Light Aircraft Association

I have been researching various potential projects and have found a few designs I would like to build. Some of these have not been approved and I have come to realise that there are many more aircraft flying in places such as the USA than have been approved over here.

I have seen cases of aircraft built or part built that cannot be finished and flown as the cost and of the stressing calcs and the necessary technical work is just too much.

Am I missing something? Surely there is a way this can be improved? Would it be possible to link up with the various aeronautical universities and have some of this work carried out either free or at a much reduced cost? Why do we have this problem here but not elsewhere around the world?

Hello Mike,

It is good to see that the desire to build aircraft is still alive and well.

This topic comes to the fore from time to time and usually invokes the same comment about the air not being different here in the UK to elsewhere in the world. The most common comparison made is that with the experimental system in the USA, which is very different to the system here and indeed to many places across Europe. It is worth noting that the system we have in the UK is determined by the CAA not by LAA Engineering! We are required to investigate each design before we can make a recommendation to the CAA for the issue of a Permit to Fly and that investigation requires data.

The best source of data is the original designer and it is often down the the kit manufacturer or agent to decide if they think that sales in the UK will generate enough revenue to justify the effort required on their part to get a design cleared. Sadly some kit manufacturers decide not to follow through with the process yet their design continues to be operated abroad.

I wish you well in your search for suitable project.

Phil Hall

Thanks Phil

Please don't think I was in any way complaining about the work done by the LAA. I understand the CAA is responsible overall.

There are however designs that fall in the area you describe. The designer doesn't think it worth the effort to get the design cleared yet they are good designs that people in the UK want to build.

That was my question really, surely more can be done to support the designer in getting their designs approved? Are there ways this can be made easier by using modern FEA methods and in conjunction with universities?

Hi Mike,
You're right, there are some fantastic designs flying around in the U.S. that we never see over here, but their Experimental category is massive and includes things with pressurised cabins, gas turbines, retracts ,,,ad infinitum. Another area where they differ from us is also in their accident stats.
The builder has pretty much got a free rein to do what he wants over there and is only subject to an FAA Inspector just prior to his first flight, although getting the FAA sign-off is no guarantee that it will fly, as he is only inspecting to see if the work is of an airworthy standard and that the all important decals are present [the ones that cover the lawyers @rses].
The liability lies with the builder and it is not unheard of in the U.S. that when it's time to change aircraft, rather than sell it , some will just dismantle it and sell its parts separately, or use things like the engine for the next project, rather than risk having an irate widow's lawyer coming after you.
If a U.S. designer isn't prepared to supply the relevant data to such countries as ours then it is down to the prospective builder to do so, although you may find that you're on to The Samaritans more often than LAA Engineering.
We are in my opinion, very well looked after in the UK by the LAA whose approach is more pragmatic and common sense driven rather than the iron fist of officialdom.
Even if a design gets LAA approval, if it's the first of a kind, the builder will have his work cut out with liaising between the designer and LAA Engineering.
You may just end up looking at the list of LAA approved aeroplanes and thinking, "Hmm, perhaps it is quite comprehensive after all". Good luck,,,the answer is out there .

Hi Mike,

I certainly didn't think you were complaining, quite opposite actually.

We do currently offer designers a huge amount of support, more often than not, with great results. The problem for those prospective builders who want to get a design cleared even if the designer isn't interested in doing so, is where to source the basic data on which to start doing calculations.

Best regards

Phil

I see your point, I also understand why nobody would want to build a sacrificial airframe.

Would there then be an opportunity to take advantage of modern 3D modelling and FEA rather than going down the sacrificial airframe route. Has the LAA looked into this and is there any kind of guidance or minimum requirements set out for somebody that wanted to do that?

Regards

Mike

Hi Mike,

I am sure that modern modelling techniques could and do help. The basic problem is still the same though, if you cant get a copy of the plans, even in paper form how do you create model? In reality measuring a completed aircraft is unlikely to get the required level of detail.

Phil

I don't think the plans are the problem, if the plans were not available then you couldn't build it anyway.

Take the Nexus Mustang for example, the plans are available, there is even one part built in the UK. The 3D model could be made from the plans and this run through FEA and the stresses generated.

This could also be used for new designs from the UK. I know there are various variations of the Flitzer and presume others too.

I use 3D design software as part of my job and the capabilities of modern software very advanced these days.