Design and Fly Planes that are Hard to Fly

[322997am]

This challenge actually has two parts. Part one consists of making and posting a design of a plane that is very difficult to fly. The second part is flying a plane that another user created.

The rules are rather simple. For part 1.

1. The plane has to actually be a plane, and possess the ability to potentially fly. It does not have to(and shouldn't) fly well, but it should be able to.
2. Stick to stock parts
3. Maybe explain in your comment why the plane may be difficult to fly

For part 2.

1. Provide proof
2. Explain what you did during the flight\

That's really it. Post designs and flights below

[Klapaucius]

I'll enter this one.  Of all my planes, this is the twitchiest.   It only has one wheel, so the trick is to get it up on the gear without destroying the flaps.   It has too much wing and no tail, so it is all over the place at any speed.  I've only successfully landed it once without breaking anything. It can be done, but the odds are NOT in your favour...

I named it Oscar, after Oscar the Grouch.

The file is on Kerbal X: https://kerbalx.com/Klapaucius/8-Part-Flying-Wing-Oscar

 

 

 

 

Edited April 10, 2019 by Klapaucius

[silks]

Part 1

All my planes fly just too well, so here's my low tech Caveman Spaceplane (CMSP), with a twist. Due to a malfunction in electronics, reaction wheels do not work and neither does the main engine! Fully fueled, it has barely enough thrust to gain altitude.

Instructions: Accelerate to around 80m/s and pull up hard. Press space and pretend to be surprised that the liquid fuel engine has no thrust. Now try to stabilize, loop around and land back on the runway. Do not use SAS (because its broken).

Craft file here (KSP 1.7.0): https://www.dropbox.com/s/6ih7oqwiv9234us/CMSP.craft?dl=0

Part 2

Oscar sure is one hell of a challenge to fly. Nearly impossible without SAS. Managed to land it in one piece but not quite on the runway. All it took was dozens of attempts and almost all of my willpower.

[Klapaucius]

On 4/16/2019 at 7:39 AM, silks said:

 

Oscar sure is one hell of a challenge to fly. Nearly impossible without SAS. Managed to land it in one piece but not quite on the runway. All it took was dozens of attempts and almost all of my willpower.

Oh wow!  I've only done that once.  You put a smile on my face this morning!  I used the thrust reverser right at the end to achieve it. And yes, it is pretty much impossible without SAS.  Oddly, the wings make it worse.  I build most of my planes to be more flyable as well, but this was an early K.R.A.S.S.H. Industries attempt at budget cutting. (I eventually did away with the wings all together, and the result flies better, though you pretty much have to bail out to survive.) https://kerbalx.com/Klapaucius/Scrooge-4-part-disposable-aircraft

 

As for your plane, I had a real problem with bouncing landing gear--it seems like that bug is still a problem. Several times it just exploded before takeoff.  I did get it in the air finally, but the second I tried to turn, I lost altitude and crashed :-O

Edited May 2, 2019 by Klapaucius

[silks]

Oops, I completely forgot about reverse thrust. Might have stopped on the runway then.

Thanks for trying out my craft - good to hear that it's challenging. 

Yes, those low tech wheels don't seem to tolerate planes this heavy. So landing and takeoff has to be really gentle. This might spoil the challenge, but here's what helps me land the plane:

Spoiler

I recommend using pitch trim (alt + S, W for windows) on takeoff and when leveling out. Slightly pulling up on takeoff reduces stress on the front wheel and should result in less crashes. Having the control surfaces in a fixed position, thanks to pitch trim, gives you slightly more lift and less drag, which lets you loop around instead of falling into the water.

 

[PhazeKL]

I'm ready to take on this challenge. Prepare to fly the plane of your dreams nightmares

[Aeroboi]

Fun challenge, this seems rather fun and will see if I can properly mess up any of the planes I've got.

Is this the invention of multiplayer

[vyznev]

When I saw this challenge, I immediately knew exactly which craft I wanted to enter: my very first (or maybe second, I'm not sure) autogyro design.  Unfortunately, I couldn't find the craft file any more, but I decided to just rebuild it.  So, for your challenge and torment, let me present this almost unflyable and extremely creatively named aircraft, the "Autogyro":

Taking off with it is a challenge. Maintaining anything resembling stable flight is a pain. Landing it is... only for the brave. 

