I have the U Can Do 60 with OS 91 FX in it. I swing a 15x6 APC prop and can take off from 15 feet roll and go straight up like a home sick angel. This plane can also let you fly like an angel with a bad seizure disorder. Don't let anyone tell you U Can Do 60 will be underpowered with 91 motor. The plane is built real light for such big size. I use it to fly on windy, overcast days in Oregon when I don't want to take out my prized warbirds or propjets. This plane likes to float too, if you're still landing like a sportflyer. [:-]