If Carling designed an LAA aircraft?

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If Carling designed an LAA aircraft?

Postby ColinC » Wed Jan 01, 2014 8:01 pm

Ok, this is deliberately a bit tongue-in-cheek as a heading, but a couple of us started a discussion over a cup of tea in the clubhouse this afternoon that would be interesting to throw open to the forum members.

One question is, if you wanted to define the requirements for a new design intended to appeal to the middle ground of LAA members who might be interested in building their own aircraft, and that might positively encourage people who may have thought it beyond their abilities, what would be its attributes?

To put this in context, there are some great designs available in kit form out there, but I don't mind admitting that I can't afford most of them. The old LAA homebuilt types like FREDs, Lutons, Taylor Mono's etc., are perhaps too much work for too little return, and the sensible two-seat designs like the Menestrele, D18 etc. are complex and time consuming.

I don't claim to have originated this idea, as it comes from many discussions over recent years, but I wonder if it possible to come up with a design that might have sufficient appeal to first of all justify the effort of designing it and to enable tooling and jigs to be made in order to make certain sub-assemblies available commercially that individuals might find hard to make at home.

If we accept that such a design could be specified, would it then be possible to put together a team of people from within the membership who could do the conceptual and detail design to a standard that is acceptable by our own Engineering Team who are our regulator? Clearly we can't ask Engineering to design it, but we have an Educational Trust who we should be able to engage to provide appropriate training covering all aspects of design through to construction and maintenance. Then, if we can deliver a design, can we engage sufficient interest from the membership to start construction, and can we as an organisation provide sufficient support and mentoring to see a worthwhile number built and flown?

A suggestion made to me, would be that if this could be made to happen, the design becomes 'open-source' and as such is available as a free reference for other would-be designers, but that the LAA or perhaps another entity like the ET, keeps the copyright to the design and the rights to licence part manufacture to approved suppliers. Sadly, we have to build in consideration of liability and blame appropriation into any plan.

So, a bit of a ramble at the start of a new year, but does anyone think the idea worth pursuing? If so, what would that aircraft be?

To open myself up to further abuse and derision, in line with our goal of promoting light aviation, should we not then be using it as the basis for the "Haynes guide to building your own aircraft" and getting onto the high street bookshelves?

Regards,

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Re: If Carling designed an LAA aircraft?

Postby TRAZZELL » Wed Jan 01, 2014 9:45 pm

I think it's a good idea Colin - the older/more traditional designs that are affordable for the average income do require a lot of work (as I am finding out!) and the kits tend to require fairly large and indivisible outlays from what I have seen. The biggest question in my mind is what would make such a design appealing, considering the very wide range of designs now available, even for plans built types. What are the top five or ten characteristics that such design would need to have to make it stand out? I guess cost of operation is fairly high up of the agenda for most of us, closely followed cruise speed, take-off distance required, payload capability, range, build time, cost of build. For me, the aesthetics are also important which is why I chose the Menestrel.

The tooling and jigs are certainly a good idea (each time I build a part from a jig I think it's a shame to then scrap the jig). Perhaps sets of jigs and fixtures for the complex structures could be loaned/rented out to builders for a modest sum or a contribution of labour. If the primary structure was made under more controlled conditions in factory rather than a home workshop it may make the regulatory acceptance easier - I think that some of the French designs use this approach.

If you pursued the Open Source route you'd need to ensure an appropriate level of governance to ensure that you had the right degree of cooperation - perhaps there are useful lessons to be learnt from the people who collaborative develop software.

As another thought, if the more relaxed SSDR microlight proposal comes to fruition, perhaps that is a way to have a single seat design which is more substantial that the current 115kg empty weight SSDR with a two seat big brother which is built under LAA supervision and operated under a permit to fly, but both being designed in a similar way.

Love the idea of a Haynes type manual - the 'build your own sports car for around £250' book sparked of a lot of folks building the Locost and is a good read for armchair builders too.

Good topic to start 2014 anyway!

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Re: If Carling designed an LAA aircraft?

