Biggest Plane with a Juno

[zolotiyeruki]

1 hour ago, GoSlash27 said:

No good reason, honestly. This challenge just gave me an excuse to build a plane similar to the Rutan Voyager. Unfortunately, the canard configuration didn't work well at low speed and I had to revert to a more traditional arrangement.

As a big fan of pretty much anything Rutan, I approve

[Rocket In My Pocket]

10 hours ago, zolotiyeruki said:

These entries are fantastic! For those who opted for structural wing segments instead of the larger wet wings, I'd love to hear the rationale. Heck, I'd love to hear more about everyone's approach.

Well I figured any "wing weight" would be slightly offset by the lift it produced, whilst any "fuel weight" over what was required to make the trip would be essentially dead weight.

Plus, I just really wanted to make a giant flying cereal box. 

Edited April 9, 2018 by Rocket In My Pocket

[hoioh]

Pretty hard, this!

Made it with 31.356t to the island runway though!

Flying this thing is the easy bit, followed by take off and the hardest bit is definitely landing: https://imgur.com/a/oQegW

Oh and don't shut down the engine! you'll lose power quickly!

Edited April 9, 2018 by hoioh

[Gordon Fecyk]

Ferram Aerospace attempt. @zolotiyeruki this was a FAR attempt, not a Stock attempt.

Final craft mass was 9.973 tonnes. Poor compared to the Stock entries, but notable. I might have brought more fuel over but I had centre of mass issues.

Craft was a tri-wing along the lines of WWI fighters to try to get more lift at lower speed. I had to reduce the wing mass to 50% of original (FAR lets you do that at the expense of strength), and tried to use flaps and spoilers. At Flaps 2 my stall speed was just over 62 m/s. Turned reaction wheels off on the cockpit. The top tail fins acted as air brakes.

With the single Juno, my first thought was, 'bi-plane.' That worked out well, but produced only a 2.5 tonne craft. I wonder how far one could extend the tri-plane design to carry more mass.

Edited April 10, 2018 by Gordon Fecyk
Added video, and pinged zolotiyeruki to change leaderboard entries

[Box of Stardust]

5 hours ago, hoioh said:

Pretty hard, this!

Made it with 31.356t to the island runway though!

Flying this thing is the easy bit, followed by take off and the hardest bit is definitely landing: https://imgur.com/a/oQegW

Oh and don't shut down the engine! you'll lose power quickly!

I only went up to 6-8 airliner wings under the assumption that any more would just be too much drag. Guess I was wrong. 

[neistridlar]

34.12 ton landed. Just barely flew. Took the entire runway to get up to speed.

 

[ManEatingApe]

Goal: Design a streamlined and manoeuvrable craft with a sleek aesthetic.

Result: Giant Tube Worm!

Acceleration was...marginal.

Just about airborne!

At least it's easy to aim 

Made it to the Island Airfield...

...sort of! 

31.76 tons (almost) to the Island Airfield

Doesn't matter...I had a lot of fun!

Full album here

Edited April 10, 2018 by ManEatingApe

[HalcyonSon]

On 4/8/2018 at 10:24 PM, Box of Stardust said:

If there's a way to get over 30t to the island, I haven't found it. 

I've experimented with various combinations of values between dead weight and wing mass. Too much wing causes too much drag, too much weight with not enough wing means not enough lift. 

Seems to me that with a +30t aircraft, 50m/s is the minimum speed needed to remain airborne, but the Juno doesn't have enough thrust to overcome the drag, nor does it have the accleration to put wings in fast enough airflow to create significant lift. And I understand KSP's funky stock drag model fairly well. No other radially attached parts other than wings and landing gear, streamlined main fuselage.

Maybe in FAR though. Whenever drag becomes a problem, FAR is usually the answer!

The last potential solution I could think of for stock KSP though is having jettisonable landing gear, but that 1. wouldn't bode well for landing on the island, and 2. probably doesn't have that much of an overall effect anyways. But when you're chasing every single reduction in drag, maybe it does count. 

Maybe place the landing gear in a cargo bay?  Same bay can be used to hold multiple ore containers and provide a small amount of lift.

[Rocket In My Pocket]

On 4/10/2018 at 4:26 PM, ManEatingApe said:

-snip-

Giant flying tubes?

Now that's just insanity! Good heavens!

Can't you just fly a box like a proper gentlemen? What will the neighbours think?

[zolotiyeruki]

If I've missed adding anyone to the leaderboard, please let me know.  It's not my intention to leave anyone out!

[hoioh]

@zolotiyeruki not sure if this is completely within the rules, but there was nothing in there about using SMARTASS for piloting, which was pretty much the only way to pilot this 40t+ behemoth to the island airstrip. It's up to you to include it or not. (I did manage 40 friggin' tons though!)

