Great plug for the course!! Our team attended in the January and March sessions and can honestly say the Karl bros saved us years of work. Couldn't recommend the course highly enough! Very well thought out, designed and presented. 👍👍
From a real world ex-Air Force and current 737 pilot, you lads are an absolute inspiration. The depth of thought you have put into every aspect of the design of the aircraft is evident. I look forward to its maiden flight and am very interested in its performance. Keep at it.
Looks great! As an avionics technician with experience on many different corporate/business aircraft, It would be really great to see a dimmable white LED strip mounted inside the glareshield to serve as a nice cockpit/instrument panel flood light. They look very nice on Embraer Legacy 450/500/600/650 and on Gulfstream 450/650, etc.
I'm betting the white glare shield is going to be highly visible reflected in the canopy.... You're building an incredible airframe, beautifully engineered. Wish I could afford one!
The Darkaero team is quite impressive. Thank you for taking the time and effort to make and publish your videos. The videos are educational and enlightening. I learn from, and I'm inspired by, each video.
Your meticulously precise attention to detail is evident in whatever the camera focuses on! Likewise, your outstanding craftsmanship throughout! These are the hallmarks of your project, all of which bode well for the every aspect of the aircraft, from concept to the flight line...
Thank you for offering that course! I just signed up and am very excited. I have limited fiberglass experience and want to do more carbon fiber. This course will be very helpful as I work on my Dragonfly MK IIH build. My first challenge is a static load test to verify the wing and canard are good. Looking forward to learning from you all!
Any kind of bumper or other springamathing to close the canopy against? Something to make sure it closes "tight," both so it doesn't rattle & to ensure a good seal is made?
I'm predicting origami foldable carbon fiber composite construction will be a self-contained unique engineering discipline. You guys are stellar introducing it. Extreme inspiration by spending time with your DarkAero channel. Thank you for sharing, guys!
Excellent engineering and construction. Thanks for sharing your journey with "us". Will the canopy release also open the latches on the rear canopy latch? (the aluminum bar mechanism). Or will they just tear away as the front of the canopy gets picked up from the slip stream
Thank you for following along John! We are planning for a two-stage operation to jettison the canopy since the canopy latch and the jettison mechanism are not coupled together.
@@DarkAeroInc In an emergency you need a single handle to completely release the canopy. An unfamiliar passenger needs to be able to escape. Suggest a Bowden cable between the pin retraction mechanism and the canopy latches.
Again your an amazing crew, the mechanism for the canopy is clean with as few parts as necessary to do the job. The four pin attachment points offer a rigid attachment to the hinged panel and makes for very simple release of the canopy. Perhaps a cleverly design of the latch handle would be to to release the latch mechanism if the canopy is lifted from the front in an emergency. Thanks for taking us along
You guys are doing AMAZING work! Alas, you may have a problem... water intrusion. I dont see a significant space for a proper door seal to keep the water out if you get caught in the rain. Maybe that is a feature that gets designed into the molds on the subsequent production unit. Secondly, finding a seal profile and dealing with turning corners is always a challenge, this is NOT a trivial task. There was a guy at Santa Paula airport near Ventura CA that made pressurized silicone door seal systems, if he was still around he might have stuff that could help. And finally make provisions that will allow you to drain the water out of the seat base and cockpit floor, it will get wet. Last plane I built, before we put in ANY electrical in, we took it outside and had the fire service empty a fire trucks water tank on the plane to make sure we were dry. FYI, took 3 tries. As for passive drain valves consider something like a "duck bill" valve. Once you get a bit of positive pressure in the cabin (as opposed to outside at 10,000ft) any water (spilled coffee, cokes redbull etc) and it will help evacuate the cabin. Ok this old fart will shut up and watch, looking forward to the first flight!
You guys are doing a great job figuring out all the little details on this project, it's very inspiring! If you'll allow a quick tangent on latches, one of the latch systems I was a fan of was from an old Cadillac I had, 1994 year or so. It was for the trunk, and it was a normal close, actuated hold down system. Not sure if I've got my terminology correct. But essentially you'd slam the trunk as normal, but then a small motor would pull the trunk fully closed say 5mm or so to create a nice tight seal. The clever bit was that since it was a slam shut trunk it still all used the same latch hardware as a normal trunk, and didn't need power to release, the motor was attached to the stationary hook on the frame. It was very clever in its implementation, at least I thought so.
I'm so impressed with you three and I really wish your project all the success in the world! I'm a mechanism designer myself and I really like that scissor mechanism! Such an elegant solution to the problem! I would personally really like to have a hole or a slot in the seatback so that I can stick my finger in there and access a feature on the aluminum bar directly in case the handle or cable mechanism fails.
