Opinions on this (fictional) aircraft please...

[Serpontaie]

My first thread; go easy :-?

Anyway here goes,
Imagine a 6 engined pedal powered aircraft where 1 person sits in a pod under each propeller. They all power the beast which is roughly 45ft long with a wingspan of approximately 55ft! Made from Carbon Fibres and composites over a Plastic/carbon fibre frame.

Max speed: 55mph
service ceiling: 1000ft
Empty weight: 130kg

I want opinions. Do you think it will fly or not?

Feel free to e-mail me at bowanator1@live.co.uk as i dont come on here very often!

[C]

A simple answer. Not a hope, certainly within those parameters you specify.

[Serpontaie]

please vote

[C]

For a start you'd be looking at a wingspan far greater then 55ft. Over 100ft and probably more than 150ft. Therein, considering the fragility of making a structure light enough (even if can find 6 very light cyclopilots), lies just one of the problems that would be encountered.

I've only ever seen single seat types of pedal powered aircraft (although I haven't spent a lot of time looking). Using two or more people would throw up a few problems.

Using rough figures, take the Gossamer Condor, the first successful pedal aircraft. The wing span was approximately 30m, the wing chord (length of the wing between the leading edge and the trailing edge) looked around 3m, so roughly the wing area was 90sqm (30x3, and using a basic assumption that the wing is a rectangle in plan view). The weight was around 30kg, and with a (light) cyclist/pilot in it would be around 90kg. This would give a wing loading of 1kg/sqm.

Put another pilot in, and say that weight goes up to about 150kg. Now in order to get the same craft in the air with the same performance (ie wing loading) the wing area would need to be increased (conveniently with these numbers) 150sqm. Using the same chord of 3m, and just varying the span you can see a span of 50m would now be

[expat]

Check out, Gossamer Albatross, this may give you a basic idea.

Matt

PS. First option.

[chornedsnorkack]

For a start you'd be looking at a wingspan far greater then 55ft. Over 100ft and probably more than 150ft. Therein, considering the fragility of making a structure light enough (even if can find 6 very light cyclopilots), lies just one of the problems that would be encountered.

I've only ever seen single seat types of pedal powered aircraft (although I haven't spent a lot of time looking). Using two or more people would throw up a few problems.

Using rough figures, take the Gossamer Condor, the first successful pedal aircraft. The wing span was approximately 30m, the wing chord (length of the wing between the leading edge and the trailing edge) looked around 3m, so roughly the wing area was 90sqm (30x3, and using a basic assumption that the wing is a rectangle in plan view). The weight was around 30kg, and with a (light) cyclist/pilot in it would be around 90kg. This would give a wing loading of 1kg/sqm.

Put another pilot in, and say that weight goes up to about 150kg. Now in order to get the same craft in the air with the same performance (ie wing loading) the wing area would need to be increased (conveniently with these numbers) 150sqm. Using the same chord of 3m, and just varying the span you can see a span of 50m would now be

Alternatively you could increase the chord and leave the span unchanged or indeed decrease it. Go to things like low aspect ratio delta wing, or biplane, or tandem wings. But when you go to low aspect ratio in any of those manners, your drag for a given lift tends to increase.

[Dr.bob7]

I was about to mention the Glossamer Albatross and Condor... but it only had 1 prop

[garryrussell]

The Albatross was very low level

What would be the purpose of this??

[Dr.bob7]

The Albatross was very low level

What would be the purpose of this??

I think the highest the Albratross got across the channel was about 25ft,

and i have no clue  :D

[expat]

The Albatross was very low level

What would be the purpose of this??

Flight is flight and often does not need a purpose, however in this case it was to fly over the English Channel by pedal power. Being up with the birds is just waisted energy for this aircraft. If you can fly from England to France at a hight of 1 inch, you have flown and met your target, job done.

Matt

[Hagar]

The Albatross was very low level

What would be the purpose of this??

Flight is flight and often does not need a purpose, however in this case it was to fly over the English Channel by pedal power. Being up with the birds is just waisted energy for this aircraft. If you can fly from England to France at a hight of 1 inch, you have flown and met your target, job done.

Matt

I suspect it wouldn't go any higher. Like a lot of seriously underpowered aircraft it would be taking advantage of "ground effect" to stay in the air. I've never seen a photo of it more than a couple of feet above the ground. http://donaldmonroe.com/gallery/index.php?album=gossamer-albatross

As for the subject of this topic I would have to agree with C. Not a chance.

[expat]

The Albatross was very low level

What would be the purpose of this??

Flight is flight and often does not need a purpose, however in this case it was to fly over the English Channel by pedal power. Being up with the birds is just waisted energy for this aircraft. If you can fly from England to France at a hight of 1 inch, you have flown and met your target, job done.

Matt

I suspect it wouldn't go any higher. Like a lot of seriously underpowered aircraft it would be taking advantage of "ground effect" to stay in the air. I've never seen a photo of it more than a couple of feet above the ground. http://donaldmonroe.com/gallery/index.php?album=gossamer-albatross

As for the subject of this topic I would have to agree with C. Not a chance.

Would it be flying fast enough to produce ground effect?

Matt

[Hagar]

Would it be flying fast enough to produce ground effect?

Matt

I'm not sure that ground effect is related to speed. As this photo shows, the Gossamer Albatross was obviously flying fast enough to stay in the air - just. [url]http://donaldmonroe.com/gallery/index.php?album=gossamer-albatross&image=ga1256_05a.jpg
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In fact they found it performed better at a slightly higher altitude. http://donaldmonroe.com/gallery/index.php?album=gossamer-albatross&image=ga1256_17a.jpg

I don't know what conditions were like on that Channel crossing. From the look of the water it was pretty calm without much wind. There wouldn't have been much in the way of thermal lift over the water either. That was probably just as well as directional control was not brilliant.

In theory if he could have climbed to a reasonable altitude at the start of the crossing he could have glided for much of the way.

[amaru]

Everything is possible with improvements! watch a video called "Giant of the Sky" (if i got it right) about the building of the A380, its amazing how one man had only the idea and now look at the A380 in action!!!