I would love to see Mike Patey and Sandy Munro do a visit to your shop, you've done a great job so far designing and building this airframe, would love to hear about challenges overcome to reach this point
LOL Mike Patey would fourfold the weight of the plane with lot of hard to produce expensive gadget parts and compensate it with a brutal power engine. The concept of the Guys of DarkAero is total different and resembles more the sophisticated high tech engineering of German Glider companies.
Batteries and electric motor up front might nicely fix your issues, but obviously fail on your distance requirements. Interesting to see how some of your early design challenges are now creating issues and opportunities… I guess this is the world of prototyping and your version 2 will be interesting to see how you change to fix the issues.
@@Captndarty 🤣 at least I have the excuse English is not my mother tongue, which is weak because I now see it should have been 'was designed by' On the other hand Mike has always those strange ideas in his mind that sometimes Im sure a plane did design Mike. He is all over a plane
Two things worth noting. Not sure on this engine, however the vernatherm does not open until 180 degs on a Lycoming, thereby allowing oil to flow thru the cooler, so wouldn’t expect much heat for the cabin before then. Also, I fly an experimental with little room to spare behind the engine. It is a royal pain to work on it.
The UL Power engines put more heat into the oil system compared to Lycomings, so the oil cooler should be a stable source of cabin heat in our setup. We also fully built up the exhaust system heat exchanger, so we can swap to this if we don’t get the results we want out of the oil cooler cabin heat. Tight packaging does make access more tricky, but we did try to maintain acceptable serviceability in our installation. Thank you for checking out the video!
I had the same thought, but more specifically about the long taxi days here in Canada... Brr! The oil takes a long time to heat up. Exhaust is warm almost immediately. Exciting project! Slippery little planes are so cool.
I own an RV, my concern on the power to weight would be what the ride is going to be like in any kind of turbulence. Not that airplane will structureally fail but the ride could be in incredibly violet. Hitting turbulence at 200mph is not fun in a light plane. I would live in fear of clear air turbulence and would be in constant vigilance of getting near jet traffic paths. Mountain flying is also brutal flying the the wake behind 10K peaks in the northwest, you definitely want to fly high and smooth. Friends had some very negative experiences with clear air turbulence. Your plane looks to lighter than my RV with 50% more speed. As soon as I feel bumps I slow way the heck down. My biggest concern is that my head will hit the canopy and I will be incapacitated, make sure those straps are tight!
Can you put a parachute in the plane? I’m with the japonesa está high IQ group and we are following you and haven’t heard if there will be a parachute in it.
I'm new to small aircraft and come from cars, but a 5.2 liter engine only putting out 200HP seems like a late 80's Corvette engine when modern v-6's have upwards of 600HP. It seems there should be a setup with your 200hp but in a 2 liter size these days.
It’s all about the RPM, engines produce a best power around 5-6k, but the prop loses efficiency after 2500rpm, so it’s a trade off. You end up with a big engine turning a direct drive prop, and not making much power for its size. Rotax is a popular engine for smaller applications which is geared, so small displacement producing decent power, and a nice slow prop..
How much new design and fabrication work would be needed to fit a UL520t into a DarkAero 1.1? Or is the packaging so tight that you won’t even consider that?
The turbo sits aft of the engine on the 520T and the exhaust tube is aft and below. The engine would have to sit far forward to accommodate this but I suppose they could do it and adjust the CG aft with other means such as reinforcement to the airframe for the added speed. They would also need a space for an intercooler.
I think the UL520iT would not give them an increase in airspeed but is designed rather increase rate of climb and power at altitude which could result in faster ground speed and possibly better net fuel economy. It’s dimensions are surprisingly similar, larger in the X & Z axis by cm’s in only, so it would require a new flaring and a rework of the engine bay intake and exhaust plumbing. Some of the future planned versions of the UL5xx will include some substantial hp boosts with or without the Turbo. Those might be better suited for an DarkAero 2 with 4 seats. We can only dream. Of course now we are talking timelines of Turbine Aeronautics Group’s TA200TP, which if comes to market might make make the UL520iT moot as it would be both smaller and lighter than even the current UL520iS.
Awesome .... thanks for the update. We could see where the air was coming into the front, but not the exit. I imagine it must be out the bottom, ahead of the landing gear doors, and ahead of the forward luggage bay? We can hardly wait for the test flights to begin.
