This is probably the first system in this airplane that I'm not enthralled with. So much complexity, so many things that all have to work perfectly. I've experienced gear problems before, when you're flying and trying to figure out why your gear is not showing down/locked, you want the simplest system possible, with the smallest number of failure modes, that can be easily overridden and manually actuated. A complex logic sequencing system run over CANBus with many potential points of failure does not instill me with confidence. Those small extend and retract latches, with beautiful tight clearances and tolerances that work so perfectly in your tests - what happens when those are contaminated with grease, or dirt, or bugs, or ice? What happens one of the motor sensors fails or mis-reads, and the logic controller drives the motor to extension at full speed? What happens if any of the logic controllers freezes or fails? What happens if any of the wires going to any of the gear gets pinched, shorted, broken? The answer is: gear-up landing, or worse (partial extension landing). In virtually every retractable aircraft I've flown, the default state of the gear is to be down and locked. That means that in most any failure mode, by design, the gear ends up down and locked. The system operates to keep the gear up, and if something fails, the gear comes down. I don't see this functionality in your design: I see multiple different failure modes in your design that result with the gear up and locked with no way of manually overriding it. You also state that the motor load on extraction is 100 watts - that's fine, but what about when it's extending the gear against relative wind in flight? Lastly, if your "gear up and locked" indication is LEDs off, then you need a "push to test" button next to them to illuminate the LEDs and ensure that they are operational, to rule out a failed LED giving a false indication of retracted gear.
Didn’t they show a purely mechanical cable-actuated fall-back solution which lets the gear drop through gravity (edit: and gas springs) in earlier videos? But I don’t know how that’s going to disengage the motors in a reliable way or make sure the latches lock in the down position.
It seems complex but these systems can be incredibly reliable. Steer by wire is coming to cars sold in the US (eg Lexus RZ450e) in which there is no mechanical link between the steering wheel and the front wheels. These systems are also extremely testable and able to provide lots of instrumented feedback at relatively low cost. Given they have a redundant system for emergency deployment, this is probably quite a bit more reliable (if engineered correctly) than it would appear at first sight.
I don't disagree. the controls are interesting, but I want manual overrides. I want fail-down features. Too many light aircraft experience gear failures.
@@mavigogun literally is a one off.. You just don't see the religious parents with millions of dollars backing this. You notice how crystal clean the work/hangers are? The large metal parts are outsourced. I would like to be proven wrong but after 5 years they are still developing landing gear? Like I said before I wish them all the best but this won't work as a business. Who will buy this "kit"?
Dear DarkAero crew - Green and Red can still confuse a pilot as to up and down, since those colors are port and starboard. And no light means not working or broken. Please use lighted icon symbols indicating Down/Locked or Up/Locked. Thank you. .
many aircraft have the green and red lights for landing gear and it's no issue. There's no common light inside the cockpit I can think of that relies on green and red to indicate port and starboard, those are only the position lights on the wingtips. Icons are fine, but they need to be very easily recognizable at a glance.
Almost every aircraft on the planet has green and red gear indication lights. The only place you see green and red lights indicating port and starboard in aviation is on the navigation lights on the exterior of the aircraft.
How do you replicate the demand on the landing gear that you'd incur in flight? Will you do wind tunnel testing? What about the icing and humidity challenges that mid level and higher altitudes pose?
In general I don't like having the "LED-OFF" state as being the indication is a valid system state. It doesn't allow for the possibility of a malfunction. I think it would be better to have a different color for each position -- 1) up and locked, 2) down and locked, and 3) in-between. With your current system you don't reliably know if a gear is up, or there is a malfunction somewhere. Yes, with LEDs having practically unlimited life, there's little danger of burning one out. However, with your existing indicator system you won't know if the gear is up, or you have a bad LED, or a broken wire, or a bad switch, etc, in your indicator circuitry. You're obviously using Red/Green bi-color LEDs. Why not use Yellow (both on) to indicate one of the states? That might let you get away without any rewiring. Though Red/Green/Blue LEDs would probably look more polished, since Yellow is often an indication of caution. Like you said, "Make your landing gear smarter!" :)) Just my 2-bits...
Not a pilot or engineer, but doesn't preflight checklist cover checking all instruments? I assume the LED's would go through their sequence when starting up (like in a car dashboard). Additionally, if the lights are constantly on while the gears are retracted it'll be super distracting, especially when flying at night. I like their implementation because I'm sure you'd feel/hear the drag if the wheels aren't fully retracted (equivalent to the LED being out as you've mentioned). It's not just the LED that has to malfunction, but also the system. All this is to say that I like their approach; there are indications of what's happening when it's needed, without distractions when not needed.
As someone who specialized on landing gear and flight controls for over a decade, I agree that an off led gives to little information. Maybe look into: Green=down Alternating G/R=gear in transition Red=up LED's are reliable, but not infallible.
@@brois841 Just thinking aloud here, a pre-flight check wouldn't indicate an in-flight system failure. I think the 3-color, never-off concept makes good sense.
@@s14slide I'm definitely not experienced in aircraft, but I really like the idea of a flashing LED indicating movement between valid states. Great idea, and also only changes the software. No additional hardware/wiring required.
As you work through the design, consider ice. Any number of planes have taken off from wet runways and had the water freeze the gear in the up position as the plane climbed to colder conditions. Just something to consider.
