A step in the wrong direction

[Foxster]

A simple challenge (apparently)...

Build a stock aircraft that looks like it is flying backwards.

Example:

This aircraft will take off right to left and it then can achieve altitude before going a bit screwy.

I'm sure you can do better.

Extra kudos if the aircraft looks completely like it should be going the other way. Even more kudos if it flies well.

Please post your (stock) craft file if possible for us all to try your creations.

Edited February 1, 2015 by Foxster

[Groot]

Yes I can, but where is the challenge?

[WhiteKnuckle]

I'll be honest, I read this challenge last night and thought "Pshh, that'll be easy, I'll just take my super-stable VTOL, swap the engines around, maybe shift the wings to get the Col behind the Com, and done!"

Nope.

Really, it is pretty simple, except for one thing. Yaw control/vertical tail fin. Pitch and roll are fine. But man, the gods of aerodynamics really don't like having a big vertical thing sticking up from the front of an aircraft. My first designs flew fine until the moment you got even a tiny bit of yaw, then they would swap ends instantly. I finally settled for putting them pretty close to the center of the aircraft.

So, after much trial and error, I give you the Bass Ackwards

Takes off vertically, can probably take off horizontally but I haven't tried.

Kick on the main engines

Turning around to head back to the runway

All lined up

Getting close...

Touchdown!

Bob is so freaking happy he isn't dead.

Note, I designed this to fly without the overpowered RCS system on, but it's there if you need it. This thing is completely flyable, but it has very small margins for error, you need to be extremely gentle with the controls. I'm using FAR, but this may fly in stock, I didn't do anything funky like set controls to negative inputs. Select the small probe core behind the nosecone (tailcone?) and control for here.

Action groups:

1. Vertical engines.

2. Horizontal engines

3. Vertical engine bay doors

4. Backwards engines (for looks)

5. Cargo bay door

9. Vertical braking thrusters

Abort: Parachutes (can also use spacebar)

Craft file: https://www.dropbox.com/s/6m39f436ge9ej4q/Bass%20Ackwards.craft?dl=0

Yes I can, but where is the challenge?

Yeah, this challenge could use a little more direction. Maybe awards for highest speed, highest altitude, and best looking?

[Foxster]

Excellent job, WhiteKnuckle.

You sure its the tailfin causing the problem? I took it off and it was still a [snip] to fly. I'm not sure just what is causing the flipping at a certain time or speed.

You know what would be cool? A plane that you can fly both directions. Take off from the runway, fly to the island runway, land, shift some fuel about, reverse the engines, fly back.

Edited February 21, 2019 by Snark
Redacted by moderator

[WhiteKnuckle]

Excellent job, WhiteKnuckle.

You sure its the tailfin causing the problem? I took it off and it was still a biatch to fly. I'm not sure just what is causing the flipping at a certain time or speed.

That was what was causing all my problems. Just a guess from looking at the shot you posted of your plane, it looks like you've only got one set of control surfaces trying to do everything. Even in stock aerodynamics that just won't work.

You know what would be cool? A plane that you can fly both directions. Take off from the runway, fly to the island runway, land, shift some fuel about, reverse the engines, fly back.

Was already thinking about it...

[WhiteKnuckle]

Ok, well it really wasn't all that hard to make this thing fly both directions. But there's a lot of steps to making the switch over. Pump fuel forwards, switch between two sets of landing gear, and remember to change control from the probe core to the cockpit.

It's also completely unusable as a VTOL now (well it sort of works when in tail first mode, but not at all with the fuel moved)

I give you the Bass Ackwards Mk2:

Takes off normally

Lining up for the island runway

Didn't get a shot of touchdown, way too much going on and the runway is super short. Kicked in the "forwards" engines to help brake...

...just barely made it.

Shot showing the two sets of landing gear

The turbojets plus the short runway make for an interesting takeoff.

Heading back to KSC

Bob is thrilled as always.

Action groups are the same as before plus:

7. Toggles "forward" landing gear

8. Toggles "rearward" landing gear

Craft file: https://www.dropbox.com/s/fx5pxsxfvz7pz48/Bass%20Ackwards%20Mk2.craft?dl=0

[Foxster]

That is so cool. I never would have thought of using two sets of landing gear.

[Groot]

I'll be honest, I read this challenge last night and thought "Pshh, that'll be easy, I'll just take my super-stable VTOL, swap the engines around, maybe shift the wings to get the Col behind the Com, and done!"

Nope.

Really, it is pretty simple, except for one thing. Yaw control/vertical tail fin.

could've just mounted another probe core in the right direction and set and control point?

[WhiteKnuckle]

could've just mounted another probe core in the right direction and set and control point?

Did that. (You have to. Even if you use FAR to reverse the inputs on the aerodynamic control surfaces the SAS units and RCS will be fighting you unless you have a probe core pointed in the right direction)

Doesn't solve the tail fin issue. Wings and roll-control surfaces are fine because they're near the middle of the craft, and the pitch-control surfaces don't really care if they're at the front or back (see Delta-wing style airplane with canards at the front) because they have the main wings to balance them out.

But the vertical stabilizer has no matching analog at the other end of the craft. It's out there by itself. In effect, when you yaw even slightly, the tail fin gets an AoA and starts producing lift either to the left or right. This is fine if this lift is behind the CoM like it would be in a normal plane, but in this case it's far in front of the CoM and you go end over end like an arrow fired backwards.