Guys, I'm bingeing your channel now. I recently came across your channel thanks to the YT algorithms and in the first 5 minutes you earned a subscription. You guys are living my dream.
Hello there, and nice job you guys are doing! I've been watching your channel for quite sometime now... In the future, when the prototype gets ready, will you consider selling the kits with other engine options? Maybe like the PBS TP100? That would be awesome, huh?
Really terrific work, gents! One question: What was that (very nicely) welded -up sump cover which I saw being offered up to the existing sump? Many thanks!
I wondered about the rules regarding heating cabin air with an oil cooler. I dont fly so have no idea. But if the oil cooler leaks, you have very messy air coming into the cabin! Could even block the windscreen! The odds are low though.
"Did we reach the limit?" That depends on which limit is referred to, limit of the airframe, or limit of ability, or limit of current technology. I'm in no position to make a valid opinion. 😉
Any chance the clean stall speed will be at or below 54 KCAS? That would make this plane a light sport per the newly announced MOSAIC rules. Awesome design and great video!
a lot of precious space is "wasted" by the nose gear. Conventional gear aircraft can free up that space for larger-volume mufflers and intake ducting for coolers.
What do the stress levels in the motor mount do when the engine shakes, since the firewall is closer to the engine? It seems they would go up because they are shorter.
Not sure about cabin heat coming thru oil cooler. You need cabin heat the most when air temps are very low, and vernatherm may not be open to send hot oil to the cooler.
So you built a plane around an obscure engine? How many A&P’s do you know across the country that can or know this engine? Also, where do you get parts for this? Aircraft Spruce has nothing and a cursory search also lead to few results.
This is an experimental plane... The whole idea is to explore the limits of the possible. ULpower have been around for quite a long time now so the manufacturer-related risk is small. This engine has a much better power to weight ratio than a lycosaur and is obviously very well designed in terms of accessibility and maintenance. In my opinion it retains all of the qualities of a Lycosaur (there are many) while bringing a welcome improvement in the areas where legacy engines are suboptimal. Look at the baffling system for example. Darkaero designed an amazing firewall forward package - I think this is the state of the art for an air cooled flat six powerplant. Hat off.
In Europe(I guess Italy) they make the ultrafast two seat aircraft called Risen. Please note, with 100hp Rotax they guarantee the top speed at sea level 320km/h (173knots) and with turbocharged Rotax 915 -142hp they guarantee maximum cruising speed at 16 thousands feet 450km/h !!! (243 knots ) !!! Will Dark Aero be able to achieve the same velocity with much stronger engine ??? Risen has got the ultimate aerodinamics IMHO. Extreemly efficient and it is all carbon fiber too. What I like about Risen compare to Dark Aero, that Risen is not using any metal(aluminum) honeycomb, but rather materials which can never ever rust.... On the other hand what I like about Dark Aero is the gear(looks strong) and the 2 baggage compartments.
The other alternative is a heat muff on the exhaust. Which has the potential to introduce carbon monoxide into the cabin if the exhaust cracks or leaks.
Hello. I believe you might have your oil sump on backwards? I’d recommend (in my humble opinion), that you consider creating a bit more space between the gear and the sump. It would be easy to modify the oil pan, so that more of the 4 litres of oil volume could sit up front, for a larger gap gear/ sump spacing. Also, you may wish to wrap your headers and exhaust in heat resist material for a couple reasons: 1. Assist in reducing idle / taxi temp firewall-forward. 2. Subtle vibration and noise attenuation. Lastly, why is the aluminium shroud butted up to the front cylinder head fins? I am thinking you did that to reduce temperature deformation of the jugs? If so, then UL should redesign the two front cylinders without cooling fins, and save a few grams weight, and reduce potential for expansion/contraction variances in the head. Please know, I am only providing my opinion in respect to your Company. 👍
I want to take that composite making course and then work for you guys mass producing this plane! I have an idea for masking a faster higher plane with a turbo prop ducted fan four seater jet. For that low speed stall as well as low drag at high speed, you may be surprised to know you can make leading edge control surfaces, even though they sound like fancy military grade aerodynamics for an F-22, they are up to you to decide how expensive the feature really is because you can make them in house. Talking about future goals, even on the DarkAero 1, perhaps a jet powered variant, even duel engine perhaps would be quite good for the high end versions. I considered placing wing mounted turbo props for rc planes on a glider. Gliders have a very long wing span though, so the range would be huge with small engines. I recently found a German supplier that makes 330lbs thrust jet engines for commercial or military UAVs and the over all size was only about 30cm diameter by 70cm length, exhaust temp was only 360 C so I mean, with a shaft driven bypass fan the efficiency would go through the roof! Imagine a van for you and your budds, but it's kind of a 747 in the speed and altitude!
