuiltairplanes.com.

 

Usually a good bunch of guys that will talk and discuss with anyone, just ask.

 

Arthur.

 

 

[Ultralights]

in was thinking a single seat, fully encolsed weight shift aircraft... but using a conventional stick control... pull back to climb, left stick to roll left etc etc..

 

 

[hiperlight]

in was thinking a single seat, fully encolsed weight shift aircraft... but using a conventional stick control... pull back to climb, left stick to roll left etc etc..

A bit like a Vampire SV2?

 

Bruce

 

 

[facthunter]

Design a plane.

 

With this subject, I think Bill Whitney's material is an essential starting point. I obtained the discs & notes some 2 or 3 years ago, and they have since been updated & improved. We often dream of exotic principles which we would like to put into form, but you don't live long enough to learn by your mistakes, so we should get the right information from others and apply to our project to ensure predictable & satisfying results. The EAA started all this , there is a lot of material available. The more I study,the less radical my concepts become. I would concentrate on good construction & an appropriate type for my uses,sourced from what is out there, with detail mods. where necessary,rather than attempt something radical with only the resources and knowledge that we generally have available, as individuals.

 

A talented group getting together... well that would be something else wouldn't it? but you couldn't expect the first few to be right straight away either. N....

 

 

[Yenn]

Thanks fellas. I will let it sit for a little while to get a few more replies and then see what the concensus is. I wouldn't expect to design anything radical as there are many talented people already trying to do that. I was looking for peoples requirements, such as load to carry, no of seats, fuel required etc.

 

I attended one of Bill Whitneys lectures a couple of years ago and it was very worth while.

 

 

[pylon500]

The more I study,the less radical my concepts become.

If only more people would follow this route!

We often hear the, 'I'm learning to fly and I'm going to design and build the first ultralight jet!'.

 

I've built two 'common' high wing flying machines, learning all the while, and now I'm about to start on a low wing machine with a bit of performance.

 

The jet comes in a few years!!!!

 

Arthur.

 

 

[Deskpilot]

Top topic guys and a very important one if we are to keep flying within the reach of Mr Average. I certainly don't have the $$$$ to buy a plastic fantstic so to design and build something the I want is my goal. I bought Bill's dvd set and that is certainly the start. However, I can hire a Jabiru very cheaply for shared flying, by that I mean a passenger, so my desire is to build a scaled, replica fighter using the wood, foam and fibreglas method. A fun plane, something radically different. My dream would be a Westland Wyvern but there are a few problems, contra rotating props being the biggest herdle. But more of that later, maybe. Assuming that I got the ok, and Bills dvd's provided all the design checks needed as proof of concept etc, I'm then faced with the phyical side of building it. Where in Australia do I find anybody who has experience in using this method of construction? How do I go about the actual structural design and who can give guidance on the rights and wrongs of the practical side of things. I have many idea's but will they work? are they safe? will they cost too much etc etc. At the moment I can but dream.

 

On a more down to earth level, low and slow obviously appeals to a lot of people and I believe there are those in our community who have the ability to design and build updated versions of older ultalight aircraft. This area of flying needs to be kept alive and encouraged, particularly with the younger set(late teens-early 20's) I say this as an alternative to fast cars and the 'I'm invinsible' mind set. Flying teaches disiplin and to fly your own design is the only way to get high, excuse the double pun, it's intended. Let's keep this topic going my friends, let's kick start the revolution here in Oz. Safe flying every body, Doug

 

 

[facthunter]

Design-a-Plane

 

Beware of the scaled down Replica They are lovely and have a lot of appeal from the nostalgia & visual side but SOMETIMES little quirks that are tolerable in the original aircraft, become major handling problems with the smaller replica. N...

 

 

[Deskpilot]

Facthunter, I'm well aware of your point and that is why one needs Bills dvd info so that if small mods are needed to correct the down sizing, it can be done before and materials are cut. Flying surfaces may well need to be modified to keep the plane safe, but the overall impression may still be maintained. Doug

 

 

[Yenn]

This is coming along nicely from my point of view. It was not my intention to design a plane for myself but to get the views of members and then we could attack the design as a group. We can all point others in the direction to get information and then thrash out the details. It appears thatpylon500 has a wealth of experience and I like the look of his current design.

