I built an aircraft using stock parts that actually flies.
It's somewhat of a copy of a Russian Miyasischev M-55. They were originally conceived to take out high altitude reconnaissance balloons that were launched by the 'Merkins during the cold war, but that all came to an end when they started using spy satellites and the Lockheed A-12. Neither of which could be dealt with by an aircraft like this. It was then reconfigured as the M-17 Stratosphera and used for reconnaissance like the U-2 spy plane. Later on, the M-55 Geophysica made its apprearance, and is still used to this day for science research.
I wanted to build a replica of the M-55 and expected it to make it off the runway and then immediately disintegrate in a high-g flat spin, so I was really surprised to find that it flew fairly stably right from the word go. It might be a unique quirk of a design like this, where the centres of mass and lift seem to synergise with one another. Or it could just be because I'm fucking awesome.
A few refinements later and it's capable of this: 25km altitude, which is practically IN SPACE. Bill Kerman looks utterly rapt.
It can also do this when it hits thicker atmosphere without killing all Kerbals on board. I'm a little bit disappoint. One day I'll figure out what those new health meter-looking things are for. I didn't find out today
Next steps are to fiddle with the angle of the empennage, because it has a tendency to either pitch up or down quite a bit, and I don't seem to have the ability to change the angle of the horiz stabiliser in infinite increments in the assembly hangar. I also need to change the control surfaces which control roll; the ones on the end of the wings are massive and almost flip it over at high speed.