Thank you Marius! What sorts of mechanisms do you design and what tools do you use to design them? We do a combination of sketches, CAD, and mock ups to come up with the correct motion. Just curious to learn if you know of any other tricks of the trade.
Thank you for your reply! I design biomedical devices and surgical tools. Not as exciting as airplanes, but just as safety critical and the effort and scrutiny to change an already approved design is just as painful... so get it right the first time :) We rely heavily on sketches and CAD as well (Solidworks, still more proficient in that than Onshape). I find that just working in an unconstrained sketch in 2D is already a great first stab at a new motion. After that we will properly model and mate an assembly, and then rapid prototype (in-house CNC mill, laser cutter, 3D printer) it as fast as possible, usually from easy to machine materials like aluminum and acetal. It's not uncommon to machine upwards of 3 different concepts for a given mechanism before committing to one. I also really like having a few drawers full of LEGO Technic for some really crude but super rapid mockups. In our case the analytical work (strength, fatigue, tolerance stackup etc) usually only gets done after the first physical prototype, at the same time that we are refining the second or last version. Oh, and finally, lots of peer review: brainstorming sessions during the initial stages and then design reviews after the first prototype. If I had been in the design review for your scissor mechanism I would have said pay close attention to your mechanical advantage. I really like that right at the beginning of the motion your mechanism has the greatest mechanical advantage. (You can increase it further by making the links skinnier and collapsing the scissor more). This is great for overcoming initial stiction and static friction. By the point where the angles in the scissor are 90deg, it looks like you have a mechanical (dis)advantage of about 2:1 from the knob to each deadbolt, meaning the deadbolt is moving twice as fast as the knob. In the last portion of the knob's travel the mechanical disadvantage continues to climb rapidly. If there's a shear load or binding on one or more deadbolts, this might make the knob very difficult to pull. I might consider making sure that all 4 deadbolts are completely disengaged by that 90deg point of the mechanism's travel. Keep up the amazing work! You guys are rocking it.
Wicked cool details on the latching and emergency release of the canopy. Have you considered a semi-permanent strap around the emergency release, something that could be broken with a pull-tab or lever? Perhaps some type of tie strap that holds the double-crossed hinge/bracket in the locked position until broken. This would enable the pilot to break the seal if things seem dicey and only then releasing the canopy if and when it is actually necessary. Love the videos and update, can't wait for your first flight, cheers!
You all have done an amazing job! I am glad to see the thought about the emergency canopy release... Just awesome! How does that emergency release interface or interact with the rear latches? Do they just come free when the front is untethered?
1) How about some stock carbonfiber pipe for the throttle? I imagine it's cheaper, faster and lighter while also keeping interferance down if it reaches up to the firewall. 2) Did you consider a compliant mechanism for the canopy relase? It can have 2 states were it locks slightly in. 3) Maybe have something that lets the flow of air help with the cockpit removal after release? Otherwise hidden inside. 4) What can someone do in case there is a fire inside/panic... are you able to forecefully open by standing up for example?
You guys are so awesome! Love your videos. Put a vernier throttle in mine please.... How about making a STOL? You sure have the talent to make it happen!
This is awesome. Two questions pop into my head and I can't resist asking: (1) will you be able to taxi on the ground with the canopy partly lifted, and the panel slightly inclined, so that you don't roast on a hot day? (2) have you given any thought to padding the glare shield for flailing heads in the event of a crash?
Quick question - it may have been addressed elsewhere already, so apologies for being redundant in such an event 😔 - but on a hot, sunny day many pilots will want to keep their canopy ajar to facilitate good cooling while taxying at slow speed, as airflow tends to be too low to keep the cockpit cool otherwise, especially with a clear acrylic canopy of this given design in bright sunshine. Thus if the canopy is opened somewhat and that also results in the movement of the instrument panel and presumably the engine’s gauges, does that then pose a problem for the pilot taxying the aircraft 🤔 I’m guessing the instrument panel’s gauges would have to remain active for taxying with the canopy slightly ajar to be possible and there would have to be a limit on how far the canopy could be opened to facilitate cockpit cooling during taxying operations ; the latter so that the sight angle for the engine instruments would not make it impossible for the pilot to read the instruments (Temps, rpm, oil pressure for example). Cheers. Ps - nice work, really impressed by how far you’ve come along 👍
Nice work. You may have requests for an intermediate close position on the canopy for ventilation on the ground. Did you guys investigate throttle by wire?
