Should probably have the NASCAR neck collar for these events. Also, are you relying on the pull from the front for any stability concerns? Emergency quick release, stability concerns if quick release?
@wingnutzster5 жыл бұрын
Congratulations! I have watched and read and understood everything in the Prandtl paper as well as A Bower's and his team's work and am amazed by this revolutionary understanding of aerodynamics which I really want to apply thoroughly in my own rigid wing foot launched project but I would love to know more about the build, construction and some of the numbers on your machine. I have sent an email so hoping to learn more.
@wingnutzster5 жыл бұрын
That spoiler/speed brake is amazingly effective it seems. Is there any outside footage of the craft in flight or on the ground?
@wingnutzster3 жыл бұрын
@Khari Jaxtyn thats brilliant how accurate you came to the truth in your opening remark about no one caring
@Capnmax3 жыл бұрын
Beautiful Prototype. Any updates on this project?
@darrylldodson66237 жыл бұрын
Red, First of all congratulations to the group for thinking outside the box and on these outstanding achievements!!! This platform looks like it may be a good candidate for a self-launch glider. The related EAA article stated that improvements were going to be made and plans to conduct more testing. Was there more flying done this summer? Can you point me to additional info?
@RedJensen7 жыл бұрын
Hi Darryll. Yes some improvements have been made, but unfortunately no further testing has been done at this point. We are trying to get together soon. The builder lives about 400 miles away, so it's not trivial. What other information would you like?
@darrylldodson66237 жыл бұрын
Thanks for responding! The video shows a low level tow, do you have any video or pics of the free flight? Was this wing load tested? Similar to Christian's inquiry: have you documented any performance specifications (empty/gross wt, g limits, glide ratio, Rate of sink, stall, wing area)?
@RedJensen6 жыл бұрын
Hi Darryll, no video of the free flights yet, except where the tow line is released. This video is from the very first flight day. We are looking to do more flights soon however. The glider will be coming back down to SoCal so that we can fit some instrumentation (alt, airspeed, GPS, IMU, CPT's, A/B vane etc) where we will capture all of the performance data. We will be heading out for more flight test early in the new year.The aircraft as it sits now is very much just a proof of concept, there are plans to build another, refine some of the techniques and details. The builder (Erich Chase) would eventually like to offer it as a product. There are quite a few moving parts to this whole thing. The physical distance between all of the involved parties and their respective schedules has made it difficult to move forward on this spare time project.
@justfly25255 жыл бұрын
Hey Red... What is the current status of the PRANDTL 4? Could you give us a video update?
@RedJensen5 жыл бұрын
Sorry no more video, but its currently being insturmented for test data and flights will resume in a couple months when it arms up.
@justfly25255 жыл бұрын
@@RedJensen Awesome... Keep us posted.
@captarmour6 жыл бұрын
congrats great work. a question if i may, would a constant chord work? (or greater chord at wingtip). im thinking i could use shorter span Elevons with wider chord to give me more control authority
@RedJensen6 жыл бұрын
Do you mean constant chord wing or aileron? Yes other shape ailerons will work, but the line about which they are hinged must remain straight. So not able to retrofit this, it has to be taken into account before it is built.
@captarmour6 жыл бұрын
no, a constant chord wing, sorry i wasn't clear. the idea is with more chord at the wingtip i would have more space to fit larger elevons and also more area out board of the wing vortex may give more thrust. also with more wing area a lightly shorter wingspan may be possible. last of all easier build.
@RedJensen6 жыл бұрын
Yep, the math says a constant chord wing will work, but we haven't done it yet.
@captarmour6 жыл бұрын
wow thanks a mil...if i may i predict it may work better than expected.
@RedJensen6 жыл бұрын
Yes the math says a constant chord wing would work as well, but we haven't done it yet.
@scottbaxter26823 жыл бұрын
Is that a Flintstone braking system ?
@petegarnett7731 Жыл бұрын
I thought foot brakes were de rigeur these days.