Postby neilld » Wed Jan 01, 2014 10:07 pm

I think this is well worth pursuing.
It seems to me that most of the available kit planes have not been "Designed for Manufacture" particularly by individuals working alone with limited resource.
It should be possible to come up with a design that is simple to assemble, & using common parts (e.g. assuming metal construction, a rectangular wing section where all ribs are identical so that a press tool could be laid down to produce many components, similarly for tailplanes etc). There are many procedures used in industry to aid DFM and it doesn't necessarily follow that a low cost DFM product has to be ugly.
Perhaps the LAA could run a design competition for a Low Cost light aircraft design to kick things off?



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Re: If Carling designed an LAA aircraft?

Postby ColinC » Thu Jan 02, 2014 12:47 am

Thanks, am pleased to have some initial responses that are positive, I was expecting to be told straight away that it was a daft idea.

To pick up on a couple of points and add a few:

Obviously the design will be a compromise but the challenge is to create something that is useable, capable, safe and affordable. Perhaps it can be a opportunity to try new materials (carbon, foam etc.) in a way where we can also perhaps offer centralised training in their proper use. Again, a role for the ET?

Tony mentioned SSDR. I would rule that out as I think that there are already a number of designs out that in that market that will satisfy the likely limited take up. I would say that objective 1 is that it must have two seats. That sets a level of difficulty, but allows proper training to take place in the aircraft. Can we agree on that as a base requirement?

I also feel that we should set out to facilitate group construction and ownership as that allows for the participation and enjoyment of those many people we come across who are perhaps too young to get a licence, or those who for reasons of age or perhaps a medical condition are no longer able to hold one. Don't forget that today's youngsters can be enticed away from their computers and we really do need some enthusiastic new blood if light aviation is to have any future. Collaborative projects are one way to create an inclusive rather than exclusive sport/hobby. That again makes an argument for two seats.

David mentioned the idea of a design competition, which is something the LAA promoted a few years ago, the most prominent result of which is the E-Go, an SSDR that is perhaps beyond the price bracket of this proposal. Personally, i think that an outline could be the subject of competition, but the hard slog of the real design is something that only two people in my acquaintance have the ability and tenacity to do, hence the group proposal. On competitions, a few years back we had a less successful engine design competition that I imagine could be resurrected and which ties very neatly into the the requirements of this project. It perhaps too raises one of the big obstacles - choice of an affordable and suitable engine.

I do hope that this can perhaps attract a few people minded to at least consider the possibilities. When you look at the design support materials that Engineering have already provided on this web site it is clear that someone Within the LAA is dangling a carrot in front of us. I am just hoping that I will not be regarded as the Ass for suggesting this particular approach!

Regards,

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Re: If Carling designed an LAA aircraft?