The gearbox assembly appears to be sealed, so it's unlikely icing would affect that part of it. The linkages look like they might have the potential to be exposed to some icing, but given how it looks like the linkages nest and articulate, as long as they design it with enough torque, I'd think it could probably break through ice fairly easily (at least on extension if nothing else, retraction might be more problematic in icy conditions). Still, definitely something worth testing.
"Any number of planes have taken off from wet runways and had the water freeze the gear in the up position as the plane climbed to colder conditions." Source?
I want to see the speed of retraction a little faster because this plane is going to accelerate so quickly, it needs to get the gear up out of the wind forces into the wheel wells very quickly. Let’s also see the gear extending with simulated “wind loads” against them, I’m not convinced those little motors can overcome wind stresses over hundred mph, manual emergency extension under wind loads also. Then I’ll be impressed.
For such a small aircraft, a simple pneumatic system is good enough. I think your electric system is too complicated and heavy compared to the pneumatic. What is about free fall system?
what about aerodynamic forces when in flight and extending the gear, would you test that at some point (I see you're adding gas struts which would make sense to aid against air flow over the gear, would be interesting to see what the power draw is in a simulated in flight extension).
They've already addressed this 100 times. The gas struts are enough to fully extend the landing gear with no motors. That means the power draw when extending gear in flight will be ~nothing.
Any concerns with having radar interfere with the CAN bus? Some cars had to implement extra things for wake-up control due to car batteries going flat at airport parking…
How do you plan for the increased wattage / power requirement to overcome drag when in use real world? Ie. do you know roughly what the additional power requirement would be? Very cool video, thanks for sharing.
Automotive electrical engineer here w/ experience w/ CAN based networks. Love the innovation. Not to be negative Ned here but I'd highly recommend a DFMEA before first flight. What happens if an ESD event takes out your CAN bus? Its not all that unusual in the automotive realm. May want some type of redundancy here. Sorry to throw a dart, just want to make sure your bases are covered.
The light bulb @6:14 is not "100 watt" by any measure. It appears to be an LED lamp, so it doesn't use 100 watts of power; no "100 watt" bulb produces 100 watts of light. I understand the use of a light bulb for the comparison, but to make any sense it has to be an old incandescent bulb that actually uses 100 watts. Since those are generally not used any more, it's not the useful example that it once was.
Why not make the gear retract system itself hold the landing gear in the retracted position? Why not copy Bonanza's gear extension gearbox idea and only have 1 motor and 1 gearbox to maintain? Also, if an electrical failure occurs, a centrally mounted gearbox behind the seat could easily be cranked down by hand like a Bonanza. I use small dc electric motors to run mechanical functions on the farm, and I have found them to be very unreliable.
Part of engineering is to create things that can manufactured at a low cost possible and keep the good traits as possible; something that these guys completely ignore. It is like watching government develop an aircraft where budget doesn't really exist. Also, with the gear leaning forward some of the worst bumps/shocks of the uneven pavement with be driven directly up into the airframe; not great.
Gear auto extend sounds very dangerous. If a pilot accidentally ends up low and slow and the plane thinks they're trying to land and puts down the gear, the extra drag could slow them down even more and cause a crash.
Huh... I would have thought a retractable system would be designed so a failure would default into a landing mode. This system does not appear to have that designed into it.
Do you guys plan on using a weight on wheels switch to prevent pilots from accidentally raising the gear on the ground? I've really enjoyed the aircraft I've flown where this is a feature and its also included an aural tone that alerts the pilot when the gear isn't down after crossing an AoA or Airspeed threshold. That way if the pilot is trying to maneuver the aircraft in a way that would appear to be landing configuration but actually isn't, the gear wouldn't auto-extend and risk being oversped when the pilot completed the maneuver and recovered.
Have you given any thoughts about designing a circuit which will allow the landing gear lights perform a flashing mode during transitioning or an unsafe condition?
How will you be simulating Air Loads on the Gear to validate reliability and function? In the automotive applications, CAN/BUS systems are not user serviceable without OBD type readers. What Service Units will be applicable to this aircraft? While Electro/Servo seems simplest, Electro/Hydraulic may be needed with air Loads. Will watch for development with interest.
I've been following this project for a couple years. I'm always blown away by the quality engineering and workmanship. Best of luck in upcoming test flights. Hope it will do everything you want it to. (It will certainly be fast!).
On the Lancairs, we have a similar gas piston for emergency deployment of our front gear. The mains will fall and lock by themselves. There is a gas pressure decline over time that results in the gas piston not having enough pressure to push the nose gear against the wind all the way until the over center links lock. If this occurs in an emergency, then there is no way around landing without the front gear being locked, and usually results in a prop strike and a scary landing. Owners are urged to routinely cause a deployment to check for this, however it is still happens way more than it should. Here, you have all 3 gear using this method, opening up the possibility of having more than one cylinder fail and not lock at the same time.
I like the idea of electric power over hydraulic retracts especially on smaller home builts. For one reason, the smaller hydraulic pumps now are almost impossible to get repaired if something goes wrong since Parker decided to condemn their use on aircraft. Also hydraulic systems can get messy at times and in general are more difficult to install compared to wires. Not sure of the eventual cost of this system electric system will be, but if they it is about the same as hydraulic, I would go with the electric, as long as it was adequately tested. And as far as testing is concerned, one thing that caught my attention was the mention of how fast the gear came down due to gravity, compared to how fast it went up. That will be the opposite during flight. The gear will take much more power to come down than it does to go up in this configuration due to drag forces. Your main gear legs have much more drag then say like the Cessna Cardinal RG main gear legs have, which have the same gear swing as your system or Lancair aircraft. There's a reason why many of these RG systems have single tube main gear as opposed to bulkier gear designs like your gear. Two reasons really, weight and air drag. More the drag, the more the power requirement. Your main gear look nice and beefy, but at least 3 times the width of single tube design such as used on a lot of home builts with hyd RG.
