8 part aircraft

[Klapaucius]

Recently discovering that my best aircraft so far that I have built only has 13 parts, I started wondering just how far I could pare the parts list down and still have a plane that can carry a Kerbal and take off and land from a runway.

Voila, I present my eight part invention. I've called it Otto, which as well as a name, is Italian for eight. Since I happen to be learning Italian at the moment, it seemed apropos.  I'd be lying if I said it was easy to fly, but neither was the GeeBee.  After a string of failures yesterday evening, I came back to my original idea and managed to get it down to one wheel for landing gear.  Taking off is actually pretty smooth as long as you are gentle.  Landing, is a challenge.  I started out with a Panther engine, and even though it got up over 800 meters per second, you could not do much with it until is slowed down again, and it was too twitchy to try bleeding off speed by nosing up.

I did manage a successful landing with a Wheesley engine. The thrust reverser is the saviour, otherwise as soon as it nose down it destroys itself. I tried both with and without the wings full of fuel. It is certainly easier to fly when heavy, but a challenge not to break on landing. So, if you takeoff full, keep flying.

So, not the safest plane, but the concept works. I'm pretty stoked!

 

With the Panther afterburner. Pretty difficult to land with this engine.

My successful landing.  Full tilt on the thrust reverser.

And what happened when I tried to take off again. KSP punishes over confidence.

Only eight parts!

 

[Klapaucius]

Since my last post not long ago, I have learned that wings are a superfluous indulgence.  So, down to SIX parts!  

After many trials, I have got it down from 100% lethal to you stand a better than 50/50 chance of surviving takeoff.

An early iteration. It took off but I had to bounce the landing gear.

 

I shifter the gear far forward. The trick is to put the flaps down until the back end lifts up, and then gently nudge it up without catching on the ground and blowing up.

 

[Klapaucius]

Evidently, the tail fins are superfluous as well. I swapped out the engine with a Panther to see what it would do. The wings ripped off on takeoff, and yet it kept flying (in some ways, it flew better). That would make this a 4 part aircraft!  There is no way this would land, but Kerbals have good parachutes, so I guess we can think of it as a cheap, disposable aircraft.

Edited May 19, 2018 by Klapaucius

[Zeiss Ikon]

Wow.  That's, what, four parts?  Make it six, by putting tricycle gear on with a slightly nose-up attitude at rest, and you might be able to take off and land.  Maybe even with a Wheesley.  I'm off to the SPH to check...

Edit: Wait, where's the fuel for that last version?  I built one and the Wheesley just flames out when I try to throttle up.

Edited May 19, 2018 by Zeiss Ikon

[SG Aero]

Yeah... that last one has no fuel...

[Zeiss Ikon]

Okay, I switched to the Mk. 1 Diverterless Supersonic Intake, which carries 200 units of fuel, moved it forward inside the Mk. 2 Cockpit so the intake was in the same position.  Now it runs, but it won't fly (yet).  Still fighting with the landing gear.

[Klapaucius]

1 hour ago, Zeiss Ikon said:

Wow.  That's, what, four parts?  Make it six, by putting tricycle gear on with a slightly nose-up attitude at rest, and you might be able to take off and land.  Maybe even with a Wheesley.  I'm off to the SPH to check...

Edit: Wait, where's the fuel for that last version?  I built one and the Wheesley just flames out when I try to throttle up.

It's the MK1 intake, which has fuel.  I learned the trick of mushing all the stuff together from deconstructing a really unusual plane on Kerbal X

https://kerbalx.com/tanisinbo

And speaking of Kerbal, X, I've uploaded all the craft there.

https://kerbalx.com/Klapaucius/craft

 

Anyway, I managed to get it off the ground. I wound up using bigger landing gear for stability.  It's ugly as sin, but it works. I nearly landed it as well. I think it is doable with some practice.  The landing gear acts as a massive airbrake, so that really helps.  It's just my approach angle is too steep. Here are the pictures:

 

I went back and tried the small gear.  Who would've thought bouncing gear could be a good thing, but it bounced it right into the air.  It got up to 1000 mps at 3,000 meters.  But, while it is a much more aesthetically pleasing craft, not having the bigger gear shifted both the weight and the airbraking.

 

 

Edited May 19, 2018 by Klapaucius

[Zeiss Ikon]

Well, I managed to make one I can get off the runway and fly without SAS, with only seven parts.  Haven't managed to land it yet, but I'm not the world's best keyboard pilot -- I probably could, with a joystick.