13:08 when that canopy detaches completely at 270mph, the pilot will become incapacitated within about 0.2 seconds. Unless there is a mechanism that holds the rear until the front flips up and over the pilots head. Or there is a ramp on the top of the instrument panel to launch it overhead. Or there is a way to guarantee the low pressure over the canopy will lift it at >30 degree departure angle to clear the pilots head. Which defies physics. It should probably have a catch at the upper-rear which is not released by the jettison handle, in order to cause the canopy to lift leading edge first, flat plate vertical overhead, and off into the breeze. But you mentioned needing to design a solution to the problem, so ill hang tight for that. It would seem to me, the design philosophy of this AC is not simplicity centric. And there are a plethora of new, untried concepts coming together into one aviation project. I wish you all lots of luck, at some point in complexity, luck becomes as important as the best engineering.
I also have reservations about forward-tilting canopies in general. How do you escape if the plane flips over in water? or if it flips over and starts on fire? Plenty of real-world examples of vans RVs and other planes doing exactly that (rarely with the fire though, thankfully, but still possible). Unless you eject the canopy before Every emergency landing. I prefer sliding canopies or other doors than can be opened in-flight.
I agree with Justin, the canopy probably needs to be able to rotate up around a point at the rear, enough to clear the pilots' heads. A gas cylinder or spring under the fairing might forcibly raise the front lip to catch the slipstream and help flip the canopy. Some high-speed aircraft had problems ejecting canopies, the ME-163 canopy, a somewhat similar design, could not release, even after pulling the eject handle, at high speed. Consider a handheld punch to break the acrylic in the event of a flip over accident. Great work and video production- look forward to progress on the design.
You'll die the moment you release it. It's a common problem in sailplanes and easily solved with a Röger hook. Please implement a similar device on the DarkAero!
Are you able to "crack the door" open in case of forced landing? That way the door is not latched shut with the airframe deformed. Interesting, I also refresh my knowledge of GD&T standards in flight.
Super interesting videos, really great to see everything coming together. Can i ask you the type of rivet that you are using at the end of this video ? Thanks and please continue
I was just thinking about your throttle housing. My concern is that, when exiting the aircraft, I’m always looking for something to leverage my weight when getting out of the seat. I would be concerned someone might place a good amount of weight on the end of that cantilevered housing and have the housing break off at the mounting location. I am really enjoying watching you guys create something that so many of us can only dream about doing. Good job.
Thank you for watching! We had a similar discussion and concern for that very scenario playing out. Inevitably someone will want to lean on it to support themselves. To help handle those loads we are planning to add some additional reinforcing carbon fiber “tapes” on the top and sides which should help beef it up.
I am so excited to see this work of art fly,, you guys are amazing. Though I have to ask, is there a risk of the wiring behind the instrument panel getting kinked or severed with extended use?
Hopefully you will be able to add a second button on the passenger side to open the canopy as well. Always nice to have that double access, vs walking around
Looking good guys! For the canopy latching mechanism, do you have any room for adjustment up and down on the latches? That might be a nice thing to add for the production version so that if there is some variance in the builder's kits or their assembly, they would still be able to get the intended latched position.
Misalignment is something we were concerned about as we assembled the hardware, but there is a solution. The "hook" for the latch mechanism is bolted to the phenolic "horn" which allows shims to be added to adjust the relative position between the interfacing components. We match bonded everything in place as a mated assembly to eliminate slop, but adjustments are still possible if we need to tune the fit for some reason.
Great video. I’ve been considering building a plane. I’m left uninspired by most of the current offerings, but the DarkAero had got my interest. I’m a 21,000 hour ATP with a major airline. Retirement is not too far off and I’d like to fly for fun and to visit friends/family. I’ve built several boats and worked in a shop repairing wooden and fiberglass sailplanes back in my college days. Also done a lot of mechanical work on boats, cars and motorcycles. I’ve got a question. What sort of climate control needs to be maintained when working with the adhesives you are using?
I am a high schooler designing a Solar car and I was curious what type of acrylic I should use that I could bend to shape and not hot form. I watched your last video on the windscreen and it seemed to be what you were describing is that what you guys did if so how do I do this and what material can I use
Hi , All your videos are amazing. I myself an aviation enthusiast with composites background. What softwares do you guys use to design composite layups? I use ANSYS Prepost and it's always difficult when i want to draft it for manufacturing. Thanks :)
Canopy release, hinge pins! You might want to rethink how you have installed all the hinge pins in the canopy release mechanism. Gravity can be a friend or an enemy. Installing the pins from the bottom makes installing the cotter pins easier, but also allows gravity to remove the hinge pin if the cotter pin breaks or come out of the hinge pin. Installing the hinge pin from the top make putting the cotter pins harder, but gravity is now holding the hinge pin in, if a cotter pin comes out. What would happen if just one of the twelve cotter pins came out and you needed to use the canopy release? How easy will it be to check (per-flight) the cotter pins after construction is complete? Can you see them from the top? Bottom?