Postby Brian Hope » Fri Jan 03, 2014 9:45 am

Hi Colin, I certainly think your idea has merit and several of the aspects already mentioned have been tried successfully in the past, though not to my knowledge in the UK. Some years ago the RSA published free plans to members of a Jean Pottier design (the high wing, wood construction P130 Coccinelle) and certainly a number were built, including by groups and schools.
Construction in ‘build centres’ is also one that has worked well in France with the D18 and the Menestrel, amongst others. People set aside a week or a fortnight to attend the workshop and build their fuselage or wing using the jigs and advice from a core of experienced helpers. The centre sold wood and ply etc but I do not know how it was otherwise funded. Certainly it would be better for such a centre not to have to be wholly commercially viable – perhaps relying on some sort of educational grant assistance – as otherwise it would add significantly to the cost of a project.
I agree that SSDR is not the way to go, the simple fact is that single seaters are very much a niche market, a two-seater will generate considerably more appeal.
Simplicity of construction is also paramount, and there are inevitably many views on how this could be achieved. Much as I am a wooden aircraft fan I think wood has to be ruled out on the grounds of availability, cost and construction time. Ideally we need an airframe built from readily available and not overly expensive materials, which to my mind means a riveted/bolted aluminium tube construction along the lines of the Rans S6. 6063 tube, extrusions and sheet is available in the UK and is already used in the microlight industry. It is not an aircraft specific material (neither is 6061 which is the ‘alternate’ material used in the US and elsewhere), it is a high quality construction industry material so the cost is far more reasonable than ‘proper’ aircraft aluminium.
For strength, the design could use a 4130 steel cockpit cage and like the Liberty, the engine, wing mounts and undercarriage can all be hung onto that. The cage could be made as a ready built component, or a workshop with all the tooling and jigs could run as often as required (maybe a couple of times a year) for builders to cut and prepare the tube and an experienced welder be on hand to weld it together.
Wing construction could be a simple ladder frame of two tube wing spars with ply or tube ribs. Thin ply ribs could be laser or CNC cut in batches to reduce cost – as could some of the ally and steel bracketry.
Another workshop session could enable builders to bend alloy tubing for empennage construction and other components that required specialist equipment.
The engine is a potentially difficult obstacle but I wouldn’t go down the road of trying to develop a new conversion. The LAA engine competition did not generate any interest and effectively died of apathy. The VW remains the proven conversion, either in kit form via people like Aerovee or Great Plains, or as a completed ready to run motor for extra cost from Sauer or Limbach. The logical route would be to design the aircraft around the VW and add 912 and Jabiru options later if there was a demand.
Simple construction does not have to mean aesthetically challenged but swoopy, purpose made design does cost money. Clever use of flat Perspex for screens, motorcycle spring dampers for undercarriages, proprietary wheels and brakes, and existing plastic fuel tanks from the boating or microlight industry can save significantly on the completed cost. Part of the challenge is to come up with a good looking aircraft whilst using the maximum amount of off the shelf components from a variety of industries.
The Champion book for the Locost generated an industry around it with people supplying everything from a set of cheap instruments to a welded chassis. On a smaller scale, existing companies could perhaps make and sell things like the cowlings and fairings. That is a market forces exercise to some extent but as the market is likely to be small, perhaps such parts could be offered to companies prepared to supply them on a budget. Alternatively ET could have them made in batches to reduce cost and pass some of that saving onto the builder.
No Colin it certainly isn’t a daft idea but trying to assess whether enough people would be interested to make it happen and establishing the infrastructure will be difficult and financially risky. It would certainly give ET a worthwhile project though.
If you can get a core of people prepared to take this farther I'm certainly more than happy to help in promoting the idea in the magazine to see if there is a realistic demand. LAA is about members helping each other to fly affordably, what better way than a not for profit design and build cooperative.
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Re: If Carling designed an LAA aircraft?

Postby Ian Melville » Fri Jan 03, 2014 9:59 am

Hi Colin,
I think there is some merit in the idea.

Dave Thatcher in the US has the same thoughts and produced the 2-seat CX5, which first flew a few weeks ago. Sadly I won't be trying to get the CX5 through the LAA approval. As far as I know, no stress analysis, and no load testing has been done. I am having enough of a battle with the CX4(also with the same design aim of low cost, easy build).

His design principles still stand:
Plans built with option for pre-made parts.
No expensive special tooling (that is reletive, and tooling can be loaned).
2 seats
All metal
VW derived power
Could be built by first time builder.

I would prefer side-by-side seating, and have engines like the Rotax 912, D Motor, and UL260 as options(other engines may be available)

I have thought about doing a design myself once the CX4 is off the ground, however I do not think I have the skill set needed to undertake such a project. Even though I have completed all the Coventry Uni courses. A group effort with a wise sage steering may work.

Cheers
Ian
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Re: If Carling designed an LAA aircraft?

Postby Ian Melville » Fri Jan 03, 2014 10:06 am

Brian,
Is it possible to get chapter and verse on the liability issues for a home-built design in the UK. Would we have to take out, or even be able to get insurance cover if it is required? and who would require this insurance?
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Re: If Carling designed an LAA aircraft?

Postby Brian Hope » Fri Jan 03, 2014 11:06 am

Hi Ian, bear in mind I'm not a legal expert by any means but the Association already supplies plans and approves designs; working within that existing structure makes a lot of sense.
The type would need LAA approval and one possible way forward would be for the design group to gift the completed approved design to the LAA - as one or two other designs have been in the past. LAA's existing covers should then take care of any liability issues and a modest income from plans would offset some of the approval costs. LAA agreement for this course of action would need to be sought of course.
Third parties providing components would be responsible for their own product liability, much as they are for anything else they supply.
I hope concern over liability does not threaten this idea, if it doesn't happen then let it be for a perfectly 'real' reason, such as not being financially viable or a suitable design not being feasible. Liability concerns need to be addressed but there is a risk in designing, building and flying aeroplanes, a risk we must mitigate as far as is reasonable. But please, let's not allow fear of that risk be the deciding factor in whether we do or do not do something that is challenging, fun and worthwhile.
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Re: If Carling designed an LAA aircraft?

