Light Aircraft Association

Hi guys,

I'm new to the LAA, and I have a question regarding welding. I am seriously looking at the Sonerai II LS as my first project. The costs seems very reasonable, and the plus side for me is the use of the VW engine, resonable performance for the cost etc.

My question is can the builder weld his own airframe. Please excuse my question if it has already been answered before, (I have looked but can't find anything on it). I've also looked on the internet and saw a link from the LAA regarding CAA approved welders, but it still doesn't help with my question, can the builder weld his own airframe here in the UK like other countries.

Obviously the cost is going to be very high to have someone else construct and weld the airframe if you can't do it yourself, as it takes around 40% of the build time. It could potentially turn this choice into a no go due to the costs.

For example, my dad was a Grade A shipyard Welder/Chief Tester/Trainer and Manager for some 35 years, and if I was wanting anybody to be welding an airframe for myself, he would obviously be my first choice along with myself (I'm also not a bad welder - plenty of lessons from the old man ).

If you can't do it yourself, how easy/hard is it to get approved as a CAA welder?

Many thanks in advance, Craig.

I would check with engineering. It's not a hard and fast rule as many think. At the end of the day your inspector must be satisfield that the welds must meet the required standard.

I stumped Malcolm McBride about a year ago when I asked him who approved the welding in kits or parts from overseas.

Thanks for the replies so far, I was hoping that some of the users on here would be the inspectors and people from engineering?

The thing for me is, I can't understand why It needs to be a CAA approved welder, as obviously the costs are going to be high (which in turn leads to limited choices in plan built aircraft). Plus the chances of there being anyone near Aberdeen are going to be quite slim I would imagine, meaning even higher costs!!!

I struggle to understand how my dad who has 35 years of specialist qualifications and certificates (for example welding within Nuclear Reactors, and pipes, brackets etc in such) wouldn't be allowed to do an airframe, just because he's not on the list! On top of that he used to be the main guy to test and approve all the important welds on Nuclear Submarines and the like....there isn't much he doesn't know about welding!

Anyway, I'm ranting on a bit

Thanks for the advice, and I will get in touch with Engineering and hopefully an inspector or two might chip in with a response also.
I will have a look on the CAA website and see about becoming approved and the costs involved (it may well work out cheaper than getting someone else to weld it!!!).

There is a scheme for LAA builders who want to weld their own aircraft. I think you have to do the initial test but you do not have to carry out the annual renewals as long as you do not work on other aircraft.

Hi Craig

Glad to see Stuarts post, looks like there may be a route for you, we are after all meant to be home builders! paying someone to do such a large part of your build seems wrong and could jepordise your project.

The frame welding on my US kit was checked by my inspector however as a kit there is knowledge and experiance of the manufacturer.

It would surely seem reasonable for you to produce some sample components which replicate the types of welds you would do on your frame, these can then be tested and sectioned to show your ability to weld your frame.

Good luck with engineering and your project, please post regarding how you get on as who knows my next project may need some welding!!!

Regards, Ian

Actually the 'CAA welder' is just the easy way for the LAA to assure themselves of the welding quality. Given the way the association is going welding approval is unlikley to get any easier.

However Aberdeen is quite well supplied with CAA welders.

Drop me a pm and I can put you in touch with a friend who is certified - he got the approval for rebuilding certified aircraft but works on a lot of permit machines as well.

If you are a decent welder, the CAA welding approvals are not hugely expensive or difficult to get.

There are vastly more experienced welders out there than CAA approved ones. A weld may look "pretty" but would it pass a full non destructive test inspection. What the LAA should look at is the qualification of a builder to do his own welding. The builder can practice on the material used in the build and then submit a weld qualification test piece for inspection and approval. However, the welder must remain in qualification in that, if he does not weld within three months, he resubmits a new test piece. There are many weld inspection and test facilities throughout the country.

When I came to make the new undercarige for my current project I made a fitted all the parts. Tack welded and jigged where neccessary and then took the assemblies to an approved welder to complete. In this way I still did most of the work myself, and the cost and effort of getting approved would have been more expensive than my final welding bill.

I appreciate that a fusalage is a bigger undertaking and you probably need the welder to come to you rather than as I did take the parts to them. I suggest if you are serious about the Sonerai why not talk to a few approved welders and see if you can come to a similar arrangement.

Stuart Penfold[/quote]

I'll say it again. Becoming a CAA approved welder is not hard. You are welding 4130 - almost exclusively - so forget the other materials. There are 3 configurations and on an annual basis you need to renew one of them. That is not much of a financial committment - compared with buying a decent TIG set anyhow!

The thickness elements really do not apply as the thickness range of an airframe is actually very limited as well.

On a rather bigger point I would suggest you talk to people who have actually flown a Sonerai II. They have to be very light and whilst they are pretty slippery they need a smooth and surprisingly long runway.

Whilst the VW engines are fairly cheap you need a 'good' conversion which at the end of the day will not be much cheaper than a 'proper' engine.

My mate often welds up tacked components - but cleanliness and real neatness is absoluely critical. It's pretty depressing having to grind it all to bits because the 'tacking' is rubbish!

Craig, if your dad has the skills he can probably get LAA permission to weld up your fuselage. I say probably because it was the case the last time I asked the question but that was a while ago and things may have changed. I'll be at Turweston tomorrow so I'll ask if that is still the case and what you would have to do.
Gasax, don't agree re VW engine costing anywhere near the price of a 'proper' engine. AeroVee is currently $6500. Even if you call that pounds by the time it is in UK tax paid, that's still getting on for £5K less than a 912 or a Jabiru 2200. On-going maintenance will also be very much cheaper - full gasket set for VW maybe a tenner, for a 912 £600 plus. Set of 4 barrels and pistons for a vw - £200 ish, single barrel and piston for a Jab - nearly £450.

The thing with chrome/moly welding is that they require post weld heat treatement to stress relieve the weld. With TIG welds you can achieve good weld profiles and finish and stress relieving can be accomplished by ensuring that the weld is lagged in order to keep it hot for a prolonged period. I like Brian's run down on the price differences - good old and reliable VW. There is still a place for it in our "sport".

Craig, LAA Engineering has a system where if you get CAA approval it can last for the life of your project and it will last until completion of that project, there is no need to keep renewing. Also a possibility to get LAA approval from LAA chief inspector Ken Craigie on an individual basis, based on industry certifications held.
Basically it is worth talking to LAA Engineering to figure the best approach depending on your dad's experience and qualifications.
Hope this helps.