Don't the lycomings have something goofy like a 1500hr tbo?

I don't make stuff up no matter which side of the bed I use.

441 issue had nothing to do with airspeed. Was a vibration mode induced by the prop that caused flutter and failure of the trim tab.

All turbine conversions of piston airplanes have their Vne lowered. P210 Silver Eagle, for example. It is just the rules the FAA requires for turboprops, no yellow arcs. This is one of the major limitations for the piston conversions over a purpose built turboprop.

The 421C Riley conversions had their Vne lowered due to the "no yellow arc" rule. I don't know what analysis Riley did or did not do on the tail.

Mike C.

I don't make stuff up no matter which side of the bed I use.

441 issue had nothing to do with airspeed. Was a vibration mode induced by the prop that caused flutter and failure of the trim tab.

All turbine conversions of piston airplanes have their Vne lowered. P210 Silver Eagle, for example. It is just the rules the FAA requires for turboprops, no yellow arcs. This is one of the major limitations for the piston conversions over a purpose built turboprop.

The 421C Riley conversions had their Vne lowered due to the "no yellow arc" rule. I don't know what analysis Riley did or did not do on the tail.

Mike C.

It doesn't have the same tail, engines, and props as the 441.

Thus it doesn't necessarily have the same flutter resonance issue as the 441.

In any case, Vne reduction in the conversion and the tail are not related in any way.

Mike C.

A pokey dotted Unicorn. Even rarer.