Affordaplane

For discussion on all aspects of the Single Seat De-Regulated, sub 115kg microlight aircraft category.


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Affordaplane

Postby Ian Melville » Mon Nov 08, 2010 10:00 pm

Has any one had a look at this for SSDR?
The empty weight is OK at 115kg, but a little low on wing area to get the loading down to 10kg/sqm.

I've just brought the plans as they are under $8 and think there is some weight to be saved in the covering and if a lighter engine is used.

Any thoughts?
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Postby Bill McCarthy » Mon Nov 08, 2010 11:41 pm

I received some "rip stop" sail cloth samples from a firm some time ago. One in particular, which was less than an ounce per square meter was impossible to tear. I tried ripping it with two pairs of pliers and it still didn't give way even after starting it off with a scissors cut.
I have looked at the various clips on the Affordaplane on Youtube and I'm sure some weight savings could be made on the rear fuselage section. The Avid Champion is another nice outfit and just below the 115kg limitation.
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Postby Ian Melville » Tue Nov 09, 2010 10:12 am

Hi Bill, I brought the plans mainly to get 'ideas', but is not far off what I may build one day. I am supposed to be building a CX4, but that is not going too well at the moment

I have seen the doubts over the weight of the A-Plane, but also note the draggy comments that require a fair few HP to overcome. So heavy and draggy is the worst of both worlds. If it does have more drag than similar a/c, then the bulk must come from the open lower wing skin. I don't like that anyway, reminds me of the Hangar Rat models. I'm guessing, but I suspect any performance gain from the undercamber is wiped out by the extra drag.

Changing the covering and reducing the weight of the rear fusalage were both on the cards as this would balance out a lighter engine.
Is that rip-stop stuff airtight? OraTex UL600 is 2oz/yrd for the uncoated.

The Avid Champion came up on the radar for the first time yesterday, so I will be looking at that as well.
Cheers
Ian
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Postby Bill McCarthy » Tue Nov 09, 2010 2:19 pm

The sail rip-stop meterial I got hold of is airtight and can hold water to a certain level (3ft rings a bell) and is PU coated (comes in width of 60" and is just under £4 per metre). I also obtained some kite rip-stop material which was lighter still and is very tear resistant.
The Oratex is impressive stuff though - I saw the agent give demonstrations into its ability to reform a tight skin with the application of an iron if it was dimpled by some hard clouts with the knuckles.
I have not seen many examples of tri-gear sub 115kg designs. I guess the rear fuselage of the tail dragger types require beefing up to take the stresses during taxiing hence adding weight there.
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Postby Ian Melville » Wed Nov 10, 2010 1:27 pm

I've had a quick look at the Champion. It was only ever available as a full kit, and that has not been available for a few years. Makes it a bit of a non-starter unless you want to import a used one.
The fusalage is also welded 4130, so copying that at home may be a bit tricky.
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Postby Bill McCarthy » Wed Nov 10, 2010 1:31 pm

The "Airbike" is another interesting design but alas, too heavy for the SSDR category.
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Postby Ian Melville » Wed Nov 10, 2010 1:35 pm

Bill McCarthy wrote:I have not seen many examples of tri-gear sub 115kg designs. I guess the rear fuselage of the tail dragger types require beefing up to take the stresses during taxiing hence adding weight there.


I wouldn't have thought much beefing up of the rear fusalage was required for a tail wheel? Nose wheels(and fixings) on the other hand need to stand up to a nose first landing and have to be quite beefy, hence are a weight penalty.
For example Cessna 170 empty is around 1357lb, and early 172 is around 1491lb. That is an extra 134lb, 10% of the airframe weight
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Postby A Bleese » Sat Nov 13, 2010 5:57 pm

I recently had a look at a few SSDR possibilities and thought that the Legal Eagle looked interesting so I asked the designer for details and, to be honest, it looked a bit marginal - ie close to 115kg and the wing only just about big enough.

I spoke to him about it and he is currently re-designing the wing to slightly reduce the loading, he should have, what he has named, "The English Wing Eagle" ready soon. So, if anyone wants any details I'd be happy to pass anything on that he comes up with.

There are a couple of other American designs that look interesting - the Hart Bird 1 and the Zipster Biplane (also by Hart).

These are just the plans built ones.
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Postby Brian Hope » Sun Nov 14, 2010 10:38 am

Hi Adrian, I think most of the designs are 'a bit marginal' when it comes to hitting 115kg. The Legal Eagle certainly has been built to comply with FAR103 though (same weight at SSDR), there is a builder report with accurate weights on the web somewhere. The easiest way to reduce the weight a little though would be to replace the half VW with a two stroke, not necessarily a Rotax 447 because they weigh pretty much the same as the VW, but there are others appreciably lighter in the 30/40 hp range. If you go to max 115kg you need about 125 sq ft of wing area, and the Eagle doesn't quite make that, adding airfoils to the struts would make them 'lifting area' and that could be added to wing area which would probably make it enough.
One aircraft that has not been mentioned yet is the Weedhopper. This original John Chotia design went on to spawn a number of clones, the AX3 and XAir amongst them but the basic B and C model Weeds have a lot to offer SSDR. They long ceased to be available as kits, but there are plans available and a 447 powered example could be built within 115kg. They can be rigged/derigged in half an hour, the wings folding up like a flexwing, and trailered home, thus keeping costs to an absolute minimum. Check out the Yahoo Weedhopper group.
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Postby Ian Melville » Sun Nov 14, 2010 11:26 am

It actully makes a lot of sense to get as close to the 115kg weight as possible, with as small a wing as possible to meet the 10kg s/m.

Unless of course you are a racing snake who only wants to fly on dead calm days :)
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SSDR

Postby Bob Tavener » Mon Nov 22, 2010 9:06 pm

Although it is not on the market yet have you looked at the e-go aeroplane? http://web.me.com/tony.bishop/e-Go/welcome.html. It is innovative and truly British.
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Postby Brian Hope » Tue Nov 23, 2010 12:26 am

I wish the e-go well, it is a clever state-of-the-art machine on which an awful lot of testing and design is being lavished. That does not come cheap and when it hits the market the projected price tag will be around £25K
Maybe I am not typical, but I see SSDR as an inexpensive, hassle-free means of flying, which rules out even spending £10K on a kit. I want a plans built, and by and large many of those posting on here seem to be of a similar mind.
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Postby merlin » Tue Nov 23, 2010 9:19 am

Brian Hope wrote:Maybe I am not typical, but I see SSDR as an inexpensive, hassle-free means of flying, which rules out even spending £10K on a kit. I want a plans built, and by and large many of those posting on here seem to be of a similar mind.


Spot on for me with the addition of the word simple to the phrase "plans built".

I would welcome some commercially available components but most of all any design needs to recognise the need to derig/rig so as to provide shelter from the weather as I've seen too many aircraft damaged by wind etc.

Finally it is probably just me but I want one that looks good/right.
roger breckell
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Postby Ian Melville » Tue Nov 23, 2010 9:41 pm

I'm in the same camp as Brian and Roger. Cheap and chearful :D

Spoke with Giotto at the RAeC Design Confrence. He is expecting e-go first flight sometime in 2011
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Postby ian herdis » Wed Nov 24, 2010 5:13 pm

Here is an other contender

T-100D Mariah
240 lb empty
146.5 sq.ft wing

Looks like only one aircraft built but the design seems to have been reserected

Weight OK and plenty of wing

Ian herdis
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