Do you know Jesus Christ can set you free from sins and save you from hell today Jesus Christ is the only hope in this world no other gods will lead you to heaven There is no security or hope with out Jesus Christ in this world come and repent of all sins today Today is the day of salvation come to the loving savior Today repent and do not go to hell Come to Jesus Christ today Jesus Christ is only way to heaven Repent and follow him today seek his heart Jesus Christ can fill the emptiness he can fill the void Heaven and hell is real cone to the loving savior today Today is the day of salvation tomorrow might be to late come to the loving savior today Romans 6.23 For the wages of sin is death; but the gift of God is eternal life through Jesus Christ our Lord. John 3:16-21 16 For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life. 17 For God sent not his Son into the world to condemn the world; but that the world through him might be saved. 18 He that believeth on him is not condemned: but he that believeth not is condemned already, because he hath not believed in the name of the only begotten Son of God. 19 And this is the condemnation, that light is come into the world, and men loved darkness rather than light, because their deeds were evil. 20 For every one that doeth evil hateth the light, neither cometh to the light, lest his deeds should be reproved. 21 But he that doeth truth cometh to the light, that his deeds may be made manifest, that they are wrought in God. Mark 1.15 15 And saying, The time is fulfilled, and the kingdom of God is at hand: repent ye, and believe the gospel. 2 Peter 3:9 The Lord is not slack concerning his promise, as some men count slackness; but is longsuffering to us-ward, not willing that any should perish, but that all should come to repentance. Hebrews 11:6 6 But without faith it is impossible to please him: for he that cometh to God must believe that he is, and that he is a rewarder of them that diligently seek him. Jesus
Glad to see your progress... It's been a while since I've seen a post... I've followed you nearly from the beginning, and your doggedness and discipline is exemplary.
Im an engineer and started a design of ultralight aircraft of 100% carbon fiber construction, several companies in Europe are doing this but I cant find anyone in the states doing this, compare Europe to USA in aviation design they (Europe) are way ahead of us. I based my design off of Burt Rutan builds, but Im using carbon fiber ribs, and aluminum I-beam front spar and rear spar is carbon fiber, with CNC hot wire foam core in between each rib and carbon fiber skins, and its made weight to qualify for UL part 103, so I passed the first challenge of making weight in the wing section, now working on fuselage and tail section, all on solidworks and OPEN VSP software
Awesome development work, thank you. It would be great to understand how versioning, release management and bills of materials (BOMs) work in your life-safety development and manufacturing environment. Particularly: * Versioning: assessment of each version's backwards-compatibility/SEMVER. * Internal Release Management: internal/engineering with internal versioned product codes. * How do you structure and maintain the multi-level BOM structures needed for managing the "assemblies of assemblies" of engineered products? It is critically important to isolate the production/factory and parts-purchasing customers from having to understand versioning. * External release (release for Sale): how are the internal versioned product codes linked to the Sales product codes that customers see? * Some discussion of the importance of 'immutability' for both the source files (source, CAD etc used by developers) and the object files (binaries, CNC files used by the factory and out-work) are achieved would be great too.
Great comment. I think the one question I would add to your list that would be cool to know is how many bananas long the plane is from prop to tail? Maybe show a banana for scale.
This reminds me of the wet wing design of the BD-4. How do you handle with sucking air during maneuvers when you unport the fuel pickups? This required either a header tank or droop pickups to prevent the issue in the BD-4.
Great question! The short answer is the fuel system utilizes a central sump (header) to keep the fuel pickups from unporting. We discuss the fuel system architecture in detail in this video: th-cam.com/video/kVOEJPPR60U/w-d-xo.html
@@DarkAeroInc aircraft looks very beautiful with the paint job but have you thought about covering the interior of the aircraft with paint as uv might go through the canopy and affect the resin. btw I really appreciate the knowledege you share Thank you.
I’d love to hear more about the interaction of gasoline with the epoxy/composites, particularly over time? Some manufacturers have had LOTS of issues with built in tanks in the marine industry. Great work though, beautiful plane!!
Especially if an internal pinhole allows fuel to move into the honeycomb spaces when new and over time with degradation due to flex and heat. That is a huge internal surface area and linear distance of joints with a requirement for a perfect seal. At some point lots of joints will be slathered with epoxy and a giant skin will be pressed into place over very many longitudinal members. Can a perfect long-lasting seal be expected?
The old-fashioned way would be some sort of "tap" test. Many years ago I owned a Grumman TR2. The bonded joints were "tested" using a nickel on edge and an experienced set of ears. Perhaps someone could devise an ultrasound method to verify that the honeycomb has remained dry. @@onethousandtwonortheast8848
I love your custom aircraft! Ultimately, all airlines will have to have mostly composites, and they will have to go with either solid oxide fuel cells (they can use their existing fuels, and get more than double the range) and smaller aircraft can use hydrogen for shorter flights like air taxis and city to city
Incredibly well thought out program. A great way to design an aircraft. I think they call it systems integration. I call it the Right Way to build an aircraft. Good job!
Is there any long term chemical testing on carbon fiber and your resins to see if long term exposure to Kerosene will weaken you wing in any way, or dissolve things into the fuel?
#1 Kerosene is utterly benign to cured laminating epoxies and #2, they aren't burning Kerosene... So you might want to ask about Gasoline. #3, Gasoline is utterly benign to cured laminating epoxies commonly available. Specifically, it is not the gasoline which hurts chemically but rather the additives. I am sure somewhere there is an exception for long term gasoline storage, but I have never heard of one.
The engine they're using has an autogas STC, but they have stated they won't be supporting that because the resin isn't compatible with the ethanol content present in most available gasoline in USA. You can get certified ethanol-free gas, aimed at the marine market I believe. I wonder if that application could be a good option.
