The first retract! | DarkAero Shop Vlog | July 10th, 2021

[@mattnsac]

Those limit switches are failure prone in multiple ways. I can tell you from experience in motorsports with mission critical parts that a hall effect sensor is the way to go for something like landing gear (either full extension or retraction). They are smaller, MUCH more reliable and not much more expensive per part. I know you said this is just prototype but I would use hall effect for ANY limit switch in the aircraft.

[@brianb-p6586]

I agree - mechanical limit switches would worry me.

[@jamesperkins3742]

You should consider using Proximity Sensors instead of mechanical limit switches. Proximity Sensors sense a metal target at its face to trigger the switch with no moving parts. I would suggest use the absolute encoder for travel and slow it down when it gets to its limits then use proximity sensors as a backup of position full up and full down. If encoder fails use limits to allow to extend/retract. An Proximity Sensor example part number FCM1-1202C-B2U2. I am assuming you can do some programming. I would be willing to help with any electrical design and programming.

[@Factory400]

I will totally buy one of these kits. Really love seeing the design and engineering unfold before my very eyes! I am an engineer and really appreciate the approach you guys take for each challenge. This is exciting, interesting, and at the end of the day it will be useful!

[@OkammakO]

Huge congrats guys. That's a massive amount of work coming together for one little move, so most people probably wont recognize how big that probably felt for the three of you. Don't feel bad about watching it operate for a couple hours and just taking it in!

[@DarkAeroInc]

It really is hard to convey the amount of work that it took to get to the milestone of cycling the gear, so we appreciate you recognizing that! :D

[@samsorrell1832]

Might consider a proximity sensor (hall sensor) type of limit switch rather than a momentary contact type. You have less environmental concerns with a prox switch. An interesting middle solution between a prox switch and a momentary is one of the switches used in window and door security systems. They are a sealed momentary which is switched by close proximity to a magnet. Of course a problem with any magnet solution is that metal debris may accumulate on its perimeter (assuming it's proximity to the switch would wipe the face fairly clean, otherwise the face could accumulate debris as well). In anycase, mud could block the momentary's travel, or moisture may penetrate it and short it closed. I love these videos, BTW. It's a great window into the design and construction of a composite aircraft.

[@davidwhite2011]

I would say an optical sensor is another option but surely many better options than a point contact switch.

[@rotohcf1400]

What you're referring to is a reed switch. I personally would be doing a hall effect and not a reed switch due to it being mechanical in nature and would be curious how well it would fare in reading reliable in hard landings, temperature extremes, and who knows what else.

[@mp6756]

Every step is done with a level of build quality and attention to detail one can't help but be impressed. What a beautiful airplane well done

[@HighDefinitionVideo]

I was blessed with two brothers who worked together for a few decades to build a decent business as well. Wishing you guys all the best!

[@foesfly3047]

The effort you men are putting into very thoughtful design, is going to pay huge dividends to we builders, in excellent component quality and fit. I estimate average build times for the Dark Aero will be less than half that of comparable Lancair and Glasair models.

[@edwardneil3039]

You guys can eliminate the limit switches if you use an encoder on the BLDC motor. It is called FOC control using an Arduino micro controller. Check it out at the Arduino website.

[@rangefreewords]

That would be a great idea, however still, you'd still want the proximity sensors to drive a miscompare.

[@garyplewa9277]

It appears that your nose wheel is castering, with perhaps limits and some friction mechanism at the pivot. I don't see an means of ensuring the wheel is always positioned straight back for retraction. Have you considered it might be turned or get turned during retract? Every retractable I've worked on, even those with steerable nose wheels, have a centering mechanism to prevent the wheel from retracting at an angle and possibly jamming. What about damping of nose wheel oscillations? Talk to a Grumman AA1 or similar aircraft owner with a fully castering nose wheel about what happens on landing with a loose (undamped) pivot. Those planes didn't earn the nickname of "The flying shopping cart" for nothing, as the nose wheel can oscillate like a shopping cart wheel on landing. Food for thought. Otherwise best of luck on your fantastic design and quality videos.