Did you consider pneumatic actuators? Extremely reliable, high forces, relatively small actuators, flexible hoses that are easy to route, push-to-connect fittings, off-the-shelf components, easy to add redundancy, etc.
Indicator lights off when retracted is a bit of a concern to me. There's no way to distinguish between an indication of normal retracted status and a complete lack of display functionality, since both correspond to lights off. Another colour of each indicator would provide a positive indication of system functionality. The locks are not currently installed. What happens to the indications if a gear extends or retracts all the way, but the lock doesn't engage? Are the locks monitored by position switches?
Will you require any type of ‘weight on wheels’ sensor into the logic unit to prevent any possibility of retraction when on the ground. Looking forward to seeing if the latches used in the locking mechanism require any sort of actuator. Looking really neat. Good luck from the UK
Is "off" as an indicator of closed a good safety option as there's no way to tell the difference between a light circuit malfunction and closed landing gear? I know there have been several industrial accidents stemming from the use of "off" as an indicator, so I'm surprised that it's allowed in aircraft.
What redundancy exists in the system in the event of a CAN bus, logic module, or electric motor failure? Will it be possible to manually lower the gear or release the up locks and have them lower by gravity?
Excellent questions. With the depth these lads have plummed in this design we can have confidence that they thought of this, however NONE of that is addressed in this video. They could know their audience better and that we would have these questions.
I just recently saw that a mini turboprop had received or was about to receive certification. Is that something you guys would consider on V2 or V?? Obviously they burn more fuel, but they are crazy light. Wonder if there is some sweet spot with a feather weight plane and power plant. Can't wait to see it fly. You guys are great ambassadors for engineers.
Wayyyyy too complicated. Landing gear systems need to be simple, robust and maintainable. This should be nothing more than electric motors with up and down limit switches. Logic circuits have no place in airplanes. And auto-extend? That is a terrible idea. "But you might forget to put the gear down..." GUMP check on final, every time....
The expense, effort and dedication required to develop a new, top-tier sport aircraft, especially for this very limited market, takes ambition and passion for aviation far far beyond nominal. I sincerely wish you good brothers, tangible life-success from this investment. I won’t be surprised if you all are employed by NASA or Elon Musk at high level before long. If so, I will congratulate you 😎🎩♠️💙
I would prefer an OLED screen with detailed info regarding gear position, system error conditions etc, besides the primitive LEDs. Also, what about a color camera that shows the gear position and the belly of the aircraft? Can partially color-blinded pilots get licensed? These guys may be confused under certain light conditions by red/green lights.
Hydraulics were used because precise control with electric motors had been unreachable until high power MOSFET and IGBT were developed. CAN bus control further reduces weight of electrical drive.
Very cool! Chuckled when you said 100w bulb and then showed an LED! I assume you'll be testing repetitive cycling of gear? What if system fails to deploy...is there any manual action if motors aren't working?
how do you determine, in flight, if an LED has failed (off) versus stuck gear? What if the right main LED failed, and so never illuminated, but the gear came down and locked? What if the right main gear failed to unlock and extend, how would you know the LED wasn't bad? What if the right main LED failed, and the gear was extended but not locked?
Wouldn't it be smarter to pivot the landing gear such that it can't collapse due to a hard landing? I.E. Have the landing gear come down from the front to the back, exactly backwards from what they have now. So much for "smarter" landing gear.
Another interesting update! I have zero experience in avionics or aircraft systems but I was suprised at 3:25 when you mentioned _automatically_ extending the gear instead of sounding an alarm and leaving the pilot fully in control. Is that standard, or a departure from what you'd normally expect in a light aircraft?
There have been a few aircraft types that featured interlocking systems extending the gear automatically at full flaps. Personally, I like the idea of an intelligently automated system. It should be better and more flexible than a fixed connection.
I don't want my machine to ever make a configuration change without my input. A warning to the pilot is sufficient. Gear up landings are never a safety problem, but unexpected uncommanded configuration changes have crashed a lot of aircraft over the years. Including airliners.
@@chester8420 would you like a copilot to make saving inputs, if you as PIC happen to miss them? The configuration change could be announced with an option to abort. It doesn't have to be man vs machine.
Guys, you focus too much in features. Think about later production more. Complicated components make production too costly, slow and weaken your product. Search for existing components more.
Sorry dudes. A big thing here. Your gear should retract against the airflow and extend with the airflow. That way if your motor fails, airflow functions as a back up for gear extension. You movement should be reversed. Again sorry… don’t shoot the messenger
I'd dump that whole system. It's super complex and prone to failure. All those electronics are going to be hard to keep running. Make it work with a manual hand leaver. You can keep all the monitoring junk. But I don't see the advantage of electronic gear with such a light aircraft.
Commercial aircraft use hydraulics because when they (or the designs on which their components were based) were first designed decades ago, only hydraulics were practical... and they may share hydraulic pumps with the flight control systems. None of that applies to any new design, at any size. Electric is certainly the logical choice for DarkAero.