Uh... well that is stupid as Methanol/Ethanol or Iso propyl alcohol are benign to epoxies when the epoxy is cured. IF EITHER is present DURING the curing process then and ONLY then will strength be severely effected based on how much of either alcohol type is present to "thin" the mixture down. True if using any Ketone as well as a thinner agent.Often people use alcohol's in epoxy when pouring or spraying as it breaks surface tension properties creating a smooth finish. If too much is present, the epoxy in question will not fully cure and strength etc properties are lost. @@g.tucker8682
You guys are doing such good work. Very impressive! That seat belt system is serious. You might be singing soprano after a high G stop, but you will probably live through it.
Good question! The "hump" is there to balance the aileron about its hinge line which helps prevent control surface flutter. This extra feature does increase drag when the aileron is deflected, but most of the time in flight the ailerons are at neutral deflection. Thanks for checking out the video!
prevents flutter. control surfaces need a counter weight there. if control surfaces get bigger it also helps with the power required to pull those control surfaces into position. only not needed on bigger aircraft who force control surfaces into position with hydraulics.
So great to watch an aircraft being developed by engineers that understand aircraft. I couldn’t stop watching the train wreck known as the Raptor project. Won’t forget how upset the builder Paul was that the test pilots didn’t like that with the stick full left the ailerons could be pushed full right. So Paul stiffened the aileron system up a bit an fired the test pilots. So happy that he didn’t kill himself when he crashed.
Hey guys, thanks for the update. I had forgotten what a slippery speedster this is designed to be! I’m glad you did the pressure testing against delaminating of the wing during unexpected loads. I would love to work on marketing your plane when it nears that point. I am so psyched to see it in the air, but I also want you to take all the time you need to do things right as I can see you will. Best of luck to your team.
Coming from a seat design engineer at a major aircraft company - well done. You guys clearly did your research on crash testing. The only thing on that 6-point is that customers (and more importantly the customer's wife) is not going to like having to put that on and wearing it the whole flight (especially for a longer endurance airplane like yours). There's a reason most modern manufacturers are going with a 3-point and inertia reel system. I'm sure you've thought through the comfort implications but considering your seat positioning it does seem necessary (although I'm not familiar with experimental aircraft seat cert requirements).
I hear there's now a market for a commercial airplane manufacturer in the U.S. that focuses on quality & safety. You guys should do a 200 person passenger jet next.
The mistakes at BO can be blamed on management, sure. But they were made by very small groups of individuals. I doubt more than two people were involved in the missing door bolts. One to forget them, and another to pencil whip the checklist documents. Two, possibly three lazy and foolish people caused that. And probably less than ten were involved in the MCAS implementation. The latter system was a hush-hush deal to satisfy certain draconian FAA type certificate regulations. Where the pitch-response and pitch up due to thrust had to meet certain criteria based on the original 737 type certificate tests, else suffer the laborious, multi-year, two dozen billion dollar punishment that is known as new type certification. And also re-training all crew for the new type rating, because of those handling differences. The MCAS system in its entirety could not be widely disclosed inside of Boeing, nor to the FAA, or to any pilots, when it was implemented by a select few individuals to satisfy those FAA handling requirements by an "other than permitted" manner. The reason it failed so catastrophically, is because it was directly tied to only 1 angle of attack vane-type sensor. But a system that can override the pilot and radically change pitch attitude based on AoA sensor data MUST be tied into no less than THREE sensors for redundancy. One, or Two is insufficient, because it wont know which to believe. It has to have three. This is not an area of expertise for computer programmers, who always and invariably expect everything to function flawlessly, and rarely consider failure modes. Since this was a secret project to remedy a potential issue with the FAA due to a change in handling, it was almost certainly kept secret and the appropriate departments were kept unaware and unable to double check this egregious error made by other departments who implemented this half baked idea. Boeing is to blame for this mistake. But the blame for Boing implementing MCAS on the 737MAX in the first place is actually the fault of the FAA.
Romans 6:23 For the wages of sin is death, but the free gift of God is eternal life in Christ Jesus our Lord. Come to Jesus Christ today Jesus Christ is only way to heaven Repent and follow him today seek his heart Jesus Christ can fill the emptiness he can fill the void Heaven and hell is real cone to the loving savior today Today is the day of salvation tomorrow might be to late come to the loving savior today John 3:16-21 16 For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life. 17 For God sent not his Son into the world to condemn the world; but that the world through him might be saved. 18 He that believeth on him is not condemned: but he that believeth not is condemned already, because he hath not believed in the name of the only begotten Son of God. 19 And this is the condemnation, that light is come into the world, and men loved darkness rather than light, because their deeds were evil. 20 For every one that doeth evil hateth the light, neither cometh to the light, lest his deeds should be reproved. 21 But he that doeth truth cometh to the light, that his deeds may be made manifest, that they are wrought in God. Mark 1.15 15 And saying, The time is fulfilled, and the kingdom of God is at hand: repent ye, and believe the gospel. 2 Peter 3:9 The Lord is not slack concerning his promise, as some men count slackness; but is longsuffering to us-ward, not willing that any should perish, but that all should come to repentance. Hebrews 11:6 6 But without faith it is impossible to please him: for he that cometh to God must believe that he is, and that he is a rewarder of them that diligently seek him. Jesus
@EllipsisAircraft Actually Boeing and MD have had many design faults that were ignored and resulted in lost lives over the decades. What has happened in the last couple of years is nothing new. Watch some air crash videos and you will see a history of wrong parts and design being ignored for profit.
DarkAero looks like it might be a great application for "pull up" style lap belts on the harness. Pulling up toward the center allows you to get the belt tighter in a constrained space. Pulling down toward the left wall/armrest might be a pain!
Speaking of load testing. Since you guys have a wet wing, does the wing get load tested again with fuel to make sure it doesn't leak after an extreme load with fuel inside?
I'm going with Crow 5-point for my RV-14 project. I have Hooker 5-point in my Decathlon. Hooker is of the highest quality and I'm happy with my harnesses, but they're a bit heavy for cross-country comfort (IMHO). Press on!
I always love to watch your progress. Wish I was 20 years younger, where I could join you. But i can live my current life through you all. thanks I am rooting for you all.