[@domminion599]

I'm wondering why you didnt use standard Press-Fit inserts for the honeycomb. It would save time and they have been used in the aircraft industry for years!

[@hugostiglitz6914]

I thought the same. Would be pretty easy to bond in the aircraft press fit inserts.

[@yesimabelugastan2213]

I love watching these its so cool to watch this process and to learn.

[@oddspaghetti4287]

About those main gear struts. Have you considered using a foam core on top of which you laminate to create the structure? you could attach the aluminum parts at the same time by first joining them to the foam core then adding the skin fiber on top of the whole thing. This way you could possibly reduce the number of steps required for the process and also make it a more reliable process. Having to bond already formed parts together and to other parts at the same time can sometimes be unreliable. Using prefabricated wound carbon fibre tubing to which you bond the aluminum endpieces might also be another option as well.

[@DarkAeroInc]

Hi there! Thank you for your interest in the project and for the suggestions! It wouldn’t be possible to laminate the carbon over the aluminum with the process we are using but a filament wound tube is something we have considered. We were actually looking at purchasing a CNC filament winder at one point.

[@davidwhite2011]

Maybe early to think about, but I would put in a vote now for the trim controls to have two buttons on the stick like a TBM 840-950 series for safety. Nothing like a trim run away to ruin a day.

[@tariqghuman]

Been waiting to see the nose gear in action…what a beauty! 😍😍😍

[@davidrobins4025]

So many creative ideas are being incorporated into this fantastic aircraft.

[@jaegpsde3877]

A lot of bolts in that central sump. Munro would make that cover snap on.

[@user2C47]

The encoder on the nose gear also seems like unnecessary cost and weight. Not sure a snap fit would work on the sump though as it's a pressure vessel, but still too many bolts. Might better to just completely change the way it's manufactured so it can be a solid tube with endcaps. Aluminum might be a better material for this part.

[@brianb-p6586]

Munro would make everything snap-together and completely unserviceable. Fortunately, no one lets Sandy Munro near aircraft.

[@brianb-p6586]

@@user2C47 No, the encoder is necessary if travel speed is to be managed, as the video explained.

[@PantelisKokkalis]

I am surprised by the depth of knowledge and the execution and attention to detail. This is not easy. You are building an airplane, not a fridge. Amazing. Almost unreal.

[@johnhartley5261]

This common sump is a bad idea. 1. Water/contaminates in one tank can't be isolated by drawing only out of the other tank. 2. Unless there are 2 check valves that weren't mentioned, a leak in one side = a leak in both sides. 3. A clogged vent line to one tank = an overfilled tank and either draining fuel on the other side or an imbalance fuel quantity. 4. Adds complexity and multiple non-redundant failure points to what should be a simple system (KISS principal). IE: any of those connectors fail = fuel leaking from both tanks with no way to isolate. Why not have a simple, tried and true, fuel selector valve? Off-Left-Right

[@richardvisscher2626]

there are 2 check valves, Rotax and UL both require a sump/header tank for the FUEL return. Otherwise you have a complex plumbing nightmare.

[@DesertRox]

Only thing wrong with these videos is there isn't enough of them! Very cool project can't wait to see it fly!

[@gregseljestad2793]

Excellent amazing incredible! Just found you guys yesterday, and am so excited to follow this amazing project. Three brothers who are very smart and are building and huge knowledge base on how to build a record breaking homebuilt airplane. Totally impressed! Love your routine of teaching the rest of us!

[@raffly4449]

Looks like the brake caliper is on the bottom. Others have learned the hard way that a flat tire may cause damage to the caliper and a brake failure. Without nose wheel steering this can result in an off runway excursion. Hopefully you have mitigated this possibility.

[@steinb6271]

Nice job guys - keep up the great work and we'll see y'all in a couple weeks at mecca! PS, you 'might' find that once you finalize the design of the header tank that you can likely make is ever so slightly lighter out off AL.

