Cheap 2 seater anyone?

[Head in the clouds]

Hi all,

 

A few folks on RecFlying have remembered me from the earlier days of hanggliding and ultralights but for those who don't here's a quick introduction -

 

I flew hanggliders for a short while in the 1970s and then built a trike around 1980.

 

In 1982 I started building ultralights in earnest with advice and assistance from other builders of the time - people like Sander Veenstra, Robbie Labahn, Werner Bekker, Gordon Bedson, Ross Nolan, Charles Ligetti among others. I built 17 planes altogether and sold all but two which I tested to destruction before building the next. Most of them were very simple structures and quick to build and they performed quite well. I tried most construction methods including welded CRMO fuselages, fabric and all metal wings, composites, aly monocoque fuselages and traditional rag and tube.

 

In the later 1980s I instructed in Drifters and then went commercial flying helicopters for the next fifteen years. A couple of years back I sold my C172 as it became just too expensive to maintain for the few hours a year that I used it and so I returned to recreational aviation.

 

For the last 18 months I have been building a new design using just about all of the most complex things I learned in the 1980s and it has recently occurred to me that the cheap, fun and easy quick-build aircraft we had so much enjoyment with 25yrs ago just don't seem to exist any more. Back then we were only allowed to have single seaters but now that we have the freedom to build two seaters we don't seem to have many folks designing their own and getting airborne at an affordable price.

 

Half the problem seems to be this need for speed that is so evident in the clubrooms. There seems to be a fair bit of leg-pulling from the plastic 100kts plus brigade if someone's plane only does 80kts or so, and I find it notable that back when we had so much fun 65kts was considered to be supersonic.

 

Let's face it you can't build a fast plane with pocket money. From my experience cost is a cubic function of speed so if you want a cheap plane build a slow one. Now before anyone stops reading on just bear this in mind - back when we were getting the most out of our flying it was the owners of the slower planes (and they were all slow, so I mean the very slow ones) who had the most fun.

 

I see these plastic and slick metal kit-planes a lot these days and they're very lovely, no doubt about that, and they're just what we all thought we wanted back then. But when you look back on it all, going away camping for the weekend, fishing and landing on beaches for a swim was so much more enjoyable for me than a 120kt dash to some airport and a cab ride into town for an expensive overnight motel, another cab and a dash home at flight levels the next day.

 

Some Drifter folks are still able to 'go anywhere' but even they're getting faster and heavier with bigger engines, struts and all that. And they're forty grand if you could buy one! I bought the first certified Drifter from Austflight for $13K in 1986.

 

There's really no reason why we can't have much less expensive aircraft, and comfortable two seaters too, as long as we accept that we won't be breaking any speed records, and if we have a design that takes advantage of the slow speed then we're back at the top of the fun stakes.

 

I've spent a lot of time reading this forum and also been on quite a few others trying to work out a configuration that would suit a majority of people who might be looking for an entry level aircraft and the cheapest quick construction method for building it. The parameters that I have set, and which are achievable are -

 

Two seats, side by side

 

Three axis control

 

Tricycle undercarriage

 

Rotax 582 power

 

Enclosed or doors-off flight

 

STOL

 

Quick folding - 2 mins for 1 person

 

No control disconnections for folding

 

Folds to trailerable/20ft container size

 

Before I say more I'd be pleased to get a bit of feedback about the whole concept -

 

What do you think?

 

Is this something you think is needed or are the plastics the 'go' now?

 

What ideas along these lines interest you?

 

I am working on the CAD model and drawings and expect to complete them in the next few months. The next stage would be to build a prototype. I live on the Gold Coast and would like to hear from people who might be interested in sharing the building and/or the finished plane and perhaps with a view to being a part of building a business around producing kits.

 

Cheers, Alan

 

 

[fly_tornado]

sounds like you have a winner on your hands

 

 

[winsor68]

I agree 100% with your sentiments HIC. Damn shame I am not on the Gold Coast because this is just the sort of thing that would keep me interested.