How do yo test the movement of the landing gear with a front wind at the landing speed?. As the deployment is forward , this fight against the wind might be considered. Will 100 wats be enought in that case? (those were all constructive questions 😁)
I commend you on your workmanship but I’m worried about the C of G change with this design. I estimate the wheels weigh at least 35 pounds shifting that much weight 3 feet forward and rearward on such a small craft will have a profound effect. Cessnas compensate buy retracting the nose gear opposite to your design. You may find you’ll need a counter weight system.
A long coil-over spring with an oil/gas damper might help to alleviate concerns with the gas spring leaking or failing with age. I know they make similar springs for automotive lift gates that are basically the same geometry as your gas strut, but have a coil over spring around it. Stabilus makes them!
3:19 Rather than autodeploying, it might be preferable to issue an audio warning. At low altitude and airspeed, a sudden change in drag or pitching moment is not always a welcome surprise. Furthermore, each time it autodeploys (especially without warning the pilot), it trains the pilot to forget gear-extension in retractable-gear aircraft.
Hello guys, Are you intended to use any kind of steering system? Or the turning will be made using differential brake and propulsion? great work, guys! keep it on!
looks like Cessna 210 landing gear, but this system doesn't seem to have the emergency extension mode. how do you get the gear down when you lose electric power? and you will loose electric power. is the plan to just belly land and hope for the best? balistic chute?
Really makes me uncomfortable that gear up is light off indication. You need a way to complete a "lamp test" to verify the lights are functioning. Seems a bit over engineered.
May be someday they will try to fly this thing. The business model of selling videos is getting old. Rutan and VanGrunsven would have had five different airplanes flying by now.
You have probably considered this but how would an operator distinguish a indication / logic failure from the gear being retracted successfully. It may not be the norm in aerospace but in some industries a positive indication is not used to show an unsafe state. I’m not saying I’m right, more for my own curiosity. It’s an interesting system design challenge. EG the lights fail to indicate when the landing gear has failed to raise. It’s common for problems to cross failure domains.
I admire what they are doing but sometimes I think that they should take a step back and and look at the complexity they are adding. Keeping things simple is the way. Adding complex electronics to a retract mechanism is asking for trouble.
Electronics work right up until they don't. Too much has to happen to do the job correctly. Count me out. Just because it can be done doesn't mean it should. Don't be smart, be reliable. There are those who have had gear failures and those who will.
'Off' is never a good state for an important indicator, especially if there are no redundancies. Any fault in an LED or power to it (or the switch) would not be noticed until you tried to deploy the landing gear.
As the owner of a turbo arrow with auto gear extension, I would urge you to really consider whether that's an appropriate feature. Personally, I wouldn't want it.
SO how do you know if one of the lights is not working, or a wire or connection is broken?No test function of the lights, and the lights going OFF means you wont know if the system is functional and retracted, or malfunctioning. You need a Test function of the lights, or they need to remain on.
It might be a good idea to use a color other than red to indicate the landing gear is in motion. Red should mean FAIL, orange could mean in-motion, green should mean good. Assigning red to dual-purpose indicate failure and gear-in-motion is less clear to the pilot.
So what happens when you add in the aerodynamic loads of the plane at approach and landing speeds? It would seem that added load of moving through the air would have a significant force on the components.
This is probably the first system in this airplane that I'm not enthralled with. So much complexity, so many things that all have to work perfectly. I've experienced gear problems before, when you're flying and trying to figure out why your gear is not showing down/locked, you want the simplest system possible, with the smallest number of failure modes, that can be easily overridden and manually actuated. A complex logic sequencing system run over CANBus with many potential points of failure does not instill me with confidence. Those small extend and retract latches, with beautiful tight clearances and tolerances that work so perfectly in your tests - what happens when those are contaminated with grease, or dirt, or bugs, or ice? What happens one of the motor sensors fails or mis-reads, and the logic controller drives the motor to extension at full speed? What happens if any of the logic controllers freezes or fails? What happens if any of the wires going to any of the gear gets pinched, shorted, broken? The answer is: gear-up landing, or worse (partial extension landing).
In virtually every retractable aircraft I've flown, the default state of the gear is to be down and locked. That means that in most any failure mode, by design, the gear ends up down and locked. The system operates to keep the gear up, and if something fails, the gear comes down. I don't see this functionality in your design: I see multiple different failure modes in your design that result with the gear up and locked with no way of manually overriding it.
You also state that the motor load on extraction is 100 watts - that's fine, but what about when it's extending the gear against relative wind in flight?
Lastly, if your "gear up and locked" indication is LEDs off, then you need a "push to test" button next to them to illuminate the LEDs and ensure that they are operational, to rule out a failed LED giving a false indication of retracted gear.
Didn’t they show a purely mechanical cable-actuated fall-back solution which lets the gear drop through gravity (edit: and gas springs) in earlier videos? But I don’t know how that’s going to disengage the motors in a reliable way or make sure the latches lock in the down position.
It seems complex but these systems can be incredibly reliable. Steer by wire is coming to cars sold in the US (eg Lexus RZ450e) in which there is no mechanical link between the steering wheel and the front wheels. These systems are also extremely testable and able to provide lots of instrumented feedback at relatively low cost. Given they have a redundant system for emergency deployment, this is probably quite a bit more reliable (if engineered correctly) than it would appear at first sight.
@@Mike-oz4cv Hmm. And gas springs are unreliable.
I don't disagree. the controls are interesting, but I want manual overrides. I want fail-down features. Too many light aircraft experience gear failures.
You must have missed the video where they show that the gear motors can be disconnected, and the gear will free-fall with the help of gas struts.
Wish I'd had the fearless ambition of these lads back in the day. This project is truly exceptional.