The biggest reason why it's so hard to fly is the same one that affects all single-rotor gyrocraft in KSP: asymmetric lift. Real life aytogyros deal with it by using a swash plate to adjust the rotor blade pitch as it rotates. That doesn't really work in KSP, so you'll inevitably have the rotor producing more lift on one side of the craft than on the other, making it want to roll over. Oh, and did I mention that the amount of roll torque varies depending on a bunch of factors, including airspeed and the spin rate of the rotor?  

Combine that with the unique aerodynamics of autogyros in general, and the result is an... interesting flying experience, to say the least.

Yet, it does fly. Not well, but well enough to count as technically flyable. I even managed to fly it all the way around the KSC, proving that it's controllable in the air.

And I even managed to pull off a safe landing... sorta. 

Anyway, here's the craft file.  Now is your chance to prove that you're the Autogyro Ace!  Get this thing in the air and show me what it can do.  (Besides crashing, I mean. I already know it can do that.)  Can you fly it to the island airfield and back?  Fly it under the R&D bridge?  Fly it... well, at all?

(To start it up, just press space to stage — this will start the engines and release the rotor.  SAS is recommended, although I'd very much like to see someone fly this without it.  The rest is up to you.  )

[ShadoxFilms]

Thought this was an interesting challenge since I'm taking a Flight Stability and Dynamics course at the moment, so I took all the things that add static and dynamic stability, and did the opposite!

Named the X-12 Drunk Dragonfly, this 18 ton aircraft features a -5 degree dihedral, forward swept design with a static margin of less than 0.05. This aircraft has marginal static longitudinal stability, unstable static roll and yaw stability, and unstable dynamic stability in all modes. The aircraft is fairly heavy (fuel helped get CM extremely close to AC) and so SAS is recommended for take off. Once you are in the air, this beast will tend to fly backwards if you arent constantly providing input to dampen out the oscillations. The drunk dragon is overly manueverable at low speeds, and can maintain level flight in dry mode at about 40 degrees AoA. The slats and use of the ailerons as flaps helps tremendously at low airspeeds, but does increase the forward pitching moment.

 

Fun to fly, but hard to control, possibly impossible to land.

[Klapaucius]

1 hour ago, ShadoxFilms said:

Thought this was an interesting challenge since I'm taking a Flight Stability and Dynamics course at the moment, so I took all the things that add static and dynamic stability, and did the opposite!

Named the X-12 Drunk Dragonfly, this 18 ton aircraft features a -5 degree dihedral, forward swept design with a static margin of less than 0.05. This aircraft has marginal static longitudinal stability, unstable static roll and yaw stability, and unstable dynamic stability in all modes. The aircraft is fairly heavy (fuel helped get CM extremely close to AC) and so SAS is recommended for take off. Once you are in the air, this beast will tend to fly backwards if you arent constantly providing input to dampen out the oscillations. The drunk dragon is overly manueverable at low speeds, and can maintain level flight in dry mode at about 40 degrees AoA. The slats and use of the ailerons as flaps helps tremendously at low airspeeds, but does increase the forward pitching moment.

 

Fun to fly, but hard to control, possibly impossible to land.

Is there a way to download it?  Part of the challenge is to fly other people's cantankerous creations.  I'm looking forward to this one. I'll also need to take @vyznev's autogiro for plummet, er, flight....

[ShadoxFilms]

23 minutes ago, Klapaucius said:

Is there a way to download it?  Part of the challenge is to fly other people's cantankerous creations.  I'm looking forward to this one. I'll also need to take @vyznev's autogiro for plummet, er, flight....

New to the forums, what's the best way to share craft files?

[Klapaucius]

11 minutes ago, ShadoxFilms said:

New to the forums, what's the best way to share craft files?

If you just want to share on the forums, Dropbox or Google Docs works. However, if you don't mind sharing with the wider world, KerbalX is the easiest. @katateochi has created a brilliant site for sharing all KSP craft. It's a lot of fun; I upload a lot to it and also enjoy test flying other folks' creations. (Apologies if I am telling you what you already know...)