[@johnrehagen8570]

Versaplanetary gearbox with integrated encoder and 20 dp 1/2 inch hex bore gears? Did y'all do FRC?

[@mayakovski]

As always the detail to the project and commitment you bring is inspiring. Cannot wait to see this fly.

[@drthik1]

Now that I'm following yall I keep getting videos in my recommended that I've already watched...all the while thinking it's a new upload

[@LuisAngel-nf1hb]

I like to share with you something that happen to me on mi Glasair III regarding the alluminum fuel lines, They with time and vibration on the tube flare and due to the squeez pressure between the fitting and the nut and the sleeve they loose strengh and finally end up getting cut, I decided to change all of them for reinforced hoses, after a complete spliting of the main supply to the servo injector, and on a 7 minute decend and landing I lost 24 gls of fuel, that thanks that the engine is not turbocharged I got away without a fire.

[@DarkAeroInc]

Luis, glad to hear you were able to make it to the ground safely after that event! I can't speak to what might have been the root cause on your Glasair III, but I can comment on our design. In the DarkAero 1, we are following FAA-AC-43.13-1B and FAA-H-80830-30A guidelines for certified aircraft including the fuel line material, fitting types, proper fitting installation/alignment, and fuel line support. When properly followed, this is a proven method for creating fuel system plumbing in certified and experimental aircraft. The referenced FAA documents can be found on the DarkAero Knowledge Base: FAA-AC-43.13-1B: www.darkaero.com/datasheets/standards/FAA-AC-43.13-1B-Techniques-and-Practices-Aircraft-Inspection-and-Repair.pdf FAA-H-80830-30A: www.darkaero.com/datasheets/standards/FAA-H-8083-30A-Maintenance-Technician-Handbook-General.pdf

[@christopherbeddoe406]

Been waiting to get my Dark Aero fix. Love you guys. Awesome work!

[@edmondthompson1523]

Great episode. Very informative. Looks like best practices all around.

[@littlejack8092]

Why do you use limit switches instead of inductive limit switches, or Hall effect sensors? Seems like a point of failure, is there any specific reason for this? Love your work and videos btw, keep it going:))

[@daveshepherd7582]

I would have thought aluminum would have been a better choice for the sump construction because of all the threaded connections….

[@samroesch]

For the rear gear legs, couldn’t they be made in one piece? They have lots of draft along their length. I’m guessing maybe this a limitation of the infusion process?

[@foesfly3047]

I assume you are considering Hall-effect type proximity sensors for gear position. I believe they are superior in reliability of function and durability compared to the simple mechanical contact switch you were holding.

[@8BitRip]

The f-22 uses limit switches on all doors for both open and close positions, as well as parts of the landing gears. I have first hand experience and I can tell you they’re extremely reliable.

[@nielsheesernielsen3614]

Yes, amazing how cheap an reliable they are in the ABS on rusty old cars.

[@nicolassalischiker3924]

my flight sim joystick uses those sensors

[@brianb-p6586]

@@8BitRip The F-22 was designed three decades ago, costs a couple hundred million dollars a copy (so the budget for switches is essentially unlimited), and gets maintenance work (by qualified techs) more times in a month than this aircraft will get (by the owner-pilot) in its life. The application note is interesting, but not very relevant.

[@pcowdrey]

The Wright Brothers would be proud of you guys. Very much so. I'm really impressed by the broad expertise that you guys have over a wide array of disciplines, and so young. Great techniques, great shop. Things are different now and for you, from how we did the development and construction of experimental small aircraft in the '60s, like we did getting together the Miss San Bernardino Formula One racer with Art Scholl in the lead, circa 1968. I like your videos and your work. Wanna see it fly. Wanna see a bunch of them fly. What cruise speed are you expecting? Patrick Cowdrey, Eagle Point, Oregon 1/1/22

[@MurrayC]

Looking good - any idea when the first test flight will be?