I'm sure they've had exactly their share of fear. "Courageous ambition", more apt, me thinks.
I wish I was 1/10th as smart as these kids!
Not to be a negative energy but its 5 years and no flight.
@@tbrowniscool this ain't a one-off- progress has been well paced.
@@mavigogun literally is a one off.. You just don't see the religious parents with millions of dollars backing this. You notice how crystal clean the work/hangers are? The large metal parts are outsourced. I would like to be proven wrong but after 5 years they are still developing landing gear?
Like I said before I wish them all the best but this won't work as a business. Who will buy this "kit"?
Dear DarkAero crew - Green and Red can still confuse a pilot as to up and down, since those colors are port and starboard. And no light means not working or broken. Please use lighted icon symbols indicating Down/Locked or Up/Locked. Thank you. .
I'd assume you can easily customise that to your taste, no biggie
@@josephc.9520 Some will forget that -> will be a biggie.
Better to make it fool proof by DA
many aircraft have the green and red lights for landing gear and it's no issue. There's no common light inside the cockpit I can think of that relies on green and red to indicate port and starboard, those are only the position lights on the wingtips. Icons are fine, but they need to be very easily recognizable at a glance.
Almost every aircraft on the planet has green and red gear indication lights. The only place you see green and red lights indicating port and starboard in aviation is on the navigation lights on the exterior of the aircraft.
It's been a while. You guys must be crazy busy, thank you for sharing this journey with us. One of the YT video series I look forward to most!
How do you replicate the demand on the landing gear that you'd incur in flight? Will you do wind tunnel testing? What about the icing and humidity challenges that mid level and higher altitudes pose?
Might consider making the service stands and any unique specialty tools / equipment, available to purchasers, once y’all get into production.
Just curious but why didn't you guys use a tail-dragger design for the landing gear? Wouldn't it be lighter and simpler?
…congrats on 100K…Please, accept this virtual “high-five” 🖐🏻
In general I don't like having the "LED-OFF" state as being the indication is a valid system state. It doesn't allow for the possibility of a malfunction. I think it would be better to have a different color for each position -- 1) up and locked, 2) down and locked, and 3) in-between. With your current system you don't reliably know if a gear is up, or there is a malfunction somewhere.
Yes, with LEDs having practically unlimited life, there's little danger of burning one out. However, with your existing indicator system you won't know if the gear is up, or you have a bad LED, or a broken wire, or a bad switch, etc, in your indicator circuitry. You're obviously using Red/Green bi-color LEDs. Why not use Yellow (both on) to indicate one of the states? That might let you get away without any rewiring. Though Red/Green/Blue LEDs would probably look more polished, since Yellow is often an indication of caution.
Like you said, "Make your landing gear smarter!" :)) Just my 2-bits...
Agreed. LED off should only indicate a failure or power-off state. Red/Yellow/Green has been a standard for decades for a reason.
Not a pilot or engineer, but doesn't preflight checklist cover checking all instruments? I assume the LED's would go through their sequence when starting up (like in a car dashboard). Additionally, if the lights are constantly on while the gears are retracted it'll be super distracting, especially when flying at night. I like their implementation because I'm sure you'd feel/hear the drag if the wheels aren't fully retracted (equivalent to the LED being out as you've mentioned). It's not just the LED that has to malfunction, but also the system.
All this is to say that I like their approach; there are indications of what's happening when it's needed, without distractions when not needed.
As someone who specialized on landing gear and flight controls for over a decade, I agree that an off led gives to little information. Maybe look into:
Green=down
Alternating G/R=gear in transition
Red=up
LED's are reliable, but not infallible.
@@brois841 Just thinking aloud here, a pre-flight check wouldn't indicate an in-flight system failure. I think the 3-color, never-off concept makes good sense.
@@s14slide I'm definitely not experienced in aircraft, but I really like the idea of a flashing LED indicating movement between valid states. Great idea, and also only changes the software. No additional hardware/wiring required.
As you work through the design, consider ice. Any number of planes have taken off from wet runways and had the water freeze the gear in the up position as the plane climbed to colder conditions. Just something to consider.
The gearbox assembly appears to be sealed, so it's unlikely icing would affect that part of it. The linkages look like they might have the potential to be exposed to some icing, but given how it looks like the linkages nest and articulate, as long as they design it with enough torque, I'd think it could probably break through ice fairly easily (at least on extension if nothing else, retraction might be more problematic in icy conditions). Still, definitely something worth testing.
Wow good call @marcericdavis. Totally didn't even think of that.
"Any number of planes have taken off from wet runways and had the water freeze the gear in the up position as the plane climbed to colder conditions."
Source?
I want to see the speed of retraction a little faster because this plane is going to accelerate so quickly, it needs to get the gear up out of the wind forces into the wheel wells very quickly. Let’s also see the gear extending with simulated “wind loads” against them, I’m not convinced those little motors can overcome wind stresses over hundred mph, manual emergency extension under wind loads also. Then I’ll be impressed.
For such a small aircraft, a simple pneumatic system is good enough. I think your electric system is too complicated and heavy compared to the pneumatic.
What is about free fall system?
what about aerodynamic forces when in flight and extending the gear, would you test that at some point (I see you're adding gas struts which would make sense to aid against air flow over the gear, would be interesting to see what the power draw is in a simulated in flight extension).
They've already addressed this 100 times. The gas struts are enough to fully extend the landing gear with no motors. That means the power draw when extending gear in flight will be ~nothing.