Sweet, I thought I saw them, but always better to ask the people who know! Thank you guys for doing such an instructive job, showing this whole process! @@DarkAeroInc
Yes, but some of the channels were lit in such a way that I could not tell if they were baffles or compartments or what. Also, DarkAero already nicely answered my question, so thanks for being needlessly aggressive.@@jayphilipwilliams
Really looking forward to the maiden flight. Doing an incredible job. I really like this airframe. When done I would like a 3 view so I can build a scale Radio Control plane.
Jesus Christ is the only hope in this world no other gods will lead you to heaven There is no security or hope with out Jesus Christ in this world come and repent of all sins today Today is the day of salvation come to the loving savior Today repent and do not go to hell Come to Jesus Christ today Jesus Christ is only way to heaven Repent and follow him today seek his heart Jesus Christ can fill the emptiness he can fill the void Heaven and hell is real cone to the loving savior today Today is the day of salvation tomorrow might be to late come to the loving savior today Holy Spirit Can give you peace guidance and purpose and the Lord will John 3:16-21 16 For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life. 17 For God sent not his Son into the world to condemn the world; but that the world through him might be saved. 18 He that believeth on him is not condemned: but he that believeth not is condemned already, because he hath not believed in the name of the only begotten Son of God. 19 And this is the condemnation, that light is come into the world, and men loved darkness rather than light, because their deeds were evil. 20 For every one that doeth evil hateth the light, neither cometh to the light, lest his deeds should be reproved. 21 But he that doeth truth cometh to the light, that his deeds may be made manifest, that they are wrought in God. Mark 1.15 15 And saying, The time is fulfilled, and the kingdom of God is at hand: repent ye, and believe the gospel. 2 Peter 3:9 The Lord is not slack concerning his promise, as some men count slackness; but is longsuffering to us-ward, not willing that any should perish, but that all should come to repentance. Hebrews 11:6 6 But without faith it is impossible to please him: for he that cometh to God must believe that he is, and that he is a rewarder of them that diligently seek him. Jesus
G,day fellas from Sydney Australia. Fantastic progress of your plane. I should have linked the seatbelt harness design to reduce impact trauma on the human body, in other words: safety, instead of sales and marketing. 🌏🇦🇺
Mechanical engineering student checking in with a question - is fatigue testing something you need to be concerned about given you are using composites? With multiple flights I imagine the wings/tanks will experience cycles of over and under pressure which could potentially lead to problems later down the road? Or are the pressures differences being experienced small enough that that kind of testing isn't necessary? Keep up the awesome work!
Hey friends! I noticed your testing method for the anticipated hydrostatic pressure on the wing/tank. Do you plan on a full-scale loaded test on this wing at some point in the future? I am talking about a complete wing on a test stand held at an angle and torture tested with a fuel analog in place. Admittedly this is expensive and time consuming, but compared to the damage to your reputation later on it could be a good investment. What I am seeing is that you are not actually trying to find a failure mode and that is a concern.
I notice that your clearance between the aileron counterweight and wing seems tight. Have you considered that moisture could propogate into that space and freeze? Locking up the controls. Just a consideration.
Riley and Brothers May the Airplane Gods Watch Over You and Saint Michael be at your Side when you Do the Air Testing. I will always want to See the Mom and Pop shops show it still alive in America.
It's hard to tell in the video, but are you using a "Formula-style" harness? That under-the-leg anti-sub belt routing is only valid with a belt system designed for it (Formula or Schroth Hybrid), and should not be used with a standard 6-point system. Crow does make a Formula restraint. I'm not sure what the reasoning is for the different linkage, but would tend to trust the engineers that developed them given the amount of research and testing that goes into these restraints. Very exciting to see the progress!
If there is a narrow direct link between the left and right tanks with the tanks at ~1/2 full, if the plane banks left all the fuel will flow to the left wing, then if the plane was to suddenly flip to banking right, all the fuel will flow to the right tank, but I hope they have something that allows air from right to left to swap or they might create a sudden strong vacume in the tank losing fule. You can see that effect on 2L coke bottels if you empty them without doing the swirl thing.
It all looks pretty cool.. will you put some of the matrix samples from the composite in fuel, just as extra observation on long term wet wing effects?
Beautiful, elegant design. Love your vids explaining your design and engineering choices. Judging based on some superficial experience with composite aircraft structures, it certainly looks like your wing is plenty strong. One question: In case of damage, like say a 6 inch dent or gouge in leading edge, how repairable will this wing be? I can think of one composite plane where all the loads in the outer 75% of the wing are carried almost entirely by the skins. It’s a strong wing, but pretty much unrepairable if damaged.
How do you solve the problem of changing the center of gravity of the Dark Arrow? When the landing gear is retracted, the center of gravity shifts backwards. I have a feeling that cleaning the landing gear after takeoff is impossible.
Love you guys! It’s awesome to see you all dedicated to this build. Your ethos is thorough and comprehensive.Putting all the newest tech ides and out of the box theology together, to produce the ultimate machine! In all aspects of flight!! I wish you all the very best of good will and success in your excellent project!!❤❤❤
have this fun little idea of building something that looks more like a motorized hang glider boat, but with a blended wing mounted over instead, wing would be tapering until it switches over to be glider wings (horizontal W shape) with a second set of wings angled from the pontoons at the low side of W, going forward to the nose, keeping it stable. (and it's a nice way to get inside from boat.) this fools the law on what is seen as a plane in my country, if the machines total wingspan is 16m, you can fly 24m over the water (wingspan x 1.5) some gliders have 30m wingspan, if you then ad on the 4m blended mid wing, you'll be able to fly 51m over the ground legally (without any license)
I know it's probably un-necessary for aviation, but have you considered a headrest for the seat? Seeing necks whip back on crash test footage without them always makes me cringe. (Granted if you ever crashed the DA1 you're probably going to need more than a headrest lol) Eagerly awaiting the first flight
I thought (and was taught) the belt was there to keep you in your seat in case of turbulence but preventing injuries in case of a crash and since you *are* the crumple zone... Do you have concrete evidence 6 point harnesses save lives on experimental aircrafts?