 

I feel that it is not so much that people "want" the plastic fantastics... rather that a market opening was identified and developed for them.

 

I feel that with the right "encouragement" there would be a market... say a machine that is easily built from simple components with moderate performance... 70 knots is plenty... less would be fine too.

 

 

[ausadvance]

im listening....very closely, the thing i struggle with most at the moment is time, however as a long term thing, Im most interested....are you thinking of aussie mossie? or are you thinking of somthing else, because as you know, we are both thinking that direction! though im thinking more tail dragger.....

 

 

[Teckair]

HIC I think you are on to a good thing as affordable aircraft are not catered for ATM, I hope to see more of your concept.

 

 

[ausadvance]

im listening....very closely, the thing i struggle with most at the moment is time, however as a long term thing, Im most interested....are you thinking of aussie mossie? or are you thinking of somthing else, because as you know, we are both thinking that direction! though im thinking more tail dragger.....

just re read my post, i think im doing alot of thinking!?

 

 

[Teckair]

It would be nice if it could be either tail or nose wheel.

 

 

[facthunter]

I have always commented on the low level of builders in the RAAus. I don't know that you can change things and the way things are looking at the moment it will get worse for builders, after all this is over.. Lots of poeple today don't work with their hands. years ago there were fitters welders mechanics everywhere. A cabinet maker can easily build a good wooden plane back then, Today they use pressed wood, glue and a staple gun.

 

I think the fast stuff is a euro thing and as they are on lighter weights they tend to go carbon fibre. You have to watch where you tread and dont pull too hard on anything when you are getting out.

 

There seems to be a couple of speed "hurdles" from about 75 knots and then at about 145 knots where the cost and concept changes. There is the really slow "quicksilver" type stuff that could really be built for very little, but you put them away when the wind gets up a little. I am not sure at all where we are going now. I think more has changed than we realise and not for the better (for us). Nev

 

 

[ausadvance]

i must say nev, i disagree. i really do believe there are still no shortage of craftsmen, and people who work with there hands as ever before. I just dont think they stand out as much these days.

 

 

[boingk]

Why not make a single seat version using something really obtainable as a powerplant? My specs are as follows for a low power single seater:

 

• Tuned Briggs & Stratton 18hp v-twin engine, direct drive to 40x36 prop.
   
   
  
• Ply fuselage, wooden/foam wings, fabric covering... or all metal.
   
   
  
• Small baggage rack capable of 5~10kg weight.
   
   
  
• Fuel tank for 3hr+ duration.
   
   
  
• Flying weight ~120kg.
   
   
  

 

 

Powerplant would cost about 2k depending on modifications. I would recommend simply reducing the stock engine to its core and dispesing of any plastic coverings, fan cooling etc. This alone would bump up your power some, and apparently this and a later model carburettor (twin barrel) gives 21hp from the good old Briggs.

 

Fuselage would be fairly narrow, no more than say 24" wide at its widest and only as deep as you needed for structural and practical reasoning. The head and upper body would be enclosed in a streamlined cowl - you could make this multi-facetted or form a plug for making a single plexi piece.

 

Essentially you're looking at something between a Robinson-Rand KR1, Leon Davis DA-11, Mory Hummel Hummelbird, Fisher Flying Products Avenger, Team Mini-Max 1600R/1650R and the SD-1 Minisport. To be honest all apparently perform well and would be great to build from kit or plans, although only the SD-1 Minisport and DA-11 are designed to use the Briggs & Stratton engine.

 

All can be made for 15k or less by the homebuilder.

 

My faith in the Briggs is mainly because it a lightish engine thats proven to be reliable and has a large corporate source of parts that isn't going to go anywhere quickly. It also has a large aftermarket scene and is regularly in use for aviation. Its contruction also includes electric start, altenator for DC current and an... oh my GAWD... easily accessible oil filter! Its rpm are roughly the same as a VW conversion such as a Jabiru, Hummel 1/2 VW or Great Plains.