@@JH-tc3yu what's the rating on the struts? (it was probably mentioned but I missed those 100 vids where it was explained)
Nice work.
Try to avoid "off" LED's as you do not know whether the LED is broken, without power or in the stored position.
I agree- a color to indicate retracted would be ideal
I can't wait for this to fly in 2047!
I can't wait to see this thing fly! I hope you live stream it!
Any concerns with having radar interfere with the CAN bus? Some cars had to implement extra things for wake-up control due to car batteries going flat at airport parking…
Related to airport parking or just general long term parking? 🤔
@@TheStuartstardust airport parking. The radar pulse would wake up the CAN bus.
How do you plan for the increased wattage / power requirement to overcome drag when in use real world? Ie. do you know roughly what the additional power requirement would be? Very cool video, thanks for sharing.
Automotive electrical engineer here w/ experience w/ CAN based networks. Love the innovation. Not to be negative Ned here but I'd highly recommend a DFMEA before first flight. What happens if an ESD event takes out your CAN bus? Its not all that unusual in the automotive realm. May want some type of redundancy here. Sorry to throw a dart, just want to make sure your bases are covered.
The light bulb @6:14 is not "100 watt" by any measure. It appears to be an LED lamp, so it doesn't use 100 watts of power; no "100 watt" bulb produces 100 watts of light. I understand the use of a light bulb for the comparison, but to make any sense it has to be an old incandescent bulb that actually uses 100 watts. Since those are generally not used any more, it's not the useful example that it once was.
Needs ground proximity sensor …. How does the panel know if altitude at any runway or off runway excursions… ref. Emergency extend / retract
I recognize those CIM style motors/Gearbox anywhere lol (We used them a lot in FRC) 0:01
Base --> Final
Final's clear? Landing gear??
Out loud, every single time
Why not make the gear retract system itself hold the landing gear in the retracted position? Why not copy Bonanza's gear extension gearbox idea and only have 1 motor and 1 gearbox to maintain? Also, if an electrical failure occurs, a centrally mounted gearbox behind the seat could easily be cranked down by hand like a Bonanza. I use small dc electric motors to run mechanical functions on the farm, and I have found them to be very unreliable.
Part of engineering is to create things that can manufactured at a low cost possible and keep the good traits as possible; something that these guys completely ignore. It is like watching government develop an aircraft where budget doesn't really exist.
Also, with the gear leaning forward some of the worst bumps/shocks of the uneven pavement with be driven directly up into the airframe; not great.
Will you eventually add fairings/doors to cover the landing gear while retracted?
Yeah they did make some in an earlier episode
It's actually much more common to find the landing gear in model planes driven by pneumatics.
Gear auto extend sounds very dangerous. If a pilot accidentally ends up low and slow and the plane thinks they're trying to land and puts down the gear, the extra drag could slow them down even more and cause a crash.
i would be more happy with a system that i knew was not over complicated and i could manually deploy, it looks more complicated than necessary
Auto gear extending does not sound like a good idea (see ditching on water). How bout just an aural warning like every other plane out there?
Isn't this like, too many points of failure for such a necessary system?
How far aft does the CG move when the gear retracts?
Larger scale model RC planes use pneumatic retracting gear.
Huh... I would have thought a retractable system would be designed so a failure would default into a landing mode. This system does not appear to have that designed into it.
I don't think that's a 100 w light bulb. Probably 100 watt equivalent but not 100 watts :-)
I'm getting Cessna 337 vibes from the rears 😀
"Begs the question" does not mean the same thing as "raises the question".
Do you guys plan on using a weight on wheels switch to prevent pilots from accidentally raising the gear on the ground? I've really enjoyed the aircraft I've flown where this is a feature and its also included an aural tone that alerts the pilot when the gear isn't down after crossing an AoA or Airspeed threshold. That way if the pilot is trying to maneuver the aircraft in a way that would appear to be landing configuration but actually isn't, the gear wouldn't auto-extend and risk being oversped when the pilot completed the maneuver and recovered.
Have you given any thoughts about designing a circuit which will allow the landing gear lights perform a flashing mode during transitioning or an unsafe condition?
How will you be simulating Air Loads on the Gear to validate reliability and function?
In the automotive applications, CAN/BUS systems are not user serviceable without OBD type readers.
What Service Units will be applicable to this aircraft?
While Electro/Servo seems simplest, Electro/Hydraulic may be needed with air Loads.
Will watch for development with interest.
Auto gear not down warning is better. Human r meant to & should err
Ah yes, Multi-rotor consumer tech on an aircraft, bound to work out well
I've been following this project for a couple years. I'm always blown away by the quality engineering and workmanship. Best of luck in upcoming test flights. Hope it will do everything you want it to. (It will certainly be fast!).
On the Lancairs, we have a similar gas piston for emergency deployment of our front gear. The mains will fall and lock by themselves. There is a gas pressure decline over time that results in the gas piston not having enough pressure to push the nose gear against the wind all the way until the over center links lock. If this occurs in an emergency, then there is no way around landing without the front gear being locked, and usually results in a prop strike and a scary landing. Owners are urged to routinely cause a deployment to check for this, however it is still happens way more than it should. Here, you have all 3 gear using this method, opening up the possibility of having more than one cylinder fail and not lock at the same time.
What is your back up for a failed motor or electrical system?
