Ok honestly, don't get me wrong, I'm a 1st-year AeroSpace student and the professors at my university are very good. But this helped me so much, maybe he's not using the official terms but the concepts are explained perfectly. Thanks a lot, you made my homework and learning material much easier to understand.
Love your videos and the information you impart. Keep up the work you do of pointing out the stupidity of the regulators and their paranoia against property destroying and life threatening small drones.
I'm 16 and getting into 3D printing wings! Currently designing the first version of my very own wing, this video helped me understand the basics! Thanks! 😁
I came across this video and I was ECSTATIC... ☺ I'm a 59yr old and I fly drones, helocopters, and now fixed wing aircraft... I need to watch all the previous videos and then catch up. This is so AMAZING and I feel like I'm back in school!!! 😃 The way it's taught is very educational and I'm delighted to have found this video... Now I'm subscribed and will be watching MORE... May you Always remain in good health and many more years of teaching... God Bless YOU! ☺
Really you need to not worry about your drawing, most of us can't draw but you get the ideas across and that is all that is important. Thank you so much for these "classes", and thank you for all you do for the hobby.
Great easy to understand video! Thanks! As a former hang glider pilot for over 3O years I have a lot of experience actually flying, Flying Wings. In particular I was an avid Class II Rigid Wing Hang Glider pilot over the years. Class 1 hang gliders are the traditional Delta (Rogollo) Wing design where the pilot solely uses body weight shift to change the CG for pitch, roll & yaw control. Class II rigid wings use either a combination of weight shift and aerodynamic control ( weight shift for pitch and tip rudders for roll/yaw ) or full 3 axis control ( combination of tip rudders, elevens and on some designs, inboard flaps). Class II full aerodynamic control hang glider pilots can sometimes still use minor body weight shift to make subtle CG changes too for better trim etc. Class II hang glider flying wings I flew, included Icarus II, Easy Riser, Icarus V, Fledgling, Apex, and the famous Mitchell Wing. All of these designs except the Mitchell Wing had some aerodynamic twist (washout) to reduce overall stall speed and reduce inboard wing stall/spin potential especially when thermal soaring and making turns at or near minimum sink rate airspeed which can be close to stall speed. Several of the last Mitchell Wing foot launched gliders built that I know about actually incorporated 3 degrees washout to reduce stall/spin tendency too which greatly improved spin prevention. So I would love to see you make a Flying Wing Video # 3 discussing things like washout, stall / spin design improvement, pros & cons of use of Flaps in addition to Elevons too. Finally I would like to draw attention to the Swift 25:1 L/D flying wing glider designed by Stanford University, Aerospace Engineering back in the 1990’s which is the most advanced and highest performing flying wing Class II, FAR 103 compliant ( Under 154lbs weight glider ever made. It can be foot launched and landed like a hang glider as well as auto, winch and aircraft tow launched and even bungee cord launched. Most incredibly they now have an electric motor launched E-Swift version!!! Thanks!
I just want to say the very biggest thank you . Taking EASA ATPL Principals of Flight exams soon and am just overwhelmed by my missing knowledge from physics, you saved me from failure.
Awesome! I'm currently going to college for aviation / commercial pilot. Who would've thought an RC channel would help me understand my aerodynamics class! Thank You!!!
Sir, you have a rare skill for explaining complex subjects in an accessible yet humorous way. I hope you do more and go into more depth as these videos are invaluable to those of us who design & build our own models. Thanks!
Very accessible! thank you. I designed and built my Fpv plane using the leverage principle , looks like a horseshoe with extending wingtips. Pic on RCgroups ,foufly blog. Long range 35mins on 1800mah, in the clouds.
Bruce, I am getting back into the hobby. I am mechanical engineer. I have always been a visual learner. Did best at school when prof could diagram out the “mechanics” of the problem is or theory. You videos are fantastic. I learn more in 15 minutes than reading hours of theoretical gobble-goop. Leave the detailed, in depth , complicated math to other..... just stick with your marker and whiteboard..... and keep doing those conceptual freehand sketches! You are really playing to people with good mechanical “instincts” ( not total math geeks) I love it !!!! Request more videos on flying wing theory...... I am learning a ton!!!! Jeff - Canada
I Designed one of my experimental Delta winged aircraft off of the things you've shown in this video, It is currently one of my best flying planes to date!
