Originally Posted by
Kelly W
This is the biggest downside of getting a huge turbine, and detaining it for a smaller jet, in addition to possibly more residual thrust. Running a P180 at 30 lb will probably force you to land sooner than a P120 at 30lb and the same fuel capacity.
Kelly with respect (and I don't doubt your math) in my experience the SFC difference is not appreciable. I have a P-180RX in a Bobcat and with the speed limited to 200 mph with a JetCat integrated speed sensor, I get plenty of flight time. From the telemetry the turbine is hardly ever at full power, and never more than 6-8 seconds at a stretch so it is lightly loaded and appears to be reliable.
and it has a shocking amount of push for low speed vertical maneuvers. I would not limit the thrust but limit the speed.
I will say however the higher residual thrust is a very real problem. And of course dialing down the thrust does nothing for this so make sure you have very effective speed brake (including the push rod geometry) and I might recommend canting the rudders as well. I have not tried this on a hotspot but it is very effective on a stingray and even the bobcat.