DISCUSSION ON BUILDING NEW GENERATION PLANES

Ketchup

4s mini mustang
What about solutions to the problem that don't require input from a computer? Is there a way to design the airframe to be stable enough in the yaw axis even without a vertical surface? I know that on some RC wings the sweep allows them to be stable and not have winglets, but are there other methods, or do they not provide enough stability? I was thinking that maybe the airframe could just be made stable on the right axes through its design, but I guess it might interfere with stealth and may not even provide enough stability to be safe.
 

Matthewdupreez

Legendary member
What about solutions to the problem that don't require input from a computer? Is there a way to design the airframe to be stable enough in the yaw axis even without a vertical surface? I know that on some RC wings the sweep allows them to be stable and not have winglets, but are there other methods, or do they not provide enough stability? I was thinking that maybe the airframe could just be made stable on the right axes through its design, but I guess it might interfere with stealth and may not even provide enough stability to be safe.
That's a rudder.....
 

L Edge

Master member
When I said without vertical surfaces I was referring to specifically vertical stabilizers and winglets. So no, it isn't a vertical stabilizer.

That's the point I am trying to make, the B2, X-47B and future Gen 6 do not have anything vertical at all. Hence, you will need a programable gyro setup to have it fly stable.

Put it another way, have you seen on this site(and others), the designer builds using a Cad system and shows a video of a scale rudderless model taking off and flying and landing using EDF's?

I went thru 6 months of crashes and 3 designs before I got the right amount of thrust vectoring(yaw) to duplicate a rudderless version.
What about solutions to the problem that don't require input from a computer? Is there a way to design the airframe to be stable enough in the yaw axis even without a vertical surface? I know that on some RC wings the sweep allows them to be stable and not have winglets, but are there other methods, or do they not provide enough stability? I was thinking that maybe the airframe could just be made stable on the right axes through its design, but I guess it might interfere with stealth and may not even provide enough stability to be safe.

Simple answer, no.
 

L Edge

Master member
4) Prandlt-D wing type configuration


I did some research on the Prandlt-D wing and some of the interesting areas they need to look at is gusty winds(it is causing tip stalls) and high speed flight. How would they design the outer portion of the wing necessary for the Prandlt-D wing to work ?

Generation 6 planes need full stability from cross winds and gusty conditions to high speed flight so until these are solved for the Prandlt-D wing, the only way for RC designers to duplicate it will be to use gyros.
 

FoamyDM

Building Fool-Flying Noob
I am not an expert, but as always is my luck, I flew my Prandlt-D Wing in Pre-Thunderstorm Gusts and higher winds, and I was testing High speeds. when my plane folded like an unreinforced FT-Explorer. What I can tell you is that the Roll was coordinated turns occurred in the center 35% of deflection. and acted like most other flying wings out side that. It was a tad lethargic on rolls, but it has 50% of the aileron surface area of a typical bird. this can be remedied by either increasing the control surface chord, or adding Flaperons inboard that only operate outside the Center 35% section. To aid in restoring gust upsets. and return to more "typical" flight. This plane flies like a bird.

I say this to help your project. This is not meant for MACH speeds, but it shows exactly the tendencies I was hoping for and expecting.
 

L Edge

Master member
Again, I am saying that if anyone attempts to build a 6th gen plane, there are issues still to be needed to work out if you use the Prandlt-D wing. Until I see some "D" wings being launched, fly around doing figure 8"s and land successfully in a video, the only way to solve the yaw issue is by using gyros.

I explored flying wings and I ended up changing the flow over the wing to fight gust and stability. Also improved it in crosswinds so it can be flown in tight places.

Anytime a surface is extended on one side of a rudderless wing(or both), it can lead to severe pitch, yaw, and roll problems. Just like the real planes, gyros are what makes it fly.

I applaud you for making aware of what problems exist for flying wings. Keep fighting it.

My interest right now is to figure out what is possible the limits on a gyro that we can use. My goal is to do a scale approach on taking a 2 engine transport and

1) put brakes on
2) start one engine and 10 seconds later, start the other
3) taxing the transport controlling an oscillating brake.
done all of the above.
now learning and playing with a gyro in the head holding,so I can simulate a takeoff and landing where it is nose up?
4try that on my transport
 

JasonK

Participation Award Recipient
Again, I am saying that if anyone attempts to build a 6th gen plane, there are issues still to be needed to work out if you use the Prandlt-D wing. Until I see some "D" wings being launched, fly around doing figure 8"s and land successfully in a video, the only way to solve the yaw issue is by using gyros.

have you not seen any of the videos of Prandlt-D wings doing just that? I have. take a look here: https://www.youtube.com/results?search_query=Prandlt-D fairly sure you should be able to find a video that has what your looking for [or what your looking for is unclear as the first one I clicked on had a launch, clearly flying under control with proverse yaw and a clean landing all with no vertical stabs]
 

L Edge

Master member
have you not seen any of the videos of Prandlt-D wings doing just that? I have. take a look here: https://www.youtube.com/results?search_query=Prandlt-D fairly sure you should be able to find a video that has what your looking for [or what your looking for is unclear as the first one I clicked on had a launch, clearly flying under control with proverse yaw and a clean landing all with no vertical stabs]

Show me a couple of videos where Rc pilots built a D wing and having flown it in gusty winds from launch to landing. Not NASA.
How would you adapt it to scale a 6th gen fighter that is rudderless?
Same with a bicopter, unless you have gyros or FC, can't be done at present.
 