Great video as always. Your teaching style is second to none, and when it comes to the aerodynamics of flight, or anything rc flying related, there is no better source for the best information. even way up here in Canada, there's always discussions amongst the guys at our flying field that are based on your videos. Always excellent info!
Would love to see one on swept forward wings. Also, your videos, energy and dedication contribute hugely to the hobby, and to our enjoyment of it. Thank you!
Really interesting, thanks! My Flite Test Mini Arrow wing has become my "fly me first" plane when I take models to the field, simply because it's so stable and friendly to fly. It's also fast and loud, which just adds to the fun. I didn't realize that so many factors go into the design of a flying wing until viewing your videos, so I now have a greater respect for the Arrow's designer.
Reminds me of the hours spent trying to build a spaceplane in kerbal space program. Thanks for another great tutorial! Here's my wiki notes for anyone interested. Planform simple.wikipedia.org/wiki/Planform Plan view simple.wikipedia.org/wiki/Plan_view Swept Wing en.wikipedia.org/wiki/Swept_wing Elevons en.wikipedia.org/wiki/Elevon Harmonic Oscillator en.wikipedia.org/wiki/Harmonic_oscillator Dihedral Effect en.wikipedia.org/wiki/Dihedral_(aeronautics) Dutch Roll en.wikipedia.org/wiki/Dutch_roll Wing Fence en.wikipedia.org/wiki/Wing_fence Washout en.wikipedia.org/wiki/Washout_(aeronautics) Wingtip Vortices en.wikipedia.org/wiki/Wingtip_vortices
omg this video was so good. ive always liked your videos, but this one tops them all because this is something ive been trying to figure out last few days. i got a new (my first) wing and it flew horribly. added som weight to the front and it turns out it flies like a dream now. Im speechless. you cannot point the importance of correct cg enough. amazing video again. thank you!
Hi Bruce, I really enjoy this type of video. You explain it plain and simple, no fluff, no BS. I first flew RC forty years ago. It's a night and day world, comparing what I started with verses what's out there today. In all that time though, I've never built or flown a flying wing. Back in the day they were a very rare bird indeed. Now however, I've meet kids that have never flown anything but a wing. I've decided that it's time I build a wing. I've watched a few of them flying and have noticed that a lot of them do suffer from the "wibbly wobbly" that you talk about in this video. I had considered wing fences and was encouraged when you brought them up. My main question I guess has to do with the sweep. The little blue wing you were using as a prop in this video looks horrible, in my opinion. Too much sweep and no taper on the wing, can't be efficient. It probably goes like hell though. I want to build one that will have a decent glide ratio. Think a motor glider. I'm not looking for speed, just grace. Is there a formula for determining a sweep and taper? Could you perhaps do a video on the matter? Thanks. Love watching you.
Over two years in to tuning quads and the best example of I and P gains to high are a passing comment in flying wing whiteboard video. You should post a P.I.D to high, 10 second video LOL Thanks again Bruce
one thing i've heard about wingtip devices (at least on conventional layouts, i.e. not flying wings) is that, as you mentioned, they function very much like an extension of the wing, that is, you get a higher aspect ratio without increasing the span - the drawback is increased drag - most airliners use them because it's easier to install than to re-engineer the entire wing - kit planes tend not to have them for the same reason.
Your videos are a joy to watch and learn from! Yes on Forward Swept Wings Video! And your funny tongue-slip, "McDonald Douglas" Skunk Works gave me a chuckle!
Funny thing about winglets/tip-fins. On the big airliners they can generate "lift" that is directed inward to the wing, but the lift vector can also be tilted slightly forward, so they help counteract their own drag.
Sir Bruce you're a clever bugger! Thanks for the video and I'd love to see one on forward swept wings too as I love the look of them but so far my attempts have been a tad unstable.