@captarmour7 жыл бұрын
With the bell shaped lift distribution may a constant chord wing with the same LE sweep work as tip losses are not a concern and more wing area at the tip may result in more thrust?
@captarmour6 жыл бұрын
haha i forgot i wrote this 6 months ago!
@Jack-ne8vm5 жыл бұрын
Curious about wing construction techniques...
@RedJensen5 жыл бұрын
What, me worry? It’s hollow molded composite, what else would you like to know?
@Jack-ne8vm5 жыл бұрын
@@RedJensen KZbin to the rescue, & beyond!
@b7gwap6 ай бұрын
Any progress on this project?
@RedJensen6 ай бұрын
Nothing more than talk at the moment.
@b7gwap6 ай бұрын
Looks like a really neat project. I’m building a Sandlin Goat 2 right now, maybe flying it later this summer if I stay at it. I’ve always thought it would be cool to have a wheeled ultralight sailplane that was a tailless design. You guys went one further and made it a Prandtl wing! Clearly know what you’re doing, and hopefully you guys can get the project up and flying again. Cheers.
@ericoschmitt4 жыл бұрын
What is the glide ratio as it is? And what would it be if the pilot was prone in a blended body such as in the Horten gliders?
@RedJensen4 жыл бұрын
We never got a chance to measure in either condition, suspect its over 20 though.
@ericoschmitt4 жыл бұрын
That makes it a bit better than an ATOS with prone pilot, so looks like an improvement. Is it foldable somehow? Any idea if an actual sailplane would get better performance than current sailplanes? Like, getting well above 50:1 in the 15 meter class?
@RedJensen4 жыл бұрын
@@ericoschmitt This one is a prototype, all composite not foldable. A faired pilot would help for sure, but it's not getting anywhere near 50:1.
@ericoschmitt4 жыл бұрын
@@RedJensen that puzzles me... Wasn't the whole idea of the Prandtl project to achieve a lower drag shape than aircraft with empenage? And doesn't lower drag mean it would have a better glide ratio? The builders of the new Horten HX-2 say it is more efficient, so I would expect that a well developed flying wing sailplane would beat a traditional competition sailplane in performance, meaning going above 50:1 in 15 meter class and above 70:1 in open class. Could flying wings possibly do that one day?
@RedJensen4 жыл бұрын
Érico Schmitt yes of course. But this particular design is not for that, it eventually will be a foot launched sailplane, not an Open class racer.
@swiftdereve7 жыл бұрын
Hello Red Jensen, congratulations for your project. I'm a Swift light PAS pilot and I'm very interested about the technical characteristics (weight, MTOW, glide ratio, speed,...) and your project for the future. Thanks. Christian
@RedJensen6 жыл бұрын
Hi Christian, The glider weighs about 140 lbs I believe, 50' span. L/D is somewhere north of the 20:1 range (based on very limited data). Cruise speed seems to be in the low 30's, we'll know more when it flies with an instrumentation package soon. Cheers Red
@swiftdereve6 жыл бұрын
Thanks very much. I thought that the glide ratio would be more....28:1 or 30:1 I'm waiting for the good calculations
@RedJensen6 жыл бұрын
Christian, we expect that the L/D is actually much better, but we don't want to overstate anything until we have accurate data. :-)
@swiftdereve6 жыл бұрын
I understand Red. Good luck in this fantastic project. An with a protection around the pilot, it will be much better. It is the same for the Swift light or Millenium with or without protection fairing.
@tessemi4 жыл бұрын
pretty sure thats the first manned test aircraft in quite a while.
@LunaRendezvous5 жыл бұрын
Are you working towards wing warping for yaw control as well as roll?
@RedJensen5 жыл бұрын
No warping at all, it a very stiff molded carbon fiber wing. In the future maybe split elevons for yaw.
@Thegillmor20106 жыл бұрын
I want one! Thanks for sharing
@gregripp2 жыл бұрын
Wouldn't a trike landing gear help?