 

Album of the nerve wrecking trip: https://imgur.com/a/98BZX

[Box of Stardust]

50 minutes ago, hoioh said:

@zolotiyeruki not sure if this is completely within the rules, but there was nothing in there about using SMARTASS for piloting, which was pretty much the only way to pilot this 40t+ behemoth to the island airstrip. It's up to you to include it or not. (I did manage 40 friggin' tons though!)

 

Album of the nerve wrecking trip: https://imgur.com/a/98BZX

Geez. 

I guess past a certain point, all the lift overcomes any possible drag.

[zolotiyeruki]

Well, I didn't address autopilot mods in the OP, so I think it passes.  Anyone object to it?  That's an astounding amount of mass for <20kN of thrust.

[Box of Stardust]

57 minutes ago, zolotiyeruki said:

Well, I didn't address autopilot mods in the OP, so I think it passes.  Anyone object to it?  That's an astounding amount of mass for <20kN of thrust.

It depends whether you want this to be just an engineering challenge, or an engineering and piloting challenge.

[Box of Stardust]

Okay, now I'm sure this is at the physical limit of craft building. Also, it's not quite 'airfield', but it's there. JunoSlab-49 - because it's a giant slab powered by a Juno that weighs in at 49t.

I manually flew this thing in a perilous equilibrium for a harrowing 20 minutes or so. I'd like to thank the Kerbal Express Airlines Challenge for forcing me to learn how to build a plane that you can fly by adjusting the trim tab.

Because wew, the margins for flying this thing were slim. I spent practically the entire time watching the vertical speed and horizontal speed readouts. I couldn't go slower than 32m/s horizontally, because that would be a risk of unrecoverable stalling, and I couldn't go further than -1m/s vertically because that was just losing too much altitude.

This was pretty much a fight to keep the slim 70m altitude above sea level advantage as far as possible. I was sea-skimming by the last 7km of this. Funny enough, whenever I wanted to check my altitude, I'd always look up at the main altimeter at the top... even though I have what's effectively a radar altimeter right above the speed readouts I was reading. It's when the terrain altitude switched to reading out in hundred centimeters that I really kept my eye on it.

Better results can only be gotten... maybe by taking the excess fuel out, replacing that mass with wings, and having an AI pilot this thing 100% perfectly? I didn't really know how to use the MechJeb AI for atmospheric flying so I didn't bother. I was also thinking that maybe the best way to do it (since it's not necessarily specified in the rules) is to turn off of the runway at some point at KSC and point straight at the island while still on the ground, so no energy is lost turning in the air. Maybe could've even attempted landing on the actual island airfield that way.

 

By the way, this was my favorite part I think:

 

The point where physics pretty much stops and gets weird.

Also, fun with aero:

 

This was originally a 53-tonner, but the 53t craft just couldn't retain enough energy/bled too much energy. So I stripped off 20 wing panels.

Edited April 13, 2018 by Box of Stardust

[Box of Stardust]

Okay, just as I said:

Remove a fuel tank, replace mass with wings. Diagonal takeoff from runway. Let a computer do the heavy lifting with extreme precision.

And here we have it: the magic Five-Oh, 50t.

[hoioh]

14 hours ago, Box of Stardust said:

It depends whether you want this to be just an engineering challenge, or an engineering and piloting challenge.

I did still correct the direction and everything by hand, basically SMARTASS is just a very advanced stability assist

@Box of Stardust I take my hat of for you sir! that is impressive! I couldn't manage with anything over 42t at launch

[zolotiyeruki]

I am frankly stunned at two things:

1. That you managed to get 50 tons to the island on one Juno
2. That your plane held together.  Whenever I stack a bunch of wings on, the Kraken appears and the plane jiggles itself to pieces.

[ManEatingApe]

1 hour ago, Box of Stardust said:

And here we have it: the magic Five-Oh, 50t.

Impressive! I thought for sure the 30-40 ton range would be the limit...that's just a distant dot in your rear view mirror.

Edited April 13, 2018 by ManEatingApe

[Box of Stardust]

35 minutes ago, zolotiyeruki said:

I am frankly stunned at two things:

1. That you managed to get 50 tons to the island on one Juno
2. That your plane held together.  Whenever I stack a bunch of wings on, the Kraken appears and the plane jiggles itself to pieces.

Yeah, uh... I went and installed KJR for that. Not even toggling All Rigid with EEX could prevent the death jiggle.

I haven't tried spacing out the wings with the offset tool though. That might prevent the death jiggle. 

29 minutes ago, ManEatingApe said:

Impressive! I thought for sure the 30-40 ton range would be the limit...that's just a distant dot in your rear view mirror.

It's honestly less of a plane than a powered glider by this point. I'll give it one more go later using MechJeb from the start of the takeoff run for maximum efficiency through robotic precision.

[Box of Stardust]

Alright.

As my final attempt any time soon, I did as I said I would and would put it under MechJeb control as soon as I figured applicable. Given this flight plan, I also increased the mass again, with the expectation that precise computer control can fly this in the narrow margin of flight that it will have.

