Electrorubber

          Entries may be any rubber powered model airplane designed prior to 1951. 

          The minimum wing loading will be 4.9oz./sq.ft. (15 gr. per sq.dm.)

               Propulsion must be: 

                   1.        A Graupner Speed 300 6.0v ferrite permanent magnet motor with max 1:5 gearbox. Max propeller diameter is 10” (254 mm).

                                 Or

                   2.        AEO C-20 KV1550  brushless motor with direct drive. Max propeller diameter is 8” (203.2 mm).

          The battery pack may be six NiMH cells or two Lithium chemistry cells of any capacity with manufacturer’s label clearly visible. 

          Folding propellers are acceptable.

          Any BEC-ESC power control system is acceptable.

          The model may be hand launched or ROG at pilot’s discretion.  

          The motor may be run only during the first 60 seconds of flight.

          The model’s score will be the sum of the best three of four 7 minute max flights.

The official rules can be download from here