 

 

[ShadoxFilms]

46 minutes ago, Klapaucius said:

If you just want to share on the forums, Dropbox or Google Docs works. However, if you don't mind sharing with the wider world, KerbalX is the easiest. @katateochi has created a brilliant site for sharing all KSP craft. It's a lot of fun; I upload a lot to it and also enjoy test flying other folks' creations. (Apologies if I am telling you what you already know...)

 

 

https://kerbalx.com/ShadoxFilms/UX-12-Dracon There ya go!

[purpleivan]

At first I thought no problem, I've got this, then I saw...

On 4/8/2019 at 6:15 PM, 322997am said:

...possess the ability to potentially fly.

and that was just so limiting. I mean it disqualifies half the planes I've ever built.

[vyznev]

It feels like this thread is suffering from an abundance of hard-to-fly planes and not enough flight attempts. To try and balance the ratio a bit, I'm taking all the previous entrants out for a spin (possibly literally).  Here's Klapaucius' Oscar the One-Legged Grouch:

On 4/10/2019 at 3:58 PM, Klapaucius said:

I'll enter this one.  Of all my planes, this is the twitchiest.   It only has one wheel, so the trick is to get it up on the gear without destroying the flaps.   It has too much wing and no tail, so it is all over the place at any speed.  I've only successfully landed it once without breaking anything. It can be done, but the odds are NOT in your favour...

Indeed they are not. It took me dozens of practice runs and quickloads to manage this:

I wanted to try recording a video, but there's something wrong with my OBS install. The video capture freezes after 30–60 seconds, and only resumes when there's a scene change (e.g. a restart / reload).  So screenshots are all I have. Sorry.

Anyway, a couple of observations:

• Takeoff is easy. Just wait for the craft to settle down, turn on SAS and start the engine. The plane simply takes off by itself.  (Well, usually. Occasionally it hits a bump in the terrain mesh and loses a wing instead. But that's pretty rare as long as the wings are level to begin with.)
• There's an unstable Dutch roll(?) mode that's easy to enter and almost impossible to get out of. Once it gets going, the plane starts wobbling more and more until the wings stall and it simply tumbles uncontrollably to the ground. Turning off yaw response on the elevons seems to make things a bit more stable, but pitching up at the wrong moment can still easily lead to tumbling out of the sky.
• A survivable landing is actually fairly easy with some practice, and with the help of the thrust reverser. What's hard is slowing down fast enough not to lose a wing or an elevon (or both wings, or the engine...) when the plane inevitably tips over.
• The "1" and "F1" keys are annoyingly close together. At least one very promising landing attempt was ruined when I hit the wrong key while trying to take a screenshot.  

Anyway, yeah, that was fun.  Now on to the next entry...

Edit: I finally got videos working with a different capture method. So here's my almost successful return flight from the island airfield:

And here's a demonstration of the Dutch roll oscillation mode. A fairly reliable way to trigger it seems to be pitching up while in a sideslip. In the video, I actually managed to stop it once before it got out of control, and then semi-deliberately triggered it again:

 

 

Edited May 5, 2019 by vyznev
added videos

[faketuxedo]

I originally posted this for this challenge, but it would fit really well here, so here I go. 

It's hard to fly, because:

1. It cannot turn

2. It must be dropped from 150 feet in the air to be able to fly and use monopropellant boosters to get it off the ground

3. It cannot land to my knowledge 

4. Once you reach 500 feet or so, the plane will decide to descend and crash into the ground.

5. It takes multiple trials to get it off the ground

In flight I launched it using method described, tried then tried to turn around and land (nope). 

Video:

https://drive.google.com/file/d/1asKoSJdP86fejLG9KurmZtIdii06rf4n/view?usp=sharing

.craft File:

https://drive.google.com/file/d/1wvQQi9yZQJpJFNuSF9H6VuNQEM73wAxP/view?usp=sharing

 

[Klapaucius]

30 minutes ago, vyznev said:

• There's an unstable Dutch roll(?) mode that's easy to enter and almost impossible to get out of.

Dutch Roll Mode. I like the marketing euphemism. I think I will include that in an updated description on KerbalX.  

