Dear Paul,

Thank you for the impressively full and informative rotary site.  I am designing a single place concept aircraft of some promise. Looking seriously into using Aixro XF40, a lighter version para-jet developed.  Using the power available in exhaust to improve fuel efficiency and maximum power would make for a very impressive setup.  Producing 10 additional hp doesn't seem challenging, However, it might mean machining many light custom parts.  Using hydrogen is also interesting.  Catching up on what's in the site will likely take me some time as reading isn't the fastest activity for me.

Thank you,

LuPi