Do you have any concerns over the internal failures UL has suffered with their engines like piston slap and crank failures? I really like the idea of UL power but there doesn’t seem to be much transparency in these issues or plans to correct them.
Would there be any benefit to wrapping those exhaust headers with some kind of insulating header wrapping weave? ... I imagine those headers get crazy hot and there's lots of other stuff in close proximity
If you want to practice maintenance on a tight cowling space, I suggest a Mooney. Seriously , please keep maintenance in mind like oil filter change and oil screen accessible
Great question! One of the main reasons we decided against mounting the battery in the back of the airplane is weight. A run of heavy 2 gauge wire would be required to connect the battery to the engine compartment. The total wire length would be about 20-25ft for the two battery leads if the battery was located behind the cabin. Mil-spec 2 gauge wire is around 100 grams per foot, which translates into about 5 pounds of wire! This is heavier than the battery itself!
A well designed cooling system will make great use of small inlets by efficiently generating the pressure delta across the cylinders. If internal losses are minimized (as is the case here)... it's the outlet baby. In other words: they can always "tropicalize" it by increasing the outlet side or creating additional depression at the outlet. So no I would not consider this a deal breaker 🙂. Darkaero are really, really smart!
Been looking at the Risen 915. Seems to me by comparison to the Dark Aero that it is a better performer all round. Are we reinventing the wheel here or is the price point going to be significantly better I wonder.
I wonder what will be the strategy to warm the battery in case you will have the cold ambient temperature. The hot air from the oil heat exchanger could be used as well. In that case looks like oil exchanger and battery could be mounted closer together so that with one actuator you can control hot/cold air mixture to keep the battery at the right temperature.
From my experience the battery no longer has to be warmed once the airplane is flying ->the airplane’s electrical system runs entirely from the alternator/generator. The battery usually has to be (should be), warmed on the ground for starting operations at extreme cold temperature. It looks like they’re running a NiCad which has some drawbacks but is inherently lighter and more compact than lead acid. I personally prefer lead acid due to experience, and the airplanes I’ve flown with NiCad batteries were all converted to lead acid. From an IFR perspective unless this aircraft has a backup alternator/generator, it may not be suitable for regular IFR flying IMHO. To be honest though it doesn’t have an airframe deicing system, so you probably wouldn’t go flying through clouds at 10,000ft anyway. It’s an interesting design and I’m keeping my eye on it! Edit: I forgot to mention the batter being located in the cowling is being passively heated by the engine at cruise speed. I’m sure it’s quite warm in there. By rights if it’s a NiCad, there should be a temp gauge for the battery to warn of thermal runaway
@@drewski5730 I agree that for the aircraft operation perspective battery can be off completely, but temperatures lower than 0C is not suitable for charge and lower than -20C is not suitable for discharge applications. Batteries usually acts like a buffer and/or conductors in electrical circuits, meaning they are filling the gaps and drops of the "flow". And I still would consider having hot/cold air actuated to the battery.
@@coredeveloper they seem to charge fine below 0 degrees 🤷♂️ The voltage doesn’t seem to change 🤷♂️ I’ve done plenty of NiCad and lead acid starts below -40C in the Arctic. It’s terrible for the battery, but it does work, it charges fine afterwards, and still lasts a decent amount of time (although I’m sure it’s lifespan gets degraded sufficiently by doing this). I’ve never seen an airplane that used a battery warmer of any kind for anything but start up.
@@alexanderarnett4966 if true, that’s a compromise that will likely limit where this airplane can be sold. Lithium batteries just don’t work for starting at winter temps in Canada, Alaska, the Midwest, and many parts of Europe. This is why along with safety that Lead acid is preferred in most northern commercial air services. Lithium and NiCad batteries are also subject to fire and explosion hazards that lead acid batteries are not.
Turbines don't scale linearly, efficiency drops with decreasing size. Blade to housing clearance is a function of bearing clearances which are based on oil fluid dynamics. This blade to housing clearance represents a much greater leakage path for the smaller engine based on total mass flow. Larger turboprop engines can rival radial engines with power recovery turbine efficiency.