"It's not a flaw; it's a MODE..."

[Rocket In My Pocket]

Do they have to be designed specifically for the competition?

I've got some truly horrible planes gathering dust in my old save file, from back when I had no friggin' clue what I was doing lol.

There are more, but these were a few of the worst offenders that sprung to mind, I'll upload a craft file if anyone is foolish enough to actually wanna fly one lol.

UPDATE: Added links.

 

The "SiameseTwin"

https://kerbalx.com/RocketInMyPocket/SiameseTwin1

An early attempt at carrying a rover afar, at the time; I thought this twin body design was rather clever! It isn't, like...at all.  Flies...alright I guess? Assuming you don't want to turn at any point.

The "NeedleNose1B"

https://kerbalx.com/RocketInMyPocket/NeedleNose1B

Yes, This farce actually has a couple versions, but this is the "best" one (and I use the word "best" begrudgingly.) Ugly, slow, awkward...prone to falling out of the sky, on top of being pointless, I mean..what did I even build this thing to do? I don't remember anymore!  ...Need I go on?

The "V-wing Test"

https://kerbalx.com/RocketInMyPocket/VwingTest1

Now, in my defense; I named this as a test, because apparently; even I didn't think it was gonna work lol. No surprise; I was right. 

Bonus Plane:

DON'T LAUGH, THIS ONE WORKS! 

Spoiler

 

Edited May 7, 2019 by Rocket In My Pocket

[Klapaucius]

31 minutes ago, Rocket In My Pocket said:

Do they have to be designed specifically for the competition?

I've got some truly horrible planes gathering dust in my old save file, from back when I had no friggin' clue what I was doing lol.

  Hide contents

 

 

No, mine is old as well.

[vyznev]

And here's my attempt at flying silks' Caveman Spaceplane.

On 4/15/2019 at 10:39 PM, silks said:

All my planes fly just too well, so here's my low tech Caveman Spaceplane (CMSP), with a twist. Due to a malfunction in electronics, reaction wheels do not work and neither does the main engine! Fully fueled, it has barely enough thrust to gain altitude.

Instructions: Accelerate to around 80m/s and pull up hard. Press space and pretend to be surprised that the liquid fuel engine has no thrust. Now try to stabilize, loop around and land back on the runway. Do not use SAS (because its broken).

This was actually my second attempt, since I forgot to read the instructions the first time. So while I was genuinely surprised by the disabled rocket engine, I also didn't realize I wasn't supposed to just enable it.   (If you'd really wanted to mess with people, you could've attached the engine to a part that doesn't provide fuel crossfeed. Can't fix that while in flight...)

Spoiler: Everything went well until I ran out of runway.  It's all my own fault for deviating from the instructions and trying to land on the island airfield instead. What can I say? I like the island airfield. But not when you're landing at 80 m/s and have lousy brakes.  

Edited May 5, 2019 by vyznev

[Klapaucius]

Well, it was a morning of many fails.  I never successfully landed any of these.

 

@vyznev  I took up your challenge of flying this without SAS. I, um, er...well, I did get it in the air.  Ironically, two of my better attempts occured after having lopped off half the tail on takeoff. That seemed to ameliorate the rolling tendency a bit.  I did one flight with SAS on, but still crashed trying to land.

 

 

The Drunk Dragonfly. Ugh....

 

 

 

I did much better this time around with the caveman and, oddly, had no gear issues today at all.   I still destroyed it whilst trying to land...

 

[vyznev]

Here are two more first impressions, and two more island landing attempts. One of them even almost succeeded.  Still, not too bad for a literal first try.

Because I got some server errors when I first tried to download ShadoxFilms' plane off KerbalX, I started with faketuxedo's weird plane instead:

3 hours ago, faketuxedo said:

It's hard to fly, because:

1. It cannot turn
2. It must be dropped from 150 feet in the air to be able to fly and use monopropellant boosters to get it off the ground
3. It cannot land to my knowledge 
4. Once you reach 500 feet or so, the plane will decide to descend and crash into the ground.
5. It takes multiple trials to get it off the ground

It's indeed pretty weird, but surprisingly flyable. Well, as long as you don't mind the reversed controls, that is. Unfortunately, my aim was a bit off on the landing attempt, and the I didn't have quite enough pitch authority to pull up and go around. But one surviving kerbal out of two is still pretty good, isn't it?  

