Magpie

[Halpm]

Hello, I'm a new member, with a new design here to show you. It's a four person tandem wing, powered by a jabiru 170 hp engine with a modified sump. So far I havn't got past building it for simulation on x-plane, and have started building an RC scale model.

 

What I'd really like is for you to use it as a target - point out anything I've missed, and why it couldn't fly etc. so I can improve on it. I'm not an engineer, I'm a musician, and therefore any input more qualified than my own is welcome. I intend to build a cozy before I attempt this, so you can see that it's a good many years in the future, but I'd like to have it s developed as possible.

 

Here's the first pic. It gives a pretty good idea of the configuration, but I'll post more later. It's a screenshot from the flight simulator x-plane 8.50 by Austin Meyer.

[argoldman]

Hello, I'm a new member, with a new design here to show you. It's a four person tandem wing, powered by a jabiru 170 hp engine with a modified sump. So far I havn't got past building it for simulation on x-plane, and have started building an RC scale model.

 

What I'd really like is for you to use it as a target - point out anything I've missed, and why it couldn't fly etc. so I can improve on it. I'm not an engineer, I'm a musician, and therefore any input more qualified than my own is welcome. I intend to build a cozy before I attempt this, so you can see that it's a good many years in the future, but I'd like to have it s developed as possible.

 

Here's the first pic. It gives a pretty good idea of the configuration, but I'll post more later. It's a screenshot from the flight simulator x-plane 8.50 by Austin Meyer.

 

Your design looks very much like a pregnant dragonfly. My suggestion is that you contact Andrew (works for NASA), on the dragonfly list, who spent many years developing a plane of similar configuration.

 

Good luck.

[Jon Matcho]

I can't comment on tandem wings, but from what little I know about the Quickies and Dragonflys I suspect that it's quite the challenge to create a 4-place out of the design. I think there's not much storage space possible in the two-place models because of a limited CG range. I wonder how well X-Plane simulates CG variables and whether it would be of any help in this area?

 

The two- and one-place Quickies have good performance. I like that enough to almost get over their odd looks.

[argoldman]

I can't comment on tandem wings, but from what little I know about the Quickies and Dragonflys I suspect that it's quite the challenge to create a 4-place out of the design. I think there's not much storage space possible in the two-place models because of a limited CG range. I wonder how well X-Plane simulates CG variables and whether it would be of any help in this area?

 

The two- and one-place Quickies have good performance. I like that enough to almost get over their odd looks.

 

John, John,

 

Beauty is in the eyes of the beholder, as well as what they are committed to.

 

When I had my dragonfly it seemed very normal, cute, in fact. I couldn't see what everybody liked about those darts that had to rest on their noses-- and of all things TWO vertical stabilizers with rudders that only deflected outward-- How odd.

 

Now that I am committed (or should be) to my Aerocanard, that odd shape and configuration is suddenly gorgeous!!

[Jon Matcho]

John, John,

Rich, should I call you Ric?

 

Beauty is in the eyes of the beholder...

Don't get me wrong, I think their gas mileage is a work of art. I would be tempted to grab one of these while I build my 4-place canard, but I'm sure that would turn into a distraction. Can't see how I can do anything more than one at a time.

 

My point was only to question building up a 4-place in this design versus another. It's all good.

[Halpm]

Your design looks very much like a pregnant dragonfly. My suggestion is that you contact Andrew (works for NASA), on the dragonfly list, who spent many years developing a plane of similar configuration.

 

Good luck.

Yep, basically a pregnant dragonfly - with a few twists. Thanks for the tip - I will contact him.

 

The idea was to create an aircraft that could be used as a high efficiency touring plane, or a relatively STOL bush plane by swapping the wings and undercart. In the picture, the aircraft is in "touring mode", but by replacing the laminar flow wings with some thick 18 percent high lift ones with junker flaps, you are suddenly left with a different plane. That's why I made the tail sit high, to get the clearence while in STOL mode.

 

I put the pilot in the back, looking over the head of the the passengers, to try and address the balance problem that Jon refers to in his post.

I had read that dragonflys and quickies had very little storage space, and was aware that simply "stretching" one would probably not lead to success. So I made the balance such that the the passengers sit on the centre of gravity, and that the pilot counterbalances the engine.

 

As far as I know, X-plane models the CG range effects of weapons on figher aircraft quite well, so I made some station loads using the weapons function in xplane and placed them in the passenger seats and baggage compartment. The magpie seems to take them in it's stride, and that's with the fairly standard airfoils that I've fitted it with at the moment (8 percent laminar flow airfoils front and back)

 

As it is the front wing is much more highly loaded than the rear, and I'm unsure as to how realistic is x-planes modelling of the interaction between planes - in fact there are many things I'm unsure about - but I hope the model will shed some light.

[Halpm]

Here's a three-view, drawn by Cameron Garner of the x-plane.org.

 

This is the turbine version, powered by an innodyn 250 hp turbine. Comments and critisisms are very welcome