How many experimental aircraft offer a full carbon fiber tub? Compare this closer to a Formula-Ford. Reclined seats require the extra anti-submarine strap of a 6pt harness, for redundancy, and ability to locate pressure points on both sides of... centerline.
Wwould appreciate if made in an option on your website to see the specs in Metrics :) (Or better way, a hybrid that aviation actually uses.. Nm, Kg and Meters... :) ) Looks like a beutiful litle airplane
You guys should look into making turbo-aero turbine engines an option. From what I can tell you two will be coming out with a finished product around the same time. I think they are planning to have 100-350 hp turbine engines. I think they will weigh less than 300lbs. Would be a nice option to have on the table at least.
Turbines are certainly the answer for appropriate applications but they really don't work very well for small aircraft. This is mainly because the fuel burn is so high. Turbines are most efficient up high and climbing high takes time and fuel. A small plane simply can't carry enough fuel.
Can not wait to buy one. I have a safety design that I think would be beneficial in providing more safety for the pilot as well. I’d love the opportunity to talk sometime!
It looks fast. Excited to see some flight testing😁 I observed that the outer end of the ailerons, specifically the tip, rotates and protrudes in the opposite direction of the control surface. Is there a specific reason for choosing this design over keeping the outer end of the wing passive and operating the aileron independently?
Is it possible to make these structures too stiff? I've always been curious about this. In cars, at least, the goal is to make the crash structures purposely less stiff and stable and therefore easier to break away from the main safety cell, but planes are different - I don't think there's a single part of a plane that would purposely be made purposely less stiff than the others. If anything, I'd assume that you'd want places like the wing-fuselage attachment areas to be EXTRA stiff (assuming weight isn't a factor). Is weight really the biggest challenge to increasing stiffness?
If a structure is too stiff it will crack. Some flex is needed to make the structure resilient. If you watch a 747 take off the wings flex upward at the tips several feet as they take the load.
@@davidr8309 I understand that. I also understand that a significant part OF that flex is a byproduct of the sheer weight of the wings themselves in addition to the compliance that's built into such a large structure simply because of mechanical tolerances. Resiliency, flexibility, and stiffness are not mutually exclusive in my opinion - you don't need isomorphic properties in all places all the time. My question is whether the stiffer properties of carbon fiber can be used to create structures SO stiff that they actually become a hindrance. Carbon fiber doesn't crack like aluminum will, and you can overbuild it to the point where it's so strong that the stiffness is just a happy byproduct.
Really interesting wing. I am wondering how did you solve the problem of unporting in unusual attitude such as slips or even normal attitude changes like approach and climb?
Both wing tanks gravity feed into a central sump tank which is where the fuel pump pickup is located. Check valves between the sump tank and wing tanks allow fuel to flow into the sump but restrict the flow of fuel back into the wing tanks. This arrangement keeps the pickup from unporting. The fuel system architecture is covered in more detail in this video: th-cam.com/video/kVOEJPPR60U/w-d-xo.html
These young men are astonishingly skilled.
And it's nice that they're growing the team!
And diligent too. I've seen lots of skilled but careless young engineers, but these guys are so clear and thoughtful in their design methodology.
Agreed.
They are doing everything "right" on engineering work.
Raised in a family where the parents don’t have rainbow hair. Guaranteed 👌
@@rosdar76is that supposed to be funny? 🙄
Nice to hear from you guys again! Closer and closer to seeing that thing FLY!
Do you know Jesus Christ can set you free from sins and save you from hell today
Jesus Christ is the only hope in this world no other gods will lead you to heaven
There is no security or hope with out Jesus Christ in this world come and repent of all sins today
Today is the day of salvation come to the loving savior Today repent and do not go to hell
Come to Jesus Christ today
Jesus Christ is only way to heaven
Repent and follow him today seek his heart Jesus Christ can fill the emptiness he can fill the void
Heaven and hell is real cone to the loving savior today
Today is the day of salvation tomorrow might be to late come to the loving savior today
Romans 6.23
For the wages of sin is death; but the gift of God is eternal life through Jesus Christ our Lord.
John 3:16-21
16 For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life. 17 For God sent not his Son into the world to condemn the world; but that the world through him might be saved. 18 He that believeth on him is not condemned: but he that believeth not is condemned already, because he hath not believed in the name of the only begotten Son of God. 19 And this is the condemnation, that light is come into the world, and men loved darkness rather than light, because their deeds were evil. 20 For every one that doeth evil hateth the light, neither cometh to the light, lest his deeds should be reproved. 21 But he that doeth truth cometh to the light, that his deeds may be made manifest, that they are wrought in God.
Mark 1.15
15 And saying, The time is fulfilled, and the kingdom of God is at hand: repent ye, and believe the gospel.
2 Peter 3:9
The Lord is not slack concerning his promise, as some men count slackness; but is longsuffering to us-ward, not willing that any should perish, but that all should come to repentance.
Hebrews 11:6
6 But without faith it is impossible to please him: for he that cometh to God must believe that he is, and that he is a rewarder of them that diligently seek him.
Jesus
Very methodical. It will be great to see it fly!
So was the Bugatti.
Glad to see your progress... It's been a while since I've seen a post... I've followed you nearly from the beginning, and your doggedness and discipline is exemplary.
Im an engineer and started a design of ultralight aircraft of 100% carbon fiber construction, several companies in Europe are doing this but I cant find anyone in the states doing this, compare Europe to USA in aviation design they (Europe) are way ahead of us. I based my design off of Burt Rutan builds, but Im using carbon fiber ribs, and aluminum I-beam front spar and rear spar is carbon fiber, with CNC hot wire foam core in between each rib and carbon fiber skins, and its made weight to qualify for UL part 103, so I passed the first challenge of making weight in the wing section, now working on fuselage and tail section, all on solidworks and OPEN VSP software
Do you have any tips to build a ultralight
Could wider crabon fibre tubing with mix of Omni and Uni weave work. Maybe integrated into nose ribs.. ?? just a thought :)
Awesome development work, thank you. It would be great to understand how versioning, release management and bills of materials (BOMs) work in your life-safety development and manufacturing environment. Particularly:
* Versioning: assessment of each version's backwards-compatibility/SEMVER.