[@flexairz]

Fuel sump: the fuel line to and from the engine seems a bit close together.. is there a separation of some sort inside of the sump?

[@DarkAeroInc]

Correct. There is an extension on the fuel pickup that runs to the center of the tank so there is separation between the inlet and outlet inside the tank.

[@ateliedemaquetes.aereoenav4894]

Muito feliz por vcs, vcs sao os caras da tecnologia fibra de carbono. amo a tecnologia aeronautica.

[@gordonfranken4985]

Are those VersaPlanetary gearboxes? You guys much have done FRC in the past! I'm a little surprised to see them on an aircraft - not sure if they have the necessarily robustness.

[@johnmarkgatti3324]

good stuff , do you guys watch Mike Patey , he is just doing his wings , with a double front fowler flap , worth checking out . ha ,he has all his own cnc etc , not jealous ...

[@dlfabrications]

Question about the sump, do you cooled the vapors going back to the wing tanks to make them liquide again? A car has a charcoal canister to catch vapors and injects them in the intake in a controlled manner.

[@GregoryACross]

Great video! Thanks for the update, guys!

[@ekinakdesir2868]

Hi, I wonder that do you use phenolic discs under high-load areas? Does it make sense?

[@wademant7848]

Great stuff - Can you share your Oshkosh Plans ?

[@good_Vibe_design]

Great progress and interesting to follow you guys. Keep them coming 👍🏻

[@syopspwnz]

One of the questions I've had is: how did you size your cnc machine and do you regret the constraints you now have? (foreseen or not) Would a larger machine really help or just be a needless expense? I guess this is the age old question about capacity and opportunity costs...

[@addisonkarisny4659]

EAA?

[@jackfisher2270]

vexpro planetary and a bag motor. nice

[@timmymartin317]

Exiting stuff guys! Keep up the hard work. It’s looking great.

[@Project2Aero]

Great stuff gentlmen👍 Love the carbon main gear🤯

[@TheCobra327]

Are you guys going to be at OSH 2021?

[@Chris9rr]

Wouldn't a proximity switch be better than a limit switch to indicate the final position of the gear? No moving parts in a proximity switch. And they are sealed

[@ScottsSynthStuff]

How do you keep fuel crossfeeding from one wing tank to the other via the header sump? It makes it really difficult to fill both tanks if fuel keeps finding its own level by flowing to the tank with less fuel. Or are you depending on this, and planning on a single fill port?

[@richardvisscher2626]

They have check valves at the outlet from each wing.

[@DarkAeroInc]

Hi Scott! Richard already answered correctly but we will echo what he stated to confirm for others, there are check valves between each wing tank and the sump. This allows fuel to flow into the sump from the wing tanks but not the other way. This prevents cross feeding when you are filling the tanks or during uncoordinated flight.

[@parrotraiser6541]

How do you calculate strength and dimensions for carbon-fibre gear legs? I'm look at designs for a fixed gear, (essentially a quarter-elliptic spring on each side), and have no idea what would be reasonable sizes. (For conventional materials, like aluminum or spring steel, you can always start by copying a machine of similar weight, if you don't want to look up the numbers and do the sums.)

[@BillWood1]

Really, really awesome progress and project! I've been watching for a while and am impressed with your work and capabilities. Some things that jump out at me on this video. The quality and attention to detail are great, but two suggestions. 1. Since the fuel sump is the lowest point in the fuel system, will you be adding some type of petcock or sampling valve? Checking the fuel for contamination or other issues at that low point is really important. Also, I am impressed with the gear design and TOTALLY appreciate the desire to save weight, but, for the few extra ounces would it make more sense to use steel at the connecting links to the gear? The gear itself looks pretty robust but I could see a few hard landings causing possible fatigue, bending, or cracking with the small crank arms. Overall though, awesome job and the project looks amazing!

[@thewheelieguy]

They show the drain port as the last thing on the sump part of the video. Presume you would draw fuel test there..

