In regards of the Phoenix, when it used a 108/80kw rotex engine, was it only needed because of the tow capability ? I guess, with only a 60kw or even running it at 70%.. like at 45kw it could be enought to take off ? Or a 60 is really needed ?
https://www.crflight.com/You are absolutely right.... Phoenix doesn´t need 100 hp (74 kW) engine. You can tow even with 80 hp (60 kW) Rotax. For normal flying would be nice to have engine with 60 hp (45 kW) - something smaller than Rotax 912 allowing more aerodynamic installation. By the way... first prototype of electra has been flying with 44 hp (33 kW) propulsion system. But I would personally prefer a bit more
However don´t forget one important advantage of Rotax engines - service. Service net + availability of spare parts is really good. Another advantage - reduction gear. This allows us to use mechanically operated in flight adjustable / feathering prop. Also liquid cooling is not that bad.
I had experience also with HKS. This nice small 4 stroke 2 cylinder engine unfortunatelly needs RPM over 4 000 to be "calm" (or 3 blade prop). This engine is very good for trikes or "normal" ultralights.
And I had also experience with Jabiru 2200. This was not soo bad, but no reduction (necessity of heavy electric prop) and air cooling were causing problems. In case of TMG is air cooled engine not real advantage. We had problems to keep it "warm" on long descends during final or during "sponzored" gliding with engine on.
On AERO Friedrichshafen are sometimes presented nice engines, but prices are similar or higher than Rotax with much smaller service support.
But I am not agains new ideas
https://www.dropbox.com/s/htftd6ttj1b2emj/Dym.mp4?dl=0CRFlight looks interesting. But for "motorglider like" airplane I need feathering or ideally adjustable and feathering prop
https://www.dropbox.com/s/ky1z5jc9g3srohq/Dym - zwolnione tempo.mp4?dl=0Very interesting - I wonder if the same is true for a ducted fan propellor setup?
-and folding propeller, FES like ?
=TWO (2) electric PHENIX ???I heard that electric Phoenix is more "motorglider" than "airplane". Of course I can start to explain why are the long wings better and why they help to decrease energy necessary for horizontal flight etc... And I know that pilots in this thread will understand me perfectly - we all enjoy gliding.
But I was tired to repeat all advantages of long wings again and again so I answered:
"OK, use the short winglets and enjoy electric Red Bull racer"