* Internal Release Management: internal/engineering with internal versioned product codes.
* How do you structure and maintain the multi-level BOM structures needed for managing the "assemblies of assemblies" of engineered products? It is critically important to isolate the production/factory and parts-purchasing customers from having to understand versioning.
* External release (release for Sale): how are the internal versioned product codes linked to the Sales product codes that customers see?
* Some discussion of the importance of 'immutability' for both the source files (source, CAD etc used by developers) and the object files (binaries, CNC files used by the factory and out-work) are achieved would be great too.
Great comment. I think the one question I would add to your list that would be cool to know is how many bananas long the plane is from prop to tail? Maybe show a banana for scale.
Just placed an order for 2! Incredible project
Best of luck in finishing the kits (if they start making them) 👍🎉
Excellent work guys , your open approach is very refreshing.
Work of art that thing
This reminds me of the wet wing design of the BD-4. How do you handle with sucking air during maneuvers when you unport the fuel pickups? This required either a header tank or droop pickups to prevent the issue in the BD-4.
Great question! The short answer is the fuel system utilizes a central sump (header) to keep the fuel pickups from unporting. We discuss the fuel system architecture in detail in this video: th-cam.com/video/kVOEJPPR60U/w-d-xo.html
@@DarkAeroInc Thanks. I'd really love to see this matched to the Viking 195t. Good to see a header tank, which will make this match up doable.
@@DarkAeroInc aircraft looks very beautiful with the paint job but have you thought about covering the interior of the aircraft with paint as uv might go through the canopy and affect the resin. btw I really appreciate the knowledege you share Thank you.
I’d love to hear more about the interaction of gasoline with the epoxy/composites, particularly over time? Some manufacturers have had LOTS of issues with built in tanks in the marine industry.
Great work though, beautiful plane!!
Especially if an internal pinhole allows fuel to move into the honeycomb spaces when new and over time with degradation due to flex and heat. That is a huge internal surface area and linear distance of joints with a requirement for a perfect seal. At some point lots of joints will be slathered with epoxy and a giant skin will be pressed into place over very many longitudinal members. Can a perfect long-lasting seal be expected?
@@tomscott1159 How are the internals examined? This design looks like a permanently sealed one.
The old-fashioned way would be some sort of "tap" test. Many years ago I owned a Grumman TR2. The bonded joints were "tested" using a nickel on edge and an experienced set of ears. Perhaps someone could devise an ultrasound method to verify that the honeycomb has remained dry.
@@onethousandtwonortheast8848
Congratulations! In addition to making an outstanding plane you are also growing a successful business. Brilliant!
Pretty impressive and amazing design! Congrats!
Can’t wait to see it fly!
I love your custom aircraft!
Ultimately, all airlines will have to have mostly composites, and they will have to go with either solid oxide fuel cells (they can use their existing fuels, and get more than double the range) and smaller aircraft can use hydrogen for shorter flights like air taxis and city to city
Incredibly well thought out program. A great way to design an aircraft. I think they call it systems integration.
I call it the Right Way to build an aircraft. Good job!
Is there any long term chemical testing on carbon fiber and your resins to see if long term exposure to Kerosene will weaken you wing in any way, or dissolve things into the fuel?
#1 Kerosene is utterly benign to cured laminating epoxies and #2, they aren't burning Kerosene... So you might want to ask about Gasoline. #3, Gasoline is utterly benign to cured laminating epoxies commonly available. Specifically, it is not the gasoline which hurts chemically but rather the additives. I am sure somewhere there is an exception for long term gasoline storage, but I have never heard of one.
The engine they're using has an autogas STC, but they have stated they won't be supporting that because the resin isn't compatible with the ethanol content present in most available gasoline in USA. You can get certified ethanol-free gas, aimed at the marine market I believe. I wonder if that application could be a good option.
Uh... well that is stupid as Methanol/Ethanol or Iso propyl alcohol are benign to epoxies when the epoxy is cured. IF EITHER is present DURING the curing process then and ONLY then will strength be severely effected based on how much of either alcohol type is present to "thin" the mixture down. True if using any Ketone as well as a thinner agent.Often people use alcohol's in epoxy when pouring or spraying as it breaks surface tension properties creating a smooth finish. If too much is present, the epoxy in question will not fully cure and strength etc properties are lost. @@g.tucker8682
To prevent problems with ethanol, coatings are required. Novalac FR530 for example.
Baby forumula is a coating in your world eh?.. Technically true... @@kraftwurx_Aviation
Amazing!!! Greetings from South Africa~!!!
Such a beautiful composition of engineering. Form follows function for every square mm. Bravo 👏👏
You guys are doing such good work. Very impressive! That seat belt system is serious. You might be singing soprano after a high G stop, but you will probably live through it.
Very cool to see the progress and testing! Thanks for sharing!
Looking great!! Greatings from Sweden
Great video as always, can't wait for the next one.
Why does the hump on the wingtip move with the ailerons? Won't it provide lots of separation when the ailerons are not at the neutral position?
Good question! The "hump" is there to balance the aileron about its hinge line which helps prevent control surface flutter. This extra feature does increase drag when the aileron is deflected, but most of the time in flight the ailerons are at neutral deflection. Thanks for checking out the video!
prevents flutter. control surfaces need a counter weight there. if control surfaces get bigger it also helps with the power required to pull those control surfaces into position. only not needed on bigger aircraft who force control surfaces into position with hydraulics.
This thing will be phenomenal to work on.
