Pipistrel is working on a new novel concept which would be a four seater and cruise 200 kts with relatively low power (200 kts at 160 hp). I have seen some references to it for quite some time now, but finally bumped into a blog post at Cafefoundation blog which includes also a rendering of the model:

Cafefoundation: Pipistrel hybrid

Looks pretty much like aerodynamically quite much cleaned up Diamond DA40 with some features somewhat resembling Nemesis NXT racer (e.g. the wing geometry) although with higher aspect ratio. I am confident that Pipistrel will succeed with this project and will show how the general aviation planes of tomorrow can be both efficient and fast and will not require many hundreds of horse power to be fast. I think this is one of the most interesting ones of the new production aircraft coming in sometime in the future.

The blog post says it is not a parallel hybrid, would that indicate then that it would be a series hybrid. It will be very interesting to see what will come up from this project. I will write more about it when I find more details.

UPDATE: Noticed from Cafefoundation page the bottom note; (Editor’s Note: Pipistrel will roll out the airplane in the new year, and will not allow disclosure of more than what has been shared here until then.) - this may mean that we don't hear more about this aircraft before 2019.

UPDATE 2: The new year referred on the previous post was written 2019, so if we are lucky, we will see roll out of the craft this year 2019 then. Lets wait and see. I am sure it will have specifications that will make some jaws dropping. Will be very interesting.

There are now several different types of composite parts readily available for use. I was interested earlier in the pultruded carbon rods, but then I was thinking how to connect them with each other easily and there was no good solution for that. I was randomly surfing the web and found this one:

http://www.dragonplate.com/default.asp

Ready-made carbon sheets (could be used as bulkheads and wing ribs)
Pultruded carbon rods
Connection parts for the pultruded carbon rods.

With the connection parts available for example from this company, one could build a new kind of tube-fabric airplane or facet mobile, just glue some rods and sheets together and you are done. No welding required and end result will be stronger and lighter! It could be possible also build wing spar/internal wing structure like on the sky lifts from the rods and connection parts. It could be interesting how much longer wings could be achieved by optimized rod structure (and it could lead to higher aspect ratio for the same weight without aileron reversal and flutter problems).

It seems that the usual condition for an aircraft PSRU is to fail. It appears to be difficult to design one (which is incredible, because similar speed reduction units are widely used in industry elsewhere and I am quite sure that there are established ways to design them properly).

I bumped into this manufacturer about which somebody flying a Ford engine was very happy about. So I decided to share the link if that interests you any.

http://www.alternate-airpower.com/

Not sure if the price-what you get ratio is anywhere one could call affordable (7500 per unit) taking in account that this is a chain drive unit rather than a sophisticated reduction gear. However, reportedly this works. And the web page says at the moment "PSRUs are temporarily unavailable ". Maybe this is temporary I hope.