GP Extra 300 60 size Building Hints
BWINNDRUM, the stock rudder will allow you to maintain or slightly climb in knife edge. If you're looking to perform knife edge loops enlarge the rudder slitghtly might be a good idea.
RE cockpit floor - there isn't one! Just make one out of 3/32" balsa if you decide to instal a pilot. If not, just hide the hole with covering material.