So great to watch an aircraft being developed by engineers that understand aircraft. I couldn’t stop watching the train wreck known as the Raptor project. Won’t forget how upset the builder Paul was that the test pilots didn’t like that with the stick full left the ailerons could be pushed full right. So Paul stiffened the aileron system up a bit an fired the test pilots. So happy that he didn’t kill himself when he crashed.
Hey guys, thanks for the update. I had forgotten what a slippery speedster this is designed to be! I’m glad you did the pressure testing against delaminating of the wing during unexpected loads. I would love to work on marketing your plane when it nears that point. I am so psyched to see it in the air, but I also want you to take all the time you need to do things right as I can see you will. Best of luck to your team.
That is a beautiful and well-engineered airplane. I wish you luck and great success.
Rapid, continuous rolls could also induce similar/greater loads from fuel sloshing under centrifugal forces.
Coming from a seat design engineer at a major aircraft company - well done. You guys clearly did your research on crash testing. The only thing on that 6-point is that customers (and more importantly the customer's wife) is not going to like having to put that on and wearing it the whole flight (especially for a longer endurance airplane like yours). There's a reason most modern manufacturers are going with a 3-point and inertia reel system. I'm sure you've thought through the comfort implications but considering your seat positioning it does seem necessary (although I'm not familiar with experimental aircraft seat cert requirements).
Very impressive work on many levels, thanks for the video
I love the progress that you guys have made, I can't wait to see it in the sky, keep up the awesome work😎
I hear there's now a market for a commercial airplane manufacturer in the U.S. that focuses on quality & safety. You guys should do a 200 person passenger jet next.
The mistakes at BO can be blamed on management, sure. But they were made by very small groups of individuals. I doubt more than two people were involved in the missing door bolts. One to forget them, and another to pencil whip the checklist documents. Two, possibly three lazy and foolish people caused that.
And probably less than ten were involved in the MCAS implementation. The latter system was a hush-hush deal to satisfy certain draconian FAA type certificate regulations. Where the pitch-response and pitch up due to thrust had to meet certain criteria based on the original 737 type certificate tests, else suffer the laborious, multi-year, two dozen billion dollar punishment that is known as new type certification. And also re-training all crew for the new type rating, because of those handling differences. The MCAS system in its entirety could not be widely disclosed inside of Boeing, nor to the FAA, or to any pilots, when it was implemented by a select few individuals to satisfy those FAA handling requirements by an "other than permitted" manner. The reason it failed so catastrophically, is because it was directly tied to only 1 angle of attack vane-type sensor. But a system that can override the pilot and radically change pitch attitude based on AoA sensor data MUST be tied into no less than THREE sensors for redundancy. One, or Two is insufficient, because it wont know which to believe. It has to have three. This is not an area of expertise for computer programmers, who always and invariably expect everything to function flawlessly, and rarely consider failure modes. Since this was a secret project to remedy a potential issue with the FAA due to a change in handling, it was almost certainly kept secret and the appropriate departments were kept unaware and unable to double check this egregious error made by other departments who implemented this half baked idea. Boeing is to blame for this mistake.
But the blame for Boing implementing MCAS on the 737MAX in the first place is actually the fault of the FAA.
Romans 6:23
For the wages of sin is death, but the free gift of God is eternal life in Christ Jesus our Lord.
Come to Jesus Christ today
Jesus Christ is only way to heaven
Repent and follow him today seek his heart Jesus Christ can fill the emptiness he can fill the void
Heaven and hell is real cone to the loving savior today
Today is the day of salvation tomorrow might be to late come to the loving savior today
John 3:16-21
16 For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life. 17 For God sent not his Son into the world to condemn the world; but that the world through him might be saved. 18 He that believeth on him is not condemned: but he that believeth not is condemned already, because he hath not believed in the name of the only begotten Son of God. 19 And this is the condemnation, that light is come into the world, and men loved darkness rather than light, because their deeds were evil. 20 For every one that doeth evil hateth the light, neither cometh to the light, lest his deeds should be reproved. 21 But he that doeth truth cometh to the light, that his deeds may be made manifest, that they are wrought in God.
Mark 1.15
15 And saying, The time is fulfilled, and the kingdom of God is at hand: repent ye, and believe the gospel.
2 Peter 3:9
The Lord is not slack concerning his promise, as some men count slackness; but is longsuffering to us-ward, not willing that any should perish, but that all should come to repentance.
Hebrews 11:6
6 But without faith it is impossible to please him: for he that cometh to God must believe that he is, and that he is a rewarder of them that diligently seek him.
Jesus
@EllipsisAircraft Actually Boeing and MD have had many design faults that were ignored and resulted in lost lives over the decades. What has happened in the last couple of years is nothing new. Watch some air crash videos and you will see a history of wrong parts and design being ignored for profit.
I was hoping to see the plane moving around on the taxiway... guess we'll just have to keep watching for further updates. :)
Me too! That's what I refer to as ground testing. Apparently, definitions can vary.
DarkAero looks like it might be a great application for "pull up" style lap belts on the harness. Pulling up toward the center allows you to get the belt tighter in a constrained space. Pulling down toward the left wall/armrest might be a pain!
Speaking of load testing. Since you guys have a wet wing, does the wing get load tested again with fuel to make sure it doesn't leak after an extreme load with fuel inside?
I'm going with Crow 5-point for my RV-14 project. I have Hooker 5-point in my Decathlon. Hooker is of the highest quality and I'm happy with my harnesses, but they're a bit heavy for cross-country comfort (IMHO). Press on!
I always love to watch your progress. Wish I was 20 years younger, where I could join you. But i can live my current life through you all. thanks I am rooting for you all.
My thoughts exactly. If I weren’t retired I would be learning composites in order to join their team. I may take their courses anyway!
I would assume you guys may have covered this before, but is there baffling in the wing to help slow/stop fuel slosh?
Yes! All the internal ribs and shear webs in the wings serve double duty as both structure and fuel tank baffling.