JasonK

Participation Award Recipient
Show me a couple of videos where Rc pilots built a D wing and having flown it in gusty winds from launch to landing. Not NASA.
How would you adapt it to scale a 6th gen fighter that is rudderless?
Same with a bicopter, unless you have gyros or FC, can't be done at present.

That link I gave you had a non NASA video showing the whole process for a D-wing. Here I will even help you get to one of the videos that does that. Also, 'Gusty' to a full scale plane is way different then what is 'gusty' to a scale plane, but I am sure you know that, so I am fairly sure your not expecting to see an RC plane fly in crazy gusts as one wouldn't expect a full scale plane to fly in a hurricane either.

6th gen fighters are going to be completely fly by wire, so I don't know why you would expect a solution that wouldn't be. Fighters use that, so they can be right at or even beyond 'stable' to have greater maneuverability. If your goal is to simulate something like that, yes it is going to be using a flight controller and have more moving surfaces then a flying wing, and we already have solutions out there like that.... say like this one:
or this one

A Bi-copter is a completely different story and I don't see how that has anything to do with a prantl-D type wing. That requires active stabilization (anything flying based on vectored thrust does), even 'old' RC helicopters had a type of active stabilization, it was just a mechanical gyro solution instead of electronic. I don't think a bi-copter could _ever_ be done without active stabilization as it isn't a stable aerodynamic design.

So if your argument is that "you can't make something that isn't stable without some sort of stabilization," that is a known thing, but doesn't appear to be adding much to the discussion.
 

Scotto

Elite member

Everything Im seeing in this video either has vertical surfaces or they fold down for stealth cruise mode and fold up for high maneuverability mode. You dont need stealth for take off and landing. Watch close in the first little bit of the video. What would be cool is your udder rudders mounted on another set of servos so you flip a switch to go from tailerons to ruddervators. I think thats the right terminology lol. The opentx has flight modes thats probly just perfect for such a setup.

I got a feeling some of this artwork is just for show and not expected to fly. But give us a few dozen million or so and we can explore its potential for you. Great work if you can get it. Im jealous :cautious:
 

dap35

Elite member

Everything Im seeing in this video either has vertical surfaces or they fold down for stealth cruise mode and fold up for high maneuverability mode. You dont need stealth for take off and landing. Watch close in the first little bit of the video. What would be cool is your udder rudders mounted on another set of servos so you flip a switch to go from tailerons to ruddervators. I think thats the right terminology lol. The opentx has flight modes thats probly just perfect for such a setup.

I got a feeling some of this artwork is just for show and not expected to fly. But give us a few dozen million or so and we can explore its potential for you. Great work if you can get it. Im jealous :cautious:
I'm not sure I understand what the push on this thread is to build an airplane without any sort of flight controller or stabilization. I believe every US plane built since the F117 has been fly by wire - ie it had computer assisted stabilization because the airframe was not stable on its own. There are so many inexpensive and simple ways to add basic stabilization in the RC world today.
 

L Edge

Master member
If you go back and read the first thread, the initial point I was trying to make got lost.

Most of the plans that are available here to build do not include any designs of the future. If you follow aviation, the future 6th gen are leaning to rudderless to reduce drag and improve stealth. So yaw really needs to be address.

For instance, how come no one has produced a B1 plans and a complete video of launching, flying and landing in weather that we fly in?

Point I am trying to bring up is that in order to accomplish this, it would be real easy to use a AS3X gyro setup where you can program it.

Has anyone explored the AS3X and understand the potential that it offers?

It is a new tool(you can even add programming mixes) that allows 3 flight modes(each setting the servo travel, expo, type of gain),to solve the problems. Most gyro just allow most pilots to adjust gain and that is it.

So if your interest is leaning to designing rudderless models, take a look at the AS3X approach.

Somehow, it got off on the wrong track to Prandtl D wings.
 

JasonK

Participation Award Recipient
it looks to me like the B1 is a traditional tailed plane (maybe you mean something like the B-21 I linked above)
1635258979579.png

Has anyone explored the AS3X and understand the potential that it offers?

most of us who do anything fancy just use a 'real' flight controller instead of something like that (more functionality and less $ on a FC board then that)
 
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Piotrsko

Master member
Northrop built stable flying wings no rudder, no computer control. Problem is they can't go sonic but they do yaw hunt so you cant accurately drop dumb bombs, hence the tip brakes. Aft fuselage area behind the COP appears to solve the yaw issue and would be radar invisible because it is shadowed by the airframe. The B21 seems to be just a hotrodded B2 with less paint issues.

Combat and stability are incompatible requirements, computer control just allows for more airframe instability before becoming pilot uncontrollable and aircraft divergence into the ground.

Read the whole thread, and while I do claim to be dyslexic, I do not fully understand what the engineering requirements really are in a very gross sense or maybe the target result seems to keep changing.

Looks like you want some sort of gyro stabilized tail-less flight system that is programmable for various systems and various stabilities using hobby parts? Or you trying to build a X29 flight control system?
 
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JasonK

Participation Award Recipient
and another design that appears to work with no vstab:

this one with no control surfaces, just 4 motors using 'quad' type stabilization.