I like the idea of electric power over hydraulic retracts especially on smaller home builts. For one reason, the smaller hydraulic pumps now are almost impossible to get repaired if something goes wrong since Parker decided to condemn their use on aircraft. Also hydraulic systems can get messy at times and in general are more difficult to install compared to wires. Not sure of the eventual cost of this system electric system will be, but if they it is about the same as hydraulic, I would go with the electric, as long as it was adequately tested. And as far as testing is concerned, one thing that caught my attention was the mention of how fast the gear came down due to gravity, compared to how fast it went up. That will be the opposite during flight. The gear will take much more power to come down than it does to go up in this configuration due to drag forces. Your main gear legs have much more drag then say like the Cessna Cardinal RG main gear legs have, which have the same gear swing as your system or Lancair aircraft. There's a reason why many of these RG systems have single tube main gear as opposed to bulkier gear designs like your gear. Two reasons really, weight and air drag. More the drag, the more the power requirement. Your main gear look nice and beefy, but at least 3 times the width of single tube design such as used on a lot of home builts with hyd RG.
Did you consider pneumatic actuators? Extremely reliable, high forces, relatively small actuators, flexible hoses that are easy to route, push-to-connect fittings, off-the-shelf components, easy to add redundancy, etc.
😆😆😆The main gear resembles Cessna's "Skymaster" undercarriage...
Indicator lights off when retracted is a bit of a concern to me. There's no way to distinguish between an indication of normal retracted status and a complete lack of display functionality, since both correspond to lights off. Another colour of each indicator would provide a positive indication of system functionality.
The locks are not currently installed. What happens to the indications if a gear extends or retracts all the way, but the lock doesn't engage? Are the locks monitored by position switches?
Awesome system! Thanks for sharing
how do you make sure that off lights don't mean the light is broken? wouldn't a blue color be more useful when the gear is retracted?
Many aircraft have a push-to-test button than illuminates all annunciators on the panel to check for burned-out bulbs. Maybe they'll incorporate one?
Will you require any type of ‘weight on wheels’ sensor into the logic unit to prevent any possibility of retraction when on the ground. Looking forward to seeing if the latches used in the locking mechanism require any sort of actuator. Looking really neat. Good luck from the UK
Is "off" as an indicator of closed a good safety option as there's no way to tell the difference between a light circuit malfunction and closed landing gear? I know there have been several industrial accidents stemming from the use of "off" as an indicator, so I'm surprised that it's allowed in aircraft.
What redundancy exists in the system in the event of a CAN bus, logic module, or electric motor failure? Will it be possible to manually lower the gear or release the up locks and have them lower by gravity?
Excellent questions. With the depth these lads have plummed in this design we can have confidence that they thought of this, however NONE of that is addressed in this video. They could know their audience better and that we would have these questions.
They literally mentioned their emergency extend system in the video.
What's the airspeed where the electrical actuators can't achieve deployment against the airflow?
I just recently saw that a mini turboprop had received or was about to receive certification. Is that something you guys would consider on V2 or V?? Obviously they burn more fuel, but they are crazy light. Wonder if there is some sweet spot with a feather weight plane and power plant. Can't wait to see it fly. You guys are great ambassadors for engineers.
74k views and 2.4k likes.. y'all are crazy for not bumping that like button...
I'm updating everything in my rv7 to use a PDM and can bus
Unfortunately, every gender & orientation has to work for survival except ST FEMALE & that is the biggest privilege.
Wayyyyy too complicated. Landing gear systems need to be simple, robust and maintainable. This should be nothing more than electric motors with up and down limit switches. Logic circuits have no place in airplanes. And auto-extend? That is a terrible idea. "But you might forget to put the gear down..." GUMP check on final, every time....
The expense, effort and dedication required to develop a new, top-tier sport aircraft, especially for this very limited market, takes ambition and passion for aviation far far beyond nominal. I sincerely wish you good brothers, tangible life-success from this investment. I won’t be surprised if you all are employed by NASA or Elon Musk at high level before long. If so, I will congratulate you
😎🎩♠️💙
I would prefer an OLED screen with detailed info regarding gear position, system error conditions etc, besides the primitive LEDs. Also, what about a color camera that shows the gear position and the belly of the aircraft?
Can partially color-blinded pilots get licensed? These guys may be confused under certain light conditions by red/green lights.
Hydraulics were used because precise control with electric motors had been unreachable until high power MOSFET and IGBT were developed. CAN bus control further reduces weight of electrical drive.
Very cool! Chuckled when you said 100w bulb and then showed an LED! I assume you'll be testing repetitive cycling of gear? What if system fails to deploy...is there any manual action if motors aren't working?
how do you determine, in flight, if an LED has failed (off) versus stuck gear?
What if the right main LED failed, and so never illuminated, but the gear came down and locked?
What if the right main gear failed to unlock and extend, how would you know the LED wasn't bad?
What if the right main LED failed, and the gear was extended but not locked?
hoo engineering service ..... ^^ ....
anyway ... just a bit slow and i would like some way to disconect the auto deploy
Wouldn't it be smarter to pivot the landing gear such that it can't collapse due to a hard landing? I.E. Have the landing gear come down from the front to the back, exactly backwards from what they have now. So much for "smarter" landing gear.
Another interesting update! I have zero experience in avionics or aircraft systems but I was suprised at 3:25 when you mentioned _automatically_ extending the gear instead of sounding an alarm and leaving the pilot fully in control. Is that standard, or a departure from what you'd normally expect in a light aircraft?
There have been a few aircraft types that featured interlocking systems extending the gear automatically at full flaps.
Personally, I like the idea of an intelligently automated system. It should be better and more flexible than a fixed connection.