@@keithjurena9319Good point but a centrifugal jet engine doesn’t have that problem. Like the Garrett Tpe but it’s still a big engine and the exhaust side is axial.
@@willjohnson3907 Centrifugal still have impeller to housing clearance issues. The key to high efficiency is pressure ratio and smaller turbines are 6:1 to 8:1. Large turbines are 10+
The firewall heat shield is rated for 2000F. We tested it to meet FAR 23.1191 and made a video about the testing here: ruclips.net/video/R25bl-EgW1k/видео.html
It looks like you did develop an augmentor exhaust system. Possibly wjth adjuztable outlets? That makes me soooo happy. For me, it makes the entire project just that much nicer.
turbo = more power = more cooling, more drag, more engine and structural weight, more complexity and failures, less flying... This plane is not pressurized and IMO its sweet spot will be 9-10 K feet. I'd rather lose a couple of knots than drag along O2 and fly with canulas... PS : this is from a turbocharged and pressurized aircraft owner/pilot.
It will be interesting to see if the oil cooler air exhaust will be adequate, or if the cooler needs to be moved forward a bit so the air can more easily exit.
@@DarkAeroInc It looks like you kept the section of the feeder duct to the oil radiator constant ? Was it not possible to implement slow expansion to increase pressure recovery and reduce internal drag? For example by molding a channel into the lower cowl?
I would love to see Mike Patey and Sandy Munro do a visit to your shop, you've done a great job so far designing and building this airframe, would love to hear about challenges overcome to reach this point
LOL Mike Patey would fourfold the weight of the plane with lot of hard to produce expensive gadget parts and compensate it with a brutal power engine. The concept of the Guys of DarkAero is total different and resembles more the sophisticated high tech engineering of German Glider companies.
@@Captndarty Which plane designed Mike from scratch with the mission of these guys? you cant compare them. Both have an other not comparable mission
Yep Sandy would be a great visit
Batteries and electric motor up front might nicely fix your issues, but obviously fail on your distance requirements.
Interesting to see how some of your early design challenges are now creating issues and opportunities… I guess this is the world of prototyping and your version 2 will be interesting to see how you change to fix the issues.
@@Captndarty 🤣 at least I have the excuse English is not my mother tongue, which is weak because I now see it should have been 'was designed by'
On the other hand Mike has always those strange ideas in his mind that sometimes Im sure a plane did design Mike. He is all over a plane
The front end has such a nice clean layout. I feel like that space is going to be really nice for inspection and maintenance.
Two things worth noting. Not sure on this engine, however the vernatherm does not open until 180 degs on a Lycoming, thereby allowing oil to flow thru the cooler, so wouldn’t expect much heat for the cabin before then. Also, I fly an experimental with little room to spare behind the engine. It is a royal pain to work on it.
The UL Power engines put more heat into the oil system compared to Lycomings, so the oil cooler should be a stable source of cabin heat in our setup. We also fully built up the exhaust system heat exchanger, so we can swap to this if we don’t get the results we want out of the oil cooler cabin heat. Tight packaging does make access more tricky, but we did try to maintain acceptable serviceability in our installation. Thank you for checking out the video!
I had the same thought, but more specifically about the long taxi days here in Canada... Brr! The oil takes a long time to heat up. Exhaust is warm almost immediately.
Exciting project! Slippery little planes are so cool.
I own an RV, my concern on the power to weight would be what the ride is going to be like in any kind of turbulence. Not that airplane will structureally fail but the ride could be in incredibly violet. Hitting turbulence at 200mph is not fun in a light plane. I would live in fear of clear air turbulence and would be in constant vigilance of getting near jet traffic paths. Mountain flying is also brutal flying the the wake behind 10K peaks in the northwest, you definitely want to fly high and smooth. Friends had some very negative experiences with clear air turbulence. Your plane looks to lighter than my RV with 50% more speed. As soon as I feel bumps I slow way the heck down. My biggest concern is that my head will hit the canopy and I will be incapacitated, make sure those straps are tight!
that engine setup is a mechanic s dream, so clean and accessible
Can you put a parachute in the plane? I’m with the japonesa está high IQ group and we are following you and haven’t heard if there will be a parachute in it.
Just wish you did longer (and more frequent) videos - á la Leo from Sampson Boat Company
Step by calculated step this aircraft is maturing really nicely. Looking forward to the test flights.