Thank you so much for this video. I have been flying wings and regular aircraft for many years, and could not get it through my head the how and why wings actually work. Again thank you so very much for this, this video is the first thing that ever made it through my ADD mind. Gary
G'day, Forward-swept Wings tend to try to twist and then snap themselves off the Fuselage, thereby requiring massively strong Spars, and heavy-duty Ribs to impart sufficient structural strength yo be able to resist such tendancies...; and when NASA tried flying an F-16 with Forward-Swept Wings, decades ago, they were looking for enhanced manouvreability (specifically, faster Roll-Rates...), but what they actually achieved was so aerodynamically-unstable that without a Computer to handle the Ailerons it was utterly unflyable, because no Human Pilot could wag the Stick fast enough to keep pace with the corrections needed in order to fly it level. So Forward-Sweep, when it works, makes the Aeroplane much heavier than it would have been if built with Rearward-Swept Wings, and if the Computerised Artificial Roll-Stability System fails then the machine becomes utterly uncontrollable and promptly rips itself apart...; in the light of which findings it was decided that the small "enhanced Roll-Rates" theoretically available over those offered by not building the Wing backwards.., simply wasn't any kind of "benefit" worth chasing after. But, Forward-Sweep looks "cool", perhaps even "kewel" ; so every now and then someone tries to find some kind of a loophole which might make the concept workable. Such is Life, Have a good one... ;-p Ciao !
The normal F-16 is inherently unstable and flying is done by a computer, with the stick input from the pilot being sent to it digitally, with no mechanical connection to the control surfaces. F-16 pilots often joke about it's the plane that is flying them. And look at the F-117, it's flying diamond shape is so aerodynamically uncontrollable that it requires computer governed fly-by-wire.
Bruce, please do more videos like this. I really enjoyed watching these videos and I definitely learned something, several things in fact. I "groove" really well with your style of sharing information, not a lot of fluff and mostly to the point with exactly the right amount of information. You really make this look easy and it's not. You're also to hard on yourself regarding your white board drawings. Very well done in my opinion.
Great overview Bruce! One of the big things you could cover next is wing loading and how blunt sections push CG even further forward. Fences, vortex generators and vortilons can help with a lot of adverse yaw issues but they're all still bandaids that cause drag. I'm really glad that emphasized that everything with a wing is a compromise or trade off, even with planform chord/sweep choices. I'd love to get you one of my 51" designs someday. Thanks again and keep up the great work. 👍
Going further, it might even be good to point out that every planform geometry has it's own unique adverse yaw frequency that can amplified with too much wing loading at slower speeds.
Great video. All my scratch built wings were fine but now I got a s800 and the wobble is intense. I'll be adding wing gates and seeing how that helps. Thanks Bruce!
Excellent! I have a wing fashioned from leftover wings from an Air Hogs Titan kid's chuck glider. It has yet to spread it wings against the wind but when it does, and depending on its tendencies, I'll be able to work with it some.
Thank you Bruce for yet another fantastic educational video! I really enjoy your technical yet simple approach to explaining these awesome topics. Keep up the good work!
One interesting alternative to winglets and wing fences is bending / tilting the outer parts of your wings downwards to give them a negative angle of attack (compared to the rest of the wing) - NASA's been experimenting recently with this on an RC tech demo aircraft called the PRANDTL-D. The idea with this is that as your spanwise flow reaches this section of the wing, it generates upwash (instead of downwash). In doing so, you lose a little bit of lift, but you actually gain thrust. Airliner winglets gain thrust as well (they angle them slightly outwards to push off the wingtip vortex), but this upwash idea can have double the improvement in lift:drag. One of these days I'll have to see myself whether its practical to try this with foamboard.
Getting a design with winglets that actually works (as listed on the tin) is extremely complicated in the real world. A simple non-optimised wingtip fence is about the best that can be done with foamboard, and when doing CFD on a non-blended fence, there is a relatively small gain in terms of vortex reduction, and lots of additional drag (hard to balance these for optimal performance). The main effect in RC models from tip fences/winglets is in gaining vertical surface area for directional stability (like a vertical fin on a conventional aeroplane).. To gain the thrust you are talking about (by directing the flow AFT), very careful aerofoil selection and washout is needed (to gain lift through vortex reduction while slow and heavy, and reduce drag and increase drive at cruise).... If you have a real interest search for some academic papers on this topic, it is very interesting...