Hi Tom! Thanks for checking out the video and for reviewing our work! The orientation of the clevis pins was deliberately chosen to simplify the installation and visual inspection of the cotter pins. There is a best practice of assembling fasteners in line with gravity and/or the slipstream when possible, but this is not done to hold the assembly together if the nut or cotter pin is lost, it's only to keep from losing the fastener as well. The basis for the best practice is described in FAA-H-8083-30A Section 7-49. Gravity and/or aerodynamic assist are not reliable means of holding an assembly together, even as a hypothetical backup, so it is the assembly and inspection requirements that drive the fastener orientation for our jettison mechanism.
I am very curious why phenolic material was chosen. Avoiding galvanic corrosion? Never used that material in a structural component. The release mechanism is quite nice. Very simple solution to a fairly complex challenge.
It would be nice if you could hide the white "end grain" on the end of the carbon panels on the throttle control mount by making the top "cap" cover the four sides, rather than having the sides protrude past the top.
This is the ideal plane for me. I want something that can fly fast, high, and efficient. I don't need it to be big. I want a continental person mover. Only thing better would be if it could do basic aerobatics.
I can't stand forward-tilting canopies. how do you escape if the plane flips over in water? or if it flips over and starts on fire? Plenty of real-world examples of vans RVs and other planes doing exactly that (rarely with the fire though, thankfully, but still possible). Unless you eject the canopy before Every emergency landing. I prefer sliding canopies or other doors than can be opened in-flight. I do like the release mechanism though.
I'm assuming there won't be any air conditioning. Alot of the old pipers I remember flying had a little window on the side with an air scoop that you could swing out that would REALLY help on hot days in Florida where I flew. Any thoughts on adding something like this?
We have two small submerged inlets (NACA style) on both sides of the fuselage which are connected to eyeball vents on either side of the instrument panel. We’ve done some ground testing with these and they allow for quite a bit of airflow into the cabin.
Why is it a problem that the throttle moves when opening the canopy? The cable shielding isn't flexible in the direction of the cable, so it wouldn't pull the butterfly when opening Is there something that I'm missing? Of course, it's a nice solution, but I'm worried that the throttle sticking out would be a pain of you accidentally banged your knee on it
When you open the canopy it will be ripped off by wind pressure comming from the rear of the aircraft if there is a strong wind. You have built a sail which could roll the aircraft. Try a model in the wind tunnel.
I’m sure you guys know this about the glare shield : it needs to be Matte Black, or else it will cause more glare than anything. Shining lights thru it is therefore not the best plan.
Do you guys have aluminum in direct contact with carbon fiber? At 7:04 it looks like there is an aluminum machining riveted with aluminum rivets through carbon fiber and later looks like aluminum core in your carbon fiber honeycomb panel behind the panel. Carbon and aluminum are dissimilar and will corrode. Especially when the aluminum much smaller relative to the carbon, like with fasteners. A small anode, the Al rivet, will corrode much faster and fail. Big aircraft OEMs will put a layer of fiberglass between carbon composites and aluminum structure and use titanium or stainless fasteners to mitigate corrosion problems.
I think I’d prefer to see the canopy release T-handle positioned in a pocket/recess in the underside of the glare shield instead of right on the panel face. That way it is both protected from accidental snagging/pulling and is not taking up valuable center-of-panel/center-of-view real estate.
We went through a number of concepts with this, but the location for the jettison handle was chosen, in part, to keep the mechanism from turning into a Rube Goldberg contraption. We do plan to implement a guard to prevent it from being pulled or snagged accidently. It is important to have it located in an easily accessible location in case a situation in flight testing dictates rapid egress. Sacrificing panel real estate is a compromise we were able to accept since this is a prototype aircraft and does not require the full kitchen sink of instruments in the center stack.
Curious question. Why is the throttle in such an awkward position? Seems hard to keep a hand on it and modulate at will. Specially considering it is shuch a high speed aircraft.
There are limits on where we can place the throttle since the control is cable actuated rather than fly-by-wire. The location under the instrument panel allows for a workable routing of the throttle cable up to the engine. Placing it in the center allows the airplane to be flown from either seat. This ends up being the standard location for the throttle in many light aircraft.
Is there a BRS designed to deploy at 270+mph? The Cirrus Jet has a large BRS. But you have to fly it very slowly in order to deploy it, making it practically useless extra weight for that jet.
@@TheJustinJ The Point of a BRS is to deploy at Zero Miles Per Hour, When your Stalling Out of the Sky, The First Test Flight of the Prototype should have one.
Really funny comment, but I do have to point out that even with the canopy closed, he had an easy way out-no seats, no wing, so he was standing (squatting?) on the shop floor. 😎
The drivers side car door has in some cases dozens of wires that flex every time the door opens and shuts. As long as the wire grade is correct, the strain relief is correct, and you aren't opening the canopy 60 times a day 7 days a week - this would be the least of my worries.