Diverting the warm air from the cooler into the cabin will AT BEST be amibient temp + 50 degrees F. Not enough to warm at altitude.
Progress is looking good, guys! Keep it up, and hopefully we'll see you at OSH in a few weeks!
You guys leave no stone unturned in your journey of designing and building this masterpiece.
Thankfully 😊
Like if there’s an engine fire, you lose battery power too.
I'm new to small aircraft and come from cars, but a 5.2 liter engine only putting out 200HP seems like a late 80's Corvette engine when modern v-6's have upwards of 600HP. It seems there should be a setup with your 200hp but in a 2 liter size these days.
It’s all about the RPM, engines produce a best power around 5-6k, but the prop loses efficiency after 2500rpm, so it’s a trade off. You end up with a big engine turning a direct drive prop, and not making much power for its size. Rotax is a popular engine for smaller applications which is geared, so small displacement producing decent power, and a nice slow prop..
How much new design and fabrication work would be needed to fit a UL520t into a DarkAero 1.1? Or is the packaging so tight that you won’t even consider that?
The turbo sits aft of the engine on the 520T and the exhaust tube is aft and below. The engine would have to sit far forward to accommodate this but I suppose they could do it and adjust the CG aft with other means such as reinforcement to the airframe for the added speed. They would also need a space for an intercooler.
I think the UL520iT would not give them an increase in airspeed but is designed rather increase rate of climb and power at altitude which could result in faster ground speed and possibly better net fuel economy. It’s dimensions are surprisingly similar, larger in the X & Z axis by cm’s in only, so it would require a new flaring and a rework of the engine bay intake and exhaust plumbing.
Some of the future planned versions of the UL5xx will include some substantial hp boosts with or without the Turbo. Those might be better suited for an DarkAero 2 with 4 seats. We can only dream.
Of course now we are talking timelines of Turbine Aeronautics Group’s TA200TP, which if comes to market might make make the UL520iT moot as it would be both smaller and lighter than even the current UL520iS.
Big engine small airframe. See: Questair Venture.
Awesome .... thanks for the update. We could see where the air was coming into the front, but not the exit. I imagine it must be out the bottom, ahead of the landing gear doors, and ahead of the forward luggage bay? We can hardly wait for the test flights to begin.
That thing is gonna be so fast it'll land 20 minutes before it takes off.
Guys, I'm bingeing your channel now. I recently came across your channel thanks to the YT algorithms and in the first 5 minutes you earned a subscription. You guys are living my dream.
it's clean and compact! I like it.
Hello there, and nice job you guys are doing! I've been watching your channel for quite sometime now... In the future, when the prototype gets ready, will you consider selling the kits with other engine options? Maybe like the PBS TP100? That would be awesome, huh?
Really terrific work, gents!
One question: What was that (very nicely) welded -up sump cover which I saw being offered up to the existing sump?
Many thanks!
I’m thinking moving the firewall forward affects LEGROOM !! With a 37 inch inseam I think about this a lot!
“Perfection is the enemy of progress.” -Winston Churchill
Do you have a paper filter in-line so that when the oiler cooler leaks, hot oil cannot spray into the cabin?
I wondered about the rules regarding heating cabin air with an oil cooler. I dont fly so have no idea. But if the oil cooler leaks, you have very messy air coming into the cabin! Could even block the windscreen!
The odds are low though.
@@olliea6052:
Anything that can go wrong eventually will.
Just out of morbid curiosity: How would a 2-stroke self igniting 4-cylinder with compressor and turbo fit your loot scheme? 😏
The UL Power engine does not have a hydraulic constant speed governor. Are you going to use an electric governor or just use a fixed-pitch propeller?
"Did we reach the limit?" That depends on which limit is referred to, limit of the airframe, or limit of ability, or limit of current technology. I'm in no position to make a valid opinion. 😉
Any chance the clean stall speed will be at or below 54 KCAS? That would make this plane a light sport per the newly announced MOSAIC rules.
Awesome design and great video!
Well, it does have flaps so that could be reached, I suppose... (with no engineering knowledge, whatsoever)
Uhh, that same engine is now available turbo charged. Would that fit??
3:25 Using the oil cooler for heat has been tried before.. it doesn’t work..Mike Patey also tried it.. it’s not effective enough.
a lot of precious space is "wasted" by the nose gear. Conventional gear aircraft can free up that space for larger-volume mufflers and intake ducting for coolers.