Not just that, but I decided to be fair and not use Kerbal Joint Reinforcement. Some minor adjustments were done- spacing out the layers from each other, and adding load-bearing struts.

Did you know struts are really heavy? I use them so little that I had no idea! But they work! The Kraken tries to attack, but this brick of wings can hold itself together.

Here it is: JunoSlab-51

(It requires MechJeb to fly, but there's no MJ module on it since I have MechJeb and Engineer For All installed, so those are integrated into my probe cores.)

And here's the demonstration, sped up for convenience:

 

[zolotiyeruki]

Your persistence is inspiring.  And mystifying   I've updated the leaderboard!  I hate to tell you this, however--on landing, your craft had burned enough fuel to fall under 51 tons (50.917).  

[Box of Stardust]

38 minutes ago, zolotiyeruki said:

Your persistence is inspiring.  And mystifying   I've updated the leaderboard!  I hate to tell you this, however--on landing, your craft had burned enough fuel to fall under 51 tons (50.917).  

Actually, fun fact, I built the JunoSlab-51 featured in the video incorrectly. I used Structural Wing Ds on the sides instead of Structural Wing Cs, which I had 'calculated' would still be flyable while landing with over 51t.

The JunoSlab-51 in the KerbalX link is the corrected version, which will land 51t on the island. I was going to do a flight of it in 1.4.2 because someone said 'it doesn't work as well in 1.4.2', so I was going to prove them wrong, but I didn't have my beacon set up, so I couldn't aim at the start precisely, and I ended up in the water about 1.5km short from the island.

[Kernel Kraken]

I just build a dual Juno biplane for the KEA challenge, it has a takeoff speed of 24 meters per second. If I remove a Juno I bet it'll work here... 

Hopefully.

[n.b.z.]

I submit the "Brutan Traveler".

• 100% stock
• 12.21 tons after landing on the island airfield

_______

On the one hand, this is not a proper challenge entry, as I didn't even try to go for the actual objective - to fly the highest possible weight I can.

On the other hand, I did build a plane as a response to this thread, it's my Biggest Plane With A Juno, both in size and weight, and I flew it to the island airport.

I ended up with merely 12.21 tons on the island airfield. But more importantly, I not only had a lot of fun building and flying the thing, I actually have a keeper. I will keep flying this plane just for the joy of flying it. I never thought I would say that about a plane with such a ridiculous TWR!

It has become my favourite thing in KSP to make airplanes just for fun flying - yes, of course using a joystick - and I put a lot of effort into tuning their handling. CoM/CoL, fuel tank layout, trim and "known" trim speeds, flaps (also with trim), control surface authority, gear params, ... if it has advanced tweakables, it will be tweaked.

So reading this thread - already thinking about a one-Juno plane - I saw GoSlash27's beautifully rutanesque plane, and the following three things occured to me:

1. Awesome! I want a Voyager-like plane, too. Using only one Juno would actually be just right for that.
2. Hmmm, no canards? I want mine with canards!
3. But GoSlash27 isn't exactly new at this, so... since I like fine-tuning a lot... making canards fly and handle really well might be a challenge all by itself?

(This is not a dig at GoSlash27 - his plane beats mine by miles in this challenge, and was what inspired me to make one myself!)

Ditching the max-weight / top-of-the-leaderboard goal allowed me to build a plane that's by no means a replica of the Voyager, but resembles it a bit closer, if only for the canard layout and the thinner booms. It's called "Brutan Traveler" because this absolutely, totally doesn't sound like a cheap knockoff of the "B. Rutan Voyager" at all.

I couldn't even resist adding a few draggy parts for the looks. The plane has two air intakes instead of one, useless winglets, and three lights hidden away in the fuselage.

The handling is superb, I had no big troubles with the canard setup. In fact, I only use the inner half of the canard as elevators, and these surfaces are set to only 70% deflection. (The reaction wheel of the Mk1 cockpit is disabled.) The canard has a slight angle of incidence, and I was delighted to find that it actually stalls before the main wing does, resulting in a benign stall behaviour and an easy recovery.

There are three flap settings (action groups 1-3): no flaps, flaps HALF, and flaps FULL. The neutral trim speeds, at sea level, for these settings are, respectively: 100, 75, and 50 m/s.

That's to say, the plane flies in a perfectly straight line without SAS and very little / occasional control inputs when flown at these numbers.

There is also a 5° downward-tilted probe core for semi-automated cruise flight (abusing SAS PROGRADE as AOA HOLD).

Challenge proof shots:

Spoiler

Cruise performance:

• 125 m/s at 3300m - no flaps
• 105 m/s at 4000m - flaps HALF

Of course it takes forever to reach those altitudes.

Thanks zolotiyeruki for this challenge, I had good fun and now have one more plane in the hangar.