Open scale electric and Open scale CO2 models are almost exact scale models, but they have to fly at least 15 seconds. And not only the flight duration is scored but also the flight realism! In 2017 there are seperate prices for electric and for CO2.
Maximum weight (including motor): 200 g
Maximum wing loading: 15 g/dm²
There are no restrictions to the dimensions
View or download the F4E Rules (0,3 Mb pdf).
The judging rules used for the F4E scale class are the BMFA-rules, which are also used in the Interscale and British Indoor Scale Nationals competitions.