SimplePlanes 2 version 0.7.8 is now LIVE, with TURBOSHAFTS, an Exhaust part with customizable particles, and the Curved Fuselage that can make weird concave shapes with one part! There are also a bunch of bug fixes and smaller improvements (propeller noises have gotten some extra love!), so check out the Patch Notes if you want to know about all that!
Turboshafts
After months of research, our top scientists have discovered that jet engines can spin things really fast, and thus the Turboshaft was born! It's like a jet engine, but rather than rapidly shooting exhaust out the back, it spins stuff attached to the end of it such as a propeller or drive shaft. 
Like the other engines in the game, turboshafts come in a few different shapes and sizes in the parts list as Small, Medium, and Large Turboprops, each of which can be customized to meet your needs. You can tweak the size, the number of compressor stages for extra power and efficiency, increase the turbine temperature for even more power, and tune the RPM to meet your torque needs. The pre-attached engine shroud can be customized, or thrown out if you'd rather not have it.
Turboshafts obviously support propellers for powerful turboprop planes, but the real beauty of them is that they also support any of the other powertrain parts, meaning you can, for instance, hook them up to a transmission and some wheels to make a jet-powered car with enough RPM to make a hyper-optimized racecar look like a toy.
Exhaust
Engines produce a lot of gas as a byproduct, and while sometimes this is directly used to propel a craft (in the case of a turbofan), usually it isn't, and it has to go somewhere.
Meet the new Exhaust part, a bona fide particle emitter in the shape of different varieties of tube. It can spit out heat distortion, flames, or smoke, and can be driven by either a powertrain engine of your choice or a custom input. Several properties of the exhaust particles, such as the density, size, speed, and drag, can be customized, and you'll get a real-time preview in the designer as you change it. If you go with smoke, you can even customize its primary and secondary colours!
Curved Fuselage
I think we can all agree that the SP2 fuselage is a miracle that makes miracles, but there's still some things it can't do very well; namely, concave or convex shapes. In order to make those you'd need to fiddle with a bunch of individual fuselages, which increases part counts and adds additional burden. So...
...why not just let you do all that with one part?
The Curved Fuselage is a special new type of fuselage you can grab at a parts list near you. It's a lot like a regular fuselage, except there's a new middle slice that essentially lets you squeeze or expand a fuselage from the middle, letting you make various complex shapes much more easily. 
Nicky showed this off in a team meeting and it blew all of us away, so we're sure you all will find plenty to do with it!
That's all for this post, we hope you have fun! Remember to check out our Roadmap to see what we're planning and to vote on what you want to see next!
(P.S: Valve just released the Steam Frame, so we're making SimplePlanes VR 75% off on Steam!)