 

Cheers - boingk

 

 

[Guest nunans]

G'day Alan

 

I read your post with interest as the notions you put forward about door open cheap slow flying side by side fun strike a chord with me for sure. I've flown J230s etc and while they go fast and make good cross country trainers and cheap tourers I don't find them that much "fun". it's not like i can pull one back to 50 knots at 500 feet and have a relaxing sticky with the door open on a warm day, and the fast shiny new RA planes look too nice to be flying out of rough paddocks speckled with cow exhaust

 

The late Tony Hayes wrote an infamous post on this forum about the change in aircraft flown by RA members over the years, and something like you are describing could actually fit the needs of a grass roots member who flys for the pure enjoyment of it rather than a cheap way to get from airport to airport.

 

 

[Sapphire]

I like the idea of making a twin with two simple cheap single ignition lawn mower type engines, mounted rear and front. Now you have safety in numbers and no assymetrical thrust.

 

 

[Head in the clouds]

Damn shame I am not on the Gold Coast because this is just the sort of thing that would keep me interested.... say a machine that is easily built from simple components with moderate performance... 70 knots is plenty... less would be fine too.

Yes, it is a shame because if it is to happen I can't do it on my own, we'd need a syndicate. And it'd have to be less than 70kts, more like Drifter speeds, perhaps 60kts full power, 55kts cruise. You just can't get a low cost plane to fly faster than that on low horsepower, so you either need a slick (read expensive) airframe or a lot more (read expensive) lightweight horsepower, or both. And then you'd just be building another plastic...

 

To get it cheap you have to use commercial grade materials and accept the limitations, one of which is low speed. However, if you build a great low speed plane, and use it for the fun that can be had simply because it is capable of low speed operation then you have an advantage rather than a disadvantage because you can go where the plastics cannot go.

 

im listening....very closely, the thing i struggle with most at the moment is time, however as a long term thing, Im most interested....are you thinking of aussie mossie? or are you thinking of somthing else, because as you know, we are both thinking that direction! though im thinking more tail dragger.....

Yes, lack of time (and money) is the big equaliser these days, we all have to work so much harder than ever, just to keep head above water, another reason why aviation is battling for survival.

No, not thinking AussieMozzie at all, the Moz is an exceptionally complex structure (retractable, folding, cantilever, pusher...) and should have around 90kts cruise. This is something quite different.

 

HIC I think you are on to a good thing as affordable aircraft are not catered for ATM, I hope to see more of your concept.

Thanks, yes it's all getting too expensive by far. I hope we can get the project happening too but it's going to need a few keen folks to kick it off if it's to happen.

 

It would be nice if it could be either tail or nose wheel.

Yes, my preference would be for a taildragger too but the only way a plane can get produced these days is if it has appeal to the majority of people and unfortunately nearly all training is done in tri-gear planes and so there are fewer and fewer people who can handle a dragger, and frankly most folk don't have the confidence to re-train. If you learnt in a dragger you wouldn't have it any other way but if you didn't...

 

There is usually the option to build any plane as a dragger but for this particular design it wouldn't be as easy as it usually is, or as convenient, but quite possible nonetheless. If you didn't plan to fold it every time you used it it wouldn't be a problem at all. As you will have gathered this isn't a folding concept in the usual way.

 

To succeed commercially in producing a plane it must satisfy the majority of the people and I'm pretty sure that very quick and easy folding (as well as low cost, side-by-side and tri-gear) is a prime requirement these days as it was in the 1980s for the same reasons. Trailers and/or small folded size solves the lack of hangarage/expensive hangarage issues.

 

To combine all of the above isn't so easy and it gets to the stage where one thing is dependent on the other, and ironically in this case the easy folding depends on it being a tri-gear, taildragger is possible but it's less convenient and the folding would take a bit longer.