I imagine the forward baggage hold reduces cabin noise quite a bit too eh??
Googled UL motor because I didn't know we had a Belgian engine manufacturer and apparently they're just 4km away from me...🤯🤯
What do the stress levels in the motor mount do when the engine shakes, since the firewall is closer to the engine? It seems they would go up because they are shorter.
Hey my wife help design a mount for a 6cyc to small plane, just when it was a week to be done lied off ( no bonus for you)
Not sure about cabin heat coming thru oil cooler. You need cabin heat the most when air temps are very low, and vernatherm may not be open to send hot oil to the cooler.
Would you consider installing a rescue system such as GRS?
keep going guys! I am excited for first flight and the opportunity to fly and then buy one!
So you built a plane around an obscure engine? How many A&P’s do you know across the country that can or know this engine? Also, where do you get parts for this? Aircraft Spruce has nothing and a cursory search also lead to few results.
This is an experimental plane... The whole idea is to explore the limits of the possible. ULpower have been around for quite a long time now so the manufacturer-related risk is small. This engine has a much better power to weight ratio than a lycosaur and is obviously very well designed in terms of accessibility and maintenance. In my opinion it retains all of the qualities of a Lycosaur (there are many) while bringing a welcome improvement in the areas where legacy engines are suboptimal. Look at the baffling system for example. Darkaero designed an amazing firewall forward package - I think this is the state of the art for an air cooled flat six powerplant. Hat off.
I currently built a Sling TSi, when can we expect to purchase your DA? Need an project after my Sling 😍
Put your money down and get on the waiting list. No tire kickers.
Is there any worry about isolating engine vibrations from the airframe with the condensed engine mount?
The engine is pretty smooth, so not much of a worry there. We have a few videos of it in operation:
ruclips.net/video/pNqLm3U56DE/видео.html
Waiting to see this masterpieace flying 🛩️😊
Will a DeltaHawk DHK180 engine fit?
hmm thought Id see something like an aero momentum engine up here.
Are you guys bringing her to EAA airventure this year?
In Europe(I guess Italy) they make the ultrafast two seat aircraft called Risen. Please note, with 100hp Rotax they guarantee the top speed at sea level 320km/h (173knots) and with turbocharged Rotax 915 -142hp they guarantee maximum cruising speed at 16 thousands feet 450km/h !!! (243 knots ) !!! Will Dark Aero be able to achieve the same velocity with much stronger engine ??? Risen has got the ultimate aerodinamics IMHO. Extreemly efficient and it is all carbon fiber too. What I like about Risen compare to Dark Aero, that Risen is not using any metal(aluminum) honeycomb, but rather materials which can never ever rust.... On the other hand what I like about Dark Aero is the gear(looks strong) and the 2 baggage compartments.
Those cowling air inlets look might small.
Is this a direct injected and port injected engine?
Like the idea of using air from the oil cooler for interior heating, as it will prioritize the engine to warm up.
The other alternative is a heat muff on the exhaust. Which has the potential to introduce carbon monoxide into the cabin if the exhaust cracks or leaks.
Hello. I believe you might have your oil sump on backwards? I’d recommend (in my humble opinion), that you consider creating a bit more space between the gear and the sump. It would be easy to modify the oil pan, so that more of the 4 litres of oil volume could sit up front, for a larger gap gear/ sump spacing. Also, you may wish to wrap your headers and exhaust in heat resist material for a couple reasons: 1. Assist in reducing idle / taxi temp firewall-forward. 2. Subtle vibration and noise attenuation. Lastly, why is the aluminium shroud butted up to the front cylinder head fins? I am thinking you did that to reduce temperature deformation of the jugs? If so, then UL should redesign the two front cylinders without cooling fins, and save a few grams weight, and reduce potential for expansion/contraction variances in the head. Please know, I am only providing my opinion in respect to your Company. 👍
Is this aircraft actually flying yet?
I want to take that composite making course and then work for you guys mass producing this plane! I have an idea for masking a faster higher plane with a turbo prop ducted fan four seater jet. For that low speed stall as well as low drag at high speed, you may be surprised to know you can make leading edge control surfaces, even though they sound like fancy military grade aerodynamics for an F-22, they are up to you to decide how expensive the feature really is because you can make them in house. Talking about future goals, even on the DarkAero 1, perhaps a jet powered variant, even duel engine perhaps would be quite good for the high end versions. I considered placing wing mounted turbo props for rc planes on a glider. Gliders have a very long wing span though, so the range would be huge with small engines. I recently found a German supplier that makes 330lbs thrust jet engines for commercial or military UAVs and the over all size was only about 30cm diameter by 70cm length, exhaust temp was only 360 C so I mean, with a shaft driven bypass fan the efficiency would go through the roof! Imagine a van for you and your budds, but it's kind of a 747 in the speed and altitude!