 

Deskpilot a scaled down warplane would be a good start I think, but I will have to admit I have no knowledge of the Westland Wyvern. I have fond memories of the Lysander but that would be a difficult project.

 

Hiperlight I haven't seen any design info on biplanes but it has been done.

 

Galpin and ultralights. Interesting but even more difficult than a biplane.

 

Has anyone done any biplane design? Does anyone else have any ideas for a desirable plane.

 

 

[pylon500]

Scaled ultralight Warbirds is one of my favorite topics, I hope to knock out a few once I'm set up in my hangar.

 

As mentioned, be wary of scaling down, many people have built the WAR replica fighters and found them to be less than friendly to fly.

 

The truth is, you don't actually need to get much smaller to save weight, infact if you build quite small you end up flying at fairly high wing loadings and can get all the nasty habits that go with it.

 

Besides, a large machine is impressive to stand next to, for example, have a look at the Titan 51.

 

A 912 powered, two seater that still just fits into the ultralight catagory, and may only do around 100kts, but has very low stall speed and is definately something to see on the flight line!!.

 

A Wyvern eh?, good long nose for C/G location, don't know if I'd worry too much about contra-props (maybe you could build the Merlin protoype!).

 

I think trying to get too carried away with scale detail (of any aircraft) would actually be detrimental to flying quality, and the time it would take to build.

 

My list includes a Hurricane, a Zero and a Harvard (need a two seater!).

 

Still haven't figured out how to get a ducted fan into a Phantom!!

 

Arthur.

 

ps, OK, it took a while to write this and another post appeared.

 

As for biplanes, and the urge to be different, I was also looking at the WW1 german Albatross with a typical alloy tube structure, and a two half moulded shell fuselage.

 

 

[Deskpilot]

One type special

 

Whilest we all have our favourite style and build criteria, lets go back to Yenns concept of a Recreational Flying Special that could be built by any handyman, without any specilised trade abilities and only the basic tools. Something that can be built under a single carport and won't cost an arm and a leg. Something that can be built rapidly enough not to put potential builders off half way through the build. I believe in the KISS principle (Keep It Simple Stupid) so lets come up with some lists of what we think would entice nonfliers to think, and believe, 'I can do that'.

 

I'll kick it off if you like;

 

Single seat

 

Tricycle undercarriage

 

Air cooled 75hp max, tractor configuration

 

High wing (Detatchable?)

 

Flaps or flapperons

 

Cockpit enclosure optional ie, doors or canopy

 

Minimal instuments

 

Minimalist, but steamlined fusealage (not open framework)

 

Max cruise speed - 80 knots? maybe higher

 

Anything else that descibes the type of a/c

 

That's a start. We can move onto the preferred build method once the style of the a/c has been ageed to. Yenn, as it's your project, you can collate everybodies ideas, I'm sure you'd love to do that, wouldn't you? If not, we need a volanteer. Looking forward to your lists ladies & gentleman.

 

Please excuse any spelling mistakes, Doug

 

\]

 

 

[dreemhi]

For some time I've had the dream of designing something really radical. My idea was basically a canard design but the thinking was to have a large mainplane and a small canard to control pitch, a pusher engine and maybe a variable flap type mainplane trailing edge to give low and high speed performance. I made some rough sketches and even put together a cardboard model of my idea. Can you believe, the damn thing actually flew. I was getting quite impressed with myself and then I discovered a couple of things. I came accross an aircraft on the web, http://www.nurflugel.com/Nurflugel/n_o_d/weird_06.htm#Goeland

 

the "pelican", not a canard but very close to what I had in mind. The other was while thumbing through a 1988 aviation mag in someones waiting room, there low and behold was Burt Rutan's "vari viggen" nearly exactly what I had in mind. I must admit the dream has had some major holes punched in it but I still keep thinking maybe:idea:

 

David

 

 

[facthunter]

Design a plane

 

I doubt if much consensus will be reached here as we all have our dream concepts, & they are probably very different.I will try to be practical and toss a few thoughts in .