I found this video very informative and it quite explained some of my past experiences with building flying wings. However, I was not able to figure out why the forward swept wing I tried to build kept flipping over. Sometimes it flipped forward and sometimes back depending on how I tampered with the cg. If you can make another part of this video to cover forward swept wings that would be great. I am sure there are so many of others in the same boat as me who would very well benefit from a video on forward swept wings. Thank you once again for all your wonderful videos.
Great class, thank you. Looking forward to Part 3, and Part 4, and Part 5. :) I appreciate the non-calculus approach. It will be interesting when wing features are dynamically computer controlled.
Thanks Bruce! I'd enjoy hearing more. I'd especially like to hear your analysis of forward-swept wings like the Ritewing Drak. And what about turbulence? As a wing enters a gusty crosswind, it makes sense that it would stably yaw into the gust, but this can induce a little yaw waggle that's hopefully quickly damped. I think one of the advantages of the Drak is that the long, tall nose will be pushed to the side equally with the vertical stabilizers, reducing yaw waggle t in unsettled air.
Excellent video Bruce! I would like to see a video about stalls. What kind of stalls exist, how to prevent them, counter them and recovery. That would be great addition to the serial.
Came back here again - this video is still brilliant ;) Everytime I start falling for fixedwings again (usually around summer) I also see the problems involved. You told me that you gave away the FPV900 because it is not stable :) Well, let's see if I can improve mine. But it's still fun. greets, Mario
Hi Bruce, Thank you very much for explaining the sweep wing planes design. Well done! I really appreciate your easy to understand logic that makes RC design more fun to learn. Perhaps you could write a book of your easy to understand explanations of RC design for those of us who love to experiment. Ron
Ok honestly, don't get me wrong, I'm a 1st-year AeroSpace student and the professors at my university are very good. But this helped me so much, maybe he's not using the official terms but the concepts are explained perfectly. Thanks a lot, you made my homework and learning material much easier to understand.
There are no official terms but languages, university is official only for univeristy. Nicolas Tesla is not taught at university...
I love these whiteboard videos. Whatever the topic I always learn something.
Love your videos and the information you impart. Keep up the work you do of pointing out the stupidity of the regulators and their paranoia against property destroying and life threatening small drones.
I'm 16 and getting into 3D printing wings! Currently designing the first version of my very own wing, this video helped me understand the basics! Thanks! 😁
Best teacher EVER!!!
Can not thank you enough!
... Everybody deserves a teacher like you!...
Just pure gold. You don't get to learn this kind of stuff on other RC channels. Thanks Bruce!
I came across this video and I was ECSTATIC... ☺ I'm a 59yr old and I fly drones, helocopters, and now fixed wing aircraft...
I need to watch all the previous videos and then catch up. This is so AMAZING and I feel like I'm back in school!!! 😃
The way it's taught is very educational and I'm delighted to have found this video... Now I'm subscribed and will be watching MORE...
May you Always remain in good health and many more years of teaching... God Bless YOU! ☺
Yes, I would like to see to forward sweep wings also. Thx Bruse,For all you do for the hobby...
Really you need to not worry about your drawing, most of us can't draw but you get the ideas across and that is all that is important.
Thank you so much for these "classes", and thank you for all you do for the hobby.
Thank you Bruce. Nobody else imparts such useful information in such an easily understood way with your unassuming dash of humor.
Great easy to understand video! Thanks! As a former hang glider pilot for over 3O years I have a lot of experience actually flying, Flying Wings. In particular I was an avid Class II Rigid Wing Hang Glider pilot over the years. Class 1 hang gliders are the traditional Delta (Rogollo) Wing design where the pilot solely uses body weight shift to change the CG for pitch, roll & yaw control. Class II rigid wings use either a combination of weight shift and aerodynamic control ( weight shift for pitch and tip rudders for roll/yaw ) or full 3 axis control ( combination of tip rudders, elevens and on some designs, inboard flaps). Class II full aerodynamic control hang glider pilots can sometimes still use minor body weight shift to make subtle CG changes too for better trim etc.