Sweet, I thought I saw them, but always better to ask the people who know! Thank you guys for doing such an instructive job, showing this whole process! @@DarkAeroInc
Did you watch this video?
Yes, but some of the channels were lit in such a way that I could not tell if they were baffles or compartments or what.
Also, DarkAero already nicely answered my question, so thanks for being needlessly aggressive.@@jayphilipwilliams
Great video guys. Thanks
Ready to buy!! Keep up the work guys!
Really looking forward to the maiden flight. Doing an incredible job. I really like this airframe. When done I would like a 3 view so I can build a scale Radio Control plane.
So cool! Any update on parachute option? Thanks!
It's like christmas when these videos come out
Excellent informative video, keep up the good work 🌟
when are you going to fly it? its been forever since you started it.
What prevents fuel being sloshed toward the wing tip in a prolonged slip?
Wait, the fuel tank extends to the tip?
Such a great story,,,hope they are super successful.
Jesus Christ is the only hope in this world no other gods will lead you to heaven
There is no security or hope with out Jesus Christ in this world come and repent of all sins today
Today is the day of salvation come to the loving savior Today repent and do not go to hell
Come to Jesus Christ today
Jesus Christ is only way to heaven
Repent and follow him today seek his heart Jesus Christ can fill the emptiness he can fill the void
Heaven and hell is real cone to the loving savior today
Today is the day of salvation tomorrow might be to late come to the loving savior today
Holy Spirit Can give you peace guidance and purpose and the Lord will
John 3:16-21
16 For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life. 17 For God sent not his Son into the world to condemn the world; but that the world through him might be saved. 18 He that believeth on him is not condemned: but he that believeth not is condemned already, because he hath not believed in the name of the only begotten Son of God. 19 And this is the condemnation, that light is come into the world, and men loved darkness rather than light, because their deeds were evil. 20 For every one that doeth evil hateth the light, neither cometh to the light, lest his deeds should be reproved. 21 But he that doeth truth cometh to the light, that his deeds may be made manifest, that they are wrought in God.
Mark 1.15
15 And saying, The time is fulfilled, and the kingdom of God is at hand: repent ye, and believe the gospel.
2 Peter 3:9
The Lord is not slack concerning his promise, as some men count slackness; but is longsuffering to us-ward, not willing that any should perish, but that all should come to repentance.
Hebrews 11:6
6 But without faith it is impossible to please him: for he that cometh to God must believe that he is, and that he is a rewarder of them that diligently seek him.
Jesus
Are your carbon fiber and resins sensitive to any alcohol in your fuel? This is a problem with the wet tanks in the Stemme Motor Glider.
Fuel full length of wing. A fully developed spin will need some rudder. Remains to be tested, I guess. Best wishes!
Best of luck on your hiring! 🙂
Great video, thanks!
G,day fellas from Sydney Australia. Fantastic progress of your plane. I should have linked the seatbelt harness design to reduce impact trauma on the human body, in other words: safety, instead of sales and marketing.
🌏🇦🇺
IVE BEEN WAITING FOR YOU GUYS TO START HIRING!
Good luck to you. All the best.
are you going to install a whole aircraft parachute?
Mechanical engineering student checking in with a question - is fatigue testing something you need to be concerned about given you are using composites? With multiple flights I imagine the wings/tanks will experience cycles of over and under pressure which could potentially lead to problems later down the road? Or are the pressures differences being experienced small enough that that kind of testing isn't necessary? Keep up the awesome work!
What a beautiful job! How has your project been financed?
Hey friends! I noticed your testing method for the anticipated hydrostatic pressure on the wing/tank. Do you plan on a full-scale loaded test on this wing at some point in the future? I am talking about a complete wing on a test stand held at an angle and torture tested with a fuel analog in place. Admittedly this is expensive and time consuming, but compared to the damage to your reputation later on it could be a good investment. What I am seeing is that you are not actually trying to find a failure mode and that is a concern.
I notice that your clearance between the aileron counterweight and wing seems tight. Have you considered that moisture could propogate into that space and freeze? Locking up the controls. Just a consideration.
Riley and Brothers May the Airplane Gods Watch Over You and Saint Michael be at your Side when you Do the Air Testing. I will always want to See the Mom and Pop shops show it still alive in America.
If I were in college I’d jump on the opportunity in a heart beat. You guys remind me of Scaled Composites back in the early 90s.
More like Lancair. 😮
Jump on what?
can't wait to see the bird flying!
It's hard to tell in the video, but are you using a "Formula-style" harness? That under-the-leg anti-sub belt routing is only valid with a belt system designed for it (Formula or Schroth Hybrid), and should not be used with a standard 6-point system. Crow does make a Formula restraint.
I'm not sure what the reasoning is for the different linkage, but would tend to trust the engineers that developed them given the amount of research and testing that goes into these restraints.
Very exciting to see the progress!
I’m happy yet surprised that there are still opportunities in this country to make things.
Been playing MS FS '24 again and would love to see the Dark Aero 1 as a plane option to fly in it!
What are the anticipated performance numbers? Cruise, range. Thanks!
If there is a narrow direct link between the left and right tanks with the tanks at ~1/2 full, if the plane banks left all the fuel will flow to the left wing, then if the plane was to suddenly flip to banking right, all the fuel will flow to the right tank, but I hope they have something that allows air from right to left to swap or they might create a sudden strong vacume in the tank losing fule. You can see that effect on 2L coke bottels if you empty them without doing the swirl thing.
It all looks pretty cool.. will you put some of the matrix samples from the composite in fuel, just as extra observation on long term wet wing effects?
let's GO! (great work guys)
Beautiful, elegant design. Love your vids explaining your design and engineering choices. Judging based on some superficial experience with composite aircraft structures, it certainly looks like your wing is plenty strong. One question: In case of damage, like say a 6 inch dent or gouge in leading edge, how repairable will this wing be? I can think of one composite plane where all the loads in the outer 75% of the wing are carried almost entirely by the skins. It’s a strong wing, but pretty much unrepairable if damaged.
