If Carling designed an LAA aircraft?

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Ian Melville
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Re: If Carling designed an LAA aircraft?

Post by Ian Melville » Sat Jan 04, 2014 9:56 am

Now you have woken us up, what is the next step captain? :)
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Re: If Carling designed an LAA aircraft?

Post by ColinC » Sat Jan 04, 2014 10:16 am

My next step is to get back to work on my new workshop whilst it has stopped raining!
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Re: If Carling designed an LAA aircraft?

Post by Brian Hope » Mon Jan 06, 2014 1:35 pm

I spoke with FD this morning on another matter and he brought up the issue of this thread which he has been following. He is enthusiastic about this idea, so if there is sufficient interest amongst the membership to proceed then we will at least be pushing on an open door as far as Engineering goes.
Incidentally I did ask about the requirement for load testing and it is not a given. If a design can be shown to be sufficiently well engineered by stress analysis then there is no need for a load test. The problems arise when stress analysis is complicated by difficult to predict load paths (as in some wire braced machines for example) or where the analysis shows marginal reserve factors.
It’s very early days and we have to decide where we go with this, I hope there are sufficient numbers of people prepared to put some effort into assessing the level of interest and, if that exists, getting this design idea up and running. Floating the idea in the magazine could well be the next step.
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Re: If Carling designed an LAA aircraft?

Post by ColinC » Mon Jan 06, 2014 3:16 pm

Thanks Brian, it is good to know that Francis is interested. I had been thinking about it a lot over the weekend, and was coming around to the opinion that we might be asking for too much, particularly in expecting the Engineering team to contribute to this.

Obviously, we need to have a good idea of what we could reasonably expect to achieve and how to deliver it before we can offer it to the wider membership (and non-membership?), so the interested parties need to develop a plan.

I am afraid that you have much better knowledge of the workings of the LAA than I. My assumption was that the Educational Trust should have a pivotal role?

Can we lean on you to advise how to take this forward?

regards,

Colin
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Re: If Carling designed an LAA aircraft?

Post by achean » Tue Jan 07, 2014 9:06 pm

Hi All, Mr Melville made me aware of this thread (I don't visit as often as I should) and I'd be keen to get involved too.

Like Ian, I've done the Coventry courses and I'm aware of how limited my skills are, partly as a result of doing the courses. As a result It'd be a great opportunity to get involved in a project that has the backing and support of the LAA engineering team, especially with the goals already expressed.
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Re: If Carling designed an LAA aircraft?

Post by TRAZZELL » Tue Jan 07, 2014 11:15 pm

I would suggest that defining a set of requirements would be the right place to start. Even if we decide the design does not have to be a commercial success (i.e. make a reasonable return on an financial investment) it would still need to be attractive to prospective builders and operators. Is there a unique selling point or is there just an optimum blend of characteristics similar to that which I suggested earlier in this thread? What would be the best way of finding a set of requirements - a (market) survey of some sort, perhaps using this forum or another social media tool?

I think that if a design project goes ahead the role of the LAA Engineering team would need to act as independent reviewers/auditors rather than integral to the team.

I look forward to further discussion!

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Re: If Carling designed an LAA aircraft?

Post by achean » Tue Jan 07, 2014 11:55 pm

I'm thinking that in actual fact there are two sets of requirements:
- one for the aircraft to be designed
- one for the other outputs of the project, the plans, educational resources, tooling for loan/hire, etc.

Setting up a poll on survey monkey might be a good way of getting an idea of what a self selecting group of people who may (or may not) progress to actually build an aircraft might want in the design, including the financial aspects. Of course, it's not feasible to have a 250 kt cruise on a VW for a £10,000 aeroplane, so some level of survey design might be required first if this was an approach people liked. By the same token, it's no good if the survey comes back with a type of aircraft that nobody in this discussion feels they'd want to commit time to.

I'd suggest that a core project team decides what the other outputs should be and sets goals about how feasible it is to obtain them. I'd also put forward that those requirements are rather likely to change as the project progresses. Out of interest, are people familiar with the Bloodhound project? In many ways, the goals already expressed on the first page have a similar educational feel about them to me, which is something I'm just as keen on as the aircraft its self.

I suspect we could quite quickly get to the 'comparing lists' stage for both project and aircraft goals.

If we could get to a position where the LAA engineering act as mentors/consultants as individual bits of work are identified/allocated/progressed/completed, would people feel that this was the right role for them? For example, could a project person tasked with stressing the main spar ask FD/JV/JT for a reference in a book or a worked example without that supporting role becoming onerous to the engineering team?

What do people think?
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Re: If Carling designed an LAA aircraft?

Post by ColinC » Wed Jan 08, 2014 1:05 am

Hi,

thanks to each of you for your support, I think that you have picked up on the potential benefits of this proposal. I remain somewhat sceptical about the chances of achieving the full set of objectives but I think that we could start out on a process of developing a plan that takes us step by step towards them and delivers valuable education along the way.

It would of course be helpful if any people who have opinions or suggestions could continue the discussion here whilst I compose my thoughts and consider how best to persuade the organisation to move it along.

Regards,

Colin
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Re: If Carling designed an LAA aircraft?

Post by neilld » Wed Jan 08, 2014 5:55 pm

TRAZZELL wrote:I would suggest that defining a set of requirements would be the right place to start.
Do you mean requirements for the product (Aircraft) or for the project?
If the former, see my earlier comments re. aircraft type, configuration etc.
Perhaps a "brainstorming" session would kick off a few ideas although not sure how to do this remotely.