Postby Ian Melville » Fri Jan 03, 2014 11:46 am

Hi Brian, I wasn't expecting you personally to be the legal expert, but one of your many contacts.

If the LAA agree, gifting the plan would be ideal, but not sure how it would work for recovering costs. IIRC there is no mechanism for a designer or design group to recover costs through the LAA. For the CX4 it was hinted that I could do this, but when I later asked for details on how, was told there was no way I could do this. That left me with the only option to invest in the project with little or no hope of any return, as Dave Thatcher would sell to anyone, bypassing the investor. For this reason Sonnex will not sell plans or kits to certain countries. For the record I am not having a dig at Mike Moulai, who has invested heavily in getting the Sonnex approved in the UK, and is entitled to see a return on that investment. BTW a plans built Sonnex would tick most of the boxes, though personally I am not keen on it's looks.

I hope concern over liability does not threaten this idea,

Me too.

Cheers
Ian
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Re: If Carling designed an LAA aircraft?

Postby Brian Hope » Fri Jan 03, 2014 2:06 pm

'IIRC there is no mechanism for a designer or design group to recover costs through the LAA.'
I'm not sure that a design group would incur too many costs as the idea is for a volunteer effort so as to keep costs to a minimum. We don't want to be paying people a fee for designing this aeroplane, it should set out from the start as a non-commercial project. However, I do know that when the RV10 came to the UK, the first UK builder paid out for some work to be done to show UK compliance for the LAA submission and recovered that cost through other builders. How this was done I don't know, probably by mutual consent from new builders of the type, hopefully there weren't any that refused to pay their dues.
Once the project is up and running (assuming an initial appraisal of viability has been carried out and decided the idea is a goer) a cash injection could come from a commitment from interested parties to show their support with a nominal ‘advance plans purchase fee’ of say £100 (a figure plucked from the air purely as an example). This would give the design group an initial cash injection to cover expenses - such as researching and buying proprietary components, use of special design software etc. I'd certainly be willing to chip in such a sum because I believe in this kind of self-help concept, hopefully there would be others prepared to do likewise.
Once the aircraft is approved and up and running, plans sales income would help defray costs incurred by the Association for approval and on-going support for the build workshops, etc.
This is all very simplistic of course, and a proper business case would need to be put together to show how the design, approval and on-going provision of workshop sessions, plans, material and component sales etc., would all fit together to ensure viability into the future. However, by starting with a cooperative, non-profit remit everyone involved would know where they stood. Non-profit does not of course mean that the operation should run at break-even or loss, it simply means any surplus is ploughed back into the venture.
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Re: If Carling designed an LAA aircraft?

Postby Ian Melville » Fri Jan 03, 2014 3:19 pm

Perhaps I should have been clearer, I was talking about costs to gain LAA approval for a new design, over and above building your personal aircraft.
The two most significant costs are the requirement for stress analysis, and/or an airframe for load tests.
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Re: If Carling designed an LAA aircraft?

Postby neilld » Fri Jan 03, 2014 5:52 pm

This idea seems to be gathering momentum & I fully agree with Brian Hope's comment that a business case would have to be made starting (perhaps) with some kind of project definition using input from interested members.
I am not suggesting a full blown QFD type approach but a more simple flowchart e,g,
2/4 seat, High / low wing, Wood/ Metal/ composite construction, tractor / pusher, tricycle/ tailwheel, conventional empennage/canard etc. etc.
I strongly suspect that the result would be 2 seat, all metal, tractor, conventional, tricycle but it would be interesting to get feedback from interested parties & gauge the degree of interest in this project.
It would also indicate the amount of design & stress analysis required i.e. less conventional = more design work.

DFN


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Re: If Carling designed an LAA aircraft?

Postby Brian Hope » Fri Jan 03, 2014 7:31 pm

'The two most significant costs are the requirement for stress analysis, and/or an airframe for load tests.'