Any submarine course ?
Do you guys have a time frame for certification and bringing this design to market? I've wanted something with usable speed..This is it!!!
When is the target maiden flight date ?
Is the Darkaero flying yet
Nice another day less for maiden flight, all thing firmly fixed for that day 👍
Do you have any concerns over the internal failures UL has suffered with their engines like piston slap and crank failures? I really like the idea of UL power but there doesn’t seem to be much transparency in these issues or plans to correct them.
Would there be any benefit to wrapping those exhaust headers with some kind of insulating header wrapping weave? ... I imagine those headers get crazy hot and there's lots of other stuff in close proximity
Future oceangate titanic 😂😂😂😂
Really impressive throughout. Header wrap to improve scavenging and reduce under cowl temps?
What about the 180 degree bend and under cowl air for the intake? I am installing one of these engines soon and am very curious about your results.
What limit did you reach?
Less video more test flight
If you want to practice maintenance on a tight cowling space, I suggest a Mooney. Seriously , please keep maintenance in mind like oil filter change and oil screen accessible
Great work guys. Keep on it.. Beautiful! Exciting that flying is going to happen soon!.
Amazing work all of you
👍
Really nice clean engine compartment… it may just be me, but those engine air intakes look tiny ?
😁
Dude,
You are Gems.
Keep it up and Stay Positive.
Why not put the battery in the back, aft of the cockpit?
Great question! One of the main reasons we decided against mounting the battery in the back of the airplane is weight. A run of heavy 2 gauge wire would be required to connect the battery to the engine compartment. The total wire length would be about 20-25ft for the two battery leads if the battery was located behind the cabin. Mil-spec 2 gauge wire is around 100 grams per foot, which translates into about 5 pounds of wire! This is heavier than the battery itself!
No I think the “limit” is something like a scramjet engine.
What will the glide ratio be? Fascinating work by the way.
Inspiring 👍🏼 ✨
I would love this in a Tail-Dragger! At least that would alleviate the space constrictions forward of the firewall. What a beautiful aircraft she is!
All I want to see it fly and what the performance is like. 🆒😎👍.
I live in Florida I feel like high temperatures would be a major problem during taxiing.
A well designed cooling system will make great use of small inlets by efficiently generating the pressure delta across the cylinders. If internal losses are minimized (as is the case here)... it's the outlet baby. In other words: they can always "tropicalize" it by increasing the outlet side or creating additional depression at the outlet. So no I would not consider this a deal breaker 🙂. Darkaero are really, really smart!
Can we buy it pre built when it's out?
That would require cerification (=$$$$).
Experimental classification requires the builder to complete >50% of the work.
Really nicely moving along. As always, I love seeing what you guys do and the quality is just amazing!
Been looking at the Risen 915. Seems to me by comparison to the Dark Aero that it is a better performer all round. Are we reinventing the wheel here or is the price point going to be significantly better I wonder.
Its gonna cost more. The Risen is designed as an ultralight with a 915 this has a big boy engine so it should be faster.
I hear Belgium, I upvote :D 😄
Beautiful! Exciting that flying is going to happen soon!
So... "Did you reach the limit" ???
I wonder what will be the strategy to warm the battery in case you will have the cold ambient temperature. The hot air from the oil heat exchanger could be used as well. In that case looks like oil exchanger and battery could be mounted closer together so that with one actuator you can control hot/cold air mixture to keep the battery at the right temperature.
From my experience the battery no longer has to be warmed once the airplane is flying ->the airplane’s electrical system runs entirely from the alternator/generator. The battery usually has to be (should be), warmed on the ground for starting operations at extreme cold temperature. It looks like they’re running a NiCad which has some drawbacks but is inherently lighter and more compact than lead acid. I personally prefer lead acid due to experience, and the airplanes I’ve flown with NiCad batteries were all converted to lead acid. From an IFR perspective unless this aircraft has a backup alternator/generator, it may not be suitable for regular IFR flying IMHO. To be honest though it doesn’t have an airframe deicing system, so you probably wouldn’t go flying through clouds at 10,000ft anyway.
