RE: RCV.90SP & 3 blade prop
Hi
The smallest prop you would want to use on the RCV90SP is a 16x16.
Otherwise you can pull a 17x13 or 18x12 2-bladed prop.
If you want to look at 3 or 4-bladed props, you would look at a 15x13.5 3B or 15.5x12 4B
I hope this helps
Best regards
Laurenne