 

A couple of things about tri-gear (and remember that I'm a dragger man) -

 

First, the main argument against tri-gear is that the three wheels in the breeze have a lot more drag than two. That's true but it all depends on the cruise airspeed and at 60kts or less the difference is negligible, in the same way that airbrakes or large flap deflections for drag increase are a waste of time on aircraft with low landing speeds.

 

Secondly, a bush pilot of thousands of hours' experience over thirty years in the 1950s to 1970s taught and showed me this. He used to fly mail, supplies and the bioscope (movies) all around the remotest parts of Australia and usually had to operate from whatever clearings were available. He started out with a C140 dragger but ended up with a C182 tri-gear which was 'a little bit modified'.

 

If the main gear is moved forward a bit from its 'normal' position then most of the weight will be on the main wheels and much less on the nose wheel -

 

Disadvantages - 1. Nosewheel steering may be a fair bit less effective but you have differential brakes and (as dragger and the more skilled tri-gear flyers will appreciate) a rudder with prop-blast to compensate. 2. Directional stability on the ground is reduced a bit, but is still positive and far more so than draggers. 3. A large diameter and wide nosewheel is beneficial so there is a slight drag penalty but not much at these low speeds. 4. A little more care has to be taken to prevent the plane falling on its tail while on the ground and without the crew's weight inside during loading and while parked mainly.

 

Advantages - 1. The nosewheel doesn't get bogged in soft sand or mud. 2. Skillful flyers can taxi with the nosewheel off the ground. 3. Wheelbarrowing is much less of a problem. 4. Punctured nosewheels are less likely and also less of a problem if they do occur, so safety is enhanced. 5. Nosing over is prevented in soft ground or due to heavy braking.

 

So, a tri-gear that is specifically set up for STOL and soft surfaces has some advantages that even draggers don't have.

 

I have always commented on the low level of builders in the RAAus. I don't know that you can change things and the way things are looking at the moment it will get worse for builders, after all this is over.. Lots of poeple today don't work with their hands. years ago there were fitters welders mechanics everywhere. A cabinet maker can easily build a good wooden plane back then, Today they use pressed wood, glue and a staple gun.I think the fast stuff is a euro thing and as they are on lighter weights they tend to go carbon fibre. You have to watch where you tread and dont pull too hard on anything when you are getting out.

There seems to be a couple of speed "hurdles" from about 75 knots and then at about 145 knots where the cost and concept changes. There is the really slow "quicksilver" type stuff that could really be built for very little, but you put them away when the wind gets up a little. I am not sure at all where we are going now. I think more has changed than we realise and not for the better (for us). Nev

Yes, I agree with all you say Nev. And have been quite surprised how 'soft' some of these new tin kits and plastics are, and I'm a lightweight! Good point about the speed hurdles too, pretty much based on the cost I'd say. My aim is to see if we can put something together at Quicksilver cost but Drifter performance with more like Foxbat accommodation, and still enough profit margin to make a kit production viable. I'd agree that there's a manual skills reduction overall and so the kits would have to be simple enough... and that means more work for the manufacturer and puts the kit price up...

 

i must say nev, i disagree. i really do believe there are still no shortage of craftsmen, and people who work with there hands as ever before. I just dont think they stand out as much these days.

I'd love to say you're right but I think there's a whole culture of homebuilding that's lost, and not just in planes. As kids we used to build our own slot cars from scratch, then free flight planes from plans and then control line planes from a box of balsa and plans, and radio control from similar. We asked for pram wheels, an axle and timber for birthday presents and built billy karts, and we made our own skateboards and sailing dinghies.

 

These days kids get a complete kit or fully assembled R/C car, ready to fly R/C helicopters, almost RTF R/C planes, Honda Odyssey buggies instead of billie kart parts, $400 skateboards and they're not allowed near a light bulb to change it in case they get electrocuted.... I know that's a generalisation but there don't seem to be many kids, except in the bush, making their own anything. Even homebuilt aeroplanes come in 'quick build' kits where there's not so much left to do but put the stickers on... (I built it myself you know... ) But I don't blame anyone for that, if you want to get in the air and have the cash for a quick build kit it beats the hell out of embarking on a ten year build.