[@BillWood1]

@@thewheelieguy awesome! I must have missed that. That would be consistent with the overall build. These guys have been pretty thorough and careful!

[@daverobinsonTnT]

Is your electrical box fastening solution less expensive ($ cost, weight & time) than simply installing potted inserts ? Basically, ( i ) - make small holes in the avionics box's top and bottom skins (carbon fiber plies) for installation of a 'thru'' insert (for bolt shank) in the composite panel; at each desired fastener location ( ii ) - clear out at least 1" diameter of honeycomb core beneath the top and above the bottom, skins (carbon fiber layers) ( iii ) - then fill the void with potting adhesive followed by the placement of 'thru' insert and allow the adhesive to cure fully ( iv ) - make small blind holes in the floor panel's top skin for installation of 'blind' threaded inserts in the composite panel; at each desired fastener location ( v ) - clear out at least 1" diameter of honeycomb core beneath the panel's top skin to a depth sufficient for installation of a blind threaded insert ( vi ) - then fill the void with potting adhesive followed by the blind threaded insert and allow the adhesive to cure fully The end result is a 'hard point' for each fastener location but without the need for any extra plies of carbon fiber being necessary. This type of installation should easily accommodate the negative 3g (up) load case. Example : Shur-Lok composite panel potted inserts Have you considered the effect of fuel imbalance (say what happens in a sustained bank if the tanks were only about half full prior to banking the aircraft, as in a prolonged sideslip due to a strong crosswind on a long final) ? Must the fuel pump be continuously on during such a maneuver (see above) and will it have the performance capability to counteract the imbalance thus preventing the aircraft's "c of g" from shifting laterally in the direction of the imbalance ? Keep up the good work (two thumbs up)

[@NSResponder]

If you have a position encoder on the motor, why do you need limit switches at all?

[@cmtetaboaco]

Those micro switch’s tends to fail, try using hall sensors!

[@mattnsac]

I just saw this after I posted my own recommendation to use hall effect. I use them exclusively in race cars and I wouldnt use anything else for a mission critical component.

[@konstantingrudnev8374]

or gerkon sensor, it's mechanical "hall" sensor

[@Will-No-Co]

Hey guys nice work. I know the aluminum and carbon fiber don’t really get along too well with one another, but I’ve always wondered if the anodizing prevents this potential problem?

[@DarkAeroInc]

We did a video about this phenomenon here: kzbin.info/www/bejne/r4PTfo2Xip2tgdk but we didn't cover anodization. The anodization adds a non conductive layer on the outside of the aluminum which would mitigate galvanic corrosion, in theory. However we don't use anodization as a primary means of preventing galvanic corrosion.

[@billdavis9350]

Do I understand the 2 vent lines on the header tank are run back to the left and right outboard tanks? Do any of the the vents actually vent to atmosphere?

[@davidwhite2011]

I think he says they they go to the wing tips. Not sure why they would have to go that far.

[@9HighFlyer9]

@@davidwhite2011 it's done that way just to over complicate the system.

[@DarkAeroInc]

@Bill Davis each wing tank has its own dual redundant vents to atmosphere at the wing tips. The sumps vent to the wing tanks and the wing tanks vent to atmosphere. The sump tank vents to the wing tank rather than directly to atmosphere because it is possible for fuel to get into the sump vent line which could then "burp" out the vent line. Venting the sump tank into the wing tanks keeps this fuel in the system rather than losing it overboard.

[@billdavis9350]

@@DarkAeroInc Sounds good…Look forward to the first flight! Keep at it your are doing a great job!

[@luderickwong]

for something important as obvious as landing gear, will there be a backup sensoring device? say, mechanical spring, lever type to ensure the gear is in right place? because it lead to my next question. can this plane release the landing gear when it is flying upside down? this is a question that doesn't make any sense in operation at all, but i guess most people watching this channel don't knows the answer.

