Hi all:

I am in the process of building a HOB 2 X 4 sailplane. I need some advice on a power unit to get it up. I was thinking on using a GWS Speed 400 motor. Will this produce enough thrust for lift and/or sustain vertical lift? Also what prop would you recommend? Should I use a gear box? I know this is a lot of questions, yet any help on this I can use for sure.

SPECS:
Wingspan: 49.5"
Wing Area: 409 sq in
Wing Loading: 9.8 oz/sq ft
Weight With Standard Radio: 28 ounces
Fuselage Length: 38.5"
Airfoil: Flat-Bottom, Polyhedral