Class II hang glider flying wings I flew, included Icarus II, Easy Riser, Icarus V, Fledgling, Apex, and the famous Mitchell Wing. All of these designs except the Mitchell Wing had some aerodynamic twist (washout) to reduce overall stall speed and reduce inboard wing stall/spin potential especially when thermal soaring and making turns at or near minimum sink rate airspeed which can be close to stall speed. Several of the last Mitchell Wing foot launched gliders built that I know about actually incorporated 3 degrees washout to reduce stall/spin tendency too which greatly improved spin prevention.
So I would love to
see you make a Flying Wing Video # 3 discussing things like washout, stall / spin design improvement, pros & cons of use of
Flaps in addition to Elevons too.
Finally I would like to draw attention to the Swift 25:1 L/D flying wing glider designed by Stanford University, Aerospace Engineering back in the 1990’s which is the most advanced and highest performing flying wing Class II, FAR 103 compliant ( Under 154lbs weight glider ever made. It can be foot launched and landed like a hang glider as well as auto, winch and aircraft tow launched and even bungee cord launched. Most incredibly they now have an electric motor launched E-Swift version!!!
Thanks!
I just want to say the very biggest thank you . Taking EASA ATPL Principals of Flight exams soon and am just overwhelmed by my missing knowledge from physics, you saved me from failure.
I wish I had physics teachers like you!
Awesome! I'm currently going to college for aviation / commercial pilot. Who would've thought an RC channel would help me understand my aerodynamics class! Thank You!!!
This really explains why/what I don't like about flying wings. I've just never liked how they fly, and this is fascinating information. Thanks Bruce!
The Killer Spud you haven't flown the right wing then
Sat here deciding whether or not to add fins / fences to my latest build and still finding this video useful. A+ !
Sir, you have a rare skill for explaining complex subjects in an accessible yet humorous way.
I hope you do more and go into more depth as these videos are invaluable to those of us who design & build our own models. Thanks!
Very accessible! thank you. I designed and built my Fpv plane using the leverage principle , looks like a horseshoe with extending wingtips. Pic on RCgroups ,foufly blog. Long range 35mins on 1800mah, in the clouds.
Bruce, I am getting back into the hobby. I am mechanical engineer. I have always been a visual learner. Did best at school when prof could diagram out the “mechanics” of the problem is or theory. You videos are fantastic. I learn more in 15 minutes than reading hours of theoretical gobble-goop. Leave the detailed, in depth , complicated math to other..... just stick with your marker and whiteboard..... and keep doing those conceptual freehand sketches! You are really playing to people with good mechanical “instincts” ( not total math geeks) I love it !!!!
Request more videos on flying wing theory...... I am learning a ton!!!!
Jeff - Canada
I chuckled every time Bruce made the wibblie-wobblie dance :D love this guy
Excellent! You are so right. Experimenting, developing the methodology, teaching yourself new skills. That's really good fun and so satisfying.
WOW!!!!!!!!!!! YOU ARE A SUPERLATIVE TEACHER!!!!!! THANK YOU, FOR MAKING THIS SO EASY TO UNDERSTAND!!!!!!! BRILLIANT!!!!!!!!
I Designed one of my experimental Delta winged aircraft off of the things you've shown in this video, It is currently one of my best flying planes to date!
I was out of the Hobby for last 20 years. Thanks to you, Bruce I want to build a Delta Wing.
Great video as always.
Your teaching style is second to none, and when it comes to the aerodynamics of flight, or anything rc flying related, there is no better source for the best information. even way up here in Canada, there's always discussions amongst the guys at our flying field that are based on your videos.
Always excellent info!
But you guys are upside down.
@@tedmoss Canada is upside down if you live in China and nobody know knows anything is in China
i love it when the white board comes out :)
ive been thinking about making my own rc plane and this really did help me make changes to make the aircraft more stable
Would love to see one on swept forward wings. Also, your videos, energy and dedication contribute hugely to the hobby, and to our enjoyment of it. Thank you!
A very good tutorial Bruce, and good use of the model to demonstrate how the various airflow influence can effect an aircraft wing. Thank you.
A smashing introduction to aerodynamics! Thank you.
Really interesting, thanks! My Flite Test Mini Arrow wing has become my "fly me first" plane when I take models to the field, simply because it's so stable and friendly to fly. It's also fast and loud, which just adds to the fun. I didn't realize that so many factors go into the design of a flying wing until viewing your videos, so I now have a greater respect for the Arrow's designer.