 

 

Eventually, KerbalX stopped giving me errors and I got a chance to test ShadoxFilms' Drunk Dragonfly too:

20 hours ago, ShadoxFilms said:

Named the X-12 Drunk Dragonfly, this 18 ton aircraft features a -5 degree dihedral, forward swept design with a static margin of less than 0.05. This aircraft has marginal static longitudinal stability, unstable static roll and yaw stability, and unstable dynamic stability in all modes. The aircraft is fairly heavy (fuel helped get CM extremely close to AC) and so SAS is recommended for take off. Once you are in the air, this beast will tend to fly backwards if you arent constantly providing input to dampen out the oscillations. The drunk dragon is overly manueverable at low speeds, and can maintain level flight in dry mode at about 40 degrees AoA. The slats and use of the ailerons as flaps helps tremendously at low airspeeds, but does increase the forward pitching moment.

Out of all the planes in this thread so far, I feel this one was by far the most flyable. Well, at least after I made a few on-the-spot adjustments, like reversing the deploy direction on the slats after my first takeoff attempt ended up in the ocean, and pumping some fuel from the rear tanks to the front ones while I was falling tail end first down from 15 km on the second attempt.  Which was pretty fun. 

The video is kind of long, because I spent some time flying around trying to see how high and fast this thing could go. Feel free to fast-forward over the boring bits. Here are some of the more notable parts:

• 1:55 — second takeoff attempt
• 3:20 — testing stability with SAS off (not too bad, but can't really maintain a stable pitch for long)
• 11:40 — reached 850 m/s in (more or less) level flight at 15 km
• 11:45 — lost stability, commenced falling down from 15 km  
• 14:25 — regained stability at 2.5 km
• 15:20 — where the **** am I? 
• 17:35 — testing stability under physics warp (it's fine)
• 21:00 — first landing attempt and go-around
• 23:25 — second landing attempt...

Spoiler: Short runway is still short. (And narrow.)  

 

1 hour ago, Klapaucius said:

@vyznev  I took up your challenge of flying this without SAS. I, um, er...well, I did get it in the air.  Ironically, two of my better attempts occured after having lopped off half the tail on takeoff. That seemed to ameliorate the rolling tendency a bit.  I did one flight with SAS on, but still crashed trying to land.

Even so, that's some pretty impressive flying right there. 

The apparent stability improvement from losing one of tail fins is something I also noticed myself. It seems to be a rather common occurrence.   I'm not sure if it's actually more stable that way, but at least it seems to make it unstable in different ways.

[faketuxedo]

1 hour ago, vyznev said:

It's indeed pretty weird, but surprisingly flyable.

That's really surprising! I must just be a really bad pilot then.

[vyznev]

49 minutes ago, faketuxedo said:

That's really surprising! I must just be a really bad pilot then.

Well, "surprisingly flyable" is a relative term. It was really more like "I'm surprised that this crazy thing can fly!"  

I was particularly surprised that I managed to take off on the first try (and even missed the tower!), but I suspect some luck was probably involved there. Still, I'm planning on trying it again to see if I can actually stick a landing. It's probably not impossible...

[Klapaucius]

9 hours ago, vyznev said:

Well, "surprisingly flyable" is a relative term. It was really more like "I'm surprised that this crazy thing can fly!"  

I was particularly surprised that I managed to take off on the first try (and even missed the tower!), but I suspect some luck was probably involved there. Still, I'm planning on trying it again to see if I can actually stick a landing. It's probably not impossible...

Taking off was the issue for me. The gear is so unstable that it was near impossible not to lose a wing. I eventually managed it by just going off the side of the runway and letting that little drop get it airborne.  I also tweaked the dampening on the gear, which may have helped. Once in the air, it was not hard to fly, though it turns VERY slowly. I lost too much altitude on the approach and could not get the nose back up. Yet another landing fail!

 

So, @faketuxedo, here it is 

 

Edited May 6, 2019 by Klapaucius