 

Why not make a single seat version using something really obtainable as a powerplant? My specs are as follows for a low power single seater:

• Tuned Briggs & Stratton 18hp v-twin engine, direct drive to 40x36 prop.....
   
   
  

Single seaters are great but are not commercially viable. It would cost very little less to build what you describe, than a two seater as I am proposing but folks want a single seater for half the price of a two seater, it simply can't be done.

 

We've gone months down the track on another very large forum with fifty or so heavily involved and very skilled people trying to determine the best and most cost effective way to build a FAR 23 Pt 103 ultralight (almost the same as our first issue of 95:10) and we investigated and revealed some really wonderful information. I can give you a link to the forum and thread if you want it.

 

The Briggs is a good engine but heavy for its horsepower and there are quite a large number of similar ones, the Subaru Robin still tops the list of the industrials for weight, power and quality. The Generac is cheapest. Valley Engineering provide the best complete package with improved performance (50hp for the big twin 1000cc) and with belt reduction drive. It can swing a larger prop for enough static thrust to have a useful climb rate. But then you're up for over $6K landed in Oz plus GST so you're not far off the cost and weight of Rotax 582. And the 582 with gearbox and designed for aircraft use is way ahead of the modified big twin with belt drive on reliability.

 

Further - there's no incentive for anyone to produce plans for anything. I'm a professional designer/draftsman these days and the plans for even a simple aircraft (say a Drifter), properly done from an initial 3D model would cost about $25K at my normal charge rate so I'd need to sell a hell of a lot of them before I could make a living out of it. Almost everyone wanting to build from plans spends their first couple of months trying to find free plans, then the next couple of months trying to find pirated plans. If they do build from pirated plans they still call it whatever the plans were for, although it was built without any designer support, required modifications and the like. Then a bunch of 'lookalikes' get around and give the design a bad reputation.

 

Kits providing critical components is the only viable commercial approach.

 

A completed single seater isn't worth much on the market either, usually not as much as the components. Let alone compensating for any of the work that's gone into building it. There are good plans and staged kits out there already for those who want single seaters, you couldn't beat their quality or prices Mini Max http://www.teammini-max.com/ Airdrome Aeroplanes http://www.airdromeaeroplanes.com/

 

I like the idea of making a twin with two simple cheap single ignition lawn mower type engines, mounted rear and front. Now you have safety in numbers and no assymetrical thrust.

Yes, I've had similar thoughts although I'd probably go for a pair on the nose a bit like the Cri Cri, the MZ34 PPG engines would be perfect. Or the Simoninis if you had the spare cash. Closely spaced engines like the Cri Cri have virtually no effect on thrust symmetry and the prop blast over the tailfeathers might be useful in a single engine situation whereas a rear-engine only situation would provide just a bit less control. And rear engines and/or extended driveshafts are a pain in the butt! However that puts it back in single seat 95:10 territory since 95:25 is limited to single engine. Even so I think RAAus should be persuing the centreline thrust twin engine thing as an amendment for the two seat 95:25 or even a dispensation because it enhances safety rather than decreasing it.

 

 

[fly_tornado]

you could look @ a titan tornado or a thundergull for a basis for your plane the construction technique is really designed around minimizing costs.

 

 

[Sapphire]

I don't think you would need a twin endorsement for two engines on the thrust line. The front and rear engines would be two independent engines with own fuel tank. Could be a Sapphire with an engine at the front in addition to the one on the back. Also concentrate on the quick single handed fold down onto a trailer bit. A hanger would cost more than the plane.

 

 

[Head in the clouds]

you could look @ a titan tornado or a thundergull for a basis for your plane the construction technique is really designed around minimizing costs.