Really enjoyed your explanations and the way you deliver them - both parts 1 and 2. Thankyou.
Reminds me of the hours spent trying to build a spaceplane in kerbal space program. Thanks for another great tutorial! Here's my wiki notes for anyone interested.
Planform
simple.wikipedia.org/wiki/Planform
Plan view
simple.wikipedia.org/wiki/Plan_view
Swept Wing
en.wikipedia.org/wiki/Swept_wing
Elevons
en.wikipedia.org/wiki/Elevon
Harmonic Oscillator
en.wikipedia.org/wiki/Harmonic_oscillator
Dihedral Effect
en.wikipedia.org/wiki/Dihedral_(aeronautics)
Dutch Roll
en.wikipedia.org/wiki/Dutch_roll
Wing Fence
en.wikipedia.org/wiki/Wing_fence
Washout
en.wikipedia.org/wiki/Washout_(aeronautics)
Wingtip Vortices
en.wikipedia.org/wiki/Wingtip_vortices
I’m preparing for my commercial check ride and this was very helpful. Thanks
Very interesting. A lot of experiments to do. I'm in the process of building a new wing. Thanks Bruce.
Swept forward video yes please. I always find your videos helpful.
omg this video was so good. ive always liked your videos, but this one tops them all because this is something ive been trying to figure out last few days. i got a new (my first) wing and it flew horribly. added som weight to the front and it turns out it flies like a dream now. Im speechless. you cannot point the importance of correct cg enough. amazing video again. thank you!
Hi Bruce, I really enjoy this type of video. You explain it plain and simple, no fluff, no BS. I first flew RC forty years ago. It's a night and day world, comparing what I started with verses what's out there today. In all that time though, I've never built or flown a flying wing. Back in the day they were a very rare bird indeed. Now however, I've meet kids that have never flown anything but a wing. I've decided that it's time I build a wing. I've watched a few of them flying and have noticed that a lot of them do suffer from the "wibbly wobbly" that you talk about in this video. I had considered wing fences and was encouraged when you brought them up. My main question I guess has to do with the sweep. The little blue wing you were using as a prop in this video looks horrible, in my opinion. Too much sweep and no taper on the wing, can't be efficient. It probably goes like hell though. I want to build one that will have a decent glide ratio. Think a motor glider. I'm not looking for speed, just grace. Is there a formula for determining a sweep and taper? Could you perhaps do a video on the matter? Thanks. Love watching you.
9:39 I think this explains why the YB49 did not have the stability to bomb accurately. thanks for the video
Over two years in to tuning quads and the best example of I and P gains to high are a passing comment in flying wing whiteboard video. You should post a P.I.D to high, 10 second video LOL
Thanks again Bruce
Excellent video . Yes please do a video on wing fences and advantages of having vertical fins on a flying wing.
Ahhh the bit about the tip-fins placement is interesting. Thanks Bruce!
one thing i've heard about wingtip devices (at least on conventional layouts, i.e. not flying wings) is that, as you mentioned, they function very much like an extension of the wing, that is, you get a higher aspect ratio without increasing the span - the drawback is increased drag - most airliners use them because it's easier to install than to re-engineer the entire wing - kit planes tend not to have them for the same reason.
I was one who was going to ask about forward-swept wings, esp. as it relates to flying wings. Great video, and keep up the great work!
Your videos are a joy to watch and learn from! Yes on Forward Swept Wings Video! And your funny tongue-slip, "McDonald Douglas" Skunk Works gave me a chuckle!
Man, these videos have helped me so much. Thank you for taking the time to make and post these beautys.
Funny thing about winglets/tip-fins. On the big airliners they can generate "lift" that is directed inward to the wing, but the lift vector can also be tilted slightly forward, so they help counteract their own drag.
The dangling wrench was hypnotic.
Sir Bruce you're a clever bugger! Thanks for the video and I'd love to see one on forward swept wings too as I love the look of them but so far my attempts have been a tad unstable.
Definitely one of your more informative videos Bruce. That should satiate the rumblings from the plankers :)
thankyou so much, your enthusiasm is infectious!