There is no requirement for an airframe to be provided for load testing. Load testing is sometimes used in lieu of an adequate stress analysis or where there might be some question of the build method that can’t be answered by a stress analysis. For a conventional design, intended from the outset for LAA Approval, it is possible to gain build approval on the basis of the stress analysis alone.
If a design group is going to design the aircraft then it should be done on the basis of carrying out the stress analysis as part of the design process. Obviously the group will need at least one person competent in doing this because outsourcing that work could be prohibitively expensive.
I think Ian that you are confusing what happens with some designs that are submitted for approval having been designed and built overseas. Often, though these designs may be perfectly satisfactory, no stress analysis or load testing has been carried out on them. The importer/UK agent is then faced with the task of showing compliance with whatever design code the aircraft comes under. That can be done by proving a satisfactory service records (if a reasonable number of examples have flown and it can be shown they have safely amassed a significant number of safe flying hours), or by stress analysis (carried out by a third party if the designer never did one), or by load testing to prove adequate strength. A combination of these methods might also be used. As far as building a prototype, that could ultimately be a guinea pig builder’s own aircraft rather than a machine funded as part of the design/approval process.
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Re: If Carling designed an LAA aircraft?

Postby Ian Melville » Fri Jan 03, 2014 7:59 pm

No confusion on my part Brian. I said 'and/or'

FD has stated to me that a design that has been designed by the stress analysis calculations(Old school or FEA) will be required to be tested to limit figures on an airframe to prove those calculations. If all went well that airframe should still be able to fly.

I would be quite happy to go down this route, however I am not a stress engineer, and the more I learn about the subject the less I know, if that makes sense. If we can get a volunteer stress engineer, great, otherwise it is a large chunk of cash.

The alternative is the time honoured method of testing an airframe up-to and including ultimate figures. That airframe (not a prototype) could not be re-used for flight. The airframe need not be a complete aircraft(load bearing parts only), and would not require finishing, but must be built to the same standard.

Cheers
Ian
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Re: If Carling designed an LAA aircraft?

Postby ColinC » Sat Jan 04, 2014 1:18 am

Wow, I just checked in to see if anyone had responded and was amazed to see that I had raised a bit of interest. I have to admit that I pretty much expected Tony, Brian and Ian to pick up on this as we have all discussed the possibilities of amateur design before. I am hoping that many others might chip in, but I expect that this might appeal only to a select group!!

I don't think that we should let liability issues kill the idea at birth. It is just one on thousands of issues we might need to deal with and probably far from the most difficult.

As I floated the idea in the first place, let me expand on what I am thinking. First of all, the idea is in two parts. The first is a Design exercise intended to be educational for those involved but with a tangible end product. The second part is that we try to support potential constructors by designing it in a way that suits amateur construction within the LAA system. However, what I haven't properly explained is that I would like to see the whole process from Design to test flights supported by the LAA's Educational Trust. In reality, the aircraft would be a live project and a focus for the ET's various course students.

I don't mind saying that I had a bit of a falling out with the old management over the direction the organisation took over Design courses and the nature of those held at Coventry. I would like to see the LAA turn that around and provide a more relevant training scheme aimed at our sort of aircraft with appropriate techniques described and without access to wind tunnels and other facilities. That is the preserve of the industry bods and as amateurs, we don't need to compete with them.

What I would like to see result from this idea is a published design that is open for all to look at and learn from in contrast to most designs the LAA deal with which are commercially sensitive.

If we need test assemblies along the way, then we should find volunteers to build them, and if we need the help of engineers skilled in particular aspects, then we should go out and get them involved. We are trying to broaden our appeal as an association and if that means dragging people in from outside aviation circles, that's a good thing for them and us.

I am going to stick my neck out here and say that if we keep the specification simple and stay with uncomplicated structures, then the stressing is not rocket science. I for one would enjoy trying to revive the retired brain cells that hold some relevant data.

Should we actually manage to complete a design and gain approval to build, then I would like to see a small number of groups get together to build a number of prototypes, again supported by the ET's skills courses. Some aspects of construction could be organised on a group buy basis and we might be able to organise workshops where people come together to use special jigs or facilities, or to get the help of welders, wood experts etc.

As an association we have much to gain by identifying ways of promoting amateur design and construction and if you look at our engineering pages this extract sums it up nicely:

This new addition to the LAA’s website sets out to stimulate interest in light aircraft design, help potential designers through the process and encourage the development of high quality designs.

With the decline in UK manufacturing over the recent decades, it seems more than ever important to keep alive a thread of creativity and enthusiasm for design and development. For some, the ability to bring a personal design from first concept to a flying prototype provides the ultimate source of satisfaction within the LAA scene.


regards,

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