I found the Mk. 1 Inline Supersonic Inlet gave too little intake air at low speed -- an engine that ought to be able to lift the craft vertically (handy on takeoff -- then the gear catches and flips it, click on "Radial Out" and it'll climb vertically out of the SNAFU) was producing less than 20% of rated thrust at static.  The Radial Intake still doesn't give full air at rest, but it's enough by the time the craft is moving to be able to fly out of a runway flip.  Fuel is in a Bagel tank clipped inside the rear of the Cockpit part (oxidizer pumped out), and COM is just about on the COL, giving very slight static stability with gear up (neutral with gear down, due to gear drag).

[Klapaucius]

4 minutes ago, Zeiss Ikon said:

Well, I managed to make one I can get off the runway and fly without SAS, with only seven parts. 

Two of those wheels are superfluous . You've got a 5-part craft there waiting to get out.

[Zeiss Ikon]

When you're going to land at 150 m/s, more than one wheel is good.  I might switch to a Medium and try it, though...

[Zeiss Ikon]

Okay, five parts can take off.

Actually easier to get off the runway than the seven part variant.  Sure runs out of fuel fast w/ only 27 units Lf in a Bagel tank.  I might have to go back to the Inline Supersonic Intake for the larger fuel capacity, now that I don't need the full 120 kN from the Wheesley to get off the tarmac.

Edited May 19, 2018 by Zeiss Ikon

[Ultimate Steve]

If you are up for it, you could ditch the gear entirely and make it a VTOL craft, or make it only able to do water landings.

[Zeiss Ikon]

In fact, I was just fiddling with that.  Problem is that in order to get anything like full thrust, and combine fuel with the intake, I have to use the Engine Nacelle, which pretty much requires a Mk. 1 Inline Cockpit, leaving me with a 6+ T lander with 6 parts (three legs is the minimum for a VTOL).  And then it loses enough thrust in reverse motion (i.e. dropping for landing) that it barely slows down at full throttle (has only 1/2 G in excess of ambient to start with).  Plus, at 200 m/s, the legs act like fins (even retracted) and it's so stable it's almost impossible to turn.

Honestly, anything in this category is a novelty anyway -- just having gotten 5 parts to fly is all I'm after with this; now I'm going back to hauling fuel to Minmus Station Alpha.

[Stargate525]

If you launch it sitting on its engine vertically, it ought to take off the pad slowly, and then you can slowly turn the sideslip into proper flight.

[Klapaucius]

On 5/20/2018 at 5:10 AM, Ultimate Steve said:

If you are up for it, you could ditch the gear entirely and make it a VTOL craft, or make it only able to do water landings.

The original idea was to create a minimalist craft that could take off and land from a runway. The 6 parter will do that with thrust reverse. The 4 part was a lark which came about after the 6 parter lost its wings on takeoff and the rest kept going. 

However, yes, it will launch and land vertically.  I tried that after a comment on KerbalX asked about it.  So far, I have not managed to do it without destroying the engine, but that is just my lack of skill getting the descent speed right. So, really, you can have a viable jet powered aircraft with only three parts (though to be fair, that MK1 cockpit has a lot of features.).  

 

Edited May 21, 2018 by Klapaucius

[Zeiss Ikon]

I couldn't get enough static thrust to launch vertically with the Mk. 1 Inline Intake and a Wheesley.  The engine was intake-limited until I had some forward velocity (I could see the thrust build even at the beginning of the taxi).  Dropping off the remaining landing gear might get you there, but I don't think there's any way you could land on the Wheesley's exahust cone without breaking something.  An Engine Nacelle with a Wheesley and a Command Chair might let you land the craft back into a cradle that supports the Wheesley on the fan shroud.  And now, of course, as long as your Kerbal has two stars or more, you could use the EVA parachute for your lifting surface, and probably get away with a single Juno, Small Round Intake, one Oscar B or sausage tank (oxidizer removed), and command chair (though you'd have to figure a way for the Kerbal to get into the chair -- climbing along the top from a Mk. 1 Command Pod seems to work well).

Hmmm.

[Zeiss Ikon]

Okay.  I'm currently running 1.4.1, so Jeb can't deploy his parachute while still in the Command Seat, but I've got a vessel built that should permit that once I upgrade.  Really simple -- except for getting Jeb into the Command Seat on the ground.  Small Circular Intake, Mk. 0 Fuel Fuselage, Juno, Command Seat on top; all this hung off a radial decoupler on an Oscar B on the nose of a Mk .1 Inline Cockpit; a Launch Clamp supports the whole thing a couple meters off the runway.  Jeb climbs out on top of the cockpit, walks to the front, and boards the seat; hit F5 so you can just F9 when you want to start again.  Pictures coming when I have time to install 1.4.3 and the corresponding Making History so i can actually fly this thing.

Edited May 21, 2018 by Zeiss Ikon