Tandem wing Design

[Stephen Jones]

Hi,

Continuing on with my interest in tandem wings.

What are they and do they hold any merit in todays aviation.

Well , Tandem meaning two . And most planes have two wings don't they .

In a tandem wing design both wings add to the lift of the plane as opposed to a covenantal plane where the rear tail plane gives negative lift .

But just to say both wings add to the lift does not mean they both give equal lift .

Take a look here.

The most well known being the HM 14 flying flea .

[Stephen Jones]

And these,

And this

All different but tandem wings .

Ok i will return later with some of my experiments .

A little person wants to use the computer right NOW .

Later Steve

[Frank Skilbeck]

I have the plans for a RC Bert Rutan Quickie, one day................

[Tim Hooper]

I built a small Westland Wendover some years back. Flew very nicely too!

tim

[Robin Colbourne]

Posted by Stephen Jones on 12/02/2016 20:05:20:

Hi,

Continuing on with my interest in tandem wings.

What are they and do they hold any merit in todays aviation.

Well , Tandem meaning two . And most planes have two wings don't they .

In a tandem wing design both wings add to the lift of the plane as opposed to a covenantal plane where the rear tail plane gives negative lift .

But just to say both wings add to the lift does not mean they both give equal lift.

Certainly interesting, and there are applications for which they are ideally suited.

From an efficiency point of view,e,g, an airliner or sailplane, you want minimum induced drag. As induced drag comes from the wingtips, its better to have a longer span, highly loaded wing and a tail with minimum downforce and therefore minimal tip vortices. Airbuses have fuel in a tailplane tank so weight instead of downforce provides the bulk of the stabilization.in the cruise. By the descent and landing phase, this fuel has been used up, so conventional stability is present.

A tandem wing could suit a load lifter needing a very wide centre of gravity range, short take off capability and a relatively short span wing. Its also a way of getting a very high aspect ratio, as done on Burt Rutan's Proteus:

[Robin Colbourne]

With regard to the Proteus above, here's a comment from someone who has actually been involved with it:

Re: Tandem wing for high efficiency? Case Proteus

I worked on Proteus (after it was flying, not the design phase) and this was definitely a point design* aircraft with a very specific payload. It was designed around carrying a belly mounted telcom antenna as a low cost satellite replacement to provide broadband service over urban areas. It needed high altitude, lowish speed, long loiter capability, combined with the need to not blanket the line of sight of the antenna hanging below. The tandem arrangement was not to the best of my knowledge aero/efficiency driven. The strange dihedral/anhedral angles in the main wing were to clear LOS for the antenna. In fact, the outboard wings are glass, not carbon, to keep from interfering with the signal. The aircraft only became a high altitude testbed when the telcom company tanked and the project evaporated and Scaled needed to find other uses for it. It's a remarkable plane and it says a lot about the original design team that it now has over 3500 hours on an airframe that was intended for a 100 hour lifespan!

Patrick

There is more discussion over the merits and otherwise of Tandem WIngs in the read from which it came, here:

**LINK**

*A point design is one in which one requirement overrides all others, It is not intended to be multi-role.

[Geoff S]

Posted by Stephen Jones on 12/02/2016 20:05:20:

Hi,

Continuing on with my interest in tandem wings.

What are they and do they hold any merit in todays aviation.

Well , Tandem meaning two . And most planes have two wings don't they .

In a tandem wing design both wings add to the lift of the plane as opposed to a covenantal plane where the rear tail plane gives negative lift .

But just to say both wings add to the lift does not mean they both give equal lift .

Take a look here.

The most well known being the HM 14 flying flea .

I suppose you know that this wing arrangement has certain failings because of the proximity of the front and rear wings. I know Ian Redshaw was very cagey when he test flew his half scale example and relied more on throttle than 'elevator' control.

As a long time tandemist (two wheel, pedalled variety) I share your interest Though, come to think of it, someone lent us a tandem tricycle for a day in France and we did 70 enjoyable miles on it.

Geoff

Geoff

[Stephen Jones]

Hi Geoff ,

Yes i know that HM14 wing arrangement had some issues if not built right which is why it got the nick name Flying coffin . that said the concept was to make a plane small and compact enough so that it would fit in a garage .

Yet would be simple to Fly .

I came across one of my own design that i made when i was a teenager .

Of coarse back then i did not know how a plane should be made in regards to any formula that should at lest be followed. i just built a rubber powered plane and it flew very well , i called it the sand hopper as the landing gear/ wire was springy and so when it came to land it would bounce back up into the air , a bit like skimming a stone across the water doing a series of smaller bounces until it came to a stop.

It wasn't until looking at this plan much later and understanding the relation ship to the wings area and the cog point had i realized that it was in fact a tandem wing design.

Steve

[Stephen Jones]

I have made a few flying Fleas in my time .

Steve

[Stephen Jones]

And these,

And when i built the blue one i added a extra wing .

Now when flying the blue one i discovered that i could fly much slower and more stable .

Steve

[Stephen Jones]

I have also built a canard which of coarse is a tandem wing

And later i added a extra tail plane to the rear which made this more stable .

Steve

[Mowerman]

Do not forget the Miles M 35 Libellula. I once had an argument with an ex Miles worker who insisted it was a canard, not as I understood, a tandem wing.

[Stephen Jones]

Hi Mowerman,

The Miles M35 later ( Libellula ) may have been called a Canard due to the fact that the front wing has a smaller surface area than the main lifting wing at the rear but is still a lifting wing.

 

The term tandem wing means that both wings add to the lift .

As i understand it anyway .

So is as you have already said it is in fact a Tandem wing .

Or to put it an other way

 

Adjective

1. Together; working as one.

 

 

Steve

 

 

 

 

Edited By Stephen Jones on 14/02/2016 21:55:29

[Richard Harris]

Steve, what's the aircraft 3rd from the top below the quickie?

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[Stephen Jones]

Hi Richard it is a Mauboussdin M40 .

Looks similar to one that Lindsay has built .

Steve

[Stephen Jones]

Hi again,

Here are some more of my experiments with tandem wings.

Those of you that visit rochdale indoor flying meetings may well of seen my fly this .

I still need to do some more experimenting with this one but it does show promise.

Steve.

[Stephen Jones]

And there is this .

Ok, so this is a Tandem wing with a third wing as i discovered that my Little Bit Special model plane (the Bee looking plane above) was able to fly slower and more stable as did my cucumber model with the extra wing.

I decided to play around with the idea a bit more . and this model also flies well .

Steve

[Stephen Jones]

Now then ,

Although the three wing model files well it looks too complicated and there had too be a simpler way of achieving the same characteristics . so i drew some connecting lines.

And came up with this,

As you can see by the red and green line the lost wing area is incorporated into the triangle shapes.

[Stephen Jones]

And so was born the Star Delta .

And this also flies very well ,

This was the experimental model..

[Stephen Jones]

And this was the follow on ,

And i have been flying it for some time at the rochdale meetings well months now .

And there i was thinking i have come up with something unique only to be told it has been done before .

In fact in 1959 and it was a control line model call Duplex Delta .

Oh humm and that`s not the 1st time i have made something that i thought was original and my own .

Steve

[Peter Miller]

Posted by Stephen Jones on 14/02/2016 22:15:21:

Hi Richard it is a Mauboussdin M40 .

Looks similar to one that Lindsay has built .

Steve

I did draw p plans for that but never did anything with it. I think I scrapped the plan

[Former Member]

[This posting has been removed]