Yes, good input thanks, but have a look at their kit price, if they could do it cheaper using that method I'm sure they would.

 

Also they're both tandem seating and those configurations have been notoriously unsuccessful in the marketplace.

 

Their big one-piece wings don't make for a small folded package, and neither would they if they were two piece strut braced and folded back.

 

I do already have a complete airframe design in place but haven't revealed it just yet because I really value input like yours FT. If I just come out with my thoughts right now it'll kill that input, but I will reveal all very soon, I just want a little more un-influenced third-party input first, please everyone...

 

 

[fly_tornado]

There is room for improvement in the Tornado, due to the number of T51 sales the Tornado has languished a fair bit for the last decade. The alloy over polystyrene design is the way to go though.

 

 

[Head in the clouds]

I don't think you would need a twin endorsement for two engines on the thrust line. The front and rear engines would be two independent engines with own fuel tank. Could be a Sapphire with an engine at the front in addition to the one on the back. Also concentrate on the quick single handed fold down onto a trailer bit. A hanger would cost more than the plane.

Whether you'd need a twin endorsement or not isn't really the issue. A 95:10 aircraft isn't limited in the number of engines and can be flown with an RAAus certificate so it could have 20 engines (or motors if electric for example) placed anywhere you like and you don't need a multi-engine endorsement. But - 95:10 aircraft are limited to one seat.

 

And - 95:25 specifically states one engine and one propellor, so you can't have more than one engine or one engine driving two propellors or one engine and no propellor (i.e. a jet). 95:25 aircraft can have one or two seats.

 

If you built a push-pull twin engined two seater then it would have to be in GA experimental category which means you need a PPL with DL(aviation) medical at the very least and would have to have a multi-engine endorsement. Actually I'm not even sure you could fly it with the reduced medical requirement if it's a twin, you might have to have the Class 2 medical.

 

The quick single handed folding method is sorted, less than 2 minutes with ease, no controls to disconnect, just rip a metre of velcro, pull out two pip pins, unclip one rigging cable connection, fold two different items, replace two pip pins in different locations to secure everything for trailering or compact storage (dimensions 5.8m long, 2.2m wide, 2.1m high). Any guesses?

 

 

[Teckair]

I thought 95:25 was certified factory built?

 

 

[Guest Howard Hughes]

i must say nev, i disagree. i really do believe there are still no shortage of craftsmen, and people who work with there hands as ever before. I just dont think they stand out as much these days.

I think probably because they do it more as a hobby! I have no real skills as a tradesmen, but if I put my mind to it I can generally build most things, even though it may take me 5 times as long as a professional!

All this aircarft for under $10k I hope!

 

 

[facthunter]

HITC have you investigated the efficiency of a centrifugal fan into a largish plenum and air jets providing the thrust and airflow improvements on the wing as well. ( boundary layer control) ?. Nev

 

 

[ave8rr]

HITC, would it be possible to come up with a bolted together frame and have sail cloth covering along the lines of the Xair or Skyranger?

 

The wings could be designed to swing back like the Skyfox. This may not achieve your ideal "folded" dimensions though.

 

I will be following this thread with interest and some good ideas have already put forward.

 

I have also been following your AssieMozzie thread on the "other" Forum . A great project but not as simple as you are looking for.

 

Will still be great to see it flying.

 

 

[Head in the clouds]

I thought 95:25 was certified factory built?

Yes, I meant 95:55, sorry.

 

HITC have you investigated the efficiency of a centrifugal fan into a largish plenum and air jets providing the thrust and airflow improvements on the wing as well. ( boundary layer control) ?. Nev

Sure have Nev. There are a lot of us (including about 30 Aussies) on another international forum which is more oriented toward design and building than flying, as this one is. And boy have we chewed the cud on most of the weird and wonderful design possibilities. Actually what you mention is one of my favourites (another is series hybrid electric power) because it has VTOL possibilities. The most likely manifestation would be a single or transverse pair of large internal fans fed from just behind the leading edge on the top surface to augment the low pressure field there and with vectoring outlet nozzles as well as upper foil surface jets for thrust and boundary layer excitation.

