LAA Approval

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Postby ivanmanley » Wed Mar 26, 2008 9:39 am

I must admit, 82hp at 2800rpm is very attractive and would allow the use of a nice prop ... maybe even CS? If I win the lottery between now and the time I need an engine, I might well be tempted :lol:

I must defend the poor old Veedub. Though "old tech" it has proven itself to be a very good and reliable engine. The problem is that in the past when fewer alternatives existed, the VW was used on airframes to which it really wasn't suited. It's been mentioned many times before, but the VW (no matter what capacity) can only sustain around 55hp due to the cooling ability of the heads. If the cowls are poorly designed on an aeroplane that needs all of that 55hp or more, and/or the aeroplane is slow flying as well, then the airflow will be insufficient to keep them within limits. Put a VW on a Turbulent, D9 or T31m ( :D ) and it will happily run for hundreds if not thousands of hours trouble free. Stick the same engine on a VP2 and expect it to lift two people and you'll be lucky to pass 100 hours!

The bigger VW's can give more power short term for take off and climbs between cruising, but unless water cooled, still have the head cooling issues. The case cracking is also a bit of a myth and was the result of trying to increase capacity by boring out too much. The bigger engines these days are stroked and also use aluminium cases rather than magnesium. I personall like the 1834 as it is pretty much the ideal cheap VW size. It only puts out around 55-60 hp, so if matched to a suitable aircraft (such as the CX4) it should not have cooling issues, and it's not overbored to achieve its capacity. If you go bigger with a VW then it gets more expensive as you need a stroked ally engine which is fine, but may have cooling issues if you keep full power on for too long. It is if you really need this higher power that alternative engines come in.

I would suggest that unless you want a rocket ship, the VW is more than adequate for the CX4. More power is nice, but in this aircraft it's a luxury. However, if luxury is your thing, then the UL260 certainly looks like it fits the bill! :D

Ivan

PS. Galaxy UL Power Engines (boy! that's a long user name) ... I see you're at wing farm? I used to occasionally fly at the Bath and Wilts gliding club, so I know just where you are (assuming it's the same Wing Farm). Any chance I could fly in some time? I'd certainly like to have a look at the UL260i even if I can't afford one :roll:
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Postby Guest » Wed Mar 26, 2008 2:08 pm

Hi Ivan,

Yeah a bit long init :?

Its the Same Wing Farm near Warminster. You are more than welcome to flyin, just call me on the number below and I will give you the brief.

What is it you are flying?

Regards
Mark
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Postby ivanmanley » Wed Mar 26, 2008 3:17 pm

Thanks,

I'll be flying a Slingsby Cadet Motorglider (T31m).

It won't be for a month or two, as the strip, having been lovely and dry three weeks ago, is now saturated :cry: I've also got my struts off to re-spray.

My email is ivan@manley1.demon.co.uk

Ivan
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Re: LAA Approval

Postby littlewing » Sat Apr 19, 2008 2:16 pm

Gerry Holland wrote:I'm considering the CX4 as my next build and referred to the LAA Engineering statement regarding type approval on Website. Why is it that the LAA has found technical shortcomings in design after initially trumpeting the opportunity this aircraft could bring to plans based home building. This is an Aircraft that does fly albeit early days and is being built by up to 100 builders in other countries without undue hindrance. It has modifications being applied as problems arise, no different to any engineering development.


I have been the first person who tried to put on track CX-4 when only one was built by designer and fown and no one set of plans sold.
Everything refused by Engeneering PFA (A.Moor that time). I have somewhere the letter where I`ve been asked to carry out almost complete recalculation of the whole design that obviously is not acceptable for the my level of engineering.

I was told "Engeneering has no time for new design developing". That is all story.
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Postby Domo1977 » Fri Oct 03, 2008 1:30 pm

I've been watching this aircraft with interest over the last few months with a view to maybe building one eventually. It's certainly a really good looking and performing aircraft and I can't wait to see a UK example fly.

I was just wondering what the current state of play is with LAA engineering and the people that are starting projects in the UK?
Are you allowed to start work on anything yet other than small parts?
How far off are the plans/build manual to being approved?
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Postby David Hall » Fri Oct 17, 2008 2:40 pm

I understand that the Log books are only a week or so away, so assembly can then proceed :D
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Postby Ian Melville » Fri Oct 17, 2008 3:02 pm

Spotthehall, funny you should be replying at the same time as I am composing a longer message!!

As a plan owner I wish I knew what the state of play is :evil:

I do know through others that Dave Thatcher has supplied stress and load calculation and load test that in most part satisfy the LAA.
The areas that I am aware of that the LAA wished to be changed are the design of the rudder pedals, and the rear fuz floor. Both of these have been redesigned by Dave, but it is up to UK builders to do the stress calcs for these changes. Dave Thatcher has indicated that there are other issues with control stops. Engine mount also needs stress calcs done.
I have found a probable inspector, who was going to seek the latest news but have heard nothing yet.
Before I commit more funds I would like to see a clear path towards approval and a ball park figure of the costs. Clearly a get together of all interested parties with the LAA person (name escapes me) is needed.
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