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Lifting body + prone position ?

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BJC

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It's like asking how would you find guys for free testing of your pimp friend's new hooker that just turned 18 and wanted to be a porn star her whole life. Are you sure there would be no candidates to fullfill her dreams? :gig:

DZ:

Get out of your fantasy zone, and get you feet back on the ground. :)


BJC
 

RPM314

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Are you kidding..? :D

In most cases when well designed and built experimentals are in question, there are a lot of pilots who would like to try it. ;)

It's like asking how would you find guys for free testing of your pimp friend's new hooker that just turned 18 and wanted to be a porn star her whole life. Are you sure there would be no candidates to fullfill her dreams? :gig:
Well if it required gettin' busy in the prone position where cardiovascular effects could cause a catastrophic sexyness failure and crash the bed into terra firma at 250kts...
 

Retroflyer_S

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Well if it required gettin' busy in the prone position where cardiovascular effects could cause a catastrophic sexyness failure and crash the bed into terra firma at 250kts...
Folks ahoy !

Let's not turn it into a mid-air sex experience thing.

More and more people are also driving velomobiles instead of bikes.
 

DangerZone

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Well if it required gettin' busy in the prone position where cardiovascular effects could cause a catastrophic sexyness failure and crash the bed into terra firma at 250kts...
I said 'well designed', not 'flawed beyond repair'... :gig:

Kidding aside, there was a moderately well designed prone homebuilt aircraft that anyone could make in their garage: the Wee Bee. :)

20559d1352315989-hi-everyone-spain-628x471.jpg

WeeBee3view_A.jpg

A bit too big, too underpowered and too slow for my taste, but we gotta admit that it was well designed for that era. ;)
 

Retroflyer_S

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How do you plan on getting a test pilot?

View attachment 43536
This is a good question...I was thinking myself, why would I leave the fun for someone else ?


I said 'well designed', not 'flawed beyond repair'... :gig:

Kidding aside, there was a moderately well designed prone homebuilt aircraft that anyone could make in their garage: the Wee Bee. :)
The size thing is a good question too. I was thinking a 15 m x 7 m twin motorglider...that can obtain 10 000 meters altitude and cruise ( there ) 200 kts using 2 x 10 hp engines.
 
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DangerZone

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This is a good question...I was thinking myself, why would I leave the fun for someone else ?

The size thing is a good question. I was thinking a 15 m x 7 m twin motorglider...that can obtain 10 000 meters altitude and cruise ( there ) 200 kts using 2 x 10 hp engines.
Exactly, why leave the fun to someone else..? :) We usually even have some expenses when flying (fuel) compared to flying 'for free'... ;)

The mentioned wing size is a bit... large. Remember Felix Baumgartner, the man who first flew across The Channel with his carbon fiber wing? His wingspan was 1.9m and he developed speeds of 200kts at altitudes slightly below 9000m.
_39345371_base_jumper_inf416.gif

It would be wise to keep the wingspan below 2.5m for subsonic wingbodies, this is the limit for international road transport (2.55m). Thus the wing can be built in one piece and transported on the roof of your car. If you position it upright you might get some funny looks and questions about the 'alien UFO' that 'caught' your car's roof. To avoid this simply invert the thing and put some cover on it. When asked by people what is it - deny it is an aircraft. You can always say it's a kid's toy and that it's purpose is for childr playing. Try doing that with a 15m wingspan and you definitely won't get away with it. :D

The engines of 2x10HP might be underpowered even for larger wingspans. The Lazair flies better with two 20HP to 30HP engines, this shortens the takeoff and allows better climb. However, if you are building a glider intended for long soaring then it might be wise to try yourself if the prone position is that comfortable for you.
 

Retroflyer_S

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Exactly, why leave the fun to someone else..? :) We usually even have some expenses when flying (fuel) compared to flying 'for free'... ;)

The mentioned wing size is a bit... large. Remember Felix Baumgartner, the man who first flew across The Channel with his carbon fiber wing? His wingspan was 1.9m and he developed speeds of 200kts at altitudes slightly below 9000m.
View attachment 43565

It would be wise to keep the wingspan below 2.5m for subsonic wingbodies, this is the limit for international road transport (2.55m). Thus the wing can be built in one piece and transported on the roof of your car. If you position it upright you might get some funny looks and questions about the 'alien UFO' that 'caught' your car's roof. To avoid this simply invert the thing and put some cover on it. When asked by people what is it - deny it is an aircraft. You can always say it's a kid's toy and that it's purpose is for childr playing. Try doing that with a 15m wingspan and you definitely won't get away with it. :D

The engines of 2x10HP might be underpowered even for larger wingspans. The Lazair flies better with two 20HP to 30HP engines, this shortens the takeoff and allows better climb. However, if you are building a glider intended for long soaring then it might be wise to try yourself if the prone position is that comfortable for you.

