Miniplane's can fly or glide inverted, it depends on if they have an inverted system for the fuel and oil or not. The idea that 'flatbottom' wings won't fly inverted seems to continue, but it is true that they very much will and do every day. People go out and practice their acro routines in Cubs, Pitts Specials, Smiths, EAAs, Stardusters, and Citabrias and Great Lakes for all sorts of Sportsman and Advanced category aerobatic competitions around the country!
My parent's Citabria 7KCAB had a Christen inverted system and dad used to endure my desire to fly inverted when I was in 8th grade, it sure took a lot of forward stick!
Dan, remember the N3N Inverted Biplane Jump at Quincy (50 times a day for 11 days) and Staggerwing acro with inverted glides, and the Aerobatic Beech Bonanza? No Stunt wings there either.
For a Smith Miniplane flying Scale a loop and inverted flight would be prototypical flight.
Chris...