Long range plane with level one air field and R&D

[Darkfine]

Okay, so I have an observe Kerbin mission that takes me to the exact opposite side of the planet. I have done a few prior to this one with a little 2 fuselage plane no problem but this one obviously is outside its range. I have tried a few different designs with the parts and size limit I have to no joy. The big problem is I can't find a stable build that will continue to fly as fuel empties.

At least I am assuming fuel emptying is the problem. Either that or there is a Bermuda Triangle on Kerbal.......

Edited December 27, 2014 by Darkfine

[The Yellow Dart]

I don't have a surefire solution for you but I have 2 ideas that might help.

If you have fuel lines unlocked you could use drop tanks to significantly extend your range. To avoid conflict with landing gear you can launch vertically or at a high angle using launch clamps, since you won't have to land with them. They tend not to mess with center of mass very much since they can be attached right near the center of mass. I recently used this method to fly to the north tundra area with 3 jets, 2 round mk 1 tanks each and 1 drop tank each. I ended up with tons of fuel to spare even after flying around to the various targets.

The other idea would be similar to a Dreamchaser but with 2 jet engines (since you can't attach a jet engine to a stack you'll have to have at least 2 on either side of a central body) and liquid fuel. It would be launched vertically into orbit on a disposable rocket with large wings to keep it aerodynamically stable, then it would reenter on the far side and be able to fly around the area with the mission targets, assuming they aren't too far apart. This method will bump up your cost and decrease recoverable value but cut real life mission time down by a lot since you can timewarp to the farside rather than physics warp at 4x only if you have a very stable plane.

[Wanderfound]

It's easy with turbojets, a complete pain without. You're best off waiting until you've got the turbos.

You can lock off some forward tanks with the right-click tweakables to ensure that the rearmost fuel drains first.

[Darkfine]

I think I have stumbled onto a design that will work. 5 long fuselage, wingspan pushed all the way back to the engine with winglets along the length. Looks goofy but so far testing is encouraging. Only issue is takeoff is a little tricky. Going to attempt the mission and report back.

[The_Rocketeer]

I know you're asking for a plane, but why not complete the contract with a sub-orbital hop in rocket and slow to a 'hover' during descent?

[Darkfine]

Success! It worked like a charm all the way to near bingo fuel. I was even able to time warp no problems.

Rocketeer, two reasons. The observe missions I am on have multiple parts to them, which leads to the second reason. Cost, with a plane you are all profit sans fuel expense. Rockets ain't cheap yo.

Follow up question however. Is there a way to lock your altitude? My flight path was a series of time warp to 7-8k, drop nose and time warp to 1k. Any way to fly level basically?

[Tex_NL]

...

Follow up question however. Is there a way to lock your altitude? My flight path was a series of time warp to 7-8k, drop nose and time warp to 1k. Any way to fly level basically?

You could try an autopilot mod like MechJeb.

MechJeb does not play nice with FAR/NEAR atmospheres but works remarkably well in the stock souposhpere.

[The_Rocketeer]

The best autopilot I've found (by no means conclusively tested) was from the Lazor system. That had simple set altitude and set heading features which is pretty much how real autopilots work. I could be wrong, but I haven't seen this in Mechjeb (admittedly I haven't tried all the features - long flights are a rarity in any case, and, well, sometimes I just prefer to do it myself!)

[Tex_NL]

Then you've never seen MechJeb's Spaceplane guidance: altitude and heading.

[GoSlash27]

Darkfine,

I'm glad it worked out for you.

A few tips for the future:

1) Try to make the plane so that the fuel tank is as close to the CoM as possible.

2) Drain the fuel tank to see where your CoM shifts

2a) If it shifts back, leave the tanks empty while you build.

2b) If it shifts forward, leave the tanks full while you build.

3) Attach and balance all wings such that the CoL is in the middle of CoM.

Finally, refill the tanks if necessary.

That's it. You'll have a nicely- balanced plane every time.

Merry Christmas,

-Slashy

[Darkfine]

Hm, not super into mods. Will just have to deal with the motion of the ocean so to speak. Thank you all for input and advice!