Wibbly wobbly??? No idea where that came from, but I love it.
Thanks for the education. I am learning a lot
Chuck
great introduction. this will help a lot of people. thanks Bruce
Thank you so much for this video. I have been flying wings and regular aircraft for many years, and could not get it through my head the how and why wings actually work. Again thank you so very much for this, this video is the first thing that ever made it through my ADD mind.
Gary
Wow.. learning much again.
Yeah, forward swept wings are very interesting, would like a video if you can.
Really like these educational type videos.
G'day,
Forward-swept Wings tend to try to twist and then snap themselves off the Fuselage, thereby requiring massively strong Spars, and heavy-duty Ribs to impart sufficient structural strength yo be able to resist such tendancies...; and when NASA tried flying an F-16 with Forward-Swept Wings, decades ago, they were looking for enhanced manouvreability (specifically, faster Roll-Rates...), but what they actually achieved was so aerodynamically-unstable that without a Computer to handle the Ailerons it was utterly unflyable, because no Human Pilot could wag the Stick fast enough to keep pace with the corrections needed in order to fly it level.
So Forward-Sweep, when it works, makes the Aeroplane much heavier than it would have been if built with Rearward-Swept Wings, and if the Computerised Artificial Roll-Stability System fails then the machine becomes utterly uncontrollable and promptly rips itself apart...; in the light of which findings it was decided that the small "enhanced Roll-Rates" theoretically available over those offered by not building the Wing backwards.., simply wasn't any kind of "benefit" worth chasing after.
But, Forward-Sweep looks "cool", perhaps even "kewel" ; so every now and then someone tries to find some kind of a loophole which might make the concept workable.
Such is Life,
Have a good one...
;-p
Ciao !
The normal F-16 is inherently unstable and flying is done by a computer, with the stick input from the pilot being sent to it digitally, with no mechanical connection to the control surfaces. F-16 pilots often joke about it's the plane that is flying them. And look at the F-117, it's flying diamond shape is so aerodynamically uncontrollable that it requires computer governed fly-by-wire.
Better explained than in my aerospace course. Thanks!
Best Science Teacher ever...
Love the theory videoes Bruce.
The experimental stuff especially.
Bruce, please do more videos like this. I really enjoyed watching these videos and I definitely learned something, several things in fact. I "groove" really well with your style of sharing information, not a lot of fluff and mostly to the point with exactly the right amount of information. You really make this look easy and it's not. You're also to hard on yourself regarding your white board drawings. Very well done in my opinion.
He’s such an amazing teacher
These aerodynamic videos are fantastic. I always learn something new.
Great overview Bruce! One of the big things you could cover next is wing loading and how blunt sections push CG even further forward. Fences, vortex generators and vortilons can help with a lot of adverse yaw issues but they're all still bandaids that cause drag. I'm really glad that emphasized that everything with a wing is a compromise or trade off, even with planform chord/sweep choices. I'd love to get you one of my 51" designs someday. Thanks again and keep up the great work. 👍
Going further, it might even be good to point out that every planform geometry has it's own unique adverse yaw frequency that can amplified with too much wing loading at slower speeds.
Great video. All my scratch built wings were fine but now I got a s800 and the wobble is intense. I'll be adding wing gates and seeing how that helps. Thanks Bruce!
Thank you!! Just watched both parts! Now I have some understanding of what's going on with those flying wings!
Itˋs all a bit Wibbly Wobbly, Timey Wimey... (Dr. Who to any that is unfamiliar with that expression). Love this aerodynamic video. Want more. 😀
Excellent! I have a wing fashioned from leftover wings from an Air Hogs Titan kid's chuck glider. It has yet to spread it wings against the wind but when it does, and depending on its tendencies, I'll be able to work with it some.
Thank you Bruce for yet another fantastic educational video! I really enjoy your technical yet simple approach to explaining these awesome topics. Keep up the good work!
One interesting alternative to winglets and wing fences is bending / tilting the outer parts of your wings downwards to give them a negative angle of attack (compared to the rest of the wing) - NASA's been experimenting recently with this on an RC tech demo aircraft called the PRANDTL-D. The idea with this is that as your spanwise flow reaches this section of the wing, it generates upwash (instead of downwash). In doing so, you lose a little bit of lift, but you actually gain thrust. Airliner winglets gain thrust as well (they angle them slightly outwards to push off the wingtip vortex), but this upwash idea can have double the improvement in lift:drag.