[@DarkAeroInc]

We have two forms of position data between the encoder and limit switches. Flying upside down would fall in the category of aerobatic maneuvers, which the aircraft is not designed for.

[@luderickwong]

@@DarkAeroInc 😄 that question comes from a bet with a pilot, an owner of a cassina, you know these guys, they always want to do naughty things in the sky. and don't be mistaken, everyone here watching this channel want to see the next DA no.2 be a “air superior” acrobatic plane 👍

[@scotthuff4485]

Will the airplane be on display at AirVenture?

[@KenLeonard]

If the wing tanks gravity feed to the sump and the engine overflow feeds to the sump, will the unused (excess) engine fuel back up because it is “competing” with the wings to fill the sump? If so, what is the result? Or is the excess fuel under pressure that will overcome the gravity feed?

[@rondesilva3077]

GREAT VIDEO (unmatched on KZbin !!!)

[@游川賢-u9v]

Sir, Can you provide me with what kind of 3D design software you used to design the aircraft? Thanks.

[@drthik1]

Fantastic, thanks for the update

[@HuskyMachining]

last my memory serves you guys where redesigning that little 3d printed part you said was a mock up part to avoid it needing to be made on a 5 axis mill. Did you have success with that?

[@DanFrederiksen]

Could the hard points be added when the sheet is made? and would a spring steel arm be too sloppy as a suspension solution? Can you make curves panels with the honeycomb?

[@thewheelieguy]

The CF-aluminum honeycomb panels are made in a supplier, and are flat sheets like plywood. Wouldn't imagine you can reform them in a curve.

[@DanFrederiksen]

@@thewheelieguy I actually think they said they ended up making those sandwich panels themselves.

[@tariqghuman]

Been waiting to see the nose gear in action…what a beauty 😍 hopefully soon I guess l…looking forward to the next video!

[@pcowdrey]

You guys are amazing. I'd much rather see a belated first flight, than a pre-mature one. You're gonna win. =PC=

[@normanrobinson1932]

This is great..!!! 😉👌 However, I seriously hope and pray you've planned to utilize "Hall Sensors" within the design to increase reliability and lower maintenance going forward..!!! 🤔💯🙏👍

[@christopherbeddoe406]

You can buy limit switches with 300,000 cycle life... that's well over 100 years of operation in this application. It's also redundant with encoder data depending on how they setup their system.

[@thorny_mcthornerson3945]

Can't wait to see the finished product. No way to build this beast when it's available but I watch the ads all the way through in hopes that a little more gets tacked on to your ad revenue checks 😉

[@DarkAeroInc]

Thank you for watching and for the support! :)

[@johnfitzpatrick2469]

G,day Dark Arrow team from Sydney Australia. Very productive stage, testing the nose landing gear. With your demonstration of the CAD drawings and specifications to outsourcing the manufacture of components.. Is titanium an optional upgrade or just not cost effective? 🌏🇦🇺

[@DarkAeroInc]

We only use titanium for the firewall heat shield. It ends up being pretty cost prohibitive for machined components. Titanium starts to shine in applications where you can replace steel. Right now we have a stainless exhaust system so we have ambitions of coming up with a titanium version for weight savings.

[@curvs4me]

Looking good guys, the forest is becoming visible through the trees

[@rclark0884]

Can you share the Shock you have selected?

[@brianb-p6586]

In the comments on another video they said that it was from TK 1 Racing.

[@far1002]

Carbon fiber is fuel safe? Or is it a special epoxy ?

[@davidwhite2011]

For the center header tank, have you mocked up anything you can leave fuel in for a while to test the resin?

[@DarkAeroInc]

The epoxy we use in the fuel tank and fuel sump is fuel compatible. Adhering to “trust but verify”, we have a number of long term fuel soak tests we have run with just pure epoxy with no detrimental effects on the mechanical properties.

[@oddspaghetti4287]

@@DarkAeroInc What epoxy are you using for those parts that require fuel compatibility if you don't mind me asking?