How do you solve the problem of changing the center of gravity of the Dark Arrow? When the landing gear is retracted, the center of gravity shifts backwards. I have a feeling that cleaning the landing gear after takeoff is impossible.
Excellent work men! Let's do 300kts!
That ain't happening 😂
Math says, given a 220hp turbo in the low FL's. Yes, it probably could.😮
Love you guys! It’s awesome to see you all dedicated to this build. Your ethos is thorough and comprehensive.Putting all the newest tech ides and out of the box theology together, to produce the ultimate machine! In all aspects of flight!!
I wish you all the very best of good will and success in your excellent project!!❤❤❤
have this fun little idea of building something that looks more like a motorized hang glider boat, but with a blended wing mounted over instead,
wing would be tapering until it switches over to be glider wings (horizontal W shape) with a second set of wings angled from the pontoons at the low side of W, going forward to the nose, keeping it stable. (and it's a nice way to get inside from boat.)
this fools the law on what is seen as a plane in my country, if the machines total wingspan is 16m, you can fly 24m over the water (wingspan x 1.5)
some gliders have 30m wingspan, if you then ad on the 4m blended mid wing, you'll be able to fly 51m over the ground legally (without any license)
I know it's probably un-necessary for aviation, but have you considered a headrest for the seat? Seeing necks whip back on crash test footage without them always makes me cringe. (Granted if you ever crashed the DA1 you're probably going to need more than a headrest lol)
Eagerly awaiting the first flight
I wish I had my degree already I would love to work with these ladies and gentlemen
I thought (and was taught) the belt was there to keep you in your seat in case of turbulence but preventing injuries in case of a crash and since you *are* the crumple zone...
Do you have concrete evidence 6 point harnesses save lives on experimental aircrafts?
How many experimental aircraft offer a full carbon fiber tub? Compare this closer to a Formula-Ford. Reclined seats require the extra anti-submarine strap of a 6pt harness, for redundancy, and ability to locate pressure points on both sides of... centerline.
@@EllipsisAircraft Many ultralights do.
But the point of carbon fibre is not to strengthen the cell but to reduce its weight.
When can we purchase one?
Wwould appreciate if made in an option on your website to see the specs in Metrics :) (Or better way, a hybrid that aviation actually uses.. Nm, Kg and Meters... :) ) Looks like a beutiful litle airplane
Very impressive! Do you have any intention of a head and neck, helmet and Hans device, restraint system?
Nobody is wearing a helmet in this style of airplane.
@@galactictomato1434actually they have mentioned it in a q&a for paying subscribers and they said that there should be enough space for a helmet.
@@Thomipangang interesting
How does the fuel effect the epoxy that’s bonding the wing together?
You guys should look into making turbo-aero turbine engines an option. From what I can tell you two will be coming out with a finished product around the same time. I think they are planning to have 100-350 hp turbine engines. I think they will weigh less than 300lbs. Would be a nice option to have on the table at least.
Turbines are certainly the answer for appropriate applications but they really don't work very well for small aircraft. This is mainly because the fuel burn is so high. Turbines are most efficient up high and climbing high takes time and fuel. A small plane simply can't carry enough fuel.
Can not wait to buy one.
I have a safety design that I think would be beneficial in providing more safety for the pilot as well. I’d love the opportunity to talk sometime!
GREAT video!
This has to be the most thoroughly design kit plane ever created.
Testing for hydrostatic pressure is interesting but how much increase in pressure would you anticipate?
Wait a second? You're going to be having fuel, in the wing? Not in tanks? Are the composites safe for that?
Another weight saving possibility is making an engine out of carbon fiber 😅 rotor engine (like in RX-8) to be exact 😎
Very cool project 👍
209 videos to get to ground test,we’ll done ❤
Radio silence from you guys for a long time now. Are there problems with the plane, problems with the team, or just busy with last minute details?
It looks fast. Excited to see some flight testing😁 I observed that the outer end of the ailerons, specifically the tip, rotates and protrudes in the opposite direction of the control surface. Is there a specific reason for choosing this design over keeping the outer end of the wing passive and operating the aileron independently?
What is that a new way of Flaps design I have seen it in Aero 2024 video
a modern velocity canar would be a blast
please make a pusher version.
Great work
When will it fly?
I want one so bad already
Is it possible to make these structures too stiff? I've always been curious about this. In cars, at least, the goal is to make the crash structures purposely less stiff and stable and therefore easier to break away from the main safety cell, but planes are different - I don't think there's a single part of a plane that would purposely be made purposely less stiff than the others. If anything, I'd assume that you'd want places like the wing-fuselage attachment areas to be EXTRA stiff (assuming weight isn't a factor). Is weight really the biggest challenge to increasing stiffness?
If a structure is too stiff it will crack. Some flex is needed to make the structure resilient. If you watch a 747 take off the wings flex upward at the tips several feet as they take the load.
@@davidr8309 I understand that. I also understand that a significant part OF that flex is a byproduct of the sheer weight of the wings themselves in addition to the compliance that's built into such a large structure simply because of mechanical tolerances. Resiliency, flexibility, and stiffness are not mutually exclusive in my opinion - you don't need isomorphic properties in all places all the time. My question is whether the stiffer properties of carbon fiber can be used to create structures SO stiff that they actually become a hindrance. Carbon fiber doesn't crack like aluminum will, and you can overbuild it to the point where it's so strong that the stiffness is just a happy byproduct.
No headrest/head restraint?
Really interesting wing. I am wondering how did you solve the problem of unporting in unusual attitude such as slips or even normal attitude changes like approach and climb?
Both wing tanks gravity feed into a central sump tank which is where the fuel pump pickup is located. Check valves between the sump tank and wing tanks allow fuel to flow into the sump but restrict the flow of fuel back into the wing tanks. This arrangement keeps the pickup from unporting. The fuel system architecture is covered in more detail in this video:
th-cam.com/video/kVOEJPPR60U/w-d-xo.html