One of these days I'll have to see myself whether its practical to try this with foamboard.
Getting a design with winglets that actually works (as listed on the tin) is extremely complicated in the real world. A simple non-optimised wingtip fence is about the best that can be done with foamboard, and when doing CFD on a non-blended fence, there is a relatively small gain in terms of vortex reduction, and lots of additional drag (hard to balance these for optimal performance). The main effect in RC models from tip fences/winglets is in gaining vertical surface area for directional stability (like a vertical fin on a conventional aeroplane)..
To gain the thrust you are talking about (by directing the flow AFT), very careful aerofoil selection and washout is needed (to gain lift through vortex reduction while slow and heavy, and reduce drag and increase drive at cruise)....
If you have a real interest search for some academic papers on this topic, it is very interesting...
I found this video very informative and it quite explained some of my past experiences with building flying wings. However, I was not able to figure out why the forward swept wing I tried to build kept flipping over. Sometimes it flipped forward and sometimes back depending on how I tampered with the cg. If you can make another part of this video to cover forward swept wings that would be great. I am sure there are so many of others in the same boat as me who would very well benefit from a video on forward swept wings. Thank you once again for all your wonderful videos.
Love the series on wings, gives all a lift.....
Thanks for the basic but always usefull information and explanation. A pratical experience for the S800 Sky Shadow... Thanks Bruce
I wish i had calculus teachers like you!
I have subscribed mostly because of the "wibbly wobbly" line.
Great stuff!
Thank you professor Beardy, this was extremely valuable.
Great class, thank you. Looking forward to Part 3, and Part 4, and Part 5. :)
I appreciate the non-calculus approach.
It will be interesting when wing features are dynamically computer controlled.
amazing teacher, absolute legend
Thanks Bruce! I'd enjoy hearing more.
I'd especially like to hear your analysis of forward-swept wings like the Ritewing Drak.
And what about turbulence? As a wing enters a gusty crosswind, it makes sense that it would stably yaw into the gust, but this can induce a little yaw waggle that's hopefully quickly damped. I think one of the advantages of the Drak is that the long, tall nose will be pushed to the side equally with the vertical stabilizers, reducing yaw waggle t in unsettled air.
Absolutely brilliant content! Thank you for making these videos. Take care
You are an excellent teacher.
The best teacher by far!!!!!
Great video [as usual] RCMR. I guess that's why both my Opteras are such fine flying birds.
don't know why i'm watching this but video is really interesting
Thanks for sharing the smarts Bruce, looks like I'm off to build a few fences
Outstanding. Thank You for your series.
I'm glad I stumbled across your page!
Really fantastic presentation!!!!!
Excellent video Bruce!
I would like to see a video about stalls. What kind of stalls exist, how to prevent them, counter them and recovery. That would be great addition to the serial.
Keep them coming Bruce, great informative video. Thanks
I always learn something here!! I'm going to try these new skills in building with foam now. Thanks Bruce
Marvellous, enjoyable and informative video Bruce. Many thanks.
Came back here again - this video is still brilliant ;) Everytime I start falling for fixedwings again (usually around summer) I also see the problems involved.
You told me that you gave away the FPV900 because it is not stable :) Well, let's see if I can improve mine. But it's still fun.
greets, Mario
Hi Bruce,
Thank you very much for explaining the sweep wing planes design. Well done! I really appreciate your easy to understand logic that makes RC design more fun to learn. Perhaps you could write a book of your easy to understand explanations of RC design for those of us who love to experiment.
Ron
この人の説明の仕方すごい好き
This is really nice explanation.
Bruce CAD. 3:09 Brill!
Zero software updates since its roll out.
Thank you. Great exploration on what's going.
Thanks Bruce, great video.
Excellent explanations! Thank you!
Nailed it as usual. Thanks Bruce.
An old video but learnt a lot from this.
Thanks. Love the theory, it really helps. So hard to get an understanding straight from a book.
very interesting Bruce..been waiting for part 2..thanks..