The F4D scale class is for scale free flight powered models of not more than 150 g (including motor) and a maximum wing loading of 15 g dm2. Allowed as motive power are CO2 motors and electric motors (battery to be carried in the model).
The judging rules used for the F4E scale class are the BMFA-rules, which are also used in the
IFFI and British Indoor Scale Nationals competitions:
F4E Open Scale, Electric/CO2 [69 KB]
Rules for all scale classes:
General scale rules [75 KB]
Judges guide [95 KB]