Hello:

About fifteen years ago I built a Precedent BiFly (48" span), it was fun but heavy. So I built a light weight version with ailerons on both wings, symmetrical wing section and a bigger fin - and it was wonderful! Now back in the present day I am thinking about building another aerobatic bipe. Unfortunately I have lost my bi-fly plan and am therefore not sure what would be the best wing / stabilizer incidence combination to go for.

Firstly does anyone know what the By-Fly stabilizer and wing incidences were set for?

Secondly what are the recommendations out there? I see that 0-0-0 is not uncommon nowadays, but I’m pretty sure the Bi-Fly was not.

also I think I'm a little confused on how to properly state incidences. A sport scale Hawker fury (30's biplane) plan I am current studying states incidences are stabilizer negative 2 1/2 degrees, upper wing positive 3 degrees and lower wing positive 2 degrees. When I tried to measure them for myself using the centre datum line as 0 degrees, incidences are stabilizer negative 6 degrees, upper wing positive 5 1/2 degrees and lower wing positive 4 degrees!

Anyway I'm pretty sure I want the top wing to have slightly lower incidence than the bottom. Whatever I build should be very aerobatic and neutrally stable.

Any advice would be appreciated!