It’s an interesting design and I’m keeping my eye on it!
Edit: I forgot to mention the batter being located in the cowling is being passively heated by the engine at cruise speed. I’m sure it’s quite warm in there. By rights if it’s a NiCad, there should be a temp gauge for the battery to warn of thermal runaway
@@drewski5730 I agree that for the aircraft operation perspective battery can be off completely, but temperatures lower than 0C is not suitable for charge and lower than -20C is not suitable for discharge applications. Batteries usually acts like a buffer and/or conductors in electrical circuits, meaning they are filling the gaps and drops of the "flow". And I still would consider having hot/cold air actuated to the battery.
@@coredeveloper they seem to charge fine below 0 degrees 🤷♂️
The voltage doesn’t seem to change 🤷♂️
I’ve done plenty of NiCad and lead acid starts below -40C in the Arctic. It’s terrible for the battery, but it does work, it charges fine afterwards, and still lasts a decent amount of time (although I’m sure it’s lifespan gets degraded sufficiently by doing this).
I’ve never seen an airplane that used a battery warmer of any kind for anything but start up.
I believe they went with Lithium not the older NiCad battery.
@@alexanderarnett4966 if true, that’s a compromise that will likely limit where this airplane can be sold. Lithium batteries just don’t work for starting at winter temps in Canada, Alaska, the Midwest, and many parts of Europe. This is why along with safety that Lead acid is preferred in most northern commercial air services. Lithium and NiCad batteries are also subject to fire and explosion hazards that lead acid batteries are not.
I feel like it's going to be hard to afford one of these beauties
Do you use shock mounts on your engine mounting points?
Yes! There are four rubber bushings between the engine and the engine mount that reduce the vibration transferred to airframe.
Wonderful. Imaginative solutions.
Turb Aero made a 200 hp turbine engine, combining the turb aero with the dark aero would be a deadly combination.
Aren't small turbine engines very impractical for fuel consumption? Where turbines shine is when they get really big, greater than 500 hp range.
Turbines don't scale linearly, efficiency drops with decreasing size. Blade to housing clearance is a function of bearing clearances which are based on oil fluid dynamics. This blade to housing clearance represents a much greater leakage path for the smaller engine based on total mass flow.
Larger turboprop engines can rival radial engines with power recovery turbine efficiency.
@@keithjurena9319Good point but a centrifugal jet engine doesn’t have that problem. Like the Garrett Tpe but it’s still a big engine and the exhaust side is axial.
@@willjohnson3907
Centrifugal still have impeller to housing clearance issues. The key to high efficiency is pressure ratio and smaller turbines are 6:1 to 8:1. Large turbines are 10+
What temps is that firewall rated for? And how long can it last in the case of a fire in the engine bay?
The firewall heat shield is rated for 2000F. We tested it to meet FAR 23.1191 and made a video about the testing here: ruclips.net/video/R25bl-EgW1k/видео.html
@@DarkAeroInc Oh wow, thanks for sharing the video that wasn't on my radar! :)
They made a Kool video of the solid engineering on the firewall. These guys are the right type for building aircraft
Excellent stuff bro
will you have a booth at Oshkosh?
It looks like you did develop an augmentor exhaust system. Possibly wjth adjuztable outlets? That makes me soooo happy. For me, it makes the entire project just that much nicer.
Great work guys. Keep on it.
Lovely work!
Well thought out.
Can’t wait till y’all put the turbo UL on there and get insane TAS up high
turbo = more power = more cooling, more drag, more engine and structural weight, more complexity and failures, less flying... This plane is not pressurized and IMO its sweet spot will be 9-10 K feet. I'd rather lose a couple of knots than drag along O2 and fly with canulas... PS : this is from a turbocharged and pressurized aircraft owner/pilot.
Race ready!
SWEET 😍
Done very well!
It will be interesting to see if the oil cooler air exhaust will be adequate, or if the cooler needs to be moved forward a bit so the air can more easily exit.
It’s not shown in this video, but there is a large gap between the cooler and the firewall to keep the exit unrestricted.
@@DarkAeroInc It looks like you kept the section of the feeder duct to the oil radiator constant ? Was it not possible to implement slow expansion to increase pressure recovery and reduce internal drag? For example by molding a channel into the lower cowl?