I could have different set of wings and engine variations for the need.

High soaring low power ( 20-30 hp ) and low flying short span ( 50-100 hp ).

Sinus has 80 hp and 15 m span ( does 250 km/t ), but Zenair 100 hp and 8 m ( does only 140 km/t ).

I remember Helios went 275 km/t ( ground speed ) and weighed 750 kg but had only 28 kW at 100 000 ft.
 
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Doggzilla

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This is not aimed at you DZ... I'm just using your post as a 'jumping off' point.


Ouch... talk about torturing a lab rat!



I think the only reason he gets decent forward visibility is because he flies at such a high angle of attack; if he flew flat, he would really have to bend his neck upward drastically. Just for fun, put on a motorcycle helmet, lay face down on your bed with your head and shoulders hanging over the edge, and hold you head up or level for as long as you comfortably can. I don't think it will be very long.



I mentioned this one before... the "Switchblade" Phasst Glider.

View attachment 43523

View attachment 43520

View attachment 43521
I always wanted to build something like this. But they really need to learn how to optimize something like this. They could be much more practical.
 

Retroflyer_S

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I always wanted to build something like this. But they really need to learn how to optimize something like this. They could be much more practical.
I have seen these creatures for a pretty long time now and they seemed to have been able to optimize some flying devices. There are hundreds of subtypes of these around. :gig:
 

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DangerZone

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I always wanted to build something like this. But they really need to learn how to optimize something like this. They could be much more practical.
They could have made an effort and built a better one. James Bond movies allways showed some advanced high tech vehicles and this one looks like a tin can.

[video=youtube;2MGGcT4xlq0]http://www.youtube.com/watch?v=2MGGcT4xlq0[/video]
 
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Retroflyer_S

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They could have made an effort and built a better one. James Bond movies allways showed some advanced high tech vehicles and this one looks like a tin can.

[video=youtube;2MGGcT4xlq0]http://www.youtube.com/watch?v=2MGGcT4xlq0[/video]
That is the prone position all right.

Now you have to study the Vincent Burnelli and Bill Horton to know more about the lifting bodies.

Seems that the term is " lifting fuselage " that I am after ( more or less ).

http://the-things-with-wings.blogspot.fi/p/burnelli-lifting-fuselage.html
 
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bmcj

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I have the old model of the Z1 helmet which does allow pretty good visibility skydiving at +300km/h speeds even when looking up slightly. Sure, it does require some effort and strong head/neck muscles but how long do you want to stare up into the blue sky?
But that is skydiving where your primary focus is the ground below you (if it's above you, you did something wrong :gig:). You can crane your neck to look out horizontally and a little bit above you, but to sustain that head angle for sustained horizontal flight has got to be strenuous.
 

Retroflyer_S

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But that is skydiving where your primary focus is the ground below you (if it's above you, you did something wrong :gig:). You can crane your neck to look out horizontally and a little bit above you, but to sustain that head angle for sustained horizontal flight has got to be strenuous.
Can't you look at the meters/gauges every now and then ? Do you have took forward all the time ?

-----

Why are these always so boxy...any other lifting body/fuselage form out there ?
 

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WonderousMountain

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Oh yes, there are all sorts of lifting/blended bodies. We who have been on this site a while have a truly wonderful history of images (if we can remember them),

and in some cases performance stats.

The question you raised is a problem in design. Rounding the edges causes a large loss in lift, as air slides off the rounded sides and to the top. That said, the boxy is a large source of drag. More to the point, any large airfoil like surface will work for a Cl of about 1.

Maybe it's time to do some serious research into what you want.
I'd love to see where it takes you.

LuPi
 

DangerZone

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That is the prone position all right.

Now you have to study the Vincent Burnelli and Bill Horton to know more about the lifting bodies.

Seems that the term is " lifting fuselage " that I am after ( more or less ).

Things With Wings - To fly or not to fly: Burnelli Lifting Fuselage
Actually, you DON'T want your body to create lift like an airfoil because it would create more drag than if not having lift. You want WINGS to create lift and the faster the aircraft flies the lower the induced drag. Thus the goal is to get parasitic/form/wetted-area/friction drag to a minimum and have as small wings as possible for the lift needed in your mission requirements.

This kind of thinking was also the obvious problem with the Phasst: it had less lift and more drag than the Gryphon which had a smaller wingspan and less wing surface area. The V stabilizer is in the wake of the whole body so it has poor authority, this was a very common problem of most 'lifting body' aircraft. Finally, such a concept of low control, lift, performance and efficiency is simply a problem waiting to become a disaster.

The ideal form with least drag is the Haack-Sears body. This is why there were many airplane fuselages which mimick this form and use wings to provide good lift for both high and low speeds. That's the biggest challenge, to find a good wing form and form adjustment technique which would allow both.
 
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