 

A couple of the more advanced aerodynamicists among us conducted the appropriate calculations and the concept would seem to be quite feasible provided that the structure could be kept light enough, and that should be possible since very high internal volume would be essential and that lends itself to a blended-wing-body (BWB) configuration with its natural structural benefits.

 

Another approach, and combining the series hybrid electric aspects is the Joby project with it's rotating/vectoring wing, have you followed it? I'm not sure of their business ethics chasing money before having a flying prototype but I think the concept is brilliant. http://www.jobyaviation.com/home.php

 

HITC, would it be possible to come up with a bolted together frame and have sail cloth covering along the lines of the Xair or Skyranger?The wings could be designed to swing back like the Skyfox. This may not achieve your ideal "folded" dimensions though.

I will be following this thread with interest and some good ideas have already put forward.

 

I have also been following your AssieMozzie thread on the "other" Forum . A great project but not as simple as you are looking for.

 

Will still be great to see it flying.

Yes bolting is feasible, although a gusseted and pop riveted light tubular frame for shape, outside a structural box section keel is lighter, and the keel gives you something solid and one-piece to hang all the critical bits off (engine, landing gear, seats, wings, tail). Sort of a hybrid.

 

I don't want to swing the wings (big clue there folks) it makes them vulnerable during road transport and controls are either very complex or have to be disconnected. It also moves the weight aft when stowed which suits a dragger but not a tri-gear. And, it's very difficult to get the width down enough so you have to have a short chord and very large span if you want reasonable performance with just a 582.

 

Sail cloth covering is a possibility but shrunk and doped polyester makes a better finish and is quite a lot lighter and doesn't need replacing every few years from UV damage. Poly can still be sewn up to make socks for good fits.

 

You're right about OzMoz - complex but it'll be rewarding I hope. I did have some ideas of kitting it originally until I got underway and the amount of CNC work and sheet metal shaping kills it for repeatability at a reasonable cost. It should be of interest at fly-ins though...

 

How's Kununurra these days by the way? I lived there for many of my comm heli years. I even won the open class of the Dam to Dam once...

 

 

[facthunter]

Thanks for the response but the Joby doesn't do it for me. With an engine driven centrifugal set up you can keep the mass central as well as blow the wing and use the cooling and exhaust for thrust and not have the hazard of a propeller either. You could sound proof the engine pretty well too as it is well enclosed, direct drive to a fairly large dia impeller Nev

 

 

[ave8rr]

Yes, I meant 95:55, sorry.I don't want to swing the wings (big clue there folks) it makes them vulnerable during road transport and controls are either very complex or have to be disconnected. It also moves the weight aft when stowed which suits a dragger but not a tri-gear. And, it's very difficult to get the width down enough so you have to have a short chord and very large span if you want reasonable performance with just a 582.

 

Sail cloth covering is a possibility but shrunk and doped polyester makes a better finish and is quite a lot lighter and doesn't need replacing every few years from UV damage. Poly can still be sewn up to make socks for good fits.

 

How's Kununurra these days by the way? I lived there for many of my comm heli years. I even won the open class of the Dam to Dam once...

I had guessed from what you had written on this thread so far that "swinging" the wing was not an option hence me mentioning it to get your response. Guess that leaves the option of folding in the vertical like your current project and of course what Sonex with their "Onex" have done.

 

Re Kunnu's. All good. Came up here in Jan 08 for what was to be 15 months managing the Argyle Diamond mine aerodrome facility. It has now been 5 years but we are heading back to Bundaberg later this year. I have a Rans S6ES kit to put together and the RV9a we have owned for a number of years to fly more frequently than has been lately. I guess you flew for Slingair / Heliwork?? I know a few of the guys there.

 

Anyway back to the topic of discussion.

 

Cheers