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Re: If Carling designed an LAA aircraft?

Post by TRAZZELL » Wed Jan 08, 2014 11:18 pm

I was thinking of aircraft requirements (range, cruise speed, payload, build cost, operating cost, construction method/materials etc.). Given the plethora (now there's a word!) of other designs available, what would make this one attractive? I guess we could devise a method of brainstorming ideas through this thread or does anyone know of accessible (and free) collaborative sites? I wouldn't discount QFD or something similar as a tool to manage requirements and identify the significant drivers for a design.

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Re: If Carling designed an LAA aircraft?

Post by neilld » Thu Jan 09, 2014 11:26 am

TRAZZELL wrote: Given the plethora (now there's a word!) of other designs available, what would make this one attractive?
In my opinion, the thing that would make this attractive would be simplicity/cost of building. I don't know what the "average" build time of a "typical" LAA type is but some projects appear to take many years to complete.
I wasn't discounting QFD but it does take a lot of effort from a lot of people and there are other ways of analysing/prioritising requirements which may be more suitable in this case.

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Re: If Carling designed an LAA aircraft?

Post by Brian Hope » Thu Jan 09, 2014 12:24 pm

I agree with David. I think the most important features of a design/build project like this are that it is affordable (as a plans built using readily available materials), that there is builder support by way of training and assistance with anything but simple construction (jigs, welding etc), and there is competitive parts availability due to batch production (laser cut or CNC’ed parts for example). The methodology by which examples of the aeroplane come to fruition is as important as the physical attributes of the actual machine.
Of course, people need to have an attraction to the design itself, but as has been pointed out, there are many different designs already out there, and many are attractive and have acceptable performance – but there is a sizeable potential aircraft owning market that isn’t buying those designs because the methodology (handing over a significant sum of money for the kit) doesn’t suit their requirements or circumstances. And current plans building does not always suit either, because apart from one or two exceptions (the Pietenpol and Minimax spring to mind) there isn’t really much of a type specific support structure, and many of the designs are relatively complex and time consuming to build.
So, when considering the actual aeroplane we want to end up with, we should keep the above uppermost in our minds. Put simply it is ACHIEVABILITY.
Redesigning the Falco or the RV8 isn’t going to provide what we really need. Working backwards from simple build technique/readily available material to an aesthetically pleasing design with typical performance for the genre, probably is.
For example, the Pioneer uses a wood fuselage structure whose attractive profile is acquired by composite add on skins, the Ikarus C42 uses a similar ‘skeleton’ technique (in alloy tube) and also gets its form from add on skins. Would it not be feasible to have a simple alloy tube fuselage structure clothed in a modern flat ‘plastic’ material to give a pleasing form that did not require painting or UV protection? Clever use of a small number of three dimensional composite mouldings could provide the required ‘flow’. Look at the Sonex, a very boxy structure but easy on the eye through subtle design.
Can there be an easier wing construction technique than the Avid/Kitfox? Alloy tube spars with laser cut ply ribs and a flat sheet leading edge glued and/or riveted together and the whole then fabric covered? A modern fabric like Oratex does away with the need for paint and toxic chemicals.
Design all that into an aesthetic structure and you have simplicity, quick build, light weight and easy parts productionisation (not even sure that is a word!).
Such an approach secured the success of the Mirror Dinghy and the Locost sports car. Could it not do the same for a two seat sportplane?
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Re: If Carling designed an LAA aircraft?

Post by Ian Melville » Thu Jan 09, 2014 7:21 pm

That is pretty much how I see it as well Brian.

Option to mix and match scratch building and purchase of parts to be as affordable as one would wish.
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Re: If Carling designed an LAA aircraft?

Post by neilld » Thu Jan 09, 2014 9:04 pm

Brian Hope wrote: the Ikarus C42 uses a similar ‘skeleton’ technique (in alloy tube) and also gets its form from add on skins. Would it not be feasible to have a simple alloy tube fuselage structure clothed in a modern flat ‘plastic’ material to give a pleasing form that did not require painting or UV protection? Clever use of a small number of three dimensional composite mouldings could provide the required ‘flow’.
Agree absolutely. There are many ways to achieve an acceptable design that have not (as far as I can see) been explored in the plethora (that word again) of kits on the market .
Fundamental to a low cost, easily manufactured product is reducion of number of components, make any complex component have multiple functions and standardise where possible. All part of the Design for Manufacture (DFM) philosophy widely exploited in the automotive industry.

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Re: If Carling designed an LAA aircraft?

Post by achean » Sun Jan 12, 2014 12:44 am

It's really hard to know what to say at this point in order to add to the debate. Which is code for saying I want to say something but don't have anything particularly helpful to add.

My own thoughts are that the product should:

o Look attractive (high wing aircraft carry off boxy construction better, IMHO)
o Be easy to build (boxy seems easier, but I'm prepared to be contradicted)
o Have predictable handling (just getting that in first)
o Be suitable for coaching/training (so should be a side-by-side design)
o Allow ease of access to the enclosed cabin (in case I want my 90 year old gran as a co-pilot, so high wing again)
o Survive, covered, at the tie-down without requiring hangarage.

The only points I think are possibly new here are ease of access to the cockpit and survivability.

Comments?
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