@doultonduck65347 жыл бұрын
does it have red lights on the bottom
@wingnutzster5 жыл бұрын
hahahah - that would explain a lot no?
@antoni9735 жыл бұрын
It’s a wonderful invention, can please set me the size mesure of the glider, wont to make one
@jazldazl91934 жыл бұрын
Want gold bars with that?
@gunnarerdmann71042 ай бұрын
Braking like the Flintstones.
@thomasrobson63707 жыл бұрын
Wow, is the 50' span a requirement for the PRANDTL wing configuration to carry one person?
@RedJensen7 жыл бұрын
The plan form of the airplane is Horten Xc, which was a 50' span, foot launched glider. When Al (Bowers) started the research, that's where the span came from.
@thomasrobson63707 жыл бұрын
I thought he was building based on the albatross, my bad..:-(
@thegreen4me6 жыл бұрын
prandtl does require a slightly larger span than a similar wing with an elliptic loading if you think about it, since the load starts to decrease closer to the body of the aircraft
@mavigogun4 жыл бұрын
thegreen4me , what “body”?!
@lucywucyyy2 жыл бұрын
i wanna see a prandtl wing slope soaring, they should take the rc one up a hill or make a hang glider from one
@petegarnett7731 Жыл бұрын
They have been doing it for years.
@1967250s6 жыл бұрын
You have recreated the Swift ultralight hang glider. Except for their highly aerodynamic pilot enclosure. What was the point of dragging this with a car for several miles? With all that drag underneath? If you wanted to reduce at least a little drag, at least get the passenger legs straight.
@RedJensen6 жыл бұрын
If you'd care to read the paper ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20160003578.pdf you may have a better understanding of why your comment is off base, or maybe not. The research is stability and control & minimum induced drag with no vertical tails, nothing like Swift actually. There wasn't much consideration for pilot streamlining at all, this was just initial flights and functional testing. Streamlining will be addressed in future iterations. Thanks for taking the time to make a pointless comment anyway though....
@bipolatelly98065 жыл бұрын
That didn't look much fun.... much.... and was that the best place you could find? 😋
@thomaspiepenbring71327 жыл бұрын
Attaching an aircraft to the ground - or to a car - generates stability. So this was not free flight because yaw-axis was completely stabilized by the car !!!
@Appletank86 жыл бұрын
They did let go halfway in other flights.
@d3xterown5 жыл бұрын
nice I dream of doing the same
@RedJensen7 жыл бұрын
No lights at all. Day VFR only :-)
@doultonduck65347 жыл бұрын
Only day ? So they don't fly them at night at all?
@RedJensen7 жыл бұрын
No, gliders don't fly at night.
@doultonduck65347 жыл бұрын
Ok Thanks
@williamhuang27805 жыл бұрын
THIS IS AWESOME!!
@liefbrunhilda9265 жыл бұрын
Love the seat belt.... lmao
@RedJensen7 жыл бұрын
Lol, except for when it wasn't.
@charlesbecker63054 жыл бұрын
4 minutes
@alexanderfoelkel83166 жыл бұрын
So, a highly aerodynamic wing with an undercarriage totally not streamlined...way to go gents...really...
@RedJensen6 жыл бұрын
This video is from the first flight day. Streamlining wasn't considered at this point for a few reasons. 1. The pilot needs to get out as quickly as possible in an emergency. 2. The cage is adjustable fore and aft for CG purposes, which we did. Next time though we'll consult your far superior aerodynamic background for advice before we share.....is that ok?
@seriousaf80206 жыл бұрын
The pilot wants to enjoy the wind dude. Well, I like the sense of having the wind blowing on my face while flying or driving a car, I don't know about other people though.
@ddegn5 жыл бұрын
@@RedJensen "we'll consult your far superior aerodynamic background" You might want to check with the people commenting under many of NASA's videos. They've got all the answers. Thanks for sharing your progress with us.