 

1. A steerable nosewheel is probably one of the hardest parts to design & build. It's a potential weakness in any design where low weight and simplicity is sought . so- Get rid of it.

 

2. Flaps & Flapperons .Do you really need either in a simple aeroplane. As for flapperons, you ruin the whole concept of differential aileron action so you get aileron drag plus ( normally the UP aileron operates thru. a larger angle than the DOWN aileron,You end up with NO UP aileron with flapperons)

 

3.Consider making the compartment that you sit in, from steeltube. You get a strong box to (a)mount the engine.(b) mount the wings.(c attach the undercarriage.(d) provide good seatbelt attach points.(e) protect you in the event of a crash. The rest can be wood, steel tube, fibreglass.sheet aluminium or whatever. There are quite a few successful designs out there using this method. N...

 

 

[rodknee]

I saw a homebuilt jet do a couple of flypasts at the Clifton flyin last weekend .Have no idea what sort it was and no pictures either as the camera was too far away .Sounded very nice though . Someone else who was there & on this forum might have some to post .

 

 

[Guest Crezzi]

It was apparently home designed and home built by the pilot (from Kingaroy I believe). I managed to get a photo of it which I'll try to post shortly

 

John

 

 

[Guest Crezzi]

Attached image of homebuilt jet at Clifton 11/03/07

 

 

 

[Guest Crezzi]

My idea was basically a canard design but the thinking was to have a large mainplane and a small canard to control pitch, a pusher engine

Sounds something like the '80's Goldwing

 

http://www.ultralightnews.com/antulbg/goldwing_ultralight.htm

 

John

 

 

[slartibartfast]

Great plane.

 

Is he sitting backwards in it to be funny?

 

 

 

[Yenn]

Now we are getting somewhere.

 

Dreemhi your ideas aare a bit too radical for novices, but I know of a lifting body plane beeing built in the Brisbane area by an ultralight flyer. I havn't seen it but am told the scale models worked well and the full size is coming along.

 

Slartibartfast that is just a cleaned up Wright flyer.

 

Deskpilot you are correct in your assesment of me. I will give it a couple of days and then collate it all. Just hope pylon 500 will keep an eye on us as he seems to have a wealth of experience and this is just a fun thing as far as I am concerned and would need someone to overlook the final product.

 

 

[Guest micgrace]

Hi

 

Why not simple aluminium tube, plates and brackets and bolts to join (instead of 4130N) and fabric construction and fibreglass bits (for streamlining) as req. as a tractor? With bit of design thought could be made reasonably streamlined. No flaps, tailwheel (simple) Pilot on CG Low or high wing (both with struts). Simple VW motor with 86mm stroke, 92mm bore (80hp), Say, about 19' long Wing loading at around 95.10 specs (higher loading for higher speed), but keep the chord down.

 

U/C single bent piece of aluminium with axles bolted on (can buy done). Wings alum. tube spars (lends itself to easy wing tips). drag & compression same. Simple, bent 3/8" tube ribs (with same for truss aka wood style assembled in rib jig, little more than a board with some off centre dowels to hold everything) Cap strip alum (also joins rib to spar), with fabric riveted to same. Same for aerilons and control surfaces (minus full cap strip).

 

Idea is to be able to construct with readily available sections invovling little bending, no welding and fast construction with little more than a few tools ie drill press, hacksaw, clecoes and other simple tools with a plan method familiar to anyone who ever put a kids swing set together (more complex than that , but principle not dissimilar)

 

Tube controls and cable as req for rudder/tailwheel. I have been building such but is mostly open cockpit parasol style The full VW engine is too much weight for 95.10 (and Cg as designed) so I'll use a 1/2 vw (plans constructed with a few twists ie full electrics instead of flip start) on a very simple bed mount that can easily mount a 2 stroke rotax on.

 

Since I go to uni, I make only slow progress, but will get there in the end.

 

Micgrace