[@davidwhite2011]

@@DarkAeroInc Ronald Regan is loving you from the grave! kzbin.info/www/bejne/d6SZqmibfpVkjqc

[@OhHeyTrevorFlowers]

Looking good, guys!

[@thomasschmidt1836]

Do or will you have a redundancy or manual backup for deploying the gear should the primary relay or other component malfunction?

[@DarkAeroInc]

Yes. It wasn't discussed in this video, but there is a manual backup for redundancy if there is a motor failure or electrical failure. There is a handle in the cockpit which can be pulled to cable actuate a mechanism that disconnects the motor from the gear train, allowing the gear to fall and lock in the down position. The gas springs in the system control the downward motion of the gear to swing down and overcome aerodynamic loads. We will demonstrate this functionality in an upcoming video on the nose gear where we go into more detail on the whole system. Thank you for watching and for the question!

[@Sturmbock71]

In the fuel system, something I got was: You vent the "sump" to the fuel tanks again? You don have a vent to the outside? And I will not call it "sump" it looks more a "hopper tank"

[@brianb-p6586]

"Sump" is an unusual choice for this, because sumps are more commonly for drainage of unwanted fluid, but is technically correct. An engine sump is a similar use of the term.

[@ОлегКо-э9к]

почему маунт шасси заканчивается на середине строительной высоты ? Почему в конструкции присутствует изгибающий момент ? Почему жесткость сечения только по одной координате преобладает ? Сколько шасси вы спроектировали перед этим проектом ?

[@GS-wx5pr]

In the words of your builder 'uncle' Mike Patey, "BACK TO WORK!"

[@tomcoryell]

Great design!

[@Simon-bz7sx]

How are you going to do deice/anti-ice?

[@DarkAeroInc]

We are not implementing an icing protection system. These sorts of systems are typically not found on experimental kit aircraft.

[@chrisjenkins9978]

Does the fuel travel from the tanks through the sump in a continuous loop?

[@thewheelieguy]

The loop is sump - fuel injector rail - sump. The small elbows are for vapor return. Not sure where they allow inlet venting to the atmosphere..

[@mgully]

Should the returning fuel return to the sump or wing tank?

[@forthwithtx5852]

Interesting stuff. I noticed that you don’t have Mike Patey’s channel in your list of great channels. I’d call that an oversight.

[@shawnwedge5833]

Amazing as usual.

[@chemix007]

dose carbon fiber resistant to fuel, on you samp?

[@DarkAeroInc]

Yes. The carbon fibers themselves are quite resistant to fuel. The thing that requires attention is the resin matrix in the carbon fiber composite. The resin we are using is also fuel compatible though.

[@mehmetgunes8586]

"No I wont probably not" lol

[@DarkAeroInc]

😂 😂😂

[@bosatsu76]

If fuel is gravity fed to the sump, how do you do aerobatics... I thought the original plan was a fully aerobatic plane... If you're upside down won't the vapor vents now fill with fuel..

[@brianb-p6586]

The aircraft will be for normal category maneuvers only, not aerobatics. That's in their FAQ video.

[@mauricehrolfe4466]

What is your emergency undercarriage deployment ?

[@DarkAeroInc]

There is a mechanism that is cable actuated from the cockpit that unlocks the gear and allows it to fall under gravity. Gas springs in the system force the gear to the down locked position, overcoming aerodynamic loads. The unlock mechanism also disengages the motor from the rest of the gear train so the strut isn’t back driving the motor. None of this was discussed in the video but we plan to show this in an upcoming video so stay tuned for that! Thank you for watching!

[@guntmar]

great stuff !

[@courtman007]

Would be interested to hear more on the layout of your fuel system

[@markleightonson1770]

Super!

[@benjaminschaefer6757]

Fine work, gents!

[@DFMurray]

"We have a left and right wing." You don't say lol

[@mikegriffith8266]

Didn't see a retract.

[@ilyakhamitov982]

up&up