I don't want my machine to ever make a configuration change without my input. A warning to the pilot is sufficient. Gear up landings are never a safety problem, but unexpected uncommanded configuration changes have crashed a lot of aircraft over the years. Including airliners.
@@chester8420 would you like a copilot to make saving inputs, if you as PIC happen to miss them?
The configuration change could be announced with an option to abort. It doesn't have to be man vs machine.
Guys, you focus too much in features. Think about later production more. Complicated components make production too costly, slow and weaken your product. Search for existing components more.
What difference in display is there between "OK" and "Display Un-powered"?
Are the linear motors stock? It's a nice and smooth running system.
Is it possible to build such a landing gear with CAN BUS control?
Sorry dudes. A big thing here. Your gear should retract against the airflow and extend with the airflow. That way if your motor fails, airflow functions as a back up for gear extension. You movement should be reversed. Again sorry… don’t shoot the messenger
Was that a vex pro gearbox?
Because that looks like a versa-planetary gearbox powered by a BAG Motor
I'd dump that whole system. It's super complex and prone to failure. All those electronics are going to be hard to keep running. Make it work with a manual hand leaver. You can keep all the monitoring junk. But I don't see the advantage of electronic gear with such a light aircraft.
Commercial aircraft use hydraulics because when they (or the designs on which their components were based) were first designed decades ago, only hydraulics were practical... and they may share hydraulic pumps with the flight control systems. None of that applies to any new design, at any size. Electric is certainly the logical choice for DarkAero.
How do yo test the movement of the landing gear with a front wind at the landing speed?.
As the deployment is forward , this fight against the wind might be considered.
Will 100 wats be enought in that case?
(those were all constructive questions 😁)
I commend you on your workmanship but I’m worried about the C of G change with this design. I estimate the wheels weigh at least 35 pounds shifting that much weight 3 feet forward and rearward on such a small craft will have a profound effect. Cessnas compensate buy retracting the nose gear opposite to your design. You may find you’ll need a counter weight system.
A long coil-over spring with an oil/gas damper might help to alleviate concerns with the gas spring leaking or failing with age. I know they make similar springs for automotive lift gates that are basically the same geometry as your gas strut, but have a coil over spring around it. Stabilus makes them!
3:19 Rather than autodeploying, it might be preferable to issue an audio warning. At low altitude and airspeed, a sudden change in drag or pitching moment is not always a welcome surprise. Furthermore, each time it autodeploys (especially without warning the pilot), it trains the pilot to forget gear-extension in retractable-gear aircraft.
Hello guys,
Are you intended to use any kind of steering system? Or the turning will be made using differential brake and propulsion?
great work, guys! keep it on!
looks like Cessna 210 landing gear, but this system doesn't seem to have the emergency extension mode. how do you get the gear down when you lose electric power? and you will loose electric power. is the plan to just belly land and hope for the best? balistic chute?
Really makes me uncomfortable that gear up is light off indication. You need a way to complete a "lamp test" to verify the lights are functioning. Seems a bit over engineered.
May be someday they will try to fly this thing. The business model of selling videos is getting old. Rutan and VanGrunsven would have had five different airplanes flying by now.
You have probably considered this but how would an operator distinguish a indication / logic failure from the gear being retracted successfully. It may not be the norm in aerospace but in some industries a positive indication is not used to show an unsafe state. I’m not saying I’m right, more for my own curiosity. It’s an interesting system design challenge. EG the lights fail to indicate when the landing gear has failed to raise. It’s common for problems to cross failure domains.
100k subs
congrats !
I admire what they are doing but sometimes I think that they should take a step back and and look at the complexity they are adding. Keeping things simple is the way. Adding complex electronics to a retract mechanism is asking for trouble.
What controllers are you using for the CAN BUS system?
Electronics work right up until they don't. Too much has to happen to do the job correctly. Count me out. Just because it can be done doesn't mean it should. Don't be smart, be reliable. There are those who have had gear failures and those who will.
'Off' is never a good state for an important indicator, especially if there are no redundancies. Any fault in an LED or power to it (or the switch) would not be noticed until you tried to deploy the landing gear.
Thinking from a systems safety/failure modes analysis: How is “off” an indication of anything other than an open circuit?
amperage ? = 1000xP/ (1.73205 x V coso x n ) your motors are to small
Speaking from personal experience with hydro. One less system to cover in hydro is a win. If the electric motor is reliable I say go for it.
Red: gear retracted and locked. Green: gear deployed and locked. Yellow: gear motors in operation.
How smart does it need to be? Up for flying and down for landing/taking off. My wife's goldfish would get most of that right.
As the owner of a turbo arrow with auto gear extension, I would urge you to really consider whether that's an appropriate feature. Personally, I wouldn't want it.
SO how do you know if one of the lights is not working, or a wire or connection is broken?No test function of the lights, and the lights going OFF means you wont know if the system is functional and retracted, or malfunctioning. You need a Test function of the lights, or they need to remain on.
It might be a good idea to use a color other than red to indicate the landing gear is in motion. Red should mean FAIL, orange could mean in-motion, green should mean good. Assigning red to dual-purpose indicate failure and gear-in-motion is less clear to the pilot.
Why not encoders so you could actually know which position the mechanisms are. In case of problems it is important to know in which position they are.
Looking forward to see the maiden flight
So what happens when you add in the aerodynamic loads of the plane at approach and landing speeds